Journal articles on the topic 'Silica'
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1
RAMOS, Vanessa Machado Babinski, Maurício Gammertt RÖHNELT, and Rodrigo BRAMBILLA. "HDPE/SILICA COMPOSITES- PART I: PREPARATION AND CHARACTERIZATION OF METHYLSILANE AND OCTYLSILANE-MODIFIED SILICAS." Periódico Tchê Química 16, no. 32 (August 20, 2019): 263–78. http://dx.doi.org/10.52571/ptq.v16.n32.2019.281_periodico32_pgs_263_278.pdf.
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This paper reports the main results concerning the synthesis and characterization of methylsilane and octylsilane-modified silicas. The modification of the silicas with these groups aims to make the silica surface hydrophobic and thus compatible with high-density polyethylene (HDPE) in HDPE/silica composites. In the present work, two types of silica were organofunctionalized: a pyrogenic silica and a silica gel. The silicas were characterized by a series of complementary techniques with the objective of investigating the nature of the surface species and their textural and morphological characteristics. The SEM images showed that the modification of the silicas with organosilanes has been not resulted in changes on the morphology and on the size of silica particles. In relation to the texture properties, determined by N2 adsorption-desorption porosimetry, the silica modification resulted in a decrease of the specific area (SBET) and the mean pore volume, a behavior attributed to the partial coverage of the adsorption sites by the organosilane molecules. The TGA analysis showed that both the methylsilane groups and the octylsilane groups on the surface of silica and silica gel are thermally stable up to 200 ° C, which enables the organofunctionalized silicas in terms of thermal stability, for the process of preparing the composites by extrusion. The results of applying these organofunctionalized silicas in the development of HDPE/silica composites will be presented in a subsequent article, part II of this research.
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Dilma Purnama Ubit, Yusmaniar Yusmaniar, and Erdawati Erdawati. "Adsorbsi Pewarna Direct Black 38 Menggunakan Komposit Silika Mesopori Dari Abu Sekam Padi/Karbon Aktif Dari Tempurung Kelapa." JRSKT - Jurnal Riset Sains dan Kimia Terapan 8, no. 1 (October 9, 2019): 1–9. http://dx.doi.org/10.21009/jrskt.081.01.
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Abstrak
Pada penelitian ini adsorben komposit silika mesopori dan karbon aktif dibuat untuk mengadsorpsi zat warna direct black 38. Silika mesopori dibuat dari abu sekam padi dan karbon aktif dibuat dari tempurung kelapa. Silika direaksikan dengan NaOH menjadi larutan natrium silikat lalu direaksikan dengan PEG yang selanjutnya PEG diekstraksi secara solvotermal sehingga menghasilkan produk silika mesopori dengan luas permukaan dan pori yang lebih besar. Silika mesopori diproses menjadi komposit dengan karbon aktif yang telah diaktivasi sebelumnya dengan larutan ZnCl2. Kandungan dari komposit silika mesopori/karbon aktif ditunjukkan melalui hasil analisis SEM bahwa komposit hasil sintesis menunjukkan penyebaran karbon dan silika terlihat pada morfologi komposit. Hasil analisis EDX menunjukan komponen penyusun komposit yaitu 38,6% karbon; 46,8% oksigen dan 14,6% silika. Hasil penelitian menunjukan bahwa kondisi optimum yang diperlukan untuk adsorpsi direct black 38 dengan komposit silika mesopori/karbon aktif yaitu pH 2 dan waktu optimum 30 menit. Adsorpsi direct black 38 oleh komposit silika mesopori/karbon aktif mengikuti isoterm adsorpsi Langmuir. Oleh karena itu, adsorpsi yang terjadi membentuk lapisan monolayer dengan kapasitas adsorpsi 68,493 mg g-1
Kata kunci: abu sekam padi, adsorpsi, karbon aktif, komposit, PEG, silika mesopori
Abstract
In this research, mesopore silica/activated carbon composite adsorbent was formed for dye adsorption direct black 38. The mesopore silica was from rice husk ash and activated carbon was from coconut shell. This rice husk ash is processed into sodium silicate solution and the solution was hybrid with PEG. Then PEG was extracted with solvotermal method to produce a higher surface area of mesopore silica. The mesopore silica was processed
into composite with activated carbon that has been activated by ZnCl2 solution. The mesopore silica/activated carbon composite was analysed by SEM and showed the distribution of carbon, silica and oxygen as composite morphology. The EDX analysis showed that the composite contains of 46.8% carbon; 3.6% oxygen and 14.6% silica. The results showed that the optimum condition required for the adsorption of direct black 38 dye with mesopore silica/activated carbon composite pH was 2 and the optimum contact time was 30 minutes. Adsorption of direct black 38 by mesopore silica/activated carbon composite followed Langmuir adsorption isotherm and formed a monolayer layer with adsorption capacity 68.493 mg g-1.
Keywords: activated carbon, adsorption, composite, mesopore silica, PEG, rice husk ash
Abstrak
Pada penelitian ini adsorben komposit silika mesopori dan karbon aktif dibuat untuk mengadsorpsi zat warna direct black 38. Silika mesopori dibuat dari abu sekam padi dan karbon aktif dibuat dari tempurung kelapa. Silika direaksikan dengan NaOH menjadi larutan natrium silikat lalu direaksikan dengan PEG yang selanjutnya PEG diekstraksi secara solvotermal sehingga menghasilkan produk silika mesopori dengan luas permukaan dan pori yang lebih besar. Silika mesopori diproses menjadi komposit dengan karbon aktif yang telah diaktivasi sebelumnya dengan larutan ZnCl2. Kandungan dari komposit silika mesopori/karbon aktif ditunjukkan melalui hasil analisis SEM bahwa komposit hasil sintesis menunjukkan penyebaran karbon dan silika terlihat pada morfologi komposit. Hasil analisis EDX menunjukan komponen penyusun komposit yaitu 38,6% karbon; 46,8% oksigen dan 14,6% silika. Hasil penelitian menunjukan bahwa kondisi optimum yang diperlukan untuk adsorpsi direct black 38 dengan komposit silika mesopori/karbon aktif yaitu pH 2 dan waktu optimum 30 menit. Adsorpsi direct black 38 oleh komposit silika mesopori/karbon aktif mengikuti isoterm adsorpsi Langmuir. Oleh karena itu, adsorpsi yang terjadi membentuk lapisan monolayer dengan kapasitas adsorpsi 68,493 mg g-1
Kata kunci: abu sekam padi, adsorpsi, karbon aktif, komposit, PEG, silika mesopori
Abstract
In this research, mesopore silica/activated carbon composite adsorbent was formed for dye adsorption direct black 38. The mesopore silica was from rice husk ash and activated carbon was from coconut shell. This rice husk ash is processed into sodium silicate solution and the solution was hybrid with PEG. Then PEG was extracted with solvotermal method to produce a higher surface area of mesopore silica. The mesopore silica was processed into composite with activated carbon that has been activated by ZnCl2 solution. The mesopore silica/activated carbon composite was analysed by SEM and showed the distribution of carbon, silica and oxygen as composite morphology. The EDX analysis showed that the composite contains of 46.8% carbon; 3.6% oxygen and 14.6% silica. The results showed that the optimum condition required for the adsorption of direct black 38 dye with mesopore silica/activated carbon composite pH was 2 and the optimum contact time was 30 minutes. Adsorption of direct black 38 by mesopore silica/activated carbon composite followed Langmuir adsorption isotherm and formed a monolayer layer with adsorption capacity 68.493 mg g-1.
Keywords: activated carbon, adsorption, composite, mesopore silica, PEG, rice husk ash
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Hamzah, Moh, Mahendra A., and Eryanti Kalembang. "Potensi Silika Kuarsa Lokal sebagai Filler Kompon Karet dalam Pembuatan Balon Peluncur Kapal." Majalah Ilmiah Pengkajian Industri 8, no. 3 (July 31, 2019): 115–20. http://dx.doi.org/10.29122/mipi.v8i3.3666.
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Secara praktis material karet untuk produk barang teknik memerlukan sejumlah bahan lain sebagai bahan tambahan yang mampu meningkatkan kemampuan proses, nilai karakteristik teknis dan memperpanjang waktu pakai. Bahan filler digunakan untuk meningkatkan karateristik teknis terkait dengan karakteristik karet. Salah satu filler yang sering diaplikasikan adalah silika, namun dalam bentuk teraktivasi. Beberapa penelitian menunjukan bahwa filler silika mampu mempengaruhi karakteristik seperti tensile strength, abrasion and tear resistance. Penggunaan filler silika pada balon peluncur kapal juga meningkatkan kinerja wet traction, dan wear resistance serta mengurangi dampak rolling resitance. Untuk mengaplikasikan silika kuarsa sebagai filler karet maka perlu mengaktivasi permukaan silika kuarsa antara lain dengan cara nanosizing atau memodifikasi permukaan silika melapisi dengan silane-69 atau PEG-4000. Saat ini produk silika lokal yang dihasilkan belum memenuhi spesifikasi silika berukuran sub mikron seperti yang dibutuhkan oleh pasar, umumnya produksi silika lokal berukuran ≥ 30 μm. Oleh karena itu utilisasi kapasitas produksi industri silika lokal belum maksimal, baru 50%. Dengan adanya sentuhan teknologi diharapkan dapat memaksimalkan potensi silika lokal.Kata kunci : Nanosilika, Balon peluncur kapal, Filler kompon karet, SilikaAbstractPractically rubber material for engineering goods requires a number of other ingredients as additives that can improve the ability of the process, the value of the technical characteristics and extend the lifetime. Filler material is used to improve the technical characteristics related to the characteristics of the rubber. One of the frequently applied filler is silica, but in the activated form. Several studies have shown that the silica filler capable of affecting characteristics such as tensile strength, abrasion and tear resistance. The use of silica filler on the balloon launcher ships also improves wet traction performance and wear resistance and reduce the impact of rolling resitance. To apply as a quartz silica filler rubber it is necessary to activate the surface of silica quartz, among others, by the way nanosizing or modify the silica surface with silane coat-69 or PEG- 4000. Currently local silica products produced not meet the specifications of sub- micron sized silica as required by the market, local silica production generally sized ≥ 30 lm. Therefore, industrial production capacity utilization is not maximized local silica, 50% new. With the touch technology is expected to maximize the potential of local silica.Keywords : Nanosilika, Balloon launcher boats, Rubber compound filler, Silica
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RAMOS, Vanessa Machado Babinski, Maurício Gammertt RÖHNELT, and Rodrigo BRAMBILLA. "HDPE/SILICA COMPOSITES-PART II: EFFECT OF SILICA PARTICLE SIZE AND SILICA MODIFICATION ON THE THERMAL AND MECHANICAL PROPERTIES." Periódico Tchê Química 16, no. 32 (August 20, 2019): 287–305. http://dx.doi.org/10.52571/ptq.v16.n32.2019.305_periodico32_pgs_287_305.pdf.
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In this work, the effect of silica particle size and organosilane type used in the silica organofunctionalization on the thermal and mechanical properties of high-density polyethylene (HDPE)/silica composites were evaluated. HDPE/silica composites were prepared by the extrusion method using two types of silica: fumed silica, with nanometric particle size and silica gel, micrometric, modified with organosilanes containing methyl or octyl functional groups. Silicas were added to the HDPE at 1% v/v concentration. The addition of the silicas to the HDPE did not influence the melt (Tm) and the crystallization (Tc) temperatures of the resulting composites but influenced its crystallinity. The mechanical property of Izod impact strength, the dynamicmechanical rheological test (DMTA) and the surface contact angle analysis showed improvements in relation to pure HDPE when used methyl-modified pyrogenic silica as filler. This result suggests that the surface modification of pyrogenic silica with methylsilane groups results in a stronger interaction of this silica with the HDPE matrix. This effect was not observed for micron-sized silica gel, where modification with organosilanes was not sufficient to guarantee interfacial interaction with the HDPE matrix.
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Hanum, Farrah Fadhillah, and Aster Rahayu. "Studi pemanfaatan dan metode pemisahan silika dari coal fly ash." Open Science and Technology 2, no. 1 (January 8, 2022): 26–32. http://dx.doi.org/10.33292/ost.vol2no1.2022.44.
