Статті в журналах: "Monolithe de silice"

1

Prabhakaran, D., C. Subashini, and M. Akhila Maheswari. "Synthesis of Mesoporous Silica Monoliths — A Novel Approach Towards Fabrication of Solid-State Optical Sensors for Environmental Applications." International Journal of Nanoscience 15, no. 05n06 (October 2016): 1660014. http://dx.doi.org/10.1142/s0219581x16600140.

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Mesoporous silica monoliths are an attractive area of research owing to their high specific surface area, uniform channels and mesoporous size (2–30[Formula: see text]nm). This paper deals with the direct templating synthesis of a mesoporous worm-like silica monolithic material using F127 — a triblock copolymer, by micro-emulsion technique using trimethyl benzene (TMB), as the solvent. The synthesized silica monolith is characterized using SEM-EDAX, XRD, BET, NMR and FT-IR. The monolith shows an ordered worm-like mesoporous structure with tuneable through pores, an excellent host for the anchoring of chromo-ionophores for the naked-eye metal ion-sensing. The mesoporous monoliths were loaded with 4-dodecyl-6-(2-pyridylazo)-phenol (DPAP) ligand through direct immobilization, thereby acting as solid-state naked-eye colorimetric ion-sensors for the sensing toxic Pb[Formula: see text] ions at parts-per-billion (ppb) level in various industrial and environmental systems. The influence of various experimental parameters such as solution pH, limiting ligand loading concentration, amount of monolith material, matrix tolerance level, limit of detection and quantification has been studied and optimized.

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2

He, Ping, Stephen J. Haswell, Paul D. I. Fletcher, Stephen M. Kelly, and Andrew Mansfield. "Scaling up of continuous-flow, microwave-assisted, organic reactions by varying the size of Pd-functionalized catalytic monoliths." Beilstein Journal of Organic Chemistry 7 (August 23, 2011): 1150–57. http://dx.doi.org/10.3762/bjoc.7.133.

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A product-scalable, catalytically mediated flow system has been developed to perform Suzuki–Miyaura reactions under a microwave heating regime, in which the volumetric throughput of a Pd-supported silica monolith can be used to increase the quantity of the product without changing the optimal operating conditions. Two silica monoliths (both 3 cm long), with comparable pore diameters and surface areas, were fabricated with diameters of 3.2 and 6.4 mm to give volumetric capacities of 0.205 and 0.790 mL, respectively. The two monoliths were functionalized with a loading of 4.5 wt % Pd and then sealed in heat-shrinkable Teflon® tubing to form a monolithic flow reactor. The Pd-supported silica monolith flow reactor was then placed into the microwave cavity and connected to an HPLC pump and a backpressure regulator to minimize the formation of gas bubbles. The flow rate and microwave power were varied to optimize the reactant contact time and temperature, respectively. Under optimal reaction conditions the quantity of product could be increased from 31 mg per hour to 340 mg per hour simply by changing the volumetric capacity of the monolith.

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3

Alzahrani, Eman. "Green Silver Nanoparticles Confined in Monolithic Silica Disk-packed Spin Column for Human Serum Albumin Preconcentration." Current Analytical Chemistry 15, no. 6 (October 3, 2019): 616–27. http://dx.doi.org/10.2174/2210676609666181204151244.

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Background: In recent times many new uses have been found for nanomaterials that have undergone homogenous immobilization within porous supports. For this paper, immobilization of SNPs on a thiol-functionalized silica monolith using a fast, easy, environmentally friendly and costeffective process was performed. This was achieved by modifying the surface of a silica-based monolith using thiol groups, and then we fabricated green SNPs in situ, reducing an inorganic precursor silver nitrate solution (AgNO3) by employing tangerine peel extract as a reducing reagent, with Ag-thiol bonds forming along the monument. Doing this allows monoliths to be prepared in such a way that, as TEM analysis demonstrated, SNPs are evenly distributed along the rod's length. Once the materials had been fabricated, they were employed as a sorbent by being placed in a centrifuge. The SNP-thiol functionalized silica monolith was then tested using a standard protein (HSA). Methods: The process involves creating monolithic materials by employing a two-part sol-gel technique before modifying the surface of the silica-based monolith using thiol groups for hosting purposes. Homogenous surface coverage was achieved through the use of a non-toxic "green" reducing reagent (tangerine peel extract) to reduce a silver nitrate solution in place to create SNPs joined to the pore surface of a thiol-functionalized silica monolith, employing bonds of Ag-thiol. Once these materials were synthesized, they were classified by utilizing a number of methods based on SEM coupled with EDAX, TEM, AFM and BET analysis. The silica-based monolith, embedded with constructed SNPs, was employed as a sorbent in the preconcentration of human serum albumin (HSA). Results: The performance of the fabricated materials was measured against a silica-based monolith with no SNPs. Also, a silica monolith with constructed SNPs embedded was employed to capture HSA within a sample of human urine mixed with a double detergent concentrate (SDS). Such a monolith containing functionalized SNPs can be a highly effective sorbent for preconcentration of proteins in complex samples. Conclusion: It was shown to have superior performance compared to a bare silica-based monolith. Additionally, it was shown that a monolithic column modified by SNPs could preconcentrate spiked HSA in urine samples.

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Thejaswini, Thurlapathi VL, and Deivasigamani Prabhakaran. "Synthesis of Mesoporous Titania–Silica Monolith Composites — A Comprehensive Study on their Photocatalytic Degradation of Acid Blue 113 Dye Under UV Light." International Journal of Nanoscience 15, no. 05n06 (October 2016): 1660012. http://dx.doi.org/10.1142/s0219581x16600127.

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The present work deals with the synthesis of bi-continuous macro and mesoporous crack-free titania–silica monoliths, with well-defined structural dimensions and high surface area. The work also highlights their potential photocatalytic environmental applications. The highly ordered titania–silica monoliths are synthesized through direct surface template method using organic precursors of silica and titania in the presence of surface directing agents such as pluronic P123 and PEG, under acetic acid medium. The monoliths are synthesized with different Ti/Si ratios to obtain monolithic designs that exhibit better photocatalytic activity for dye degradation. The titania–silica monoliths are characterized using XRD, SEM, EDAX, FT-IR, TG–DTA and BET analysis. The photocatalytic activity of the synthesized monoliths is tested on the photodegradation of a textile dye (acid blue 113). It is observed that the monolith with 7:3 ratio of Ti/Si showed significant photocatalysis behavior in the presence of UV light. The influence of various physico-chemical properties such as, solution pH, photocatalyst dosage, light intensity, dye concentration, effect of oxidants, etc. are analyzed and optimized using a customized photoreactor set-up. Under optimized conditions, the monoliths exhibited superior degradation kinetics, with the dye dissipation complete within 10[Formula: see text]min of photolysis. The mesoporous catalysts are recoverable and reusable up to four cycles of repeated usage.

