Academic literature on the topic 'Mesoporou'
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Journal articles on the topic "Mesoporou"
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Preethi, T., M. P. Padmapriya, B. Abarna, and G. R. Rajarajeswari. "Choline chloride–zinc chloride ionic liquid as a green template for the sol–gel synthesis of mesoporous titania." RSC Advances 7, no. 17 (2017): 10081–91. http://dx.doi.org/10.1039/c6ra28478g.
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Zhang, Xin, Lian Jun Wang, and Wan Jiang. "Preparation of Stable Pt Nanoparticles Supported by Mesoporous Silica SBA-15." Materials Science Forum 745-746 (February 2013): 539–44. http://dx.doi.org/10.4028/www.scientific.net/msf.745-746.539.
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A simple two-step procedure towards the Pt nanoparticles and mesoporou silicate SBA-15 composite was developed in this work. The ultrasonic irradiation and the calcinations involved in the preparation did not destroy the size and morphology of prepared Pt nanoparticles, and no agglomeration of Pt nanoparticles was observed, thus stable Pt nanoparticles supported by SBA-15 host were formed. The hexagonal ordered structure of SBA-15 also remained. This stable composite are mainly used as the starting material in fabricating stable Pt nanoparticles doped glass.
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Nguyen Truong Gia, Hao, Huy Tran Huynh Gia, Phuong Nguyen Thi Truc, Tu Le Nguyen Quang, Dung Nguyen Van, An Ngo Thanh, and Long Nguyen Quang. "Preparation and characterization of mesoporous zeolite from solid waste." Vietnam Journal of Catalysis and Adsorption 9, no. 4 (December 31, 2020): 64–69. http://dx.doi.org/10.51316/jca.2020.071.
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In this study, experimental results on mesoporous zeolite preparation from a common solid waste, the rice husk ash by a top-down and bottom-up approach were reported. In top-down method, the consecutive treatments of zeolite by acid and alkaline in the presence of a cationic surfactant (CTAB) successfully generated mesopores in the zeolite. In bottom-up method, the sufficient added amount of CTAB in the gel composition could form mesopores in the zeolite. The obtained mesoporous zeolite possessed mesopore with a size of around 3-6 nm in both top-down and bottom-up approaches. As a result, the pore volume of the mesoporous zeolite was significantly increased by more than 60% when comparing to the “parent” rice-husk-ash derived zeolite. Significantly, the mesopore surface area of the mesoporous zeolite could be 2.4 times higher than that of the parent zeolite.
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Liang, Jun, and Fu Ping Wang. "Synthesis and Characterization of Mesoporous SAPO-11 by Using Carbon Particles." Advanced Materials Research 306-307 (August 2011): 1576–79. http://dx.doi.org/10.4028/www.scientific.net/amr.306-307.1576.
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Mesoporous SAPO-11 was synthesized hydrothermally by using carbon black and di-n-propylamime (DPA) as templates for the expected mesopores and micropores respectively. The samples were characterized with XRD, nitrogen physisorption, SEM and NH3-TPD techniques. The mesopore volumes of mesoporous SAPO-11 are in range of 0.037 - 0.052 cm3/g. The same amounts of the acid sites according to NH3-TPD results in both mesoporous and conventional SAPO-11 products indicate that the carbon black involved in the synthesis doesn’t affect the crystallization efficiency of SAPO-11. The mesoporous SAPO-11 samples exhibit higher activity compared with conventional ones, especially under low reaction temperature. The enhanced activity can be attributed to the introduction of the mesopores in the zeolite crystals, which decreases the intracrystalline mass transfer limitations.
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Gao, Qiang, Zong Wei Chen, Jun Xu, and Yao Xu. "pH-Controlled Drug Release from Mesoporous Silica Spheres with Switchable Gates." Advanced Materials Research 236-238 (May 2011): 2142–45. http://dx.doi.org/10.4028/www.scientific.net/amr.236-238.2142.
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Mesoporous silica sphere (MSS) with switchable gates was prepared by the graft of pH-sensitive propyldiethylenetriamine groups (multiamine chains) around mesopore outlets. The textural parameters of the resultant material had been analyzed. In the following test of in vitrodrug release, the gated mesoporous material showed high response to solution pH. At high pH (pH 7.5), ibuprofen (IBU) that loaded in this carrier released rapidly and completely (within 2 h); at low pH (pH 4.0 or 5.0), only a small part of the IBU (13 wt%) was slowly released from this carrier and the most of IBU was effectively confined in mesopores.
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Jiang, Yan Qiu, Ye Tang Pan, Xiao Wei Li, Wen Jing Cheng, Jian Min Sun, Kai Feng Lin, and Zi Chen Wang. "Preparation and Characterization of Hollow Spheres with Cubic Mesoporous Shell." Advanced Materials Research 785-786 (September 2013): 382–85. http://dx.doi.org/10.4028/www.scientific.net/amr.785-786.382.
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This work demonstrated an approach of oil/water (O/W) microemulsion on preparation of hollow spheres with mesopores in the shell, in which a cationic surfactant was used as structural directing agent, alkane molecule as mesopore-swelling agent and oil droplets. The morphology and pore architecture of the obtained hollow spheres were characterized by SEM, XRD, TEM and N2adsorption/desorption isotherms. Cubic (Ia3d) mesopores are present in the shell and provide open channels for mass transport in between the hollow core and outer environment. The obtained hollow spheres with cubic mesoporous shell possess the potential of being used as nanoreactor and nanocontainer in the fields of catalysis and drug delivery.
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Tagaya, Motohiro, Kenji Shinozaki, and Yuri Maruko. "A Simple Incorporation Route of Tris(8-hydroxyquinoline)aluminum(III) into Transparent Mesoporous Silica Films and Their Photofunctions." Journal of Applied Chemistry 2017 (August 14, 2017): 1–10. http://dx.doi.org/10.1155/2017/7351263.
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The molecular aggregation states of tris(8-hydroxyquinoline)aluminum(III) (Alq) adsorbed in the transparent mesoporous silica (MPS) films with the different pore sizes (3.0 and 5.4 nm) were successfully clarified. The Alq molecules were easily incorporated into the films from the solution without the segregation on the surfaces. The adsorbed amount of Alq was controlled by changing the added amount in the initial solution to resultantly give the transparent and yellow-color films. The photoluminescence spectra significantly revealed that the state of Alq molecules in the mesopore varied depending on the adsorbed amount of Alq as well as the pore size, suggesting the characteristic mobility of the adsorbed Alq molecules in the mesopores as compared with that at the bulk or solution state. Therefore, the guest-guest interactions between Alq molecules as well as the host-guest interactions between Alq and mesopore were elucidated. This finding by the use of the mesoporous film hosts will be utilized for including luminescence species and be applicable for optical devices.
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Kang, Jukyoung, Tack-Jin Kim, Jong Won Park, Kyo-Young Lee, Doh Hee Park, Sungbin Park, Seok Kim, and Yongju Jung. "A Mesoporous Chelating Polymer-Carbon Composite for the Hyper-Efficient Separation of Heavy Metal Ions." Journal of Nanoscience and Nanotechnology 20, no. 5 (May 1, 2020): 3042–46. http://dx.doi.org/10.1166/jnn.2020.17471.
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The removal of heavy-metal ions from wastewater is an important objective from a public-health perspective, and chelating agents can be used to achieve this aim. Herein, we report the synthesis of mesoporous carbon as a chelating polymer host using nanoarchitectonics approach. Carboxymethylated polyethyleneimine, a chelating polymer, was incorporated into the mesopore walls of mesoporous carbon to create a polymer-mesoporous-carbon composite. Nitrogen adsorption– desorption experiments and scanning electron microscopy (SEM) were used to illustrate the structural advantages of the composite. Co2+ adsorption by the composite material was examined using cobalt nitrate solutions at pH 3. The study revealed that the Co2+-absorption data are most closely modeled by the Langmuir isotherm. The maximum adsorption capacity, calculated by linear regression, was determined to be about 40 mg-Co/g-composite at pH 3. The composite exhibited about a six-times higher adsorption capacity toward a dilute Co solution (12.5 ppm) than that of the pristine mesoporous carbon. In addition, the composite showed a substantially higher distribution coefficient (Kd = 1.54×105) compared to that (Kd = 2.05×102) of the mesoporous carbon. Overall, we expect that the mesoporous composite, with its large mesopores (~20 nm), will be in high demand for adsorption applications.
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Nakanishi, Kazuki, and Kazuyoshi Kanamori. "Phase Separation in Sol-Gel Systems of Organic-Inorganic Hybrids." Advances in Science and Technology 45 (October 2006): 759–68. http://dx.doi.org/10.4028/www.scientific.net/ast.45.759.