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Penggunaan batubara sebagai sumber energi masih belum tergantikan hingga saat ini, sehingga kajian mengenai pemanfaatan abu batubara masih sangat perlu untuk dikembangkan. Abu batubara merupakan limbah hasil proses pembakaran batu bara yang komposisinya akan berbeda sesuai dengan jenis batubara yang digunakan dan proses pembakaran yang dilakukan. Salah satu komposisi penyusun utama dari abu batubara ini adalah silika. Silika memiliki potensi untuk dimanfaatkan dalam berbagai tujuan seperti untuk pengolahan limbah, untuk bahan aditif dalam pertanian, hingga sebagai nanosilika. Paper ini berisi informasi mengenai pemanfaatan silika dari abu batubara yang sudah ada serta metode yang efektif untuk mendapatkan silika dari limbah abu batu bara ini. Dari pembahasan diketahui bahwa studi pemanfaatan silika saat ini umumnya berfokus ke arah sintesis zeolite. Penelitian pemanfaatan silika sebagai nanosilika baru mulai dikembangkan baru-baru ini. Sementara itu, pemanfaatan silika tidak terlepas dari metode ekstraksi silika dari coal fly ash tersebut. Dari pembahasan diketahui NaOH masih menjadi pilihan utama dalam proses leaching silika. Studi ini diharapkan dapat memberikan informasi bagi kemajuan riset dalam rangkapengolahan dan pemanfaatan limbah. The use of coal as an energy source has not been replaced until now, subsequently the studies on the utilization of coal fly ash still need to be developed. Coal fly ash is waste from the coal combustion process whose composition will differ according to the type of coal used and the combustion process carried out. One of the main constituents of coal ash is silica. Silica has the potential to be used in various purposes such as for waste treatment, for additives in agriculture, to nanosilica. This paper contains information on the utilization of silica from existing coal fly ash and an effective method for obtaining silica from the coal fly ash. Based on the discussion, it is known that the current study of the use of silica generally focuses on the synthesis of zeolite. The research on the use of silica as nanosilica has only recently been developed. Meanwhile, the role of silica is related to the method of extracting silica from the coal fly ash. It is known that NaOH is the main leaching solution in the case of silica leaching process. This study is expected to provide information for research progress in the context of processing and utilizing waste.
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Chiao, May. "In silica in silico." Nature Physics 5, no. 10 (October 2009): 709. http://dx.doi.org/10.1038/nphys1407.
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Hartanto, Djoko, Yusmaniar Yusmaniar, and Erdawati Erdawati. "Ekstraksi Karbon Aktif Bebas Silika dari Arang Sekam Padi untuk Adsorpsi Zat Warna Methyl Orange." JRSKT - Jurnal Riset Sains dan Kimia Terapan 9, no. 1 (June 30, 2023): 1–10. http://dx.doi.org/10.21009/jrskt.091.01.
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Abstrak Ekstrak karbon aktif bebas silika disintesis dari arang sekam padi berhasil diperoleh melalui perbandingan mol karbon:NaOH sebesar 1:3. Hasil karakterisasi SEM pada karbon aktif menunjukkan morfologi materialnya berbentuk butiran dan hasil karakterisasi EDX menunjukkan komposisimya terdiri dari 93.29% karbon; 6.71% oksigen dan 0% silika. Hasil karakterisasi FTIR karbon aktif bebas silika menunjukkan tidak adanya puncak silika pada bilangan gelombang 1100 cm-1. Berdasarkan hasil karakterisasi SAA, karbon aktif bebas silika memiliki luas permukaan sebesar 6.0018 m2g-1 yang tergolong jenis mikropori. Proses adsorpsi dari karbon aktif bebas silika dalam penyerapan zat warna methyl orange optimum pada massa adsorben sebanyak 200 mg dan maksimum pada massa adsorben 250 mg. Kata kunci: adsorpsi, karbon aktif bebas silika, methyl orange. Abstract The extraction of activated carbon free silica from rice husk with 1:3 mole ratio of carbon : sodium hydroxide has been successfully performed. The SEM result on activated carbon show the morphology of the material is granular and the EDX result showed the composition consisted of 93.29% carbon, 6.71% oxygen, 0% silica. The result of characterization FTIR not showing silica any peak of silica in wavelength 1100 cm-1. Based of characterization of SAA, indicates the material of activated carbon free silica has a surface area of 6.0018 m2/g, has a microporous type. The adsorption process on methyl orange pigment optimum at 200 mg and maximum at 250 mg. Keywords: adsorption, activated carbon free silica, methyl orange.
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Fairus, Sirin, H. Haryono, Mas H. Sugita, and Agus Sudrajat. "Proses pembuatan waterglass dari pasir silika dengan pelebur natrium hidroksida." Jurnal Teknik Kimia Indonesia 8, no. 2 (October 2, 2018): 56. http://dx.doi.org/10.5614/jtki.2009.8.2.4.
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Waterglass from silica sand production process with buster sodium hydroxideWaterglass may be prepared by the fusion process of silica sand using alkali. Waterglass component, which mainly contains SiO2 and Na2O, have various applications depending on their composition. Waterglass is usually used in the soap and detergent, paper, textile, and ceramic industries, in the cleaning of metals, the manufacture of silica gel, and others. This research was done to study the effect of silica sand particle size and the quantity of NaOH as fluxing agent on the yield and SiO2 content of waterglass produced by the alkali fusion process in a furnace. Silica sand particle size was varied at 35/40 and 50/60 mesh. The quantity of NaOH fluxing agent was varied at 1:1, 1.5:1, 2.4:1, 3.2:1, and 4:1 g/g to mass of the silica sand. Other fusion process variables, namely temperature, time, and silica sand quantity, were held constant at 500oC, 2 hours, and 10 gram, respectively. Research results indicated that decreasing silica sand particle size resulted in the increasing SiO2 and Na2O content. Increasing NaOH fluxing agent quantity increases the Na2O content of the waterglass. In this research, the highest SiO2 content of the waterglass of 34.6 %-mass SiO2, was obtained at an NaOH content of 2.4:1 g/g to mass of the silica sand, and silica sand particle size of 50/60 mesh.Keywords: silica sand, NaOH fluxing agent, particle size, waterglass AbstrakWaterglass dapat dibuat melalui proses peleburan pasir silika dengan alkali. Kandungan dalam waterglass, terutama berupa SiO2 dan Na2O mempunyai berbagai kegunaan tergantung pada komposisinya masing-masing. Biasanya waterglass digunakan pada industri sabun atau deterjen, kertas, tekstil, keramik, digunakan untuk pembersihan logam, pembuatan silika gel, dan lain sebagainya. Penelitian ini bertujuan untuk mempelajari pengaruh ukuran partikel pasir silika dan jumlah NaOH sebagai pelebur terhadap perolehan waterglass dan kadar SiO2 pada pembuatan waterglass dengan proses peleburan alkali di dalam furnace. Variabel berupa ukuran partikel pasir silika dipelajari pada ukuran 35/40 dan 50/60 mesh. Sedangkan banyaknya pelebur NaOH divariasikan sebanyak 1:1, 1,5:1, 2,4:1, 3,2:1, dan 4:1 g/g terhadap pasir silika. Kondisi peleburan lainnya berupa temperatur, waktu dan jumlah pasir silika, dilakukan pada nilai konstan, secara berturutan pada 500°C, 2 jam, dan 10 gram. Hasil penelitian menunjukkan bahwa pada penggunaan pasir silika dengan ukuran partikel yang makin kecil diperoleh waterglass dengan kadar SiO2 dan Na2O yang makin besar. Dan dengan makin banyaknya penggunaan pelebur NaOH, diperoleh kadar Na2O dalam waterglass juga makin tinggi. Pada penelitian ini waterglass dengan kadar SiO2 tertinggi diperoleh pada penggunaan pelebur NaOH sebanyak 2,4:1 g/g terhadap pasir silika dan ukuran pasir silika sebesar 50/60 mesh, yaitu sebesar 34,6 %-b SiO2.Kata kunci: pasir silika, pelebur NaOH, ukuran partikel, waterglass.
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Rahayu, Aster, Maryudi Maryudi, Joni Aldilla Fajri, Lee Wah Lim, and Nuraini Nuraini. "Synthesis of Silica-PEG By Physically Coating With PEG 4000 For Absorption of Ion Nitrate." Elkawnie 8, no. 2 (December 31, 2022): 250. http://dx.doi.org/10.22373/ekw.v8i2.14680.
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Abstract: All production activities will eventually produce waste, especially liquid waste. The nitrate ion (NO3-) is one of the substances in liquid waste that can have a significant impact on water systems and human health. Several methods can be used to treat the nitrate contained in the water, such as adsorption, phytoremediation, and wetland treatment. One of its methods was adsorption. The silica was modified with polymer due to its huge carbon chain. This research was focused on optimizing the ability of silica-based materials using PEG by physically coating them since PEG has a long carbon chain that could be transformed into a helix. In this research, the adsorbent will be prepared from modified silica gel with PEG 4000 by physical coating. Several parameters will be observed, including the effect of coating time, silica-PEG ratio, and PEG concentration. The capacity of silica-PEG to absorb NO3- is being studied. The characterization of functional group content in silica-PEG was carried out by Fourier Transform Infrared (FTIR). The study results show that the coating time was 10 minutes with the ratio of silica to PEG of 1:5, and the concentration of PEG used was 15%, indicating the optimum performance of silica-PEG when used as an absorbent, which achieved 84.44 % nitrate removal. An increase in the absorption capacity of silica-PEG demonstrates the ability of silica-PEG as a porous material. It was compared to silica gel without the PEG coating process, which was 9.09% to 84.44%.Abstrak: Semua kegiatan produksi pada akhirnya akan menghasilkan limbah, terutama limbah cair. Limbah cair biasanya akan bermuara di sungai dan berakhir di laut. Salah satu zat dalam limbah cair adalah ion nitrat (NO3-) yang mana dalam jumlah banyak dapat mengganggu sistem perairan dan kesehatan. Beberapa metode dapat digunakan untuk mengolah nitrat yang terkandung dalam air, seperti adsorpsi. Salah satunya dimodifikasi dengan polimer karena memiliki rantai karbon yang besar. Penelitian ini dikonsentrasikan untuk menyelidiki optimalisasi kemampuan silika dengan PEG dengan pelapisan fisik karena PEG memiliki rantai karbon panjang yang dapat bertransformasi menjadi heliks. Dalam penelitian ini, adsorben akan dibuat dari silika gel termodifikasi dengan PEG 4000 dengan pelapisan fisik. Beberapa parameter yang akan diamati antara lain pengaruh waktu pelapisan, rasio silika-PEG, konsentrasi PEG, dan temperatur pelapisan. Kinerja silika-PEG untuk menyerap NO3- diselidiki. Karakterisasi kandungan gugus fungsi pada silika-PEG dilakukan dengan Fourier Transform InfraRed (FTIR). Hasil penelitian menunjukkan bahwa waktu pelapisan adalah 10 menit dengan perbandingan silika dan PEG 1:5, dan konsentrasi PEG yang digunakan adalah 15%, menunjukkan kinerja silika-PEG yang optimum bila digunakan sebagai penyerap NO3-. Kemampuan silika-PEG sebagai bahan berpori dibuktikan dengan peningkatan kapasitas penyerapan silika-PEG dibandingkan silika gel tanpa proses pelapisan PEG.
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Fathurrahman, Muhammad, Usep Suhendar, Ani Iryani, Diana Widiastuti, Sherin Nurhafidza Ahmad, and Esya Juniar. "Sintesis dan Karakterisasi Komposit Eugenol-Silika Gel dari Abu Tongkol Jagung serta Analisis Antibakteri dan Daya Serap terhadap Air." ALCHEMY Jurnal Penelitian Kimia 18, no. 1 (February 2, 2022): 10. http://dx.doi.org/10.20961/alchemy.18.1.47161.10-18.
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<p dir="ltr">Tongkol jagung mempunyai kandungan silika yang cukup tinggi, yaitu 67,41% dari total abunya yang memungkinkan untuk dimanfaatkan untuk pembuatan komposit eugenol-silika gel. Penelitian ini bertujuan mempelajari pembuatan komposit eugenol-silika gel dengan bahan dasar abu tongkol jagung menggunakan metode sol gel, diikuti dengan analisis daya serap air dan aktivitas antibakteri terhadap <em>E. coli</em> dan <em>S. aureus</em>. Komposit eugenol-silika gel ini dikarakterisasi menggunakan <em>Fourier Transform Infrared</em> (FTIR), <em>X-ray Diffraction</em> (XRD), <em>Scanning Electron Microscope</em> (SEM) dan <em>Thermogravimetric Analysis</em> (TGA). Hasil karakterisasi dengan FTIR menunjukkan bahwa sintesis komposit eugenol-silika gel berhasil dilakukan. Analisis menggunakan XRD menunjukkan bahwa komposit eugenol-silika gel memiliki bentuk amorf. Karakteristik mikrostruktur menggunakan SEM menunjukkan permukaan yang tidak merata dan terdapat gumpalan (<em>cluster</em>) yang menandakan adanya bentuk butiran-butiran yang beragam berbentuk bulat atau globular pada permukaan komposit eugenol-silika gel. Analisis termogravimetri yang dilakukan sampai suhu 600 °C menunjukkan total prosentase pengurangan massa komposit eugenol silika-gel sebesar 13,10%. Daya serap air komposit eugenol-silika gel memiliki nilai persentase yang lebih tinggi dibandingkan dengan silika gel <em>food grade</em>. Akan tetapi, komposit eugenol-silika gel tidak memiliki aktivitas antibakteri terhadap <em>E. coli</em> dan <em>S. aureus</em>.</p><div><p dir="ltr"><strong>Synthesis and Characterization of Eugenol-Silica Gel Composite from Corn Cob Ash and Analysis of Antibacterial and Water Absorption. </strong>Corn cobs have high silica content, specifically 67.41% of the total ash, possibly used for eugenol-silica gel composite manufacture. This study aims to synthesize eugenol-silica gel composite with corn cob ash as the base material by sol gel method, followed by analyzing water absorption and antibacterial activity against <em>E. coli</em> and <em>S. aureus</em>.<strong> </strong>The method used is the sol-gel method. This eugenol-silica gel composite was characterized using Fourier Transform Infrared (FTIR), X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Thermogravimetric Analysis (TGA). The characterization results by FTIR showed that the synthesis of the eugenol-silica gel composite was successfully carried out. Analysis using XRD showed that the eugenol-silica gel composite had an amorphous form. Microstructural characteristics using SEM showed an uneven surface and clusters indicating the presence of various globular or spherical shapes on the surface of the eugenol-silica gel composite. Thermogravimetric analysis carried out until a temperature of 600 °C showed the total percentage reduction in mass of the eugenol silica-gel composite was 13.10%. The water absorption of eugenol-silica gel composite has a higher percentage value than food-grade silica gel. However, eugenol-silica gel composite has no antibacterial activity against <em>E. coli</em> and <em>S. aureus. </em></p></div>
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Agung M, Galang Fajar, Muhammad Rizal Hanafie Sy, and Primata Mardina. "EKSTRAKSI SILIKA DARI ABU SEKAM PADI DENGAN PELARUT KOH." Konversi 2, no. 1 (April 1, 2013): 28. http://dx.doi.org/10.20527/k.v2i1.125.