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5

Chen, Ai Bing, Wen Wei Zang, Chao Liu, Yan Yan Wang, Man Ling Jia, Bo Li, and Yi Feng Yu. "Preparation of Monolithic Transparent Mesoporous Silica and Mesoporous Onion-Like Carbon." Advanced Materials Research 557-559 (July 2012): 1518–21. http://dx.doi.org/10.4028/www.scientific.net/amr.557-559.1518.

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Large-sized, crack-free silica monoliths have been fabricated by a fast and convenient way via EISA method using P123 as soft template and 1-hexadecyl-3-methylimidazolium bromide (［C16mim］Br) as additive. The hydrogen bonds formed between ILs and the silano groups of silica gel play crucial roles in the form of the bulk, transparent silica monolith. The mesoporous structure onion-like carbon monoliths were prepared with the transparent silica monolith as template via the nanocasting technique. The mesoporous silica and carbon monoliths have been characterized by the XRD, HRTEM, N2sorption and elemental analysis. The results reveal that pore diameter of the mesoporous carbon about 3.47nm, and the specific surface area of carbon with a nitrogen content of 4.2%, can be tuned from 408.2-629.0m2/g. HRTEM shows that this carbon material with nanoonions structure.

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6

Aydoğan, Cemil, İbrahim Y. Erdoğan, and Ziad El-Rassi. "Hydrophobic AEROSIL®R972 Fumed Silica Nanoparticles Incorporated Monolithic Nano-Columns for Small Molecule and Protein Separation by Nano-Liquid Chromatography." Molecules 27, no. 7 (April 1, 2022): 2306. http://dx.doi.org/10.3390/molecules27072306.

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A new feature of hydrophobic fumed silica nanoparticles (HFSNPs) when they apply to the preparation of monolithic nano-columns using narrow monolithic fused silica capillary columns (e.g., 50-µm inner diameter) was presented. The monolithic nano-columns were synthesized by an in-situ polymerization using butyl methacrylate (BMA) and ethylene dimethacrylate (EDMA) at various concentrations of AEROSIL®R972, called HFSNPs. Dimethyl formamide (DMF) and water were used as the porogenic solvents. These columns (referred to as HFSNP monoliths) were successfully characterized by using scanning electron microscopy (SEM) and reversed-phase nano-LC using alkylbenzenes and polyaromatic hydrocarbons as solute probes. The reproducibility values based on run-to-run, column-to-column and batch-to-batch were found as 2.3%, 2.48% and 2.99% (n = 3), respectively. The optimized column also indicated promising hydrophobic interactions under reversed-phase conditions, while the feasibility of the column allowed high efficiency and high throughput nano-LC separations. The potential of the final HFSNP monolith in relation to intact protein separation was successfully demonstrated using six intact proteins, including ribonuclease A, cytochrome C, carbonic anhydrase isozyme II, lysozyme, myoglobin, and α-chymotrypsinogen A in nano-LC. The results showed that HFSNP-based monolithic nanocolumns are promising materials and are powerful tools for sensitive separations.

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7

Chen, Ai Bing, Yun Hong Yu, Yi Feng Yu, Hai Jun Lv, Ting Ting Xing, Yue Tong Li, and Wen Wei Zang. "Monolithic Macroporous-Mesoporous Carbon Using Ionic Liquids as Carbon Source." Advanced Materials Research 988 (July 2014): 23–26. http://dx.doi.org/10.4028/www.scientific.net/amr.988.23.

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A facile approach is employed for the preparation of hierarchically porous structures monolithic ordered macroporous-mesoporous silica materials (OMS) using the commercially available and cheap polyurethane (PU) foam as monolithic template, triblock copolymer P123 (EO20PO70EO20) as structure-directing agent and tetraethyl orthosilicate (TEOS) as silica source, then monolithic ordered macro porous-mesoporous carbon materials (OMC) is synthesized by using monolithic ordered macroporous-mesoporous silica materials as hard template and ionic liquids as the carbon source. The silica and carbon monoliths possess uniform pore sizes (3.74-3.84 nm) and ordered mesostructure.

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8

Lu, Lu, Yu Lei Wei, Jie Lin, and Lei Qian. "Fabrication of Silica Monoliths with Hierarchically Porous Structure from Freeze-Drying." Materials Science Forum 814 (March 2015): 76–80. http://dx.doi.org/10.4028/www.scientific.net/msf.814.76.

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This paper provides a novel route to prepare silica monoliths with hierarchical porous structure via freeze drying. In this method, macroporous silica monoliths were first produced by freeze-drying and calcination. By adjusting the concentration of cetyltrimethylammonium bromide in ethylsilicate, a layer of mesoporous thin film was attached on the macroporous silica monolith. The structural characterization of the hierarchical porous monoliths were studied by field emission scanning electron microscopy, mercury porosimeter and nitrogen adsorption-desorption techniques (BET). It turned out that the pore distribution of the obtained monoliths was ranged from 3.72 nm to 23.21nm and the maximum specific surface area calculated from BET was about 288 m2/g, which indicated the existence of hierarchical structure in the obtained material.

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9

Carroll, Mary, Ann Anderson, Sri Mangu, Zineb Hajjaj, and Margeaux Capron. "Aesthetic Aerogel Window Design for Sustainable Buildings." Sustainability 14, no. 5 (March 2, 2022): 2887. http://dx.doi.org/10.3390/su14052887.

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Transport of heat through windows accounts for more than 25% of heating and cooling losses in residential buildings. Silica-based aerogels are translucent with extremely low thermal conductivity, which make them attractive for incorporation into the interspaces of glazing units. Widespread incorporation of monolithic-silica-aerogel-based windows could result in significant energy savings associated with the heating and cooling of buildings. However, monolithic silica aerogels do not have the optical clarity of vision glass, due to light scattering by the solid matrix, and often have surface imperfections, both of which render these materials less appealing for glazing applications. Here, we demonstrate a variety of approaches to preparing aesthetically pleasing monolithic silica aerogel by a rapid supercritical extraction method for incorporation into glazing units, including: (1) process improvements that result in monoliths with higher visible light transmission; (2) innovative mold design for the preparation of uniform aerogel monoliths; (3) glazing designs that use thinner monoliths; and (4) the incorporation of artistic effects using dyes and laser etching to prepare glazing units with mosaic- or stained-glass-like patterns in which surface imperfections are perceived as features of the design rather than flaws.

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10

Li, Hongwei, Junhui Pan, Chengtao Gao, Mengyu Ma, Liangyu Lu, Yuzhu Xiong, and Fuping Dong. "Mercapto-Functionalized Porous Organosilica Monoliths Loaded with Gold Nanoparticles for Catalytic Application." Molecules 24, no. 23 (November 29, 2019): 4366. http://dx.doi.org/10.3390/molecules24234366.