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Organic-inorganic hybrid monoliths with well-defined macropores and/or mesopores have been synthesized by a sol-gel process accompanied by polymerization-induced phase separation. Using aklyltrialkoxysilanes and alkylene-bridged alkoxysilanes, two different categories of organo-siloxane networks have been characterized in view of macroporoisity based on phase separation as well as mesoporosity based on supramolecular templating by surfactants. The alkyl-terminated polysiloxane network exhibited substantial surface hydrophobicity together with the mechanical flexibility. On the other hand, the alkylene-bridged network behaved much more similarly to those prepared from tetraalkoxysilanes with regard to surface hydrophilicity, mechanical rigidness and mesopore-forming ability. Supramolecular templating of mesopores embedded in the gel skeletons comprising well-defined macroporous network has proven to give wide variety of hierarchically designed macro-mesoporous organic-inorganic hybrid materials.
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Yokogawa, Yoshiyuki, Ryota Fumimoto, and Suguru Inamura. "Protein Adsorption on Spark Plasma Sintered Mesoporous Silicate Compacts." Key Engineering Materials 758 (November 2017): 14–18. http://dx.doi.org/10.4028/www.scientific.net/kem.758.14.
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The preparation of mesoporous silica compact through spark plasma sintering (SPS) and adsorption / desorption of protein onto SPS mesoporous silica (MPS) compact is reported. MPS powders, prepared using triblock copolymer, PEO20PPO70PEO20, were compacted in carbon die and heated at 400 or 500 °C for 5 min under uniaxial pressure. The products are referred to as MPS-400 and MPS-500, respectively. The MPS sinters keep the mesoporous configuration, but the mode diameter of MPS-400 was smaller than that of MPS powders and MPS-500. The adsorbed amounts of protein on MPS-400 was higher than that on MPS-500, while the pore diameter, BET surface area, pore volume of MPS-400 are less than those of MPS-500. The interstices in MPS-500 are narrower than that in MPS-400, which may restrict the protein to penetrate through the narrow channels to reach the mesopores of MPS. The quantity of adsorbed amount of protein on MPS sinters does not depend on mesopore configuration but on the macropore configuration of the MPS sinters.
Dissertations / Theses on the topic "Mesoporou"
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Gallo, Jean Marcel Ribeiro. "Síntese de carbonos cerâmicos mesoporosos para aplicação como eletrodos em células a combustível a metanol direto." [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/250419.
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Orientadores: Heloise de Oliveira Pastore, Leonardo MarcheseTese (doutorado) - Universidade Estadual de Campinas, Instituto de Química
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Resumo: Esse trabalho teve como objetivo a aplicação de peneiras moleculares mesoporosas de sílica como suporte para metal em aplicações em eletrodos na Célula a combustível a metanol direto (DMFC). As peneiras moleculares mais importantes, MCM-41, MCM-48 e SBA-15, foram escolhidas. Em um primeiro momento a reprodutibilidade das sínteses foi verificada. Como pesquisa lateral foi estudada a acidez de superfície da SBA-15 contendo alumínio obtida por síntese direta. Além disso, foi desenvolvida a primeira síntese direta para a [Al]-SBA-15 Sílica é um isolante elétrico e, portanto, não pode ser utilizada como um eletrodo, deste modo, uma nova família de compósitos chamada Carbonos Cerâmicos Mesoporosos (MCC) foi preparada pela adição de grafite comercial na síntese das sílicas mesoporosas (MCM-41, MCM-48 ou SBA-15). A grafite não influenciou na formação da mesofase de sílica, de qualquer maneira, a MCC-MCM-41 e a MCC-MCM-48 cresceram na superfície da grafite. As MCCs preparadas com razão em massa sílica/carbono de 1/1 e 1/1.25 apresentaram condutividades elétricas similares enquanto MCCs com menos quantidade de carbono se mostraram isolantes elétricos. As MCCs(1/1) modificadas com 20 % em massa de paládio foram usadas na DMFC chegando no máximo a desempenhos 10 vezes menores que o do sistema usando o suporte comercia Vulcan XC-72R. Esse comportamento foi atribuida a menos condutividade elétrica dos MCCs. Para aumentar a condutividade elétrica dos MCCs(1/1), o agente direcionador orgânico usado na síntese da fase silícica foi carbononizado ( ao invez de calcinado, como feito anteriormente) Alternativamente, os MCCs foram sintetizados com uma razão em massa sílica/carbono de 1/3. Os testes dos MCCs contendo 20 % em massa de platina no cátodo da DMFC mostraram melhores resultados para a MCC-SBA-15(1/3) e a MCC-MCM-48(1/1) pirolisada. Por outro lado, o despenho do sistema usando o suporte Vulcan-XC-72R foi o dobro. Modificados com 60 % em massa da liga PtRu, o MCC-SBA-15(1/3) e o MCC-MCM-48(1/1) pirolisado foram aplicados no ânodo da DMFC, alcançando desempenhos 20 e 40 % maiores que a Vulcan XC-72R.
Abstract: The present work aimed at using mesoporous silica as metal support for Direct Methanol Fuel Cell (DMFC) electrodes. The most important mesoporous silica, MCM-41, MCM-48 and SBA-15, were chosen. In a first moment their synthesis were verified with respect to the reproductibility. As side results, the surface acidity of aluminum containing SBA-15 obtained by direct synthesis was also studied and it is also reported the first [Al]-SBA-16 obtained by direct synthesis was reported. Silica is electrically insulating and thus cannot be used directly in a cell electrode, thus it was reported here the preparation of the novel composite named Mesoporous Carbon Ceramics (MCC) obtained by the addition of commercial graphite into the mesoporous silica synthesis (MCM-41, MCM-48 or SBA-15). The graphite did not influence in the formation of the silica mesophase, however, MCC-MCM-41 and MCC-MCM-48 grow on the graphite surface. The MCCs prepared with silica/carbon weight ratio of 1/1 and 1/1.25 presented similar electrical conductivities while lower carbon loading MCCs were found insulating. The MCCs(1/1) modified with 20 wt % of platinum were used on Direct Methanol Fuel Cell electrodes (DMFC) reaching performances more ten 10 times lower than that of a system using the commercial metal support Vulcan XC-72R, probably due to their lower electrical conductivity. To increase the electrical conductivity of the MCCs(1/1), the surfactant used to synthesize the silica phase was carbonized (instead of calcined as done for the previous materials). Alternatively, MCCs was synthesized with silica/carbon weight ratio of 1/3. The test of 20 wt. % platinum-containing MCCs on the cathode of the DMFC showed that the best results were obtained for the MCC-SBA-15(1/3) and for the template-pyrolysed MCC-MCM-48(1/1), however, the performance was approximately half of that of the system using Vulcan-XC-72R. When modified with 60 wt % of PtRu alloy, MCC-SBA-15(1/3) and to the template-pyrolysed MCC-MCM-48(1/1) and applied on the DMFC anode, the performances at 343 K was ca. 20 and 40 % higher that that obtained for the system using Vulcan XC-72R.
Doutorado
Quimica Inorganica
Doutor em Ciências
2
Moscofian, Andrea Sales de Oliveira. "Filossilicatos de magnesio e silicas mesoporosas organofuncionalizados para o uso na remoção de corantes industriais." [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/250079.
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Orientador: Claudio AiroldiTese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica
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Resumo: Filossilicatos de magnésio e sílicas mesoporosas, com grupos orgânicos ligados às estruturas poliméricas inorgânicas, foram estudados na remoção de corantes. Para a síntese dos materiais nanoestruturados organofuncionalizados foram empregados agentes sililantes, (H3CO)3Si-R1, em que R1 é a cadeia carbônica contendo grupos funcionais: 3-aminopropiltrimetoxissilano, cloreto de octadecildimetil(3-trimetoxissilil-propil)amônio, 3-mercaptopropiltrimetoxissilano, 3-etilenodiaminopropiltrimetoxissilano e 3-dietilenotriaminopropiltrimetoxissilano. Através do processo sol-gel foram obtidos filossilicatos com estruturas inorgânicas similares àquelas dos silicatos lamelares naturais e sílicas mesoporosas empregando-se o surfatante CTAB como direcionador da estrutura inorgânica. As moléculas pendentes nos poros dos novos materiais com cargas positivas ou protonadas interagiram com as cargas negativas dos corantes utilizados na indústria têxtil: amarelo reativo GR, vermelho reativo RB e azul reativo RN. O estudo de adsorção mostrou que o filossilicato contendo cloreto de octadecildimetil(3-trimetoxissilil-propil)amônio, Fil-COTA, foi o material que apresentou a maior capacidade de adsorção, 1343 mg gpara o corante amarelo GR, 1286 mg g para o azul reativo RN e 344 mg gpara o vermelho reativo RB. Também foram realizados testes em amostras reais de efluente têxtil. Os resultados mostraram que não é necessário ajustar o pH inicial, a saturação do material ocorre após 3 h, sendo necessária uma massa mínima de 2,5 g dm de Fil-COTA. Portanto, este material é promissor no tratamento de efluentes têxteis reais.