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Sekam padi sebagai limbah yang berlimpah khususnya di negara agraris, adalah salah satu sumber penghasil silika terbesar. Sekam padi mengandung sekitar 90%-98% silika setelah mengalami pembakaran sempurna. Pengambilan silika dari abu sekam padi dilakukan dengan proses ekstraksi padat cair menggunakan larutan alkali sebagai pelarut. Tujuan dari penelitian ini adalah untuk mengetahui pengaruh konsentrasi larutan alkali dan waktu operasi terhadap yield dari silika. Proses ekstraksi dilakukan dalam skala laboratorium. Sepuluh gram abu sekam padi dimasukkan ke dalam 60 mL larutan alkali dengan konsentrasi tertentu (5%w/w, 10% w/w dan 15% w/w) untuk diekstrak kandungan silika dengan waktu operasi tertentu (30, 60 dan 90 menit). Setelah proses ekstraksi selesai, larutan tersebut ditambahkan larutan HCl 1 N untuk mengendapkan silika. Silika yang terbentuk kemudian dipisahkan dari sisa larutan dengan penyaringan. Untuk menghilangkan kelembaban pada silika yang dihasilkan, maka dilanjutkan dengan proses pengeringan. Hasil penelitian menunjukkan yield silika terbesar adalah 50,49% terjadi pada KOH 10% dan waktu ekstraksi 90 menit. Keywords: abu sekam padi, silika, KOH Rice husks, the most abundant waste material in agricultural country, is the one of the silica rich raw materials. Rice husks contain about 90%-98% of silica after completed combustion. Recovery silica from ash of rice husks was done by solid-liquid extraction using alkali solution. Different concentration of alkali solution (5% w/w, 10% w/w and 10% w/w) and different operation time (30, 60 and 90 minutes) were used to investigate their influence on yields of silica. The extraction process was carried out in laboratory scale. After extraction, process was continued by acidic solidification, filtration and drying. The result showed the biggest yield of silica was 50, 49% at 10% KOH for 90 minutes . Keywords: ash of rice husks, silica, KOH
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Hermida, Lilis, Joni Agustian, Ahmad Zuhairi Abdullah, and Abdul Rahman Mohamed. "Review of large-pore mesostructured cellular foam (MCF) silica and its applications." Open Chemistry 17, no. 1 (November 13, 2019): 1000–1016. http://dx.doi.org/10.1515/chem-2019-0107.
Full textAbstract:
AbstractThe unique properties of mesostructured cellular foam (MCF) silica such as, large pore size, continuous three-dimensional (3D) pore system and hydrothermal robust materialallow favorable conditions for incorporating active sites to produce modified MCF silica as catalysts, biocatalysts and adsorbents. Recently, the modified MCF silicas were reported to be efficient catalysts for the hydrogenation of phenylacetylene, heck coupling reaction of arylboronic acid, etc. Biocatalysts derived from modified MCF silicas were found to be a potential to convert glucose to gluconic acid, hydrolysis of N-benzoyl-DLarginine-p-nitroanilide (BAPNA) and casein, transesterification of racemic 1 phenyl- ethanol and hydrolytic, etc. Several separation processes such as CO2 capture and adsorption of L-tryptophan, lysozyme and bovine serum were sucessfully conducted using adsorbents derived from modified MCF silicas. This paper reviews the synthesis of the MCF silica material and the incorporation of active sites or immobilization of enzymes in the MCF silica material. Additionally, a detailed understanding of the characterization of the modified MCF silicas, which includes pore size, active sites/enzymes sizes, amount of active sites/enzymes bound with the MCF silica, was also discussed to obtain their potentialities as catalysts, biocatalysts and adsorbents. The review also describes recent progress on the applications of the MCF silica.
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Rahayu, Aster, Maryudi Maryudi, Farrah Fadhillah Hanum, Joni Aldilla Fajri, Winda Dwi Anggraini, and Ummi Khasanah. "Review: Pengolahan limbah cair industri dengan menggunakan silika." Open Science and Technology 2, no. 1 (January 8, 2022): 1–12. http://dx.doi.org/10.33292/ost.vol2no1.2022.38.
Full textAbstract:
Pada era industrial, limbah cair industri menjadi salah satu masalah yang serius. Limbah cair industri yang tidak sesuai dengan baku mutu dibuang secara langsung ke badan air yang mengakibatkan pencemaran lingkungan. Karenanya pengolahan limbah harus ditangani sejak awal selama proses produksi. Salah satu material yang sering digunakan sebagai adsorben dalam proses adsorpsi yaitu silika. Silika merupakan adsorben yang memiliki struktur geometri pori, sifat kimia pada permukaan dapat dimodifikasi dan sangat mudah diproduksi. Silika dapat diperoleh dari beberapa sumber diantaranya yaitu sekam padi dari limbah hasil pertanian. Review ini bertujuan untuk mengetahui kemampuan silika sebagai bahan pengolahan limbah industri. Silika dapat digunakan dalam proses pengolahan limbah cair beberapa industri sepeti batik, laundri, industri tahu dan beberapa limbah industri lainnya. Silika paling efektif diaplikasikan pada pengolahan limbah industri tekstil. Silika mampu mengurangi kekeruhan dan kadar warna limbah cair industri khususnya tekstil. Nilai koefisien penurunan tertinggi sebesar 96,86% untuk warna, sedangkan kekeruhan sebesar 99,31%. Nilai ini didapatkan dari berat campuran silika 5 gram (28,65 %wt), volume limbah 100% dengan kandungan warna 1,123 Co dan kekeruhan 180,5 NTU. Industrial liquid waste is one of the serious problems in the industrial era. Disposal of industrial liquid waste that is not in accordance with quality standards directly into water bodies can cause environmental pollution. Therefore, wastewater treatment must be handled early during the production process. Silica is one of the most commonly used adsorbents in the adsorption process. This is due to the ease with which silica is produced and the surface properties (pore geometry structure and surface chemistry) that can be modified. Silica can be obtained from several sources, one of which is rice husk which is a waste from agriculture. This review aims to determine the role of silica as an industrial wastewater treatment material. From several articles obtained, silica can be used in the processing of wastewater from batik industrial, laundri industrial, tofu industrial and several other industries. Silica is most effectively used in the textile industry wastewater treatment. Silica can reduce the color and turbidity of the textile industry wastewater. The highest removal coefficient value is 96.86% for color and 99.31% for turbidity obtained from a 5-gram (28.65 %wt) silica mixture mass, 100% waste volume with color content of 1.123 Co and turbidity of 180.5 NTU.
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Haryono, Atiek Rostika Noviyanti, and Engela Evy Ernawati. "Sintesis, Karakterisasi, dan Uji Adsorpsi Komposit Silika/Karbon dari Limbah Sekam Padi sebagai Adsorben Tembaga (II)." Jurnal Teknologi Lingkungan 24, no. 1 (January 31, 2023): 058–66. http://dx.doi.org/10.55981/jtl.2023.241.
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Copper ion as one of the pollutants in industrial wastewater can be treated by the adsorption method. One type of adsorbent can be prepared from rice husk. Rice husk as agricultural waste contains carbon and silica which can act as metal adsorbents. The purpose of this study was to synthesize and characterize silica/carbon composites, as well as test their adsorption as adsorbent on copper (II) ion adsorption by determining the optimum composition of silica/carbon, adsorption capacity, and model of isotherm adsorption. The research method consisted of gasification of rice husks, extraction of silica from rice husk charcoal with potassium carbonate as solvent, manufacture of silica/carbon composites, and adsorption tests. The results showed that the mass ratio of silica to carbon of 2:1 was the optimum composition in the synthesis of silica/carbon composites as adsorbent for the adsorption of copper (II) ion. The silica/carbon composite adsorbent in this composition had the highest adsorption capacity for copper (II) ion and surface area is 75.88 mg/g and 233.45 m2/g, respectively. The optimum adsorption time was obtained for 40 minutes and the model of adsorption isotherm in the form of Freundlich adsorption with R2 = 0.9582. Abstrak Ion tembaga sebagai salah satu polutan dalam air limbah industri dapat ditangani dengan metode adsorpsi. Salah satu jenis adsorben dapat disiapkan dari sekam padi. Sekam padi sebagai limbah pertanian mengandung karbon dan silika yang dapat berperan sebagai adsorben logam. Tujuan dari penelitian ini adalah melakukan sintesis dan karakterisasi komposit silika/karbon, serta uji adsorpsinya sebagai adsorben pada adsorpsi ion tembaga (II) melalui penentuan komposisi optimum dari silika/karbon, kapasitas adsorpsi, dan model adsorpsi isoterm. Metode penelitian terdiri dari gasifikasi sekam padi, ekstraksi silika dari arang sekam padi dengan pelarut kalium karbonat, pembuatan komposit silika/karbon, dan uji adsorpsi. Hasil penelitian menunjukkan bahwa rasio massa silika terhadap karbon sebesar 2:1 merupakan komposisi optimum pada sintesis komposit silika/karbon sebagai adsorben untuk adsorpsi ion tembaga (II). Adsorben komposit silika/karbon pada komposisi tersebut memiliki kapasitas adsorpsi terhadap ion tembaga (II) dan luas permukaan paling tinggi yaitu berturut-turut sebesar 75,88 mg/g dan 233,45 m2/g. Waktu optimum adsorpsi diperoleh selama 40 menit dan dengan model adsorpsi isoterm berupa adsorpsi Freundlich dengan nilai R2 = 0,9582.
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Liang, Yutao, Jinchuan Zhang, Yang Liu, Xuan Tang, Zhen Li, Jianghui Ding, Yang Wang, and Sen Yang. "Evidence for Biogenic Silica Occurrence in the Lower Silurian Longmaxi Shale in Southeastern Chongqing, China." Minerals 10, no. 11 (October 24, 2020): 945. http://dx.doi.org/10.3390/min10110945.
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The gas shale in the Lower Silurian Longmaxi Formation contains a considerable amount of biogenic silica. Various originated silicas in shale, derived from different depositional environment, are commonly associated with different degrees of organic matter enrichment, resulting in different mechanical and physical properties of shale reservoirs. Thin section identification, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), total organic carbon (TOC) analysis, X-ray diffraction (XRD) analysis, and X-ray fluorescence (XRF) spectroscopy were used to investigate the Lower Silurian Longmaxi shale from Well Yuye 1 in southeastern Chongqing, China to obtain a better understanding of the origin of silica in the Longmaxi Shale. The results show ubiquitous cryptocrystalline silicas with poorly crystalline morphology, which differs from that of the detrital silica, authigenic silica, and hydrothermal silica, proving that the cryptocrystalline silicas may have a biogenic origin. Major element and mineral composition analysis indicate no correlations between K2O/Al2O3 and SiO2/Al2O3 and between illite and SiO2, and negative correlations between TiO2 and SiO2/Al2O3, between illite and quartz and excess Si, and between Al2O3 and excess Si, and all samples being located in the area of non-hydrothermal origin in the Al-Fe-Mn diagram, excluding silicas of terrigenous detrital origin, clay mineral transformed origin, and hydrothermal origin. Moreover, the fact that almost all samples plot above the illite Si/Al line in the cross-plot of Si versus Al and the mean values of Al/(Al + Fe + Mn) and Si/(Si + Al + Fe + Ca) are close to the values of biogenic silica prove that the silicas are primarily of biogenic origin. Positive correlations between TOC and quartz and excess Si and numerous siliceous organisms are observed, indicating that the silicas are associated with siliceous organisms. The postmortem siliceous organisms underwent silica diagenesis via a dissolution-precipitation mechanism following the sequence of opal-A → opal-CT → cryptocrystalline biogenic silica as the burial depth and temperature increased.
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Sujoto, Vincent Sutresno Hadi, I. Wayan Christ Widhi Herman Tangkas, Widi Astuti, Slamet Sumardi, Siti Nurul Aisyiyah Jenie, Aron Pangihutan Christian Tampubolon, Syamsumin Syamsumin, Andhika Putera Utama, Himawan Tri Bayu Murti Petrus, and Yuni Kusumastuti. "Penentuan kondisi optimum pembuatan silica gel menggunakan silika geothermal dengan metode sol-gel." Jurnal Rekayasa Proses 17, no. 2 (December 31, 2023): 122–28. http://dx.doi.org/10.22146/jrekpros.77696.