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Porous organosilica monoliths have attracted much attention from both the academic and industrial fields due to their porous structure; excellent mechanical property and easily functionalized surface. A new mercapto-functionalized silicone monolith from a precursor mixture containing methyltrimethoxysilane; 3-mercaptopropyltrimethoxysilane; and 3-mercaptopropyl(dimethoxy)methylsilane prepared via a two-step acid/base hydrolysis–polycondensation process was reported. Silane precursor ratios and surfactant type were varied to control the networks of porous monolithic gels. Gold nanoparticles were loaded onto the surface of the porous organosilica monolith (POM). Versatile characterization techniques were utilized to investigate the properties of the synthesized materials with and without gold nanoparticles. Scanning electron microscopy was used to investigate the morphology of the as-synthesized porous monolith materials. Fourier transform infrared spectroscopy was applied to confirm the surface chemistry. 29Si nuclear magnetic resonance was used to investigate the hydrolysis and polycondensation of organosilane precursors. Transmission electron microscopy was carried out to prove the existence of well-dispersed gold nanoparticles on the porous materials. Ultraviolet–visible spectroscopy was utilized to evaluate the high catalytic performance of the as-synthesized Au/POM particles

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Im, Hee-Jung, Byunghwan Lee, Suree S. Brown та Sheng Dai. "Neutron Scintillators of Transparent Silica Xerogel Monolith via a Sealed Container System and π–π Interactions". Journal of Nanoscience and Nanotechnology 7, № 11 (1 листопада 2007): 3784–87. http://dx.doi.org/10.1166/jnn.2007.016.

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Transparent crack-free lithiated sol–gel scintillating monoliths were developed by taking advantage of a sealed container system for a syneresis and the π–π interactions between sol–gel components and organic fluors to yield a better homogeneity and scintillating efficiency. The transparency of the resulting materials indicates that the new scintillating material composites are mesoscopically dispersed. The silica monolith can be prepared without cladding the monolith with an engineering plastic such as a poly(ether ether ketone) (PEEK) or a liquid mounting medium. A successful detection of neutron particles by using these lithiated scintillating monoliths was demonstrated.

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Im, Hee-Jung, Byunghwan Lee, Suree S. Brown та Sheng Dai. "Neutron Scintillators of Transparent Silica Xerogel Monolith via a Sealed Container System and π–π Interactions". Journal of Nanoscience and Nanotechnology 7, № 11 (1 листопада 2007): 3784–87. http://dx.doi.org/10.1166/jnn.2007.18072.

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Transparent crack-free lithiated sol–gel scintillating monoliths were developed by taking advantage of a sealed container system for a syneresis and the π–π interactions between sol–gel components and organic fluors to yield a better homogeneity and scintillating efficiency. The transparency of the resulting materials indicates that the new scintillating material composites are mesoscopically dispersed. The silica monolith can be prepared without cladding the monolith with an engineering plastic such as a poly(ether ether ketone) (PEEK) or a liquid mounting medium. A successful detection of neutron particles by using these lithiated scintillating monoliths was demonstrated.

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13

Ni, Xing Yuan, Ji Chao Wang, Guang Wu Liu, Zhi Hua Zhang, Jun Shen, Bin Zhou, and Guang Ming Wu. "Preparation and Properties of Super Insulation Material SiO₂ Aerogel." Advanced Materials Research 516-517 (May 2012): 1531–35. http://dx.doi.org/10.4028/www.scientific.net/amr.516-517.1531.

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Nano-porous monolithic SiO2 aerogel as insulation material was prepared from silicon alkoxide as the precursor materials, followed by ethanol supercritical drying in this paper. In order to improve the mechanical properties of silica aerogel monoliths, the ceramic fibers were mixed in the pure aerogel, or integrating inorganic fiber materials as skeleton materials with low thermal conductivity supporting. Instron 5566, 5500R Material Testing Machine was used to measure the mechanical intensity. SEM was used to characterize the morphology of the silica aerogel monoliths. The thermal properties of the silica aerogels were determined by using the Hot Disk device. The results show that new type composite materials had a low effect on the thermal conductivities of the silica aerogel monoliths, but improved the mechanical intensity clearly. It made a great progress in the practical application of the SiO2 aerogel monoliths.

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14

Mairizki, Fitri, Rahmiana Zein, and Edison Munaf. "KARAKTERISASI KOLOM MONOLIT METHACRYLATE-BASED POLYMER YANG DIMODIFIKASI DENGAN TRIMETILAMIN." Jurnal Katalisator 2, no. 2 (October 6, 2017): 88. http://dx.doi.org/10.22216/jk.v2i2.2457.

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Methacrylate-based polymer monolithic column provide higher polarity and better stability over a wide pH range so itswidely used as stationary phase in ion chromatography. Therefore, the aim of this research was to determine the characteristic of methacrylate-based polymer monolithic column modified with trimethylamine including surface morphology, functional group, permeability, and ion exchange capacity.Methacrylate-based polymer monolithic column was prepared in fused-silica capillary (80 mm, 0,32 mm i.d. x 0,45 mm o.d.), by in situ polymerization reaction using glycidyl methacrylate as monomer; ethylene dimethacrylate as crosslinker; 1-propanol, 1,4-butanediol, and water as porogene; trimethylamine as modifier. The morphology of the monolithic column was characterized by using Scanning Electron Microscope (SEM) and functional group wascharacterized by using Fourier Transform Infra Red Spectroscopy (FT-IR). Monolith columnhas good mechanical stability with permeability was 9.88x10-7 mL//m and ion exchange capacity was 82,10 mmol /mL. Kolom monolit methacrylate-based polymer memberikan polaritas yang lebih tinggi dan stabilitas yang lebih baik pada rentang pH yang luas sehingga menjadi fasa diam yang banyak digunakan pada kromatografi ion.Oleh karena itu, tujuan penelitian ini adalah untuk menentukan karakteristik kolom monolit methacrylate-based polymer yang dimodifikasi dengan trimetilamin meliputi bentuk morfologi permukaan, gugus fungsi, permeabilitas, dan kapasitas penukar ion.Kolom monolit dibuatpada fused-silica capillary (80 mm, 0,32 mm i.d. x 0,45 mm o.d.) dengan reaksi polimerisasi in situ menggunakan glisidil metakrilat sebagai monomer; etilen dimetakrilat sebagai crosslinker; 1-propanol, 1,4-butanadiol, dan air sebagai porogen; trimetilamin sebagai modifier. Bentuk morfologi permukaan kolom monolit dikarakterisasi dengan Scanning Electron Microscope (SEM) dan gugus fungsi dikarakterisasi dengan Fourier Transform Infra Red Spectroscopy (FT-IR).Kolom monolitmemiliki kestabilan mekanik yang baik dengan permeabilitas sebesar 9,88x10-7 mL/m dan kapasitas penukar ion sebesar 82,10 mmol/mL.

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15

Spilstead, Kara B., Stephen J. Haswell, Neil W. Barnett, Xavier A. Conlan, Paul G. Stevenson, and Paul S. Francis. "Development of a resin based silica monolithic column encapsulation." Analytical Methods 7, no. 12 (2015): 4908–11. http://dx.doi.org/10.1039/c5ay00722d.

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A robust technique for the encapsulation of silica-monolithic columns into microfluidic devices. This new approach overcomes the deleterious wall-effects of previous approaches and enables direct fluidic connection to the monolith using standard fittings.