Abstract: Magnesium phyllosilicates and mesoporous silicas, with organic groups anchored onto an inorganic polymeric backbones were studied for dye removal. In the synthesis of the organofunctionalized nanostructured materials, the silylanting agents, (H3CO)3Si-R1, where R1 represents carbonic chain containing functional groups: 3-aminopropyltrimethoxysilane, octadecyl (3-trimethoxysylilpropyl)ammonium chloride, 3 ¿ mercaptopropyltri-methoxysilane, 3-ethylenediaminetrymethoxysilane and 3-diethy-lenetriaminetrymethoxysilane were employed. The sol-gel process was used and phyllosilicates with inorganic lamellar structures similar to those of natural silicate and mesoporous silicas were obtained using the surfactant CTAB as template to direct inorganic structure in the latter case. The pendent molecules in pores of the new material with positive charge interact with the negative charge of the dyes used in the textile industry: reactive yellow GR, reactive red RB and reactive blue RN. The adsorption study showed that the phyllosilicate containing octadecyldimethyl(3-trimethoxysilylpropyl)ammonium chloride, Fil-COTA, presented the highest adsorption capacity, 1343 mg g for reactive yellow GR, 1286 mg g for reactive blue RN and 344 mg g for reactive red RB. Real samples of textile effluents were also tested. The results showed that it is not necessary to ajust the inicial pH, surface saturation occurs after 3 h and the minimum mass necessary is 2,5 g dm of Fil-COTA. Thus, this is a promising material for textile effluent treatement.
Doutorado
Quimica Inorganica
Doutor em Ciências
3
Badshah, Syed. "Híbridos inorgânico-orgânicos nanoestruturados de sílica mesoporosa e filossilicatos - energética da remoção de cátions na interface sólido/líquido." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/250054.
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Orientador: Claudio AiroldiTese (doutorado) - Universidade Estadual de Campinas, Instituto de Química
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Resumo: No presente trabalho, híbridos inorgânico-orgânicos nanoestruturados de sílica mesoporosa e de filossilicatos de magnésio lamelares com estrutura similar ao talco foram sintetizados e caracterizados. A máxima capacidade sorptiva de cátions dos híbridos e as características energéticas das interações dos cátions com centros básicos, na interface sólido/líquido, foram também estudadas. A sílica mesoporosa análoga aos materiais SBA-15 tem sido sintetizada por meio do tribloco co-polímero EO20-PO70 -EO20 (P123 - Pluronic®), que atua como um agente direcionador estrutural. Os materiais SBA-15 sintetizados foram funcionalizados com vários agentes sililantes, os quais apresentam os seguintes grupos funcionais: amida, nitrila e marfolina ou base de Schiff do anel tiofênico. Os agentes sililantes com os grupos funcionais mencionados acima foram sintetizados por meio de reações de adição de Michael do aceptor de Michael a,b - insaturado (acrilamida, acrilonitrila e 4- acriloilmarfolina), ou por meio da reação de base de Schiff do 2-tiofenocaboxaldeído com os agentes sililantes aminados, comercialmente disponíveis. As técnicas de espalhamento de raios X a baixa ângulo (SAXS) e de adsorção/desorção de nitrogênio para a SBA-15 pura e a SBA-15 funcionalizada mostraram um arranjo estrutural hexagonal bem-ordenado nos materiais. Os filossilicatos lamelares híbridos com diferentes porções orgânicas presentes dentro dos nanoespaços lamelares foram sintetizados por meio de reações sol-gel de uma única etapa. Com esse intuito, os agentes sililantes com vários grupos funcionais (tiopropanamida, tiocarbamato, nitrila e base de Schiff ou anel tiofênico) foram sintetizados e reagiram com uma solução metanólica de nitrato de magnésio, sob condições básicas. A difratometria de raios X indicou distâncias basais maiores de que 1 nm para os filossilicatos híbridos sintéticos. A técnica de difração de raios X também mostrou que a estrutura inorgânica dos filossilicatos híbridos era similar àquela do talco natural. A estrutura inorgânica do filossilicato híbrido é composta de camadas octaédricas ocupadas pelo átomo de magnésio hexacoordenado presentes entre duas camadas tetraédricas silícicas, em que a porção orgânica está covalentemente ligada à camada tetraédrica da estrutura em camadas. A integridade das porções orgânicas ligadas à rede inorgânica da sílica mesoporosa ou dos filossilicatos foi confirmada por meio da Espectroscopia no Infravermelho com transformada de Fourier e por meio da técnica de Ressonância Magnética no estado sólido para os núcleos Si e C. A máxima incorporação de porções orgânicas foi determinada por meio da análise elementar. As porções orgânicas ligadas aos materiais híbridos contêm: nitrogênio, oxigênio e enxofre, os quais correspondem aos sítios básicos disponíveis para a remoção de espécies como: Pb, Cu, Cd e Ni. As capacidades sorptivas máximas dos materiais híbridos para tais cátions foram obtidas por meio de Isotermas de adsorção de Langmuir. Os resultados revelam que os filossilicatos lamelares híbridos apresentam elevada capacidade para remoção de cátions em comparação com os materiais SBA-15, devido ao elevado grau de funcionalização. A energética das interações entre os cátions e os centros básicos ao longo da interface sólido/líquido foram determinadas através da microcalorimetria. As variações negativas da energia de Gibbs, de entalpia e os valores positivos de variação entrópica indicam interações espontâneas e favoráveis entre os sólidos e os íons metálicos. Esses resultados favoráveis indicam que os híbridos sintetizados podem ser úteis na remoção de cátions tóxicos de soluções aquosas, auxiliando na despoluição de ecossistemas
Abstract: In the present work, nanostructured inorganic-organic hybrids based on mesoporous silica and lamellar magnesium phyllosilicates with talc-like structure were synthesized and characterized. The maximum cations sorption capacity of the hybrids and energetic features from cation- basic center interactions at the solid liquid interface were also studied. The mesoporous silica analogous to SBA-15 materials has been synthesized through the triblock co-polymer EO20-PO70 -EO20 (P123 ¿ Pluronic®) as a structured directing agent. The synthesized SBA-15 materials were functionalized with various silylating agents having organic functional groups of amide, nitrile, and marpholine or Schiff base of thiophenic ring. The silylating agents with the aforementioned functional groups were synthesized either by the Michael addition reactions of a,b-unsaturated Michael acceptor (acrylamide, acrylonitrile and 4-acryloylmarpholine) or by the Schiff base reaction of 2-thiophenecaboxaldehyde with commercially available aminated silylating agents. Small angle X-ray scattering (SAXS) and nitrogen adsorption/desorption experiments for both SBA-15 and functionalized SBA-15 showed well-ordered hexagonal array structure. The lamellar phyllosilicates hybrids with different organic moieties inside the lamellar nanospaces were synthesized through a single step sol-gel reaction. For this purpose, silylating agents with various functional groups (thiopropanamide, thiocarbamate, nitrile and Schiff base of thiophenic ring) were synthesized and reacted with methanolic solution of magnesium nitrate under basic conditions. The X-ray diffraction showed basal distances of more than 1 nanometer for the synthetic hybrid phyllosilicates. The XRD also showed that the inorganic structure of the hybrid phyllosilicates was similar to that of natural talc. The inorganic network of the hybrid phyllosilicate is composed of octahedral sheet occupied by hexacoordinated magnesium atom sandwiched between two tetrahedral silicic sheets, and the organic moiety is covalently bonded to the tetrahedral sheet of the layered structure. The integrity of organic moieties attached to the inorganic network of mesoporous silica or phyllosilicates was confirmed by the Fourier transform infrared spectroscopy and nuclear magnetic resonance in the solid-state for the Si and C nuclei. The maximum incorporation of organic moieties was determined through elemental analysis. The attached organic moieties of the hybrid materials contain nitrogen, oxygen or sulfur basic centers available for divalent lead, copper, cadmium and nickel cation removal. The maximum sorption capacities of the hybrids for such cations were obtained through Langmuir adsorption isotherms. The results reveal that the lamellar magnesium phyllosilicate hybrids present high capacity for cations removal as compared to functionalized SBA-15 materials, due to a high degree of functionalization. The energetic of cation-basic centers interactions at the solid/liquid interface were determined through microcalorimetry. The negative Gibbs energy, exothermic enthalpy and positive entropic values indicate spontaneous and favorable interactions between the solids and metal ions. These favorable results indicated that the synthesized hybrids can be useful for removal of toxic cations from aqueous solutions for the improvement of ecosystem
Doutorado
Quimica Inorganica
Doutor em Ciências
4
Valente, Tain? Dias. "S?ntese da mordenita a partir da Al-SBA-15." Universidade Federal Rural do Rio de Janeiro, 2015. https://tede.ufrrj.br/jspui/handle/jspui/1352.