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Salah satu permasalahan yang muncul di lapangan pembangkit listrik panas bumi (PLTP) adalah terjadinya silica scaling dalam sistem pemipaaan akibat konsentrasi padatan terlarut yang tinggi pada air geotermal (geothermal brine). Silica scalling dapat menyebabkan penurunan efisiensi pembangkitan energi listrik dari panas bumi. Pada penelitian ini lumpur silika yang dihasilkan dari lapangan pembangkit listrik panas bumi akan dimanfaatkan sebagai raw material sintesis silica gel. Silica gel disintesis menggunakan metode sol-gel dengan variasi rasio natrium silikat dan air (1:3 ; 1:4 ; dan 1:5) dan konsentrasi asam klorida ( 0,5 M ; 1 M; dan 2 M). Karakteristik silica gel dilihat menggunakan analisis Forier Transform Infra Red (FTIR). Secara umum, pita serapan yang muncul pada spektra sample silica gel menunjukkan bahwa gugus fungsional yang terdapat pada silica gel adalah gugus silanol (Si-OH) dan gugus siloksan (Si-O-Si). Panjang gelombang 1055,86 cm-1 menunjukkan gugus Si-O, yang mengindikasikan adanya vibrasi SiO4 dan polimerisasi Si-O-Si saat pembentukan silica gel. Selain itu, kapasitas penjerapan air oleh silika gel menunjukkan bahwa sampel dengan kode A7 memiliki kapasitas penjerapan air terbesar, yaitu mencapai 0,9331 gr air/ gram silica gel. Analisis Response Surface Methodology (RSM) mengindikasikan bahwa konsentrasi asam memberikan pengaruh singnifikan terhadap pembentukan silica gel dibandingkan dengan variasi pengenceran natrium silikat.
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Polimpung, Priskilla Wulandari, Heinrich Taunaumang, and Jeferson Polii. "ANALISIS TERJADINYA SCALING SILICA PADA CONDENSER DAN COOLING TOWER." Jurnal FisTa : Fisika dan Terapannya 2, no. 1 (April 30, 2021): 38–42. http://dx.doi.org/10.53682/fista.v2i1.104.
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Silica scaling in geothermal production fields can clog the fluid flow rate. Research has been conducted to determine the occurrence of scaling sillica in brine. The method used in processing this data is by using an application in the form of steam tables and Microsoft Excel. Therefore, a study of the potential for silica scaling in activities that utilize geothermal energy is needed. In this study, a study on the potential for silica scaling in a geothermal power plant in the Lahendong area unit 2 cluster 13.The purpose of this study was to estimate the possibility of scaling silica in the condenser and cooling tower in the geothermal field. After the research was carried out, it could be concluded that the results of the calculation of scaling sillica in the Lahendong geothermal field were the condenser at 11.2 ppm while cooling tower was 72.5 ppm. When silica concentration in this field is compared with the calculated silica concentration, the silica will not settle in the condenser or the cooling tower.This is because the silica concentration in the field is smaller than the calculated silica concentration, so there is no silica scaling at the inlet or outlet of condenser and cooling tower.
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Bramantya, Bramantya, Losendra Primamas Yonando, Muhammad Rifaldi, and Rama Oktavian. "Sintesis dan Karakterisasi Silika Aerogel Hidrofobik dan Oliofilik dari Pasir Laut sebagai Absorben Tumpahan Minyak." Jurnal Teknik Kimia dan Lingkungan 2, no. 2 (October 24, 2018): 49. http://dx.doi.org/10.33795/jtkl.v2i2.69.
Full textAbstract:
Proses pengolahan minyak di Indonesia sangat menguntungkan untuk perekonomian negara. Tetapi disamping itu, terdapat hal yang meyebabkan kerugian yaitu terjadinya tumpahan minyak. Tumpahan minyak bisa diatasi salah satunya dengan menggunakan absorben. Silika aerogel dapat digunakan sebagai absorben. Bahan baku utama sintesis silika aerogel adalah silika. Pada pasir laut di Indonesia rata-rata mengandung silika yang cukup tinggi yaitu sebesar 70%. Penelitian ini dilakukan untuk mengetahui pengaruh precursor dalam modifikasi material silika aerogel yang bersifat oliofilik dan hidrofobik. Pembuatan silika aerogel terbagi menjadi beberapa bagian yaitu pembuatan waterglass (sodium metasilikat) dari pasir laut, kemudian pembuatan silika aerogel dari waterglass. Dalam metode ini digunakan beberapa variabel pembanding yaitu dengan penambahan TEOS (tetraetil ortosilikat) dan heksana dengan perbandingan volume 1:1, 1:2, dan 1:3 sedangkan untuk penambahan etanol divariabelkan konsentrasi volumenya dengan rincian 10%, 20%, dan 30%. Bahan baku pasir laut dan produk silika aerogel dilakukan karakterisasi yang bertujuan untuk mengetahui sifat-sifatnya. Bahan baku pasir laut diuji dengan metode XRF (X-Ray Fluorescence) bertujuan mengetahui komponen yang terkandung dalam pasir silika dengan hasil SiO2 98,9%, K2O 1,2%, CaO 0,6%, TiO2 0,766%, V2O5 0,007%, MnO 0,028%, Fe2O3 0,431%, NiO 0,01%, CuO 0,035%, Yb2O3 0,03%. Sedangkan produk silika aerogel dilakukan uji sudut kontak dan uji serapan minyak, dari hasil uji sudut kontak didapat hasil pada sampel dua dengan penambahan TEOS dan heksana sebanyak 1:2 dan etanol 20% memiliki sudut kontak sebesar 143,95o sedangkan untuk uji serapan minyak sampel dua memiliki kemampuan menyerap minyak sebesar 13,98 g/g silika aerogel.Oil processing in Indonesia is very profitable for the economy of the country. However, in the exploration process there might be an oil spill which can cause a loss in oil production. Oil spill can be overcome by using absorbent. Silica aerogel can be used as absorbent. The main raw material of silica absorbent is silica. Sea sand in Indonesia contains high enough silica reaches 70% on average. This research was conducted to determine the effect of precursors in the modification of silica aerogel which is oliophilic and hydrophobic. The synthesys of silica aerogel was divided into several parts, namely synthesys waterglass from the sea sand and synthesys silica aerogel from waterglass. In this method, several variables were used with addition of TEOS (tetraethyl orthosilicate) and hexane with volume ratio 1:1, 1:2, and 1:3, while for addition of ethanol was varied with volume concentration of 10%, 20%, and 30%. Sea sand as raw material and silica aerogel as product was characterized in order to determine their properties. Sea sand were characterized using XRF (X-Ray Fluorescence) method contains SiO2 98.9%, K2O 1.2%, CaO 0.6%, TiO2 0.766%, V2O5 0.007%, MnO 0.028%, Fe2O3 0.431%, NiO 0.01%, CuO 0.035%, Yb2O3 0.03%. While the silica aerogel was characterixed by contact angle method and oil absorption test. In result, sample with addition of TEOS:hexane as much as 1:2 and ethanol 20% have contact angle of 143.95oand has ability to absorb oil 13.98 g/g silica aerogel.
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Pingak, Redi K., Albert Z. Johannes, and Laura A. S. Lapono. "ANALISIS POTENSI PASIR TABLOLONG DAN PASIR KOKA SEBAGAI SUMBER SILIKA MENGGUNAKAN UJI XRF DAN XRD." Jurnal Fisika : Fisika Sains dan Aplikasinya 3, no. 2 (December 19, 2018): 132–36. http://dx.doi.org/10.35508/fisa.v3i2.614.
Full textAbstract:
Abstrak
Silika memiliki banyak aplikasi sehingga penelitian tentang sintesis silika dari bahan alam yang praktis dan murah sangat penting untuk dilakukan. Dari warnanya, pasir Tablolong dan pasir Koka adalah dua pasir alam di NTT yang diduga mengandung silika dengan kemurnian yang cukup tinggi. Tujuan penelitian ini adalah mengetahui kandungan awal silika dalam pasir Tablolong dan pasir Koka untuk mengetahui potensi kedua pasir alam ini sebagai penghasil silika dengan kemurnian yang tinggi. Sampel pasir Tablolong dan Koka dambil dan dibersihkan, dicuci dengan akuades, kemudian dikeringkan pada suhu 150 0C selama 8 jam untuk menghilangkan kadar airnya. Sampel kemudian dihaluskan menggunakan mortar selama 30 menit dan disaring menggunakan ayakan 100 mesh. Sampel pasir Tablolong dan Koka ini kemudian diuji XRF dan XRD. Berdasarkan uji XRF, diperoleh kandungan silika dalam pasir Tablolong adalah 34,04% dan pasir Koka sebesar 38,91% dan merupakan senyawa oksida dengan kandungan terbanyak kedua dalam pasir setelah CaO. Hasil uji XRD juga bersesuaian dengan hasil uji XRF, dimana fase dominan dalam pasir Tablolong dan Koka adalah fase kalsit CaCO3 dan fase dominan kedua adalah fase quartz SiO2. Berdasarkan kedua hasil ini, dapat disimpulkan bahwa pasir dari kedua lokasi ini berpotensi sebagai penghasil silika dengan kemurnian tinggi. Oleh karena itu, dapat disarankan untuk mensintesis silika dari kedua lokasi ini menggunakan metode-metode sintesis yang umum seperti metode kopresipitasi dan metode alkali-fusion.
Kata kunci: pasir Tablolong, pasir Koka, silika, XRF, XRD
Abstract
Silica has many applications and therefore research on synthesis of silica from natural resources is important. From their colors, sand from Tablolong dan Koka beach in NTT could have silica with high purity. The aim of the research is to determine silica content in sand from Tablolong and Koka beach to know the potential of the two beaches as silica sources. Sand from the two locations was cleaned, washed and dried at 150 0C for 8 hours. It was then milled for 30 minutes and filtered using 100 mesh filter. After that, it was characterised using XRF and XRD. From the XRF results, silica content in pasir Tablolong was about 34,04% and 38,91% in pasir Koka and was the second largest in terms of compound content, only smaller in percentage than CaO. XRD also confirmed the XRF results, where the dominant phases in the sand were calcite CaCO3 and quartz SiO2. From these results, it can be concluded that sand from Tablolong and Koka beach have potential as natural sources of silica with high purity. Therefore, synthesis of silica with well-known methods such as coprecipitation and alkali-fusion from the two locations is recommended.
Keywords: Tablolong sand, Koka sand, silica, XRF, XRD
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Pingak, Redi K., Albert Z. Johannes, and Laura A. S. Lapono. "ANALISIS POTENSI PASIR TABLOLONG DAN PASIR KOKA SEBAGAI SUMBER SILIKA MENGGUNAKAN UJI XRF DAN XRD." Jurnal Fisika : Fisika Sains dan Aplikasinya 3, no. 3 (December 19, 2018): 132–36. http://dx.doi.org/10.35508/fisa.v3i3.614.
Full textAbstract:
Abstrak
Silika memiliki banyak aplikasi sehingga penelitian tentang sintesis silika dari bahan alam yang praktis dan murah sangat penting untuk dilakukan. Dari warnanya, pasir Tablolong dan pasir Koka adalah dua pasir alam di NTT yang diduga mengandung silika dengan kemurnian yang cukup tinggi. Tujuan penelitian ini adalah mengetahui kandungan awal silika dalam pasir Tablolong dan pasir Koka untuk mengetahui potensi kedua pasir alam ini sebagai penghasil silika dengan kemurnian yang tinggi. Sampel pasir Tablolong dan Koka dambil dan dibersihkan, dicuci dengan akuades, kemudian dikeringkan pada suhu 150 0C selama 8 jam untuk menghilangkan kadar airnya. Sampel kemudian dihaluskan menggunakan mortar selama 30 menit dan disaring menggunakan ayakan 100 mesh. Sampel pasir Tablolong dan Koka ini kemudian diuji XRF dan XRD. Berdasarkan uji XRF, diperoleh kandungan silika dalam pasir Tablolong adalah 34,04% dan pasir Koka sebesar 38,91% dan merupakan senyawa oksida dengan kandungan terbanyak kedua dalam pasir setelah CaO. Hasil uji XRD juga bersesuaian dengan hasil uji XRF, dimana fase dominan dalam pasir Tablolong dan Koka adalah fase kalsit CaCO3 dan fase dominan kedua adalah fase quartz SiO2. Berdasarkan kedua hasil ini, dapat disimpulkan bahwa pasir dari kedua lokasi ini berpotensi sebagai penghasil silika dengan kemurnian tinggi. Oleh karena itu, dapat disarankan untuk mensintesis silika dari kedua lokasi ini menggunakan metode-metode sintesis yang umum seperti metode kopresipitasi dan metode alkali-fusion.