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16

Buntem, Radchada, and Kewarin Pramual. "Amine-Functionalized Silica Monolith as a Copper Ion Adsorbent." Advanced Materials Research 1131 (December 2015): 198–202. http://dx.doi.org/10.4028/www.scientific.net/amr.1131.198.

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Amine-functionalized silica monoliths were prepared by co-condensation between tetraethyl orthosilicate and N-[3-(trimethoxysilyl) propyl] ethylenediamine.The mixture between ethanol, H2O, tetraethyl orthosilicate, N-[3-(trimethoxysilyl) propyl] ethylenediamine and 1M HCl was stirred for 1 hour at room temperature to obtain a clear silica sol. 1.2 g of the sol was poured into plastic vial with the paraffin cover and left for 2 days for the polymerization process to obtain the gel. The disc-shape gel was dried in the oven at 50 °C for 10 hours. The silica monolith obtained was weighed and analyzed by IR spectroscopy and BET method. The disc-shape silica monoliths were further used for copper ion adsorption studies. The factors affecting the copper ion adsorption like pH, copper ion concentration and metal ion interference were studied. The pHs of CuCl2 aqueous solutions were varied from pH 2 to pH 6. While the Cu2+ concentrations under this study were 10-1, 10-2, 10-3, 10-4, 10-5 and 10-6 M. The cationic interferences used were Cd2+ and Ni2+. For the copper ion concentration, the higher the concentration results in the higher adsorption capacity. At the lower concentrations like 10-4, 10-5 and 10-6 M, a complete adsorption was obtained. The color of the Cu2+ - loaded monolith was changed to blue due to the complex between amino groups on the silica and the Cu2+ as evidenced by IR analysis. The monolith after adsorption was also analyzed by SEM/EDS. The inferences like Cd2+ and Ni2+ affect the Cu2+ adsorption at different degree. The desorption could be successfully performed by using 0.1 M HCl solution.

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17

Son, Se Gu, Seong Yeob Hong, and Young Do Kim. "Preparation and Characterization of High Compressive Strength Geopolymeric Monoliths Using Silica Waste." Materials Science Forum 569 (January 2008): 305–8. http://dx.doi.org/10.4028/www.scientific.net/msf.569.305.

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The goal of the present work was investigated development of ET(Environmental Technology) industrial geopolymer materials from mixture Silica Mine Waste(SW) and ground granulated blast furnace slag(GGBFS) and alkali activator solution(sodium silicate) by the Geopolymer Technique at ambient temperature. As for the synthesis of geopolymeric monoliths, four different GGBFS content(10wt%, 20wt%, 30wt%, 40wt%) and three types of GGBFS(GGBFS-1(blaine 4,000cm2/g), GGBFS-2(6,000cm2/g), GGBFS-3(8,000cm2/g)) are investigated to obtain the optimum synthesis condition based on the high compressive strength. The weight ratio between the alkali activator solution and dry mix(SW and GGBFS) were 0.25 and 0.3, respectively. The results showed that geopolymeric monolith containing 30wt% GGBFS exhibits higher compressive strength and increased along with increase of GGBFS blaine. The compressive strengths of GGBFS-1, GGBFS-2 and GGBFS-3 are 66.7MPa, 83.1MPa, 94.1MPa, respectively. Additionally, scanning electron microscope (SEM) techniques are used to characterize the microstructure of the geopolymeric monoliths. SEM observation shows that it is possible to have amorphous aluminosilicate gel and calcite forming simultaneously within monoliths. XRD patterns indicate that geopolymeric monolith is composed of amorphous aluminosilicate phase and calcite and quartz.

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18

Aprilita, Nurul Hidayat, Rania Bakry, Christian W. Huck, and Guenther K. Bonn. "POLY(GLYCIDYL METHACRYLATE-DIVINYLBENZENE) MONOLITHIC CAPILLARY AS A STATIONARY PHASE FOR THE REVERSED-PHASE CHROMATOGRAPHIC SEPARATION OF PROTEINS." Indonesian Journal of Chemistry 5, no. 1 (June 14, 2010): 1–6. http://dx.doi.org/10.22146/ijc.21830.

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Capillary column with monolithic stationary phase was prepared from silanized fused-silica capillary of 200 µm I.D. by in situ free radical polymerization of divinylbenzene with glycidy methacrylate in the presence of decanol and tetrahydrofuran as porogens. The hydrodynamic and chromatographic properties of this monolith, such as backpressure at different flow-rate, pore size distribution, van Deemter plot and the effect of varying gradient-rate were investigated. Poly(glycidyl methacrylate-divinylbenzene) monolithic capillary has been used successfully for the reversed-phase chromatographic separation of proteins. Keywords: monolithic stationary phase, poly(glycidyl methacrylate-divinylbenzene), proteins

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19

Eangpayung, Supattra, Supan Yodyingyong, and Darapond Triampo. "Preparation of Silica Aerogels Monoliths from Hydrophobic Silica Gels and Pluronic10R5 via Sol–Gel Process." Science of Advanced Materials 12, no. 2 (February 1, 2020): 206–11. http://dx.doi.org/10.1166/sam.2020.3627.

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Silica aerogel, the most common type of aerogels, comprised of 95% air in its structure which made the aerogel has a high surface area, high porosity, low density, and low thermal conductivity. Because of its structure and high porosity, one of its major weakness compared to other materials is being very brittle. This study aims at strengthening the connection points between silica nanoparticles using Pluronic10R5 (poly(propylene oxide)8–poly(ethylene oxide)22–poly(propylene oxide)8) where the Pluronic10R5 was used to reduce phase separation during the silica condensation reaction in the sol–gel process. Silica aerogel monoliths were prepared via a sol–gel process from hydrophobic silica gels and Pluronic10R5 with an ambient pressure drying (APD) process. Results from the compression test showed that the Pluronic10R5/silica aerogels have improved mechanical property by ten times that of unmodified silica aerogels. A thermogravimetric analysis (TGA) showed a mass loss at 300–400 °C that is attributed to the surface methyl group, while a mass loss at 200 °C refers to the loss of Pluronic10R5 which confirms the incorporation of Pluronic10R5 into the monolith. Moreover, infrared (IR) images revealed that the top surface temperature of Pluronic10R5/silica aerogels monolith is about 80 °C differs from the bottom heat source temperature of 160 °C.

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20

Moravcová, Dana, and Josef Planeta. "Monolithic Silica Capillary Columns with Improved Retention and Selectivity for Amino Acids." Separations 5, no. 4 (October 2, 2018): 48. http://dx.doi.org/10.3390/separations5040048.