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In the present dissertation it was conducted the study of the synthesis of mesoporous molecular sieve Al-SBA-15 by direct synthesis in agitated reactor having the following molar ratio: 14 SiO2: 1 Al2O3: 0.235 P123: 1800 H2O. Initially, a study was done to optimize the synthesis of Al-SBA-15. Through this study, it was found that the operating conditions that resulted in the SBA-15 sample with a higher degree of ordering were gel aging time equal to 15 hours at 40 ? C and then at 100 ? C for 8 hours. These optimal conditions were used to perform scaling up to 5 gallon reactor. Samples of Al-SBA-15 were subjected to carbonization in order to fill the pores of SBA-15 with carbonaceous material and prevent the collapse of its structure. The carbonized samples were used as a source of silica for the synthesis of mordenite in dry medium using the transmission technique in the vapor phase (VPT). The purpose of this procedure was to obtain the mordenite having mesopores. For the preparation of the mordenite by VPT, several conditions were used, varying the synthesis time and form of addition of the reactants, presence or absence of an organic driver. The samples were characterized by X-ray and nitrogen adsorption. It was observed that in most of the experiments, there was no formation of mordenite phase. In the experiments in this phase was obtained, there was no significant mesoporosity training. Apparently, the presence of carbonaceous material was not sufficient to preserve the mesoporous structure of SBA-15. Key
No presente trabalho foi realizado o estudo da s?ntese da peneira molecular mesoporosa Al-SBA-15 a partir da s?ntese direta em reator agitado apresentando a seguinte propor??o molar: 14 SiO2: 1 Al2O3: 0,235 P123: 1800 H2O. Inicialmente, foi feito um estudo visando otimizar a s?ntese da Al-SBA-15. Atrav?s deste estudo, foi verificado que as condi??es operacionais que resultaram na amostra de SBA-15 com maior grau de ordenamento foram com tempo de envelhecimento do gel de s?ntese igual a 15 horas a 40?C e depois a 100?C por 8 horas. Estas condi??es otimizadas foram utilizadas para efetuar o aumento de escala para o reator de 5 gal?es. As amostras de Al-SBA-15 foram submetidas a carboniza??o com o objetivo de preencher os poros da SBA-15 com material carbon?ceo e evitar o colapso de sua estrutura. As amostras carbonizadas foram utilizadas como fonte de s?lica para a s?ntese da mordenita em meio seco utilizando a t?cnica de transporte em fase vapor (VPT). O objetivo deste procedimento foi a obten??o de mordenita tendo mesoporos. Para o preparo da mordenita por VPT, v?rias condi??es foram utilizadas, variando o tempo de s?ntese e forma de adi??o dos reagentes, presen?a ou aus?ncia de um direcionador org?nico. As amostras obtidas foram caracterizadas por difra??o de raios X e adsor??o de nitrog?nio. Foi observado que na maioria dos experimentos n?o houve a forma??o da fase mordenita. Nos experimentos em que esta fase foi obtida, n?o foi observada forma??o de mesoporosidade significativa. Aparentemente, a presen?a de material carbon?ceo n?o foi suficiente para preservar a estrutura mesoporosa da SBA-15. Palavras chave:
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Grecco, Saulo de Tarso Figueiredo. "Preparação de zeólitas mordenita com estrutura hierárquica de poros." Instituto de Química, 2013. http://repositorio.ufba.br/ri/handle/ri/16481.
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As restrições difusionais aos reagentes, causadas pelos microporos, limitam o uso das zeólitas no processamento de moléculas pesadas. Isto demanda o desenvolvimento de materiais que combinem as propriedades de zeólitas com as de materiais mesoporosos. Um número significativo de procedimentos experimentais, pré ou pós síntese, vem sendo sugerido para a obtenção de zeólitas hierarquicamente estruturadas. As metodologias de síntese mais bem sucedidas envolvem o uso de agentes geradores de mesoporosidade (agentes orgânicos e nanopartículas) ou nanomoldes (moldagem em nanoespaços), que geram sólidos com mesoporosidade intracristalina com uma estreita distribuição de tamanho de poros; isto resulta em sólidos contendo mesoporos, além dos microporos intrínsecos das zeólitas. Entretanto, ainda não existem estudos sistemáticos, que permitam estabelecer o efeito das variáveis de preparação sobre as características dos sólidos finais. A fim de superar essa dificuldade, neste trabalho foi estudado o efeito do tempo e da temperatura de cristalização do gel de síntese sobre as características de materiais baseados em mordenita com estrutura hierárquica de poros. Na preparação das amostras, adicionou-se um organossilano gerador de mesoporosidade (TPOAC, cloreto de [3- (trimetoxissilil)propil]octadecildimetilamônio), ao gel de síntese da mordenita, que foi cristalizado por diferentes períodos e em distintas temperaturas. Os sólidos obtidos foram submetidos à troca iônica com cloreto de amônio e posterior calcinação, de modo a obter a forma ácida do material. As amostras foram caracterizadas por termogravimetria, espectroscopia no infravermelho com transformada de Fourier, difração de raios X, análise textural por adsorção de nitrogênio, ressonância magnética nuclear de 29Si e de 27Al, microscopia eletrônica de varredura e medidas de acidez por dessorção de amônia à temperatura programada. Observou-se que a formação da mordenita contendo mesoporos é influenciada pelo tempo e temperatura de cristalização do gel da zeólita. O emprego de tempos relativamente curtos ou baixas temperaturas favorece a formação de um sólido amorfo, enquanto longos tempos ou elevadas temperaturas favorecem a formação de mesoporos intracristalinos na mordenita. Por outro lado, tempos e temperaturas intermediárias favoreceram a formação da mordenita com uma estrutura hierárquica de poros e mesoporos desordenados. O aumento da cristalinidade da mordenita acarreta uma diminuição na área e no volume de mesoporos, mas promove um acréscimo na área e no volume de microporos. A área externa também tende a diminuir devido ao aumento do tamanho do cristal da mordenita em função da cristalinidade. Os sólidos obtidos foram susceptíveis à desaluminação durante a etapa de calcinação. A extensão da desaluminação diminuiu com o aumento do tempo ou da temperatura de cristalização, devido à inserção dos átomos de alumínio na rede da zeólita em formação. Porém, em tempos de cristalização longos e temperaturas altas, pode ocorrer a redispersão dos átomos de alumínio. Todos os sólidos apresentaram elevada acidez que aumentou com a cristalinidade. Entretanto, nas amostras preparadas em tempos curtos e temperaturas baixas, a maioria dos sítios apresentou força ácida moderada, enquanto aquelas obtidas em tempos longos e temperaturas altas apresentaram maior quantidade de sítios ácidos fortes.