Kata kunci: pasir Tablolong, pasir Koka, silika, XRF, XRD
Abstract
Silica has many applications and therefore research on synthesis of silica from natural resources is important. From their colors, sand from Tablolong dan Koka beach in NTT could have silica with high purity. The aim of the research is to determine silica content in sand from Tablolong and Koka beach to know the potential of the two beaches as silica sources. Sand from the two locations was cleaned, washed and dried at 150 0C for 8 hours. It was then milled for 30 minutes and filtered using 100 mesh filter. After that, it was characterised using XRF and XRD. From the XRF results, silica content in pasir Tablolong was about 34,04% and 38,91% in pasir Koka and was the second largest in terms of compound content, only smaller in percentage than CaO. XRD also confirmed the XRF results, where the dominant phases in the sand were calcite CaCO3 and quartz SiO2. From these results, it can be concluded that sand from Tablolong and Koka beach have potential as natural sources of silica with high purity. Therefore, synthesis of silica with well-known methods such as coprecipitation and alkali-fusion from the two locations is recommended.
Keywords: Tablolong sand, Koka sand, silica, XRF, XRD
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Donnet, J. B., Y. J. Li, T. K. Wang, H. Balard, and G. T. Burns. "Surface Energy of Silica Xerogels and Fumed Silica by Inverse Gas Chromatography and Inverse Liquid Chromatography." Rubber Chemistry and Technology 75, no. 5 (November 1, 2002): 811–24. http://dx.doi.org/10.5254/1.3547685.
Full textAbstract:
Abstract Inverse gas chromatography (IGC) and inverse liquid chromatography (ILC) have been used to detect the interaction energy between silicas (fumed silicas and silica xerogels) surfaces and probes molecules. The silica surfaces were modified chemically by trimethylsiloxane functions. Either IGC or ILC have detected the adsorption energy change following the surface modification. In IGC technique, the results with several probes show clearly the physico-chemical properties of the silica surfaces. ILC was developed to use bigger probe molecules which are more similar in structure to polymers. In this work, squalene, a non volatile molecule with 30 carbon atoms and several double bonds, was used in ILC to simulate elastomer molecules.
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Kang, Misun, Jong-tak Lee, and Jae Young Bae. "Facile Mesoporous Hollow Silica Synthesis for Formaldehyde Adsorption." International Journal of Molecular Sciences 24, no. 4 (February 20, 2023): 4208. http://dx.doi.org/10.3390/ijms24044208.
Full textAbstract:
Formaldehyde emitted from household products is classified as a hazardous substance that can adversely affect human health. Recently, various studies related to adsorption materials for reducing formaldehyde have been widely reported. In this study, mesoporous and mesoporous hollow silicas with amine functional groups introduced were utilized as adsorption materials for formaldehyde. Formaldehyde adsorption characteristics of mesoporous and mesoporous hollow silicas having well-developed pores were compared based on their synthesis methods—with or without a calcination process. Mesoporous hollow silica synthesized through a non-calcination process had the best formaldehyde adsorption characteristics, followed by mesoporous hollow silica synthesized through a calcination process and mesoporous silica. This is because a hollow structure has better adsorption properties than mesoporous silica due to large internal pores. The specific surface area of mesoporous hollow silica synthesized without a calcination process was also higher than that synthesized with a calcination process, leading to a better adsorption performance. This research suggests a facile synthetic method of mesoporous hollow silica and confirms its noticeable potential as a support for the adsorption of harmful gases.
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Yuliatun, Leny, Nuryono Nuryono, Eko Sri Kunarti, and Widjijono Widjijono. "Effect of sonication and reflux treatment on silica characteristics of rice husk ash as raw material for dental pulpotomy." Journal of Aceh Physics Society 11, no. 4 (December 3, 2022): 96–100. http://dx.doi.org/10.24815/jacps.v11i4.27950.
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Abstrak. Penelitian ini bertujuan untuk mengekstraksi dan memunikan silika dari abu sekam padi (ASP) dan melihat karakteristik silika yang dihasilkan apabila diberi perlakuan sonikasi dan refluks. Metode yang digunakan dalam penelitian ini adalah sol-gel menggunakan pelarut NaOH dan HCl kemudian diberi perlakuan sonikasi dan refluks serta pencucian untuk meminimalisir keberadaan natrium pada silika yang dihasilkan. Berdasarkan penelitian yang dilakukan, presentase silika dari metode sonikasi dan refluks adalah 96,4% dan 93%. Silika yang dihasilkan dari kedua metode mempunyai fase amorf dengan puncak melebar pada (2θ) 22º. Spektra FTIR antara kedua metode tidak menunjukkan perbedaan dengan puncak pada pita serapan 470 cm-1, 802 cm-1, dan1103 cm-1 yaitu vibrasi dari Si-O siloksan (≡Si-O-Si≡). Pita serapan 3448 cm-1 adalah vibrasi ulur –OH dari silanol (≡Si-OH). Citra SEM menunjukkan bentuk yang berbeda pada silika yang dimurnikan dengan metode sonikasi dan refluks yaitu agregasi bulat teratur dan tak beraturan. Ukuran partikel dari silika dari metode sonikasi adalah 0,4448 µm. Berdasarkan hasil karakterisasi yang dilakukan, dapat disimpulkan bahwa ekstraksi silika sebagai bahan baku pembuatan material pulpotomi dapat efektif dilakukan menggunakan metode sol-gel dan dimurnikan menggunakan sonikasi. Abstract. This study aims to extract and purify silica from rice husk ash (RHA) and see the characteristics of the silica produced when treated with sonication and reflux. The method used in this study was sol-gel using NaOH and HCl solvents and then treated with sonication and reflux and washing to minimize the presence of sodium in the silica. Based on the research, the percentage of silica from the sonication and reflux method was 96.4% and 93%, respectively. Silica produced by both methods has an amorphous phase with a broad peak at (2θ) 22º. The FTIR spectra between the two methods showed no difference with peaks in the absorption bands of 470 cm-1, 802 cm-1, and 1103 cm-1, namely the vibration of Si-O siloxane (≡Si-O-Si≡). The absorption band of 3448 cm-1 is the –OH stretching vibration of silanol (≡Si-OH). SEM images show different shapes of silica purified by sonication and reflux methods, namely regular aggregation, and irregular form. The particle size of silica from the sonication method is 0.4448 µm. Based on the results of the characterization carried out, it can be concluded that the extraction of silica as a raw material for the of pulpotomy can be effectively carried out using the sol-gel method and purified using sonication.
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He, Xiaozhen, Ilkka Rytöluoto, Rafal Anyszka, Amirhossein Mahtabani, Minna Niittymäki, Eetta Saarimäki, Christelle Mazel, et al. "Combining good dispersion with tailored charge trapping in nanodielectrics by hybrid functionalization of silica." e-Polymers 21, no. 1 (January 1, 2021): 897–909. http://dx.doi.org/10.1515/epoly-2021-0054.
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Abstract Fumed silica-filled polypropylene (PP)-based nanodielectrics were studied in this work. To not only improve the dispersion of the silica but also introduce deep charge traps into the polymeric matrix, five types of modified silicas were manufactured with different surface modifications. The modified silica surfaces comprise an inner and a surface layer. The inner layer contains a polar urethane group for tailoring the charge trap properties of the PP/propylene–ethylene copolymer nanocomposites, whereas the surface layer consists of hydrocarbons (ethyl-, tert-butyl-, cyclopentyl-, phenyl-, or naphthalenyl moieties) in order to gain a good dispersion of the silica in the unpolar polymer blend. Scanning electron microscopic pictures proved that these tailored silicas show a much better dispersion than the unmodified one. Thermally stimulated depolarization current measurements revealed the ability of the silica to introduce deep charge traps with low trap density. The trap depth distribution depends on the type of the unpolar surface layer consisting of the different hydrocarbons. Among these five differently modified silicas, the introduction of the one with a surface layer consisting of tert-butyl moieties resulted in the lowest charge injection and the lowest charge current in the nanocomposite, proving good dielectric performance. Additionally, this silica exhibits good dispersion in the polymeric matrix, indicating a promising performance for nanodielectric application.
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Purnawan, Candra, Tri Martini, and Ima Puspita Rini. "Sintesis dan Karakterisasi Silika Abu Ampas Tebu Termodifikasi Arginin sebagai Adsorben Ion Logam Cu(II)." ALCHEMY Jurnal Penelitian Kimia 14, no. 2 (September 13, 2018): 333. http://dx.doi.org/10.20961/alchemy.14.2.19512.334-349.
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<p>Telah dilakukan penelitian tentang sintesis dan karakterisasi silika dari abu ampas tebu termodifikasi arginin dengan senyawa penggandeng glisidoksipropiltrimetoksisilan (GPTMS) sebagai adsorben ion logam Cu(II). Penelitian ini bertujuan untuk mengetahui karakterisasi silika abu ampas tebu termodifikasi arginin dengan senyawa penggandeng GPTMS sebagai adsorben ion logam Cu(II). Sintesis silika termodifikasi arginin dengan senyawa penggandeng GPTMS dilakukan dengan metode sol-gel. Adsorben tersebut dikarakterisasi dengan XRD, FTIR dan SAA. Uji kemampuan adsorpsi dilakukan menggunakan metode batch dengan larutan ion logam Cu(II), variasi pH, waktu kontak dan konsentrasi. Hasil penelitian menunjukkan perubahan difraktogram XRD pada silika termodifikasi dan silika abu ampas tebu (silika AAT). Difraktogram menunjukkan puncak melebar pada 2θ sebesar 10-15° dan 20-25°. Analisis FTIR menunjukkan Serapan baru –CH, ̶ NH tekuk, ̶ CN berturut-turut pada daerah 2947, 1570, dan 1356 cm<sup>-1</sup>. Analisis SAA menunjukkan peningkatan luas permukaan pada silika termodifikasi arginin daripada silika dari 64,31 m<sup>2</sup>/g menjadi 382,67 m<sup>2</sup>/g. Kondisi terbaik adsorpsi ion logam Cu(II) dengan adsorben silika termodifikasi arginin terjadi pada pH 6 dengan waktu kontak 45 menit. Silika termodifikasi arginin mengalami peningkatan kapasitas adsorpsi dibandingkan silika dengan kapasitas adsorpsi yaitu dari 0,12 mg/g menjadi 0,52 mg/g. Isoterm adsorpsi ion logam Cu(II) lebih dominan mengikuti isoterm Langmuir dengan r = 0,997.</p><p><strong>Synthesis </strong><strong>a</strong><strong>nd Characterization </strong><strong>o</strong><strong>f Arginine-Modified Silica </strong><strong>f</strong><strong>rom Baggase Ash </strong><strong>a</strong><strong>s C</strong><strong>u</strong><strong>(I</strong><strong>I</strong><strong>) Ions Adsorbent</strong><strong>.</strong> The synthesis and characterization of arginine modified silica from bagasse ash with crosslinker glycydoxypropyltrimethoxyxylane (GPTMS) as an adsorbent for Cu (II) ions has been studied. This research aimed to determine the characterization of arginine modified silica with crosslinker GPTMS as an adsorbent for Cu(II) ions. Synthesis arginine modified silica with crosslinker GPTMS was conducted using sol-gel method. The adsorbent was characterized by XRD, FTIR and SAA. Adsorption ability test conducted using the batch method with a solution of Cu(II) ions, variation of pH, contact time and concentration. The results showed the change in the XRD diffractogram of arginine modified silica from bagasse (silica ATT). XRD diffractogram releaved broad peaks at 2θ 10-15° and 20-25°. FTIR analysis showed a new absorption -CH, -NH bending, -C-N on area of 2947, 1570, and 1356 cm<sup>-1</sup>, respectively SAA analysis showed that the arginine-modified silica with crosslinker GPTMS has higher surface area than silica from 64.31 m<sup>2</sup>/g to 382.67 m<sup>2</sup>/g. The best conditions for copper adsorption with adsorbent arginine modified silica occured at pH 6 with a contact time of 45 minutes. Arginine modified silica has higher adsorption capacity than silica with a adsorption capacity from 0.12 mg/g to 0.52 mg/g. Adsorption of Cu (II) metal ions more dominantly follows Langmuir isotherms with r = 0.997.<strong></strong></p><p> </p>
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Mahmud, Mudrikah Sofia, Farah Diana Mohd Daud, Norshahida Sarifuddin, Hafizah Hanim Mohd Zaki, Norhuda Hidayah Nordin, and Nur Farahiyah Mohammad. "Partial Replacement of Silica Nanoparticles in Cement Paste for CO2 Regeneration Capture Application." IIUM Engineering Journal 25, no. 2 (July 14, 2024): 299–308. http://dx.doi.org/10.31436/iiumej.v25i2.3058.