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A strategy for the preparation of silica-based monolithic capillary columns (150 × 0.1 mm) with high selectivity to amino acids is presented. The zwitterionic columns were prepared by coating the silica monolith with [2-(methacryloyloxy)ethyl]-dimethyl-(3-sulfopropyl)-ammonium hydroxide via 3-(trimethoxysilyl)propyl methacrylate. The columns were evaluated under isocratic conditions in hydrophilic interaction liquid chromatography. The best separation of amino acids was obtained on the monolithic column prepared by a stepwise modification procedure where the modification step was repeated four times. The mixture of fifteen amino acids was separated within 13 min using the mobile phase consisting of 75% acetonitrile and 25% 5 mmol/L ammonium acetate at pH 4.5.

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21

Ahmed, Adham, Peter Myers, and Haifei Zhang. "Silica Microspheres-in-Pores Composite Monoliths with Fluorescence and Potential for Water Remediation." Nanomaterials 11, no. 10 (October 12, 2021): 2681. http://dx.doi.org/10.3390/nano11102681.

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Water pollution is a severe worldwide issue. Constructing advanced porous composite materials has been an efficient route to water remediation via adsorption. In this study, a unique microspheres-in-pores monolithic structure was fabricated. An emulsion-templated polymer monolith was first prepared and silica microspheres were subsequently formed in the porous polymer. A silica precursor was modified with a fluorescent dye and co-condensed with other precursors to fabricate porous composites with fluorescent properties, which were enhanced by the presence of Ag nanoparticles in the polymer matrix. This unique material showed good promise in water remediation by removing organic dyes and heavy metal ions from wastewater via a flowing filter or monolithic column separation.

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22

Gutiérrez, Ireri Segura, Verónica Hernández Morales, Eric Mauricio Rivera Muñoz, Rufino Nava Mendoza, Ludwig Lagarde Soto, Carmen Leticia Peza Ledesma, Doris Solís Casados, and Barbara Pawelec. "Efficient Removal of Hg(II) from Water under Mildly Acidic Conditions with Hierarchical SiO2 Monoliths Functionalized with –SH Groups." Materials 15, no. 4 (February 20, 2022): 1580. http://dx.doi.org/10.3390/ma15041580.

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In this work, novel adsorbents based on 3D hierarchical silica monoliths functionalized with thiol groups were used for the removal of Hg(II) ions from an acidic aqueous solution (pH 3.5). Silica monoliths were synthesized by using two different pluronic triblock polymers (P123 and F127) to study the effect of porous structure on their sorption capacity. Before and after functionalization by grafting with 3-mercaptopropyltrimethoxysilane (MPTMS), the monoliths were characterized by several techniques, and their Hg(II) removal potential was evaluated in batch experiments at 28 °C and pH 3.5, using different initial concentrations of Hg(II) ions in water (200–500 mg L−1). The thiol groups of the monoliths calcined at 550 °C showed thermal stability up to 300 °C (from TG/DTG). The functionalized monolith synthesized with P123 polymer and polyethylene glycol showed favorable hierarchical macro-mesopores for Hg(II) adsorption. M(P123)–SH exhibited 97% removal of Hg(II) at concentration 200 mg L−1. Its maximum adsorption capacity (12.2 mmol g−1) was two times higher than that of M(F127)–SH, demonstrating that the 3D hierarchical macro-mesoporosity allowing accessibility of Hg(II) to thiol groups favors the physical and chemical adsorption of Hg(II) under slightly acidic conditions.

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23

Moravcová, Dana, and Josef Planeta. "Silica Monolithic Capillary Columns for Hilic Separations." Hungarian Journal of Industry and Chemistry 46, no. 1 (July 1, 2018): 39–42. http://dx.doi.org/10.1515/hjic-2018-0009.

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Abstract The monolithic capillary columns (0.1 mm x 150 mm) prepared by the acidic hydrolysis of tetramethoxysilane (TMOS) in the presence of polyethylene glycol (PEG) and urea were modified by zwitterionic stationary phases and evaluated under HILIC separation conditions by employing a mixture containing nucleosides and nucleotides. The polymeric layer of zwitterions did not affect the high separation efficiency of the original silica monolith. The prepared zwitterionic columns exhibited high separation efficiencies in a range 61,000-289,000 theoretical plates/m for a 2- methacryloyloxyethyl phosphorylcholine-based stationary phase and in a range 59,000-135,000 theoretical plates/m for a [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide-based stationary phase under optimal separation conditions. The grafted layer of zwitterions on the silica monolithic surface also significantly improved the separation selectivity to compounds of interest

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24

Rossetti, Ilenia, Elnaz Bahadori, Antonio Tripodi, and Gianguido Ramis. "Structured Monolithic Catalysts vs. Fixed Bed for the Oxidative Dehydrogenation of Propane." Materials 12, no. 6 (March 16, 2019): 884. http://dx.doi.org/10.3390/ma12060884.

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The deposition of V-based catalysts for the oxidative dehydrogenation of propane to propene on cordierite honeycomb monoliths was optimised as a strategy to decrease the contact time in a structured reactor with respect to a conventional fixed bed one. 10 wt% VOx supported over SiO2 or Al2O3 were used as catalysts, deposed over the monolith using silica or alumina as primer, respectively. Both the alumina supported catalyst and the bohemite primer precursor were effectively deposed by dip-coating from stable powder suspensions, whereas insufficient adhesion was obtained when loading pre-synthesised SiO2 over the cordierite. A new method based on sol-gel production of SiO2 from tetraethylortosilicate (TEOS) over the monolith surface was set up. A correlation was derived for the prevision of the amount of silica deposed depending on the amount of TEOS. Both primer and catalyst loading were optimised as for uniformity and stability of the coating and resulted 0.5–1 wt % primer and 0.15 wt % of catalyst. Activity testing confirmed the strong improvement of propene productivity by increasing the time factor (i.e. Ncm3 of flowing reactant/min gcat), which ended in a one order of magnitude increase of productivity for the honeycomb-supported samples with respect to the fixed bed configuration.

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25

Miglio, Vanessa, Chiara Zaccone, Chiara Vittoni, Ilaria Braschi, Enrico Buscaroli, Giovanni Golemme, Leonardo Marchese, and Chiara Bisio. "Silica Monolith for the Removal of Pollutants from Gas and Aqueous Phases." Molecules 26, no. 5 (March 1, 2021): 1316. http://dx.doi.org/10.3390/molecules26051316.

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This study focused on the application of mesoporous silica monoliths for the removal of organic pollutants. The physico-chemical textural and surface properties of the monoliths were investigated. The homogeneity of the textural properties along the entire length of the monoliths was assessed, as well as the reproducibility of the synthesis method. The adsorption properties of the monoliths for gaseous toluene, as a model of Volatile Organic Compounds (VOCs), were evaluated and compared to those of a reference meso-structured silica powder (MCM-41) of commercial origin. Silica monoliths adsorbed comparable amounts of toluene with respect to MCM-41, with better performances at low pressure. Finally, considering their potential application in water phase, the adsorption properties of monoliths toward Rhodamine B, selected as a model molecule of water soluble pollutants, were studied together with their stability in water. After 24 h of contact, the silica monoliths were able to adsorb up to the 70% of 1.5 × 10−2 mM Rhodamine B in water solution.