The diffusion restrictions of the reactants caused by the micropores limit the use of zeolites for processing heavy molecules. This demands for the development of materials that can combine the properties of zeolites and of mesoporous materials. A significant number of experimental procedures, pre or post synthesis, has been suggested for obtaining hierarchically structured zeolites. The most successful synthesis involve the use of mesoporosity generating agents (nanoparticles and organic agents) or nanotemplates (templating in nanospaces), which generate solids with intracristaline mesoporosity with a narrow pore size distribution. This results in solids containing mesoporous besides the intrinsic zeolite micropores. However, there is not any systematic study which allows to state the effect of crystallization time and temperature of the synthesis gel on the properties of the final solid. In order to overcome this difficulty, the effect of time and temperature of the synthesis gel on the properties of mordenite-based materials with hierarchical pore structure was studied in this work. In the samples preparation a mesoporosity generating organosilane (TPOAC, [3-(trimethoxysilyl) propyl] octadecyldimethylammonium chloride) was added to the synthesis gel of mordenite, which was crystallized for different times and temperatures. The solids were then submitted to ion exchange with ammonium chloride and further calcination to obtain the acidic form of the zeolite. The samples were characterized by thermogravimetry, Fourier transformed infrared spectroscopy, X-ray diffraction, textural analysis by nitrogen adsorption, 29Si and 27Al NMR, scanning electron microscopy and acidity measurements by ammonia desorption. It was observed that the formation of mordenite containing mesoporous is affected by the time and temperature of crystallization of the zeolite gel. The use of relatively short times and low temperatures favors the formation of an amorphous solid, while long times or high temperatures favor the formation of intracristaline mesoporosity in the mordenite. On the other hand, intermediate times and temperatures favor the formation of mordenite with hierarchical pore structure and disordered mesopores. The increase in mordenite crystallinity leads to a decrease in mesopore area and volume but promotes an increase in micropore area and volume. The external area also tends to decrease due to the increased crystal size as a function of mordenite crystallinity. The solids obtained were susceptible to dealumination during the calcination step. The degree of dealumination decreased with the increasing crystallization time or temperature due to the insertion of aluminum atoms in the zeolite lattice. However, at long crystallization times and high crystallization temperatures the redispersion of aluminum atoms can occur. All solids showed high acidity which increased as a function of crystallinity. However, the samples prepared at short times and low temperatures showed the majority of moderate acid sites of medium strength, whereas those obtained at long times and high temperatures have more strong acid sites. Thus, intermediate times and temperatures favor the formation of solids having zeolitic characteristics and high mesoporosity.
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Silva, Bruno José Barros da. "Obtenção de materiais com estrutura hierárquica de poros através da dessilicação da Zeólita Zsm-22." Universidade Federal de Alagoas, 2017. http://www.repositorio.ufal.br/handle/riufal/1710.
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The present work deals with the generation of mesoporosity in ZSM-22 zeolite (TON structure). In a first part the synthesis of ZSM-22 was studied through a methodology similar to that presented by Valyocsik (1990), followed by an addition of an amphiphilic trimethoxyphenylsilane organosilane (TMPHS) in the synthesis gel, and by another substitution of 20% of the silica required for the synthesis by silanized silica beads by TMPHS. In the second part, the formation of mesoporosity by post-synthesis treatment with NaOH solution was studied, varying the concentration of 0.2, 0.4 and 0.6 mol.L-1 at a temperature of 70 °C per 1hour. The zeolites obtained were characterized by X-ray diffractometry (XRD), nitrogen adsorption at -196 °C, scanning electron microscopy (SEM), thermogravimetric analysis (ATG), absorption spectroscopy in the infrared region with Fourier transform (FT-IR) and desorption of ammonia at the programmed temperature. The catalysts that presented the best textural properties were submitted to the catalytic test with the n-hexane cracking model reaction. The diffractograms of the synthesized samples showed that they presented the main peaks referring to the TON structure, and that the desilicated samples maintained in their entirety their crystalline structure. The thermogravimetric curves presented four mass loss events, reaching values close to 10% of total loss. Infrared identified absorption bands characteristic of zeolitic materials. The micrographs of the TON-P sample showed crystal agglomerates in cylindrical form 2 μm in length. The pore diameter distribution of the desilicated samples presented a distribution in the range of 2 to 100 nm, proving one of additional mesoporosity due to the desilication process, with a higher formation of mesopores for the samples submitted to the treatments with higher OH- concentration, which caused an increase in the total acidity by the reduction of the Si/Al ratio. The desilicated samples presented a lower conversion compared to the precursor, but with higher stability in the conversion rate, with selectivity to formation of propene and isobutane.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
O presente trabalho abordou a geração de mesoporosidade na zeólita ZSM-22 (estrutura TON). Numa primeira parte estudou-se a síntese da ZSM-22 via metodologia similar à apresentada por Valyocsik (1990), seguida por uma adição de um organossilano anfifílico trimetoxifenilsilano (TMPHS) no gel de síntese, e por outra via substituição de 20% da sílica requerida para a síntese por esferas de sílica nanométricas silanizadas por TMPHS. Na segunda parte estudou-se a formação de mesoporosidade por tratamento pós-síntese com solução de NaOH, variando-se a concentração de 0,2, 0,4 e 0,6 mol.L-1 à temperatura de 70°C por 1 hora. As zeólitas obtidas foram caracterizadas por difratometria de raios X (DRX), adsorção de nitrogênio à -196°C, microscopia eletrônica de varredura (MEV), análises termogravimétricas (ATG), espectroscopia de absorção na região do infravermelho com transformada de Fourier (FT-IR) e dessorção de amônia à temperatura programada. Os catalisadores que apresentaram melhores propriedades texturais foram submetidos ao teste catalítico com a reação modelo de craqueamento do n-hexano. Os difratogramas das amostras sintetizadas mostraram que estas apresentaram os principais picos referente à estrutura TON, e que as amostras dessilicadas mantiveram na sua integralidade sua estrutura cristalina. As curvas termogravimétricas apresentaram quatro eventos de perda de massa, obtendo-se valores próximos a 10% de perda total. Os infravermelhos identificaram bandas de absorção características dos materiais zeolíticos. As micrografias da amostra TON-P mostraram aglomerados de cristais em forma cilíndrica com 2 µm de comprimento. A distribuição de diâmetro de poros das amostras dessilicadas apresentaram uma distribuição na faixa de 2 a 100 nm, comprovando-se uma de mesoporosidade adicional devido ao processo de dessilicação, havendo maior formação de mesoporos para as amostras submetidas aos tratamentos com maior concentração de OH-, o que provocou um aumento na acidez total pela diminuição da razão Si/Al. As amostras dessilicadas apresentaram uma menor conversão perante a precursora, mas tendo maior estabilidade na taxa de conversão, havendo uma seletividade para formação de propeno e isobutano.
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Oliveira, Fernando Jose Volpi Eusebio de. "Hibridos inorganico-organicos mesoporosos nanoestruturados = aspectos estruturais e energeticos das interações cations-centros basicos na interface solido/liquido." [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/250026.
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Orientador: Claudio AiroldiTese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica
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Resumo: Três conjuntos de sílicas mesoporosas foram sintetizados com os agentes direcionadores dodecilamina, brometo de cetiltrimetilamônio (CTAB) e co-polímero tribloco EO20-PO70-EO20 (P123 ¿ Pluronic®). As matrizes inorgânicas foram funcionalizadas com agentes sililantes contendo de um a três átomos de nitrogênio nas cadeias. Além disso, estes silanos reagiram com o ligante tiocarbamida, em uma etapa livre de solvente, anteriormente à formação da sílica, em processo de co-condensação. A rota de síntese empregada para as amostras preparadas a partir do direcionador P123 foi a pósfuncionalização. Para as estruturas obtidas utilizando-se dodecilamina, do tipo HMS, observou-se o colapso da estrutura após a extração do direcionador, conforme mostraram os espectros de IV e os difratogramas antes e depois do processo de remoção. Contudo, as amostras apresentaram tamanho médio de poros na faixa que constituem os materiais mesoporosos, sendo então investigados no estudo da remoção de metais tóxicos. Para as amostras preparadas CTAB e P123 foram observados os sinais da reflexão típica de materiais do grupo p6mm, denominada 2D-hexagonal, cujas amostras análogas aos materiais MCM-41 e SBA-15, respectivamente. Todos os híbridos modificados com tiocarbamida foram aplicados em sorção de íons metálicos, ajustados ao modelo não linear de sorção de Langmuir. As interações na interface sólido/líquido foram determinadas por microcalorimetria. Os resultados revelaram que os materiais do tipo SBA-15 apresentam alta capacidade de remoção de Cu, Cd e Pb, devido ao procedimento de pós-funcionalização. As amostras obtidas por co-condensação, do tipo HMS e MCM-41, apresentaram capacidade máxima de sorção superior aos resultados observados na literatura para materiais análogos. Os experimentos calorimétricos mostraram que as interações entre os sólidos e os íons metálicos são exotérmicas, com exceção dos íons Pb. Outro aspecto destacado trata-se da importância do termo entrópico, que parece reger o processo na maioria dos casos, devido à liberação de moléculas de água coordenadas aos íons e às matrizes. Portanto, todos os sistemas estudados apresentaram um comportamento energeticamente favorável.