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A promising, supplementary material, highly reactive silica nanoparticles tend to react with calcium species (Ca2+) in cement, which produces more hydrated phases. The high amount of calcium species and the potential of capturing carbon dioxide (CO2) through carbonation implies the suitability of cement paste as a CO2 sorbent material. However, limited studies could be found highlighting the effect of silica nanoparticle inclusion on the CO2 capture property of hardened cement paste. Thus, this study investigates the effect of silica nanoparticle partial replacement on the CO2 capture capacity and regeneration performance of hardened cement paste. XRD and SEM analysis proved the formation of more hydrated phases upon partially replacing silica nanoparticles in cement. Partial replacement of 3 % with silica nanoparticles significantly improved CO2 regeneration capture at room temperature among the other cement paste samples. This study found that the presence of silica nanoparticles in cement paste triggered the formation of more hydrated phases, which served as active sites for CO2 capture to occur and, thus, improved the CO2 capture capacity and regeneration performance. ABSTRAK: Sebagai salah satu bahan tambahan yang berpotensi, nanozarah silika sangat reaktif dan cenderung bertindak balas dengan spesies kalsium (Ca2+) dalam simen di mana terhasilnya lebih banyak fasa terhidrat. Jumlah spesies kalsium yang tinggi dan berpotensi menangkap karbon dioksida (CO2) melalui pengkarbonan menunjukkan kesesuaian pes simen digunakan sebagai bahan penyerap CO2. Walau bagaimanapun, kajian adalah terhad terhadap kesan kemasukan nanozarah silika pada sifat tangkapan pes simen CO2 yang dikeraskan. Oleh itu, kajian ini adalah berkenaan kesan penggantian separa nanopartikel silika ke atas kapasiti tangkapan CO2 dan prestasi penjanaan semula pes simen yang dikeraskan. Analisis XRD dan SEM membuktikan pembentukan lebih banyak fasa terhidrat apabila penggantian separa nanopartikel silika pada simen. Penggantian separa nanopartikel silika 3% menunjukkan peningkatan ketara tangkapan penjanaan semula CO2 pada suhu bilik di antara sampel pes simen lain. Kajian ini mendapati bahawa kehadiran nanozarah silika dalam pes simen mencetuskan pembentukan lebih banyak fasa terhidrat yang berfungsi sebagai tapak aktif bagi penangkapan CO2 berlaku dan dengan ini, membawa kepada peningkatan kapasiti penangkapan CO2 dan prestasi penjanaan semula.
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Friska, Vira, Ardian Putra, and Almuhsinin Almuhsinin. "Struktur dan Karakteristik Termal Sinter Silika Mata Air Panas Panti, Pasaman." Jurnal Fisika Unand 9, no. 3 (August 14, 2020): 408–14. http://dx.doi.org/10.25077/jfu.9.3.408-414.2020.
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Telah dilakukan penelitian tentang struktur dan karakteristik termal sinter silika pada mata air panas Panti, Kabupaten Pasaman. Karakterisasi termal menggunakan metode Differential Thermal Analysis (DTA) dengan suhu pemanasan maksimal 1100°C untuk melihat perubahan fasa kristalin dari sinter silika. Berdasarkan hasil uji DTA, suhu terjadinya proses endoterm hampir sama pada kedua sampel yaitu titik A pada suhu 91,9°C dan titik B 91,8°C. Silika pada titik A mengalami transisi α → β-quartz pada suhu 710,8°C selanjutnya perubahan β-quartz → β-tridymite pada suhu 848,8°C. Sampel silika pada titik B mengalami transisi fasa pada suhu yang lebih rendah dibanding titik A yaitu perubahan α → β-quartz pada suhu 523,7°C dan β-quartz → β-tridymite pada suhu 711,2°C. Titik A membutuhkan suhu yang lebih tinggi untuk berubah dari β-quartz → β-tridymite dibandingkan pada titik B. Ini mengindikasikan bahwa sampel pada titik B memiliki kandungan silika yang lebih tinggi dibandingkan titik A. Struktur sinter silika diuji menggunakan X-Ray Diffractometer (XRD). Hasil uji XRD menunjukkan bahwa sinter silika pada kedua titik memiliki fase opal-CT. Hal ini mengindikasikan bahwa sinter silika pada mata air panas panti, Pasaman memiliki usia 10.000 tahun dan aktifitas termal panas bumi daerah penelitian ini sudah ada puluhan ribu tahun. Structure and thermal characteristics of silica sinter on hot spring in Panti, Pasaman District has been investigated. The thermal characteristics used the Differential Thermal Analysis (DTA) method with a maximum heat temperature of 1100°C to see the crystalline phase changes from silica sinter. Based on DTA test, the temperature of the endothermic process is almost the same in both samples, are 91,9°C at point A and 91,8°C at point B. The change α → β-quartz at point A occurs at 710,8°C and β-quartz → β-tridymite occurs at 848,8°C. Silica sinter at point B have transitioned at temperatures lower than point A, the change α → β-quartz occurs at 523,7°C and β-quartz → β-tridymite at 711,2°C. Siica at point A requires a higher temperature to change from β-quartz → β-tridymite than that at point B, this indicates that the sample at point B has a higher silica content than point A. The silica sinter structure was tested using an X-Ray Diffractometer (XRD). The XRD results showed that the phase of silica sinters at both points is opal-CT. It indicates that silica sinters at the hotspring in Panti, Pasaman has an age 10,000 years and the geothermal thermal activity of this research area has existed for tens of thousands of years.
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Wibowo, Emas Agus Prastyo, Adi Wahyu Arzanto, Khoironni Devi Maulana, and Aden Dhana Rizkita. "PREPARASI DAN KARAKTERISASI NANOSILIKA DARI JERAMI PADI." JURNAL ILMIAH SAINS 18, no. 1 (July 19, 2018): 35. http://dx.doi.org/10.35799/jis.18.1.2018.19089.
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PREPARASI DAN KARAKTERISASI NANOSILIKA DARI JERAMI PADIABSTRAKPenelitian ini dilakukan untuk mengetahui karakteristik silika yang diekstraksi dari jerami padi yang diperoleh dari wilayah usaha tani padi Pekalongan. Silika diperoleh dengan metode sol-gel, yang melibatkan ekstraksi silika dengan larutan alkali dan gelasi silika menggunakan larutan asam. Ditemukan bahwa hasil tertinggi diperoleh dari ekstraksi menggunakan larutan KOH 5% dengan waktu ekstraksi 60 menit, dan pH gelasi 7.0. Persiapan berhasil diproduksi dengan memanaskan jerami padi pada suhu 10 °C/menit dan menahannya pada suhu 500°C untuk memudahkan penguraian dan pengadopsian bahan organik sambil menghindari pengapian otomatis. Komposisi kimia SiO2 diperkuat oleh EDS dan FTIR dan sifat amorf oleh XRD.Serbuk nanosilika dengan ukuran pori rata – rata 45,3869 nm dan memiliki permukaan spesifik (94,761 m2/g).Kata kunci: Jerami padi; Nanopartikel silika, Sol gel PREPAPARATION AND CHARACTERIZATION NANOSILICAFROM RICE STAWABSTRACTThis study was carried out to investigate the characteristics of silica extracted from rice straw obtained from rice farming region of Pekalongan. The silica was obtained using sol-gel method, which involves extraction of silica using alkalis solution and gelation of the silica using acid solution. It was found that the highest yield was obtained from the extraction using 5% KOH solution with the extraction time of 60 minutes, and gelation pH of 7.0. Preparation was successfully produced by heating rice straw at 10 °C/min and holding at 500°C to facilitate decomposition and gasification of the organics while avoiding auto-ignition. The SiO2 chemical composition was confirmed by EDS and FTIR and the amorphous nature by XRD. Nanosilica powders with a 45,3869 nm average pore size and have specific surface (94,761 m2/g).Keywords: Rice straw; Silica nanoparticles, Sol gel
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Desfitri, Erda Rahmilaila, Reni Desmiarti, Munas Martynis, and Suci Rahma Dhani. "Analisis dan Karakterisasi Potensi Pozzolan Sebagai Sumber Silika (SiO2) Untuk Meningkatkan Nilai Sumber Daya Lokal." Jurnal Rekayasa Hijau 6, no. 2 (December 13, 2022): 96–105. http://dx.doi.org/10.26760/jrh.v6i2.96-105.
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ABSTRAKKabupaten Padang Pariaman memiliki sumber daya pozzolan yang belum termanfaatkan secara optimal. Pozzolan adalah bahan yang mengandung senyawa silika dan alumina. Untuk pemanfaatan yang optimal dilakukan analisis dan karakterisasi potensi pozzolan sebagai sumber silika. Silika bisa dimanfaatkan untuk bahan baku utama diberbagai industri, seperti industri gelas, keramik, katalis, pertanian dan untuk pengolahan limbah. Untuk mengetahui potensi pozzolan sebagai sumber silika dilakukan analisis kualitatif dan kuantitaif menggunakan XRD dan XRF. Berdasarkan hasil analisis pola difraksi sinar-X dengan measurement program PANalitycal ditemukan senyawa SiO2 yang tertinggi teramati pada posisi 2θ sebesar 20o dan 26o. Sedangkan analisis XRF dilakukan untuk mendapatkan informasi jumlah elemen dan oksida logam yang terkandung pada pozzolan. Hasil analisi XRF menunjukkan bahwa kadar SiO2 yang terdapat pada pozzolan adalah sejumalh 62,56%. Senyawa lain yang ditemukan pada pozzolan diantaranya Al2O3, SiO2, P2O5, K2O, CaO dan Fe2O3. Hasil penelitian menunjukkan bahwa pozzolan sangat berpotensi untuk dijadikan sumber silika.ABSTRACTPadang Pariaman regency has pozzolanic resources that have not been utilized optimally. Pozzolan is a material containing silica and alumina. For optimal utilization, analysis and characterization of the potential of pozzolan as a source of silica have been done. Silica can be used as a raw material in several industries, for example, glass, ceramic, catalyst industry, farm, and waste treatment. Qualitative and quantitative analyses by XRD and XRF were carried out to investigate pozzolan as a source of silica. Based on x-ray diffraction pattern with measurement of PANalitycal program was found SiO2 compound on 2θ position, 20o dan 26odegree. XRF analysis is used to get information chemical composition of pozzolan. XRF analysis found silica composition is 62,56%. Other compounds also found in pozzolans such as Al2O3, SiO2, P2O5, K2O, CaO, and Fe2O3. The result shows that pozzolan in Padang Pariaman Regency has the potential as a source of silica.
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Sopa N.R, Yra Maya, Sartika Nisumanti, and Denie Chandra. "Pengaruh Penambahan Silica Fume Terhadap Kuat Tekan Beton Fc’25." Publikasi Riset Orientasi Teknik Sipil (Proteksi) 5, no. 1 (June 21, 2023): 1–6. http://dx.doi.org/10.26740/proteksi.v5n1.p1-6.
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Beton salah satu bahan utama dalam bidang kontstruksi. Bangunan insfrastruktur seperti gedung, jembatan, irigasi dan jalan semuanya menggunakan beton sebagai bahan utama. Silica fume adalah material pozzolan yang halus, berbentuk butiran, sangat kecil, mengandung senyawa silika dioksida (SiO2) dan alumina (Al2O3) yang berpengaruh dalam proses pengerasan pada beton. Penggunaan silica fume pada campuran beton dapat menghasilkan beton dengan kuat tekan yang tinggi. Penelitian ini bertujuan untuk mengetahui pengaruh penambahan silica fume dengan variasi kadar silica fume sebesar 10% dan 20%. Menggunkan metode eksperimen sesuai standar SNI 03-2834-2000 untuk memperoleh hasil yang akan mengkonfirmasi variasi yang diteliti. Hasil dari penelitian menunjukkan kuat tekan optimum terdapat pada kadar silica fume sebesar 20% dengan kuat tekan beton 27,20 MPa pada umur beton 28 hari, dengan meningkatnya proporsi campuran silica fume kemampuan kerja beton semakin meningkat. Dari hasil penelitian tersebut dapat diketahui semakin tinggi kadar silica fume maka workabilitas beton semakin berkurang, hal ini terjadi karena sifat silica fume yang menyerap air.
Kata Kunci: Beton, Silica Fume, Kuat Tekan Beton
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Zakaria, Tatan, and Anita Dyah Juniarti. "MENGATASI MASALAH SILICA SAND MELTING PADA KETEL UAP TEKANAN RENDAH (BUBLING FLUIDIZER BED) DENGAN MENGGUNAKAN TQM DI PT. DDD TANGERANG." Jurnal Intent: Jurnal Industri dan Teknologi Terpadu 3, no. 1 (February 19, 2020): 32–41. http://dx.doi.org/10.47080/intent.v3i1.798.
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Ketel Uap adalah salah satu dari sekian banyak mesin konversi energi yang sangat diperlukan industri dan perusahaan. Baik sebagai mesin pembangkit listrik ataupun sebagai penghasil uap proses produksi. Untuk menghasilkan produksi uap air (steam), proses pembakaran dalam ruang bakar suatu ketel uap memerlukan bahan bakar. Bahan bakar ketel uap terdiri dari 3 karegori : Padat, Cair dan Gas. Bubling Fluidized Bed Boiler (BFBB) adalah salah satu dari sekian banyak tipe ketel uap, dimana untuk proses pembakaran di ruang bakar (furnace) memerlukan media pasir silika (Silica Sand). Kestabilan temperatur, spesifiksi pasir silika, keseimbangan udara pembakaran serta jenis batubara adalah persyaratan utama untuk beroperasinya ketel uap jenis ini. Salah satu bermasalah maka mengakibatkan ketel uap gagal beroperasi. Salah satu penyebab gagal beroperasinya ketel uap ini adalah diakibatkan pasir silika leleh (Silica Sand Melting). Data didapatkan sebelum perbaikan ada 16 kali kerusakan akibat pasir silika leleh. Dengan menganalisa akar penyebab masalah, melakukan perencanaan perbaikan, dan mengimplementasikan perbaikan dari tools pada metoda Total Quality Control, didapatkan hasil selama 7 bulan setelah perbaikan, ketel uap tidak terjadi gagal operasi karena pasir silika leleh (silica sand melting).