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26

Hu, Wen, Tao Shen, Hongying Hou, Guoyou Gan, Biju Zheng, Fengxian Li, and Jianhong Yi. "Collagen-biomorphic porous carbon nanofiber monoliths: Biosilicification-assisted sustainable synthesis and application in Li-S battery." Functional Materials Letters 09, no. 01 (February 2016): 1650015. http://dx.doi.org/10.1142/s1793604716500156.

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Monolithic carbon has been synthesized via a sustainable biomimetic route utilizing intrafibrillar silicified collagen sponge as precursor and morphogenesis template. The mineralized silica in the biohybrid prevents collapse of the carbon during pyrolysis. Upon biosilica removal results show that the carbon monoliths inherit the porous fiber structure of the mother collagen. The carbon nanofiber framework facilitates the construction of a high electrical conductive pathway, while the internal spaces developed among the intertwined fibrillar network and pores within nanofiber walls offer room for sulfur storage. The as-obtained carbon-sulfur cathode exhibits an accessible discharge capacity approaching 800[Formula: see text]mAh g[Formula: see text] in Li–S battery.

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27

Nekrashevich, Vladimir, Roman Mamonov, Tatiana Torzhenova, Irina Vorobyova, and Marat Khazimov. "Theory and practice of feed silage in containers made of airtight film." BIO Web of Conferences 17 (2020): 00041. http://dx.doi.org/10.1051/bioconf/20201700041.

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The article provides a brief analysis of research results in the field of preparation and storage of silage feed. A brief description of the innovative energy – resource saving technology for the preparation and storage of silage in vacuum-processed containers made from an airtight film is given. The theory of compaction of feed in a container due to its self-weight of the silage and vacuum pressure is presented. It is shown that only vacuum gauge pressure acts on the top of a container, and the difference between the gauge pressure and the lateral and axial pressure, respectively act on the side and bottom of it. The practice of using vacuum-processed containers during silage has shown that a compacted layer is formed over the entire surface of the obtained monolith, which prevents the exit of juice and air from silage. With the porosity of the mass approaching zero, the density of grinded mass of plants approaches the density of their stems and further compaction of silage is senseless. Sufficient vacuum for silage is 60–70 kPa. The density of the compressed silage monoliths in this case is 700–800 kg/m3.

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28

Wang, Xueting, Natalia Martin, Johan Nilsson, Stefan Carlson, Johan Gustafson, Magnus Skoglundh, and Per-Anders Carlsson. "Copper-Modified Zeolites and Silica for Conversion of Methane to Methanol." Catalysts 8, no. 11 (November 15, 2018): 545. http://dx.doi.org/10.3390/catal8110545.

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Powder materials containing copper ions supported on ZSM-5 (Cu-Zeolite Socony Mobil-5) and SSZ-13 (Cu-Standard Oil synthesised zeolite-13), and predominantly CuO nanoparticles on amorphous SiO 2 were synthesised, characterised, wash-coated onto ceramic monoliths and, for the first time, compared as catalysts for direct conversion of methane to methanol (DCMM) at ambient pressure (1 atm) using O 2 , N 2 O and NO as oxidants. Methanol production was monitored and quantified using Fourier transform infrared spectroscopy. Methanol is formed over all monolith samples, though the formation is considerably higher for the copper-exchanged zeolites. Hence, copper ions are the main active sites for DCMM. The minor amount of methanol produced over the Cu/SiO 2 sample, however, suggests that zeolites are not the sole substrate that can host those active copper sites but also silica. Further, we present the first ambient pressure in situ infrared spectroscopic measurements revealing the formation and consumption of surface methoxy species, which are considered to be key intermediates in the DCMM reaction.

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29

Beloti, Luiz, Luis Miranda, and Maria Queiroz. "Butyl Methacrylate-Co-Ethylene Glycol Dimethacrylate Monolith for Online in-Tube SPME-UHPLC-MS/MS to Determine Chlopromazine, Clozapine, Quetiapine, Olanzapine, and Their Metabolites in Plasma Samples." Molecules 24, no. 2 (January 16, 2019): 310. http://dx.doi.org/10.3390/molecules24020310.

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This manuscript describes a sensitive, selective, and online in-tube solid-phase microextraction coupled with an ultrahigh performance liquid chromatography-tandem mass spectrometry (in-tube SPME-UHPLC-MS/MS) method to determine chlopromazine, clozapine, quetiapine, olanzapine, and their metabolites in plasma samples from schizophrenic patients. Organic poly(butyl methacrylate-co-ethylene glycol dimethacrylate) monolith was synthesized on the internal surface of a fused silica capillary (covalent bonds) for in-tube SPME. Analyte extraction and analysis was conducted by connecting the monolithic capillary to an UHPLC-MS/MS system. The monolith was characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectrometry (FTIR). The developed method presented adequate linearity for all the target antipsychotics: R2 was higher than 0.9975, lack-of-fit ranged from 0.115 to 0.955, precision had variation coefficients lower than 14.2%, and accuracy had relative standard error values ranging from −13.5% to 14.6%, with the exception of the lower limit of quantification (LLOQ). The LLOQ values in plasma samples were 10 ng mL−1 for all analytes. The developed method was successfully applied to determine antipsychotics and their metabolites in plasma samples from schizophrenic patients.

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30

Asmari, Mufarreh, Xiaoyu Wang, Natalia Casado, Marjan Piponski, Sergiy Kovalenko, Liliya Logoyda, Rasha Sayed Hanafi, and Sami El Deeb. "Chiral Monolithic Silica-Based HPLC Columns for Enantiomeric Separation and Determination: Functionalization of Chiral Selector and Recognition of Selector-Selectand Interaction." Molecules 26, no. 17 (August 29, 2021): 5241. http://dx.doi.org/10.3390/molecules26175241.

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This review draws attention to the use of chiral monolithic silica HPLC columns for the enantiomeric separation and determination of chiral compounds. Properties and advantages of monolithic silica HPLC columns are also highlighted in comparison to conventional particle-packed, fused-core, and sub-2-µm HPLC columns. Nano-LC capillary monolithic silica columns as well as polymeric-based and hybrid-based monolithic columns are also demonstrated to show good enantioresolution abilities. Methods for introducing the chiral selector into the monolithic silica column in the form of mobile phase additive, by encapsulation and surface coating, or by covalent functionalization are described. The application of molecular modeling methods to elucidate the selector–selectand interaction is discussed. An application for enantiomeric impurity determination is also considered.

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31

El Assal, Zouhair, Satu Ojala, Asmaa Drif, Mohamed Zbair, Mohammed Bensitel, Laurence Pirault-Roy, Tuomas Nevanperä, Satu Pitkäaho, Riitta L. Keiski, and Rachid Brahmi. "Total Oxidation of Dichloromethane over Silica Modified Alumina Catalysts Washcoated on Ceramic Monoliths." Catalysts 8, no. 8 (August 20, 2018): 339. http://dx.doi.org/10.3390/catal8080339.