Abstract: Three set of mesoporous silicas have been synthesized through dodecylamine, cetiltrimethylamonium bromide (CTAB) and the triblock co-polymer EO20-PO70-EO20 (P123 ¿ Pluronic®) as structure directing agents (sda). The inorganic matrices have been functionalized with silylating agents presenting from one to three nitrogen atoms on their chains. In addition, these silanes reacted with thiocarbamide through a free-solvent step, before the silica formation, by co-condensation process. However the synthetic route for the samples templated by P123 was the post-grafting. For the structures obtained by using dodecylamine, HMS-like, it was observed the structure collapsed after template removal, as shown by IR spectra and XRD patterns, before and after the removal process. These samples presented pore size comprised on mesoporous range, being then investigated for toxic metal removal capacity. For the samples prepared from CTAB and P123, the typical reflections for p6mm group materials, named 2D-hexagonal, were observed, and these samples are analogous to MCM-41 and SBA-15 materials, respectively. All thiocarbamide-modified hybrids were applied to metal ions sorption, being adjusted to Langmuir non-linear fit model. The interactions at the solid/liquid interface were determined through microcalorimetry. The results reveal that the SBA-15-like materials present high removal capacity for Cu, Cd e Pb, due to the post-grafting procedure. The samples obtained through cocondensation route, HMS- and MCM-41-like, presented maximum sorption capacity higher than those results for analogous published materials. With exception of Pb, all calorimetric determinations showed that the interactions between the solids and metal ions are exothermic. Another highlighted feature is about the importance of the entropic term that seems to rule the processes for several cases, due to the ion and surface coordinated water molecules displacement. Thus, all studied systems presented an energetically favorable behavior.
Doutorado
Quimica Inorganica
Doutor em Ciências
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Costa, Luelc Souza da 1984. "Materiais híbridos mesoestruturados funcionalizados via co-condensaçãoi aplicados na sorção." [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/250045.
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Orientador: Claudio AiroldiDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química
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Resumo: A síntese de sílicas mesoporosas funcionalizadas pela a rota de co-condensação tem despertado a atenção de diversos grupos de pesquisas devido a sua praticidade. Esta síntese consiste na condensação simultânea entre as moléculas dos organossilanos e as moléculas da fonte de silício (TEOS) através do método sol-gel. Isso faz com que a incorporação de grupos orgânicos na estrutura da sílica ocorra de forma direta. No entanto, em muitos casos, os híbridos preparados dessa forma podem apresenta uma má formação estrutural devido a presença dos grupos orgânicos. Nesse trabalho foram sintetizados materiais híbridos com o agente direcionador copolímero tribloco EO20-PO70-EO20 (P123 ¿ Pluronic®). Foram escolhidos grupos organossilanos contendo em suas estruturas sítios básicos Lewis tais como grupos carbonílicos, enxofre e nitrogenados. Os espectros na região do infravermelho juntamente com a análise elementar e ressonância magnética nuclear mostraram concordância que o ancoramento dos grupos orgânicos na matriz inorgânica dos híbridos ocorreu de forma satisfatória. As isotermas de sorção e dessorção de nitrogênio mostraram que todas as isotermas são do tipo IV com histerese do tipo H1 que são característicos de matérias mesoporosos e que os poros dos materiais estão na faixa de mesoporosidade, a área superficial é dependente do tamanho da molécula utilizada na funcionalização. Foram observados os sinais da reflexão típica de materiais do grupo p6mm, denominada 2D-hexagonal, análogas ao material SBA-15. Portanto, todos os híbridos foram sintetizados de forma ordenada como proposto. Os materiais híbridos foram aplicados em sorção de íons metálicos, e na sorção de corantes. Os dados experimentais foram ajustados aos modelos de isoterma de sorção de Langmuir, Freudlich e Sips usando os métodos de regressão não linear. As sílicas apresentaram boa capacidade de sorção tanto para os metais quanto para o corante. Fato esse devido aos sítios básicos de Lewis, de nitrogênio e enxofre presentes e a possibilidade desses grupos serem protonados em solução e estes sítios interagirem com os grupos sulfonados do corante.
Abstract: The synthesis of functionalized mesoporous silicas by a co-condensation route has attracted attention of many research groups due to its practicality. The synthesis consists of the simultaneous condensation among organosilane molecules and the molecules of silicon source by sol-gel method. This makes the incorporation of organic groups in the silica structure occurs directly. However, in many cases, the hybrids may this way prepared has a structural deformation due to the presence of the organic groups. In this work were synthesized hybrid materials with directing agent triblock copolymer EO20-PO70-EO20 (P123 - Pluronic ®).Were chosen organosilanes containing groups in their structures Lewis basic sites such as carbonyl groups, nitrogen and sulfur. Infrared spectra combined with elemental analysis and nuclear magnetic resonance proved that the organic chains were satisfactorily anchored to the inorganic matrices. The nitrogen adsorption-desorption analyses generated isotherms of type IV and hysteresis H1 that are typical of mesoporous materials, where asthe pore size distribution showed that the pores of the silicas are in the mesoporous range. The BET method was applied to acquire the surface areas of the solids, which were found to be dependent on the size of the molecule used for the functionalization processes. SAXS patterns of all samples demonstrated well-resolved peaks characteristic of the typical p6mm space group, called 2D-hexagonal, similar to SBA-15.The hybrid materials were applied to the sorption of metallic ion sand dyes, showing good sorption capacities for both kinds of contaminants. The nitrogen and sulfur Lewis basic sites anchored to the silica inorganic back bone can be protonated to interact with the sulfonated groups of the dyes. The experimental data were fitted to the Langmuir, Freundlich and Sips sorption isotherms using the non-linear regression.
Mestrado
Quimica Inorganica
Mestre em Química
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Lopes, Glenda Cristina da Silva. "Produ??o de mordenita mesoporosa por s?ntese direta usando diferentes direcionadores." Universidade Federal Rural do Rio de Janeiro, 2016. https://tede.ufrrj.br/jspui/handle/jspui/1759.
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Funda??o de Apoio a Pesquisa Cient?fica e Tecnol?gica da UFRRJ-FAPUR
In the present dissertation it was conduced the study of the mesoporous mordenite production by the direct synthesis using hydrothermal media or dry gel convertion. Activated charcoal, starch, carboxymethylcellulose and carbon black were used as mesoporosity templating. To evaluate the effect of these templates, samples were prepared with molar composition of 20 SiO2: 1 Al2O3: 6 Na2O: 600 H2O, by hydrothermal synthesis and 20 SiO2: 1 Al2O3: 4 Na2O, by dry synthesis, following procedures described in the literature and adding different amounts of templates to the synthesis gel. As reagents for the synthesis gel assay, were utilized sodium hydroxide, sodium aluminate, silica (Aerosil 200) and deionized water. The synthesis temperature was 175 ? C, while the synthesis time was 5 days and 3 days for the hydrothermal and dry method, respectively. For characterization of the samples was used X-ray diffraction (XRD), analysis by nitrogen adsorption/desorption measurements and determination of the acidity by temperature programmed desorption of ammonia (NH3-TPD). An evaluation of the samples was carried out using the n-heptane cracking reaction at 380 ? C. By X-ray diffraction, it was observed that the majority of the experiments formated of mordenite phase. The textural properties, particularly the volume of mesopores, improved in most samples synthesized in the presence of the template, however, the values obtained were lower than those defined in the literature for mesoporous materials. The samples showed only a peak of ammonia adsorption in NH3-TPD profiles, related to weak acid sites. Most samples synthesized in the presence of drivers showed an increase in the conversion of n-heptane, while the samples obtained by dry gel convertion showed higher conversion than the hydrothermally synthesized.
No presente trabalho foi realizado o estudo da produ??o de mordenita mesoporosa a partir da s?ntese direta, em meio hidrot?rmico e seco, na presen?a do carv?o ativado, amido, carboximetilcelulose e negro de fumo como direcionadores de mesoporosidade. Para avaliar o efeito desses direcionadores, foram preparadas amostras com composi??o molar de 20 SiO2: 1 Al2O3: 6 Na2O: 600 H2O, pela s?ntese hidrot?rmica e 20 SiO2: 1 Al2O3: 4 Na2O, pela s?ntese seca, seguindo os procedimentos descritos na literatura e adicionando quantidades diferentes dos direcionadores ao gel de s?ntese. Como reagentes para o gel de s?ntese, foram utilizados hidr?xido de s?dio, aluminato de s?dio, s?lica (aerosil 200) e ?gua deionizada. A temperatura de s?ntese foi de 175 ?C, enquanto o tempo de s?ntese foi de 5 dias e 3 dias, para o m?todo hidrot?rmico e seco, respectivamente. Para caracteriza??o das amostras usou-se difra??o de raios X (DRX), an?lise textural por medidas de adsor??o/dessor??o de nitrog?nio e determina??o da acidez por dessor??o de am?nia ? temperatura programada (TPD-NH3). Realizou-se a avalia??o catal?tica das amostras atrav?s da rea??o de craqueamento de n-heptano a 380 ?C. Pelos difratogramas de raios X, foi observado que na maioria dos experimentos ocorreu a forma??o da mordenita. As propriedades texturais, especialmente o volume de mesoporos, melhoraram na maioria das amostras sintetizadas na presen?a do direcionador, por?m, os valores obtidos foram inferiores aos definidos pela literatura para materiais mesoporosos. As amostras apresentaram apenas um pico de adsor??o de am?nia nos perfis de TPD-NH3, referentes aos s?tios ?cidos fracos. A maioria das amostras sintetizadas na presen?a dos direcionadores apresentou aumento na convers?o do n-heptano, sendo que as amostras obtidas por s?ntese em meio seco apresentaram maior convers?o do que as sintetizadas em meio hidrot?rmico.