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Roychoudhury, A., P. P. De, N. Roychoudhury, and A. Vidal. "Chemical Interaction between Chlorosulfonated Polyethylene and Silica—Effect of Surface Modifications of Silica." Rubber Chemistry and Technology 68, no. 5 (November 1, 1995): 815–23. http://dx.doi.org/10.5254/1.3538777.
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Abstract The surface of precipitated silica was modified by heat treatment (800°C, 4 h) and hexadecanol treatment. Diffuse reflectance infrared Fourier transform spectroscopic (DRIFTS) measurements reveal that the modification of the silica surface reduces the silanol content. Heat treatment causes condensation of the silanol groups forming siloxane linkages, while hexadecanol treatment causes esterification, thereby, shielding the free silanol groups. As a result, the modified silicas exhibit much less interaction with polar molecules (e.g. water, chloroform), compared to the unreacted silica. Bound rubber formation in the chlorosulfonated polyethylene (CSM)/silica system is also adversely affected by the modification of the filler surface. CSM upon heat treatment (180°C, 1 h) loses -SO2Cl groups and the modified polymer lacks in its ability to form bound rubber. Accordingly, it is believed that the rubber-filler interaction occurs between the silanol groups of the silica and sulfonyl chloride groups of CSM.
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Gun'ko, V. M. "Porosity and packing features of nano- and micro-particles of carbon and silica adsorbents." Surface 15(30) (December 30, 2023): 80–96. http://dx.doi.org/10.15407/surface.2023.15.080.
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Comparative characterization of the particulate morphology and texture of various silicas (fumed silicas, silica gels, ordered mesoporous silicas) and carbons (chars and activated carbons, AC) is of interest from both theoretical and practical points of view since it allows one better understanding of advantages and disadvantages of various adsorbents upon their interactions with different adsorbates, co-adsorbates, and solutes in various dispersion media. Complete characterization needs application of a certain set of methods that is analyzed in the present paper. It is shown that the main difference in the textural characteristics of silica and carbon adsorbents is due to the absence (silicas) or presence (carbons) of nanopores in nanoparticles (NP). A great contribution of these pores in strongly activated carbons provides the specific surface area values greater by an order of magnitude than that of fumed silicas. Despite a high activation degree of AC, contribution of closed pores or pores inaccessible for nitrogen molecules remains relatively large in contrast to fumed silica A–300 composed of nonporous nanoparticles synthesized in the flame at higher temperature (~80% of melting temperature, Tm, for amorphous silica) than carbon activation temperature (~25%of Tm for carbons). Therefore, the pores inaccessible for nitrogen molecules in fumed silica could be attributed to narrow voids around contact area between neighboring NP in their aggregates, but for AC, there are both closed pores and open nanopores inaccessible for nitrogen molecules. For complete characterization of the morphology and texture of various adsorbents, such methods as transmission and scanning electron microscopies, probe (nitrogen, argon) adsorption, smallangle X-ray scattering (SAXS)and X-ray diffraction (XRD)could be used with appropriate software to analyze the data. The latter is especially important for the analyses of indirect data (e.g., adsorption, SAXS, XRD) characterizing the materials.
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Kooyman, Patricia J., Markéta Slabová, Vladimír Bosáček, Jiří Čejka, Jiří Rathouský, and Arnošt Zukal. "The Influence of pH on the Structure of Templated Mesoporous Silicas Prepared from Sodium Metasilicate." Collection of Czechoslovak Chemical Communications 66, no. 4 (2001): 555–66. http://dx.doi.org/10.1135/cccc20010555.
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A recently developed homogeneous precipitation method was used for the investigation of the influence of pH on the structure of mesoporous silicas prepared from sodium metasilicate in the presence of a quaternary alkyl ammonium surfactant as a structure directing agent. The rate of pH decrease affects the assembly of mesoscopically ordered composites and, consequently, the porous structure of mesoporous silicas prepared from them by calcination. Pure MCM-41 molecular sieve was prepared by controlling the pH decrease of the reaction mixture so as to achieve the final pH 7.8. The as-made material prepared at higher pH (final value 10.1) is characterized by a lower degree of silica polycondensation. Due to the shrinkage of this material during calcination, a less well-ordered silica with extraordinary large surface area was prepared. A large decrease in pH (final value 5.2) led to non-organized polycondensation of silica species besides the organized assembly of the ordered material, which resulted in the formation of silica with a bimodal mesoporous structure.
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Rassamee, Watcharin, Woothichai Thaijaroen, and Thirawudh Pongprayoon. "Mechanical and Dynamic Properties of Silica-Filled Rubber Compounds." Advanced Materials Research 781-784 (September 2013): 475–78. http://dx.doi.org/10.4028/www.scientific.net/amr.781-784.475.
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Natural rubber compound using different silicas, including unmodified silica, admicellar-modified silica and silica with silane coupling agent, were studied. The properties including cure characteristics, mechanical properties and dynamic properties were examined with the comparison of three compounds. The results show that cure characteristics of admicellar silica/rubber compound (Ad-Si/R) was shorter than those of unmodified silica/rubber compound (Un-Si/R) and silane coupling silica/rubber compound (Sil-Si/R). Mechanical properties of Ad-Si/R and Sil-Si/R were better than those of Un-Si/R. In addition, wet grip and rolling resistance analyzed from tan δ (5 Hz) at 0°C and 60°C, respectively, by DMA were found that the wet grip of Ad-Si/R was the best, whereas the rolling resistance of Sil-Si/R was the best, in the comparison.
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Vaikuntam, Sankar Raman, Eshwaran Subramani Bhagavatheswaran, Fei Xiang, Sven Wießner, Gert Heinrich, Amit Das, and Klaus Werner Stöckelhuber. "Friction, Abrasion and Crack Growth Behavior of In-Situ and Ex-Situ Silica Filled Rubber Composites." Materials 13, no. 2 (January 7, 2020): 270. http://dx.doi.org/10.3390/ma13020270.
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The article focuses on comparing the friction, abrasion, and crack growth behavior of two different kinds of silica-filled tire tread compounds loaded with (a) in-situ generated alkoxide silica and (b) commercial precipitated silica-filled compounds. The rubber matrix consists of solution styrene butadiene rubber polymers (SSBR). The in-situ generated particles are entirely different in filler morphology, i.e., in terms of size and physical structure, when compared to the precipitated silica. However, both types of the silicas were identified as amorphous in nature. Influence of filler morphology and surface modification of silica on the end performances of the rubbers like dynamic friction, abrasion index, and fatigue crack propagation were investigated. Compared to precipitated silica composites, in-situ derived silica composites offer better abrasion behavior and improved crack propagation with and without admixture of silane coupling agents. Silane modification, particle morphology, and crosslink density were identified as further vital parameters influencing the investigated rubber properties.
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Park, Man, Sridhar Komarneni, W. T. Lim, N. H. Heo, and J. Choi. "Microporous Semicrystalline Silica Materials." Journal of Materials Research 15, no. 7 (July 2000): 1437–40. http://dx.doi.org/10.1557/jmr.2000.0208.
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A new family of microporous semicrystalline silica materials (MSSMs) were developed at room temperature from acidic mixtures of alkyl-substituted silane and tetramethylalkoxysilane. Hydrolyzed alkyl-substituted silica precursors, having hydrophilic silanol groups and hydrophobic alkyl groups, presumably act not only as templates but also as sol stabilizers for continuous pore engineering of silica materials in the micropore region. Depending on the substituted alkyl (SUA) groups in initial sols, MSSMs have distinct broad x-ray diffraction peaks in low 2θ range of 2° to 12°, distinguishable thermal behavior of SUA groups, highly flexible processability, and discrete micropore size with good thermal stability of micropores after the removal of SUA groups. These designer microporous silicas are expected to be useful for molecular sieving applications.
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Kanda, Makoto, Aya Kaide, Takashi Saeki, and Hiroshi Tochigi. "Preparation and Rheology of Magnetorheological Fluid Using Six Kinds of Fumed Silica as Stabilizing Additives." MATEC Web of Conferences 333 (2021): 02006. http://dx.doi.org/10.1051/matecconf/202133302006.
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In this study, magnetorheological fluid (MRF) was prepared with several kinds of hydrophobic fumed silica in order to improve MRF stability while maintaining desirable fluidity. We conducted steady flow measurements and oil separation tests under gravity and centrifugal conditions. The linkage of fumed silica particles was also observed morphologically by transmission electron microscopy. We found that the MRF sedimentation stability correlated with viscosity in the lower shear rate range. The oil separation ratio improved with the addition of the fumed silicas examined in this study. The surface characteristics of the silica particles affected the stabilization ability. The addition of hydrophobic fumed silica can desirably increase MRF magnetic properties.
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Kanda, Makoto, Aya Kaide, Takashi Saeki, and Hiroshi Tochigi. "Preparation and Rheology of Magnetorheological Fluid Using Six Kinds of Fumed Silica as Stabilizing Additives." MATEC Web of Conferences 333 (2021): 02006. http://dx.doi.org/10.1051/matecconf/202133302006.
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In this study, magnetorheological fluid (MRF) was prepared with several kinds of hydrophobic fumed silica in order to improve MRF stability while maintaining desirable fluidity. We conducted steady flow measurements and oil separation tests under gravity and centrifugal conditions. The linkage of fumed silica particles was also observed morphologically by transmission electron microscopy. We found that the MRF sedimentation stability correlated with viscosity in the lower shear rate range. The oil separation ratio improved with the addition of the fumed silicas examined in this study. The surface characteristics of the silica particles affected the stabilization ability. The addition of hydrophobic fumed silica can desirably increase MRF magnetic properties.
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Sampurno, Ridho, Ilham Jangkit Pamuncak, Nova Eka Saputra, Yanatra Budi Pramana, and Krisyanti Budipramana. "Pengembangan Media Lumpur Lapindo Sebagai Bahan Tambah Pembuatan Keramik." STIGMA: Jurnal Matematika dan Ilmu Pengetahuan Alam Unipa 16, no. 1 (May 20, 2023): 28–34. http://dx.doi.org/10.36456/stigma.16.1.7408.28-34.
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Industry Keramik sanitary seperti closet, wastafel, cangkir, mangkok mengalami peningkatan akan kebutuhannya setiap tahunnya. Dalam pembuatan keramik dibutuhkan beberapa bahan antara lain feldspar, silica, clay, talk dan melalui proses yang berurutan antara lain: milling/ penggilingan, casting (pengecoran), pengeringan, dry body inspection/ pengecekan kekeringan, glazing/pewarnaan dan kalsinasi. Pada lumpur lapindo terdapat kandungan silica yang dapat di manfaatkan untuk pembuatan keramik. Untuk mendapatkan hasil silika yang murni pada lumpur lapindo maka perlu melakukan proses sol gel, pada percobaan didapatkan silika murni sebesar 75,4 %
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Shi, Jian, Quan Liu, and Dong Sheng Wang. "Studies on the Realationship between the Speciation Distribution and Si/Fe Ratio of Poly-Silica-Ferric-Chloride." Advanced Materials Research 156-157 (October 2010): 1339–42. http://dx.doi.org/10.4028/www.scientific.net/amr.156-157.1339.
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Interactions between ferric species and silica have been shown to play a large part in the coagulation of suspensions. These effects are quite distinct from those associated with polymeric or colloid silica. The interaction of monosilicic acid with Fe ions has been discussed in this paper. Compared with traditional iron salt, poly-silica-ferric-chloride (PFSC) is characterized by having higher molecular weight, less positive charge, lower Feb and higher Fec. In addition, the Si/Fe is higher and the Silica is higher and Silicc is lower. With increasing Si/Fe ratio the effective diameter of PFSC increases. Along with the increase of Si/Fe ratio, more complicated polymers are formed and the particle size distribution is broadened. Resluts show that some co-polymerized species or aggregates between silica and Fe( ) polymers are formed.
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Okel, Timothy A., and Walter H. Waddell. "Silica Properties/Rubber Performance Correlation. Carbon Black-Filled Rubber Compounds." Rubber Chemistry and Technology 67, no. 2 (May 1, 1994): 217–36. http://dx.doi.org/10.5254/1.3557523.
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Abstract The effectiveness of predicting rubber performance based on measured silica physical properties in silica- and carbon black-filled compounds is presented for three rubber formulations: an off-the-road tire tread, a wire coat stock and a V-belt. Correlation and regression analyses were performed using SAS software for sixteen physical properties of thirteen precipitated silicas, and sixteen rubber compound performance characteristics of the three compounds. Silica physical properties studied include various measurements of surface area and structure, particle size, pH and impurities. Rubber performance characteristics studied include cure properties and physical properties such as stress/strain, tear strength, cut growth resistance, abrasion resistance and heat build-up. The present study confirms that silica surface area is the single best predictor of the effect that varying silica physical properties have on the physical performance of cured, carbon black-filled rubber compounds containing precipitated silica. Silica structure, as measured by DBP absorption and nitrogen or mercury pore volume, is a secondary predictor of certain rubber physical properties. The confidence limits of the predictions is dependent upon the concentration of precipitated silica used in the carbon black-filled rubber compound.