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Silica modified alumina was used in this study for coating of a cordierite monolith substrate with two different channel densities. The performance of the prepared monolith catalysts was evaluated in catalytic total oxidation of dichloromethane before and after Pt impregnation. The characteristics similar to the powder form catalysts were kept rather successfully after washcoating the monolith as evidenced by electron microscopy (FESEM) and N2 physisorption. A dichloromethane (DCM) conversion of higher than 80% at 500 °C was reached over all the catalysts with 200 cpsi. The maximum conversion was obtained with the catalyst containing 10 mol % of silica. The total amount of major byproducts (CO, CH3Cl and CH2O) were slightly decreased by increasing the silica loading, and remarkably after Pt impregnation. After impregnation of Pt, the HCl yields were increased for two samples with the higher loading of silica (10 and 15 mol %) and reached the maximum when silica loading was 10%. Even though Pt impregnation did not significantly affect the DCM conversion, it improved the selectivity. Comparison between the two substrates (200 and 600 cpsi) evidenced that the key parameters of the monolith influencing the DCM oxidation are low value of open fraction area, hydraulic diameter, thermal integrity factor and high value of mechanical integrity factor and geometric surface area.

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32

Nagase, Kenichi, Jun Kobayashi, Akihiko Kikuchi, Yoshikatsu Akiyama, Hideko Kanazawa, and Teruo Okano. "Thermoresponsive hydrophobic copolymer brushes modified porous monolithic silica for high-resolution bioseparation." RSC Advances 5, no. 81 (2015): 66155–67. http://dx.doi.org/10.1039/c5ra11038f.

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Thermoresponsive-hydrophobic copolymer brushes were prepared on porous monolithic silica rods through surface initiated ATRP. The monolithic silica can separate biomolecules with high resolution and in short analysis times.

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33

Furqani, Firda, Lee Wah Lim, and Toyohide Takeuchi. "One-pot Facile Preparation of Amino-functionalized Silica Hybrid Monoliths for Mixed-mode Chromatography." Journal of the Indonesian Chemical Society 2, no. 2 (December 30, 2019): 81. http://dx.doi.org/10.34311/jics.2019.02.2.81.

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Silica hybrid monolithic columns were prepared using two precursors, in which organo-functionalized trialkoxysilanes are mixed with tetraalkoxysilanes. In this study, several types of amino-functionalized silica hybrid monolithic columns were prepared via single-step “one-pot” approach, and the amount of silica precursors, porogens, as well as the reaction conditions were optimized. The preparation was carried out by mixing the silica precursors, i.e. tetraethoxysilane (TEOS) or tetramethoxysilane (TMOS) with amino precursors such as aminopropyltrimethoxysilane (APTES), aminoethylaminopropyl-trimethoxysilane (AEAPTMS), and phenylaminopropyltrimethoxysilane (PAPTMS) in a porogenic solution. The chromatographic performance of these hybrid monolithic columns was optimized by investigating several parameters through the separation of inorganic anions (IO3-, BrO3-, Br-, NO2-, NO3-, I-, SCN-) and some polar compounds (thymine, thymidine, adenosine, adenine, uridine). Results showed that the silica hybrid monolithic columns could be operated at higher flow-rate that favors rapid separation. The run-to-run repeatability of Si-APTES and Si-PAPTMS hybrid monolithic columns were satisfactory with relative standard deviations (n = 5) of less than 8% for all the analyte anions.

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34

Padilla, Ornel, Jessica Munera, Jaime Gallego, and Alexander Santamaria. "Approach to the Characterization of Monolithic Catalysts Based on La Perovskite-like Oxides and Their Application for VOC Oxidation under Simulated Indoor Environment Conditions." Catalysts 12, no. 2 (January 28, 2022): 168. http://dx.doi.org/10.3390/catal12020168.

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Catalysts are very important in controlling the pollutant emissions and are used for hundreds of chemical processes. Currently, noble metal-based catalysts are being replaced for other kinds of materials. In this study, three lanthanum-based perovskite-like oxides were synthesized (LaCo, LaCoMn, and LaMn) by the glycine-combustion method. The powder catalysts obtained were supported onto cordierite ceramic monoliths using an optimized washcoating methodology to obtain the subsequent monolithic catalysts (LaCo-S, LaCoMn-S, and LaMn-S). Sample characterization confirmed the formation of the perovskite-like phase in the powder materials as well as the presence of the perovskite phase after supporting it onto the monolithic structure. The XPS analysis showed a general decrease in lattice oxygen species for monolithic catalysts, mainly caused by the colloidal silica used as a binder agent during the washcoating process. Additionally, some variations in the oxidation state distribution for elements in Co-containing systems suggest a stronger interaction between cordierite and such catalysts. The catalytic activity results indicated that powder and monolithic catalysts were active for single-component VOC oxidation in the following order: 2-propanol > n-hexane ≅ mixture > toluene, and there was no evidence of loss of catalytic activity after supporting the catalysts. However, LaMn-S had a better catalytic performance for all VOC tested under dry conditions, achieving oxidation temperatures between 230–420 °C. The oxidation efficiency for the VOC mixture was strongly affected by the presence of moisture linking the oxidation efficiency at wet conditions to the VOC chemical nature. Additionally, for higher VOC concentrations, the catalyst efficiency decreased due to the limited number of active sites.

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35

Colón, Héctor, Xin Zhang, Jessica K. Murphy, José G. Rivera, and Luis A. Colón. "Allyl-functionalized hybrid silica monoliths." Chemical Communications, no. 22 (2005): 2826. http://dx.doi.org/10.1039/b502870a.

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36

Pirard, J. P., P. Petit, A. Mohsine, B. Michaux, F. Noville, and A. J. Lecloux. "Silica-zirconia monoliths from gels." Journal of Sol-Gel Science and Technology 2, no. 1-3 (1994): 875–80. http://dx.doi.org/10.1007/bf00486368.

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37

Lyu, Yanting, Taka-Aki Asoh, and Hiroshi Uyama. "Hierarchical silica monolith prepared using cellulose monolith as template." Polymer Degradation and Stability 177 (July 2020): 109164. http://dx.doi.org/10.1016/j.polymdegradstab.2020.109164.

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38

Fujino, Shigeru, and Hiroshi Ikeda. "Room Temperature Imprint Using Crack-Free Monolithic SiO2-PVA Nanocomposite for Fabricating Microhole Array on Silica Glass." Journal of Nanomaterials 2015 (2015): 1–7. http://dx.doi.org/10.1155/2015/584320.

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This paper aims to fabricate microhole arrays onto a silica glass via a room temperature imprint and subsequent sintering by using a monolithic SiO2-poly(vinyl alcohol) (PVA) nanocomposite as the silica glass precursor. The SiO2-PVA suspension was prepared from fumed silica particles and PVA, followed by drying to obtain tailored SiO2-PVA nanocomposites. The dependence of particle size of the fumed silica particles on pore size of the nanocomposite was examined. Nanocomposites prepared from 7 nm silica particles possessed suitable mesopores, whereas the corresponding nanocomposites prepared from 30 nm silica particles hardly possessed mesopores. The pore size of the nanocomposites increased as a function of decreasing pH of the SiO2-PVA suspension. As a consequence, the crack-free monolithic SiO2-PVA nanocomposite was obtained using 7 nm silica particles via the suspension at pH 3. Micropatterns were imprinted on the monolithic SiO2-PVA nanocomposite at room temperature. The imprinted nanocomposite was sintered to a transparent silica glass at 1200°C in air. The fabricated sintered glass possessed the microhole array on their surface with aspect ratios identical to the mold.