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Oliveira, Vaeudo Valdimiro 1982. "Sílicas mesoporosas e silicatos lamelares contendo agentes organofuncionalizados : sorção e liberação controlada de fármacos." [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/250068.
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Orientador: Claudio AiroldiTese (doutorado) - Universidade Estadual de Campinas, Instituto de Química
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Resumo: Na presente investigação foram sintetizados os híbridos inorgânico-orgânicos micro/mesoestruturados: a) silicato lamelar do tipo kanemita sódica, b) sua forma quimicamente modificada com cobre e c) sílica mesoporosa SBA-16. A combinação dos reagentes Na2SiO3/NaOH/etanol e Na2SiO3/NaOH/Cu(NO3)2/etanol propiciaram a obtenção de kanemita sódica e sua forma contendo o cobre incorporado na estrutura inorgânica, através da substituição isomórfica do silício nas razões molares Si/Cu = 50, 100 e 200. Para as sílicas mesoporosas foram usados sistemas formados por copolímeros F127/TEOS/H2O, F127/TEOS/etanol/H2O e F127/TEOS/butanol/H2O em meio ácido. Os materiais organofuncionalizados previamente intercalado com dimetilsulfóxido (DMSO) e etilenodiamina (EN) formam os sólidos lamelares Na-KN-DMSO, Na-KN-EN e Cu-KN-EN, através do processo de pós-síntese com o agente sililante 3-iodopropiltrimetoxissilano, que reagiu subsequentemente com dietil iminodiacetato e benzidina, formando os híbridos mesoporosos. Os híbridos lamelares foram aplicados na sorção de metais e corantes em soluções aquosas. Dentre os cátions bário, cobalto e cobre, o cobre foi mais facilmente sorvido em Na-KN-EN quando comparado com Na-KN-DMSO. No caso dos corantes verde brilhante e azul reativo 15, o primeiro foi também mais eficiente na sorção. No processo de liberação de fármacos amoxicilina e omeprazol foram utilizados os híbridos mesoporosos. Os dados de liberação mostram que o primeiro fármaco apresentou uma cinética de liberação satisfatória no fluido intestinal simulado (FIS), enquanto que o omeprazol liberou em maior quantidade no fluido gástrico simulado (FGS)
Abstract: The present investigation deals with the syntheses of inorganic-organic nano/mesostrutered hybrids: a) sodic lamellar silicate kanemite, b) its chemically modified form with copper and c) SBA-16 mesoporous silicas. The reagents combination Na2SiO3/NaOH/ethanol and Na2SiO3/NaOH/Cu(NO3)2/ethanol enabled to obtain sodic kanemite and its synthesized form containing incorporated copper in the inorganic structure, through the isomorphic substitution of silicon using the molar ratio Si/Cu = 50, 100 and 200. For mesoporous silicas the copolymers F127/TEOS/H2O, F127/TEOS/ethanol/H2O and F127/TEOS/butanol/H2O in acidic condition were used. The synthesized organofunctionalized materials were previously intercalated with dimethylsulfoxide (DMSO) and ethylenediamine (EN) in the Na-KN-DMSO, Na-KN-EN and Cu-KN-EM lamellar solids, through the post-synthesis process with the silylating agent 3-iodopropyltrimethoxysilane, which subsequently reacted with diethyl iminodiacetate and benzidine. The lamellar hybrids were applied for cation and dye sorption processes. Among barium, cobalt and copper, the last cation was more favorable sorbed in Na-KN-EN, when compared with Na-KN-DMSO. In case of brilliant green and reactive blue 15 dyes, the first one was also more efficient in sorption. The controlled drug delivery process, amoxicillin and omeprazole were applied with mesoporous hybrid systems. The delivery data demonstrated that the first drug presented a satisfactory kinetic in the simulated intestinal fluid (SIF), while omeprazole presented high amount in the simulated gastric fluid (SGF)
Doutorado
Quimica Inorganica
Doutor em Ciências
Books on the topic "Mesoporou"
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García-Martínez, Javier, and Kunhao Li, eds. Mesoporous Zeolites. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2015. http://dx.doi.org/10.1002/9783527673957.
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Khan, Waheed. Novel mesoporous catalysts. Manchester: UMIST, 1998.
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Ha, Chang-Sik, and Sung Soo Park. Periodic Mesoporous Organosilicas. Singapore: Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-13-2959-3.
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Zhao, Dongyuan, Ying Wan, and Wuzong Zhou. Ordered Mesoporous Materials. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2013. http://dx.doi.org/10.1002/9783527647866.
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Steel, A. Novel mesoporous materials. Manchester: UMIST, 1996.
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C, Sequeira C. A., Hudson M. J, and North Atlantic Treaty Organization. Scientific Affairs Division., eds. Multifunctional mesoporous inorganic solids. Dordrecht: Kluwer Academic Publishers, 1993.
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Innocenzi, Plinio. Mesoporous Ordered Silica Films. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-89536-5.
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Sequeira, César A. C., and Michael J. Hudson, eds. Multifunctional Mesoporous Inorganic Solids. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-015-8139-4.
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Sequeira, César A. C. Multifunctional Mesoporous Inorganic Solids. Dordrecht: Springer Netherlands, 1993.
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Hou, Huilin, Linli Xu, Weiyou Yang, and Wai-Yeung Wong. One-Dimensional Mesoporous Inorganic Nanomaterials. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-89105-3.
Full textBook chapters on the topic "Mesoporou"
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Pérez-Pariente, Joaquín, and Teresa Álvaro-Muñoz. "Strategies to Improve the Accessibility to the Intracrystalline Void of Zeolite Materials: Some Chemical Reflections." In Mesoporous Zeolites, 1–30. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2015. http://dx.doi.org/10.1002/9783527673957.ch1.
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Li, Kunhao, Michael Beaver, Barry Speronello, and Javier García-Martínez. "Surfactant-Templated Mesostructuring of Zeolites: From Discovery to Commercialization." In Mesoporous Zeolites, 321–48. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2015. http://dx.doi.org/10.1002/9783527673957.ch10.
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Thommes, Matthias, Rémy Guillet-Nicolas, and Katie A. Cychosz. "Physical Adsorption Characterization of Mesoporous Zeolites." In Mesoporous Zeolites, 349–84. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2015. http://dx.doi.org/10.1002/9783527673957.ch11.
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Kärger, Jörg, Rustem Valiullin, Dirk Enke, and Roger Gläser. "Measuring Mass Transport in Hierarchical Pore Systems." In Mesoporous Zeolites, 385–424. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2015. http://dx.doi.org/10.1002/9783527673957.ch12.
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Wan, Wei, Changhong Xiao, and Xiaodong Zou. "Structural Characterization of Zeolites and Mesoporous Zeolite Materials by Electron Microscopy." In Mesoporous Zeolites, 425–60. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2015. http://dx.doi.org/10.1002/9783527673957.ch13.
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Datka, Jerzy, Karolina Tarach, and Kinga Góra-Marek. "Acidic Properties of Hierarchical Zeolites." In Mesoporous Zeolites, 461–96. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2015. http://dx.doi.org/10.1002/9783527673957.ch14.
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Triantafyllidis, Kostas S., Eleni F. Iliopoulou, Stamatia A. Karakoulia, Christos K. Nitsos, and Angelos A. Lappas. "Mesoporous Zeolite Catalysts for Biomass Conversion to Fuels and Chemicals." In Mesoporous Zeolites, 497–540. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2015. http://dx.doi.org/10.1002/9783527673957.ch15.
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Millini, Roberto, and Giuseppe Bellussi. "Industrial Perspectives for Mesoporous Zeolites." In Mesoporous Zeolites, 541–64. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2015. http://dx.doi.org/10.1002/9783527673957.ch16.
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Pastore, Heloise de Oliveira, and Dilson Cardoso. "Zeolite Structures of Nanometer Morphology: Small Dimensions, New Possibilities." In Mesoporous Zeolites, 31–78. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2015. http://dx.doi.org/10.1002/9783527673957.ch2.
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Vuong, Gia-Thanh, and Trong-On Do. "Nanozeolites and Nanoporous Zeolitic Composites: Synthesis and Applications." In Mesoporous Zeolites, 79–114. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2015. http://dx.doi.org/10.1002/9783527673957.ch3.
Full textConference papers on the topic "Mesoporou"
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Phuong, Nguyen Thi Truc, Cu Hoang Minh, Hung Hoa Lam, Ngo Tran Hoang Duong, and Long Quang Nguyen. "An Ultrafast and Green Synthesis of Mesoporous Zeolite X for Great Enhancement in Methylene Blue Adsorption." In 5th International Conference on Advanced Materials Science. Switzerland: Trans Tech Publications Ltd, 2023. http://dx.doi.org/10.4028/p-6rb9r6.
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Following the global trend of green material synthesis, the microwave-assisted acid leaching process has significantly reduced the treated time to introduce mesoporosity into zeolite FAU (type X). Instead of hours, mesoporous zeolite has appeared for 5 minutes only. The material's success was demonstrated by various characterizations like the hysteresis loops of the Nitrogen adsorption-desorption curves, the X zeolitic structure through X-ray diffraction (XRD) patterns, and the morphology by scanning electron microscopy (SEM) – energy dispersive X-ray (EDX) spectroscopy analysis. Less than 10 wt% of acetic acid concentration is enough to increase the zeolite's external surface area from 34.4 m2/g to 234.4 m2/g which indicates the formation of mesopores. Intending to enhance mesoporosity while minimizing microporous loss, 0.9 wt% acetic concentration corresponding to 172.6 m2/g external area value and 630 m2/g BET surface area value is prominent in the samples. In addition, mesopore enhancement has played an extreme role in significantly improving the methylene blue adsorption with molecular transport facilitation. Methylene blue adsorption results of all mesoporous zeolites were many times higher (2-6 times) than the original microporous sample under the same adsorption conditions.
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Daiguji, Hirofumi, Daisuke Nakayama, Asuka Takahashi, Sho Kataoka, and Akira Endo. "Ion Transport in Mesoporous Silica Thin Films." In ASME/JSME 2011 8th Thermal Engineering Joint Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/ajtec2011-44526.
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Mesoporous silica SBA-16 thin films were synthesized on a Si substrate via the dip-coating method. SEM analysis revealed that these films possess highly ordered 3D cubic structure. After these films were filled with either pure water or KCl aqueous solutions, the ionic current passing through the mesopores was measured by applying electric field to find out ion transport phenomena. If the ion transport phenomena in mesoporous silica are completely elucidated, this will enhance its use in applications where it is intended to be employed as a catalyst, filter, and adsorbent. The measured I-V curves were non-linear. This document discusses the relationship between the non-linear I-V curves and the ionic flow inside the 3D cubic pore structure. The effect of the dimensions and surface properties of mesopores on the I-V curves are also discussed.
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Hwang, Junho, and Hirofumi Daiguji. "Proton Transport in Mesoporous Silica SBA-16 Thin Films With Three-Dimensional Cubic Structures." In ASME 2013 11th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/icnmm2013-73112.
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Mesoporous silica SBA-16 thin films with highly ordered 3D cubic structures were synthesized by evaporation-induced self-assembly method, using an F127 triblock copolymer as the structure-directing agent via dip coating, to investigate proton transport of aqueous solutions confined in mesopores. Using electrochemical measurements of ionic current under DC electric fields, we elucidated proton transport phenomena through mesopores of SBA-16 thin films. At low concentrations, ranging from 10−7 to 10−5 M, the I–V curves of KCl and HCl aqueous solutions were nonlinear. However, at 10−4 and 10−3 M, while I–V curves of KCl aqueous solutions displayed nonlinear behavior, those of HCl aqueous solutions were almost linear. The linear behavior can be attributed to a decrease in the electric potential barrier owing to a reduction in the surface charge density, which is caused by the protonation of silanol groups on the inner surface of mesopores. At high concentrations, ranging from 10−2 to 1 M, the I–V curves of KCl and HCl aqueous solutions were almost linear because the effect of surface charge of mesopores on ion transport was marginal.
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Yamashita, Kyohei, and Hirofumi Daiguji. "Molecular Simulation of Adsorbed Water on Mesoporous Silica Thin Films." In ASME 2013 11th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/icnmm2013-73131.
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Grand canonical Monte Carlo (GCMC) and canonical ensemble molecular dynamics (NVT-MD) simulations were performed to investigate water adsorption properties in mesoporous silica thin films. The effect of pore radius on the adsorption properties was assessed using two models of mesoporous silica thin films having different pore radius and film thickness (1.38 and 5.66 nm in Model 1, respectively, and 1.81 and 7.30 nm in Model 2, respectively). In the simulations, a water adsorption layer or water menisci were formed in a mesopore accompanying the growth or shrinkage of stable adsorption layers on the upper and lower surfaces. The stable two water adsorption layers were formed on the pore surface in both models. The curvature radius of a water meniscus decreased monotonically and approached a constant value. In addition, NVT-MD simulations were performed to investigate the kinetics of water uptake into a model of mesoporous silica thin film having a radius and thickness of 1.38 and 7.93 nm (Model 3). The calculation results showed that the kinetics of water uptake depended on the number of water molecules and there were two different transport mechanisms in the pore. One was diffusion of water along the pore surface, and the other was capillary rise of liquid water.
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Mamaev, A. V., D. D. Hrynshpan, N. G. Tsygankova, and T. A. Savitskaya. "OBTAINING HIGHLY ACTIVE MESOPOROUS COAL FROM WASTE OF THE WOOD PROCESSING INDUSTRY." In SAKHAROV READINGS 2022: ENVIRONMENTAL PROBLEMS OF THE XXI CENTURY. International Sakharov Environmental Institute of Belarusian State University, 2022. http://dx.doi.org/10.46646/sakh-2022-2-304-307.
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A method for producing of mesoporous activated carbon with a high specific surface area equal to 1289 m2/g is considered. The resulting coal has a very high sorption capacity for methylene blue, equal to 610 mg/g, and also exhibits ion-exchange properties with respect to heavy metal ions. Coal obtained in this method, in terms of its performance, significantly exceeds the best world analogues, but its cost is 4 times lower than the cost of imported activated carbon. Due to the presence of mesopores, activated carbon has a wide range of applications, and its production in Belarus will be profitable and help reduce the amount of wood waste generated.
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Fang, Jin, Laurent Pilon, Christian Reitz, Torsten Brezesinski, E. Joseph Nemanick, and Sarah H. Tolbert. "Thermal Conductivity of Amorphous and Crystalline Mesoporous Titania Thin Films From 30 to 320 K." In ASME/JSME 2011 8th Thermal Engineering Joint Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/ajtec2011-44047.
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This paper reports, for the first time, the cross-plane thermal conductivity of amorphous and crystalline templated cubic mesoporous titania thin films from 30 to 320 K. Both sol-gel and nanocrystal-based films were synthesized by evaporation-induced self-assembly with porosity of 30% to 35%, respectively. The pore diameter in sol-gel mesoporous films ranged from 14 to 25 nm and film thickness from 120 to 370 nm. Crystalline domains in crystalline mesoporous films were 9 to 13 nm in diameter. The thermal conductivity was measured between 30 and 320 K using the 3ω method. The experimental setup and the associated analysis were first validated by comparing experimental measurements with data reported in the literature for high purity silicon substrate and thermal oxide films over the temperature range considered. The thermal conductivity of sol-gel dense and mesoporous TiO2 films was found to increase with increasing temperature. The thermal conductivity of polycrystalline dense film was strongly dependent on temperature while that of dense amorphous and mesoporous films increased slowly with increasing temperature. The amorphous mesoporous TiO2 films featured very small thermal conductivity due to the fact that heat was mainly transferred by very localized non-propagating vibrational modes. Despite the particles crystallinity, the nanocrystal-based film showed significantly lower thermal conductivity than that of the sol-gel polycrystalline mesoporous thin films due to the strong phonon scattering at the nanocrystal boundaries.
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Tamada, Makio, and Yuta Sunami. "Establishment of Mass Production Method of Mesoporous Silica Thin Film and Development of Porous Carbon Thin Film Using 1,4-Dihydroxyanthraquinone As Carbon Source." In ASME 2019 28th Conference on Information