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Nikmah, Ziadatul Choirum, Widyati Slamet, and Budi Adi Kristanto. "Aplikasi silika dan NAA terhadap pertumbuhan Anggrek Bulan (Phalaenopsis amabilis l.) pada tahap aklimatisasi." Journal of Agro Complex 1, no. 3 (October 27, 2017): 101. http://dx.doi.org/10.14710/joac.1.3.101-110.
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The purpose of the research was to study the influence silica and concentration of NAA for moon orchid (Phalaenopsis amabilis L.) growth in acclimatization. The experiment was assigned in completely randomized factorial design with the first factor was silica (non silika and with silica) and the second factor was NAA concentrations (0, 50, 100, and 150 ppm). Each treatments was repeated three times. Parameters measured were the percentage of plant life, number of leaves, length of leaf, width of leaf, number of roots, length of root and fresh weight of plants. Data were subjected to ANOVA and followed by Duncan Multiple Range Test. The result showed that aplication silica increased fresh weight of plants. Application of NAA concentrations (50, 100, and 150 ppm) decreased percentage of plant life, leaght of leaf, and fresh weight of plants. Interaction of silica and NAA concentrations showed did not significantly effect. Keyword : Moon orchid, silica, NAA, aclimatization
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Aranguren, Mirta I., Elsi Mora, Christopher W. Macosko, and John Saam. "Rheological and Mechanical Properties of Filled Rubber: Silica-Silicone." Rubber Chemistry and Technology 67, no. 5 (November 1, 1994): 820–33. http://dx.doi.org/10.5254/1.3538713.
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Abstract This work focuses on the relationship between the morphology of filled rubbers and their behavior at small and large deformations. Composites were made from vinyl terminated polydimethylsiloxane (PDMS) and different fumed silicas. Filler concentration range was kept between 0 to 40 phr (parts of silica per hundred parts of PDMS). Small deformation tests done in oscillatory shear showed that there is coupling of the filler agglomeration and crosslinking effects at high crosslink density while the coupling is negligible at low crosslinking levels. Since crosslinking (hydrosilation) proceeds through the end vinyl groups of the PDMS, lower molecular weight polymers produce rubbers with higher elastic modulus than do high molecular weight silicones. However, the rubbers formed from low molecular weight PDMS break at lower extensions. As in the case of uncured composites, the moduli of the samples increase with silica concentration and amount of silanols on the silica. A silica treated with divinyltetramethyldisilazane gave rubbers of high modulus similar to those obtained from untreated silicas, highlighting the importance of good adhesion between filler and polymer.
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Chebotarev, A. N., D. V. Snigur, D. O. Barbalat, O. M. Rakhlytskaya, O. M. Zhukovetska, and K. V. Snihur. "SORPTION OF BISMUTON (III) IONS FROM AQUEOUS SOLUTIONS BY SILICAS MODIFIED BY ORGANIC REAGENTS." Odesa National University Herald. Chemistry 26, no. 2(78) (July 31, 2021): 73–88. http://dx.doi.org/10.18524/2304-0947.2021.2(78).233830.
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In current paper, adsorbents based on silica L 40/100 modified with 4-(2-pyridylazo)resorcinol, 1-(2-pyrylazo)naphthol‑2, pyrocatechol violet and sodium N, N‑diethyldithiocarbamate were obtained. Adsorbents were modified by non-covalent immobilization of organic analytical reagents on the silica surface. It is noted that the preparation of such adsorbents is fast and easy to manufacture. The conditions of Bismuth (III) adsorption from dilute aqueous solutions by the proposed adsorbents are studied and optimized. The optimal values of the medium acidity for the effective Bismuth (III) preconcentration by the proposed adsorbents based on silica modified with organic analytical reagents have been established. It is shown that the use of modified silicas allows efficient (95–98%) removal of Bismuth (III) from dilute aqueous solutions. Under optimal adsorption conditions, the capacity of modified adsorbents is determined. It is established that the modification of silica leads to a significant (2–3 times) increase in the capacity of the obtained sorbents by Bismuth (III) in comparison with the unmodified silica, which is associated with the processes of complexation on the surface. The desorption of Bismuth (III) from the surface of unmodified and modified silicas by solutions of mineral acids has been studied. It is shown that Bi(III) is quantitatively desorbed from the surface of unmodified silicas by solutions of sulfuric and nitric acids, and in the case of modified silicas the degree of desorption is small and does not exceed 35%. The data obtained can then be used to develop a test system for determination of Bismuth (III) via corresponding colorimetric scales or for quantitative solid phase extraction and adsorption-spectroscopic quantification of Bismuth (III) in some real samples.
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Regia, Rinda Andhita, and Katharina Oginawati. "POTENSI BAHAYA DEBU SILIKA TERHADAP KESEHATAN PANDAI BESI DESA MEKARMAJU KABUPATEN BANDUNG." Jurnal Dampak 14, no. 2 (July 31, 2017): 73. http://dx.doi.org/10.25077/dampak.14.2.73-80.2017.
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Mekarmaju Village in Bandung Regency is a place of the greatest blacksmith that still exist in West Java. Their activity using the grinding tool causes dust formation in work area. Silica is the chemical element in dust with the second highest grade after Fe and it is classified in Group 1 substances as carcinogenic to humans. Blacksmith are very potentially have lung disease due to frequent of crystalline silica exposure through inhalation, not using personal protective equipment like masks and the condition of knife and agricultural equipment workshop that are not supported by adequate ventilation. The purpose of this research is to analyze the potencial hazard of crystalline silica exposure to the health of blacksmith in Mekarmaju village. This research was done with an exposed group of 30 people. Respirable crystalline silica analysis was done by the X-ray Diffraction (XRD) method based on MDHS 101 in 2005. The results showed the average of crystalline silica concentration for 8 hours was 0.2147 mg/m3 where 16 people exceeded SE 01/MEN/1997, 27 people exceeded the TLV-TWA ACGIH and 6 people exceeded the PEL OSHA. Average of Chronic Daily Intake (CDI) value was 0.0140 mg/kg.day. Based on threshold value in PER.13/MEN/X/2011, there were 6 people have Hazard Index (HI) value more than 1 which means that their daily activity in work area will endanger the health of lungs.Keywords: Mekarmaju village, hazard index, concentration, crystalline silica, blacksmithABSTRAKDesa Mekarmaju di Kabupaten Bandung merupakan tempat pandai besi terbesar yang masih ada di Jawa Barat. Kegiatan menggunakan gerinda menyebabkan terbentuknya debu pada area kerja. Silika merupakan unsur kimia pada debu dengan kadar tertinggi kedua setelah Fe dan silika diklasifikasikan sebagai Grup 1 yaitu karsinogenik bagi manusia. Pekerja pandai besi sangat berpotensi mengidap penyakit paru-paru karena seringnya terpapar kristal silika melalui inhalasi, tidak menggunakan alat pelindung diri berupa masker dan kondisi lingkungan kerja yang tidak didukung oleh ventilasi yang memadai. Tujuan dari penelitian ini adalah menganalisis potensi bahaya kristal silika terhadap kesehatan pandai besi di Desa Mekarmaju. Jumlah responden yang terlibat dalam penelitian ini sebanyak 30 orang. Analisis kristal silika terinhalasi dilakukan dengan metode X-ray Diffraction (XRD) berdasarkan MDHS 101 tahun 2005. Hasil penelitian menunjukkan konsentrasi kristal silika rata-rata selama 8 jam kerja adalah 0,2147 mg/m3. Dari 30 orang responden, 16 orang melebihi NAB SE 01/MEN/1997, 27 orang melebihi TLV-TWA ACGIH, dan 6 orang melebihi PEL OSHA. Chronic Daily Intake (CDI) kristal silika rata-rata sebesar 0,0140 mg/kg.hari. Berdasarkan NAB kristal silika PER.13/MEN/X/2011, terdapat 6 orang memiliki nilai Hazard Index (HI) lebih besar dari 1 yang berarti pekerjaan yang dilakukan oleh 6 orang tersebut termasuk pekerjaan yang membahayakan kesehatan paru-paru.Kata kunci: Desa Mekarmaju, hazard index, konsentrasi, kristal silika, pandai besi
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Fitri, Medya Ayunda, Farikha Alfi Syahriyah, and Yulia Tri Rahkadima. "Penggunaan Tanah Vertisol Sebagai Bahan Baku Pembuatan Silika." Jurnal Teknik Kimia dan Lingkungan 5, no. 1 (April 29, 2021): 50. http://dx.doi.org/10.33795/jtkl.v5i1.212.
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Penggunaan silika sering digunakan dalam berbagai industri. Tujuan penelitian ini adalah untuk mengetahui kadar silika pada tanah vertisol di desa Bringinbendo. Penelitian ini dimulai dengan perendaman tanah pada aquadest, kemudian dicuci sebanyak 3 kali dan dikeringkan pada 110°C selama 24 jam. Selanjutnya dihaluskan hingga ukuran 250 mesh. Tahapan kedua yaitu sintesis silika dengan metode ekstraksi alkali dan diikuti presipitasi asam. 20 gram serbuk tanah diekstraksi dalam 100 ml NaOH (3, 5, dan 7M) sambil diaduk dan dipanaskan pada 80°C. Selanjutnya ditambahkan aquadest sebanyak 250 ml dan disaring menggunakan kertas Whatman. Filtrat dititrasi dengan HCl 5M sambil diaduk hingga pH mencapai 7. Suspensi dipertahankan pada temperatur kamar selama 24 jam, disaring, dan dicuci sebanyak 5 kali dengan aquadest kemudian dikeringkan. Hasil dari penelitian yaitu massa silika paling besar terdapat pada konsentrasi NaOH 7M pada waktu 1 jam yaitu 2,59 gram dan tanah vertisol di Desa Bringinbendo memiliki kadar silika dalam kategori sedang dengan persentase sebesar 77,7%.Silica is widely used in industry. The aim of this study was to determine the silica content in vertisol soil in Bringinbendo village. This research was started by soaking the soil in aquadest, then washed 3 times and dried it at 110 ° C for 24 hours. Furthermore, smoothed to 250 mesh size. The second stage is the synthesis of silica using the alkaline extraction method and the treatment of acids. 20 grams of soil powder were extracted in 100 ml NaOH (3, 5, dan 7M) while stirring and heated at 80 ° C. Next, 250 ml of aquadest was added and filtered using Whatman paper. The filtrate was titrated with 5M HCl while stirring until the pH reached 7. The suspension was maintained at room temperature for 24 hours, filtered, and 5 times with aquadest then dried. The results of the mass study were that the greatest silica was found in 7M NaOH concentration at 1 hour, namely 2.59 grams and vertisol soil in Bringinbendo Village had silica content in the medium category with a proportion of 77.7%.
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Tan, Ewe-Hong, Siegfried Wolff, Marinus Haddeman, Heinz Peter Grewatta, and Meng-Jiao Wang. "Filler—Elastomer Interactions. Part IX. Performance of Silicas in Polar Elastomers." Rubber Chemistry and Technology 66, no. 4 (September 1, 1993): 594–604. http://dx.doi.org/10.5254/1.3538332.
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Abstract Inverse gas—solid chromatography of silicas showed that the free energies of adsorption of polar probes were much higher than those obtained with n-alkanes. This implies that polymer—silica interaction is more pronounced in polar rubbers than in nonpolar rubbers such as polybutadiene. Using a series of silica and carbon-black-loaded acrylonitnle—butadiene (NBR) compounds with different acrylonitrile (ACN) content, this paper shows the changes in viscoelastic properties of the silica compounds can be attributed to improved polymer—filler interactions relative to the interactions involved in carbon-black compounds.
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Gorgol, Marek, Agnieszka Kierys, and Radosław Zaleski. "Positron Lifetime Annihilation Study of Porous Composites and Silicas Synthesized Using Polymer Templates." Defect and Diffusion Forum 373 (March 2017): 280–83. http://dx.doi.org/10.4028/www.scientific.net/ddf.373.280.
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The porous structure of polymer-silica composites, based on three polymer templates, which differ in a porosity and hydrophobicity, was examined using positron annihilation lifetime spectroscopy. Additionally, the investigation of silicas obtained after removal of polymers during calcination of composite materials, was performed. In composites based on hydrophobic polymers, silica condensates only in larger free volumes, while SiO2 deeply penetrates spaces between polymer chains, when the template is polar. Moreover, the structure of the silica gel, obtained after polymer removal, depends on chemical character of the template, rather than its porosity.
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Wang, Hairui, Hao Chen, Zhen Xu, Sibing Wang, Baozong Li, and Yi Li. "Control the Morphologies and the Pore Architectures of Mesoporous Silicas through a Dual-Templating Approach." Journal of Nanomaterials 2012 (2012): 1–8. http://dx.doi.org/10.1155/2012/371289.
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Mesoporous silica nanospheres were prepared using a chiral cationic low-molecular-weight amphiphile and organic solvents such as toluene, cyclohexane, and tetrachlorocarbon through a dual-templating approach. X-ray diffraction, nitrogen sorption, field emission scanning electron microscopy, and transmission electron microscopy techniques have been used to characterize the mesoporous silicas. The volume ratio of toluene to water plays an important role in controlling the morphologies and the pore architectures of the mesoporous silicas. It was also found that mesoporous silica nanoflakes can be prepared by adding tetrahydrofuran to the reaction mixtures.