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39

Staniak, Michał, Magdalena Wójciak, Ireneusz Sowa, Katarzyna Tyszczuk-Rotko, Maciej Strzemski, Sławomir Dresler, and Wojciech Myśliński. "Silica-Based Monolithic Columns as a Tool in HPLC—An Overview of Application in Analysis of Active Compounds in Biological Samples." Molecules 25, no. 14 (July 9, 2020): 3149. http://dx.doi.org/10.3390/molecules25143149.

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Monolithic fillings used in chromatography are of great interest among scientists since the first reports of their synthesis and use were published. In the 20 years since silica-based monolithic columns were introduced into the commercial market, numerous papers describing their chromatographical properties and utility in various branches of industry and scientific investigations were presented. This review is focused on possible applications of commercially available silica-based HPLC monolithic columns in the analysis of biological samples.

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40

Chen, Ya Shun, Li Jia, Wei Liu, Zhong Zhou Yi, and Fang Fang He. "Preparation and Evaluation of Monolithic Silica Capillary Column for Reversed-Phase Capillary Liquid Chromatography." Advanced Materials Research 485 (February 2012): 136–39. http://dx.doi.org/10.4028/www.scientific.net/amr.485.136.

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Octadecyl-functionalized monolithic silica capillary columns with inner diameters of 100 and 200 micrometers for reversed-phase capillary liquid chromatography were prepared in the fused-silica capillary via sol-gel process. Their performance was evaluated and compared by the separation of alkylbenzenes (toluene, ethylbenzene, propylbenzene, butylbenzene). The column back pressure and linear velocity of mobile phase were investigated. The results show that the monolithic silica capillary columns exhibit good performance for the separation of alkylbenzenes.

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41

Zhou, Yuhong, Qian Liang, Zhilun Zhang, Zhaodi Wang, and Mingxian Huang. "Chiral separations with crosslinked cellulose derivatives attached onto hybrid silica monolith particles via the thiol–ene click reaction." Analytical Methods 12, no. 21 (2020): 2727–34. http://dx.doi.org/10.1039/d0ay00772b.

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42

Chen, Dong, Xiaodong Wang, Wenhui Ding, Wenbing Zou, Qiong Zhu, and Jun Shen. "Silica Aerogel Monoliths Derived from Silica Hydrosol with Various Surfactants." Molecules 23, no. 12 (December 4, 2018): 3192. http://dx.doi.org/10.3390/molecules23123192.

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Owing to their ultra-low thermal conductivity, silica aerogels are promising thermal insulators; however, their extensive application is limited by their high production cost. Thus, scientists have started to explore low-cost and easy preparation processes of silica aerogels. In this work, a low-cost method was proposed to prepare silica aerogels with industrial silica hydrosol and a subsequent ambient pressure drying (APD) process. Various surfactants (cationic, amphoteric, or anionic) were added to avoid solvent exchange and surface modification during the APD process. The effects of various surfactants on the microstructure, thermal conductivity, and thermal stability of the silica aerogels were studied. The results showed that the silica aerogels prepared with a cationic or anionic surfactant have better thermal stability than that prepared with an amphoteric surfactant. After being heated at 600 °C, the silica aerogel prepared with a cationic surfactant showed the highest specific surface area of 131 m2∙g−1 and the lowest thermal conductivity of 0.038 W∙m−1∙K−1. The obtained low-cost silica aerogel with low thermal conductivity could be widely applied as a thermal insulator for building and industrial energy-saving applications.

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43

Loche, D., L. Malfatti, D. Carboni, V. Alzari, A. Mariani, and M. F. Casula. "Incorporation of graphene into silica-based aerogels and application for water remediation." RSC Advances 6, no. 71 (2016): 66516–23. http://dx.doi.org/10.1039/c6ra09618b.

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Graphene/silica nanocomposites in the form of highly porous aerogels are obtained for the first time by integrating a novel approach for the production of low defectivity graphene with a two-step route for the synthesis of a silica-based monolith.

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44

Brevet, David, Claire Jouannin, Corine Tourné-Péteilh, Jean-Marie Devoisselle, André Vioux, and Lydie Viau. "Self-encapsulation of a drug-containing ionic liquid into mesoporous silica monoliths or nanoparticles by a sol–gel process." RSC Advances 6, no. 86 (2016): 82916–23. http://dx.doi.org/10.1039/c6ra17431k.

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45

Malik, Abds-Sami, Daniel M. Dabbs, Howard E. Katz, and Ilhan A. Aksay. "Silica Monoliths Templated on L3Liquid Crystal." Langmuir 22, no. 1 (January 2006): 325–31. http://dx.doi.org/10.1021/la0514718.

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46

Xiong, Liangming, and Masayuki Nogami. "Proton-conducting Ordered Mesostructured Silica Monoliths." Chemistry Letters 35, no. 8 (August 2006): 972–73. http://dx.doi.org/10.1246/cl.2006.972.

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47

He, Fang, Juan Cheng, Ju-Ying Wu, Yu-Hong Huang, Xiao-Hua Zhu, and Zhen-Tao Qi. "Dual modification of silica aerogel monoliths." Journal of Sol-Gel Science and Technology 90, no. 2 (March 20, 2019): 323–29. http://dx.doi.org/10.1007/s10971-019-04954-z.

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48

Kohns, Richard, Christian P. Haas, Alexandra Höltzel, Christian Splith, Dirk Enke, and Ulrich Tallarek. "Hierarchical silica monoliths with submicron macropores as continuous-flow microreactors for reaction kinetic and mechanistic studies in heterogeneous catalysis." Reaction Chemistry & Engineering 3, no. 3 (2018): 353–64. http://dx.doi.org/10.1039/c8re00037a.

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49

von der Lehr, Martin, Rüdiger Ellinghaus, and Bernd M. Smarsly. "Hierarchically porous monolithic silica with varying porosity using bis(trimethoxysilyl)arenes as precursors." New Journal of Chemistry 40, no. 5 (2016): 4455–63. http://dx.doi.org/10.1039/c6nj00758a.

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50

Nickel, Winfried, Martin Oschatz, Martin von der Lehr, Matthias Leistner, Guang-Ping Hao, Philipp Adelhelm, Philipp Müller, Bernd M. Smarsly, and Stefan Kaskel. "Direct synthesis of carbide-derived carbon monoliths with hierarchical pore design by hard-templating." J. Mater. Chem. A 2, no. 32 (2014): 12703–7. http://dx.doi.org/10.1039/c4ta02260b.

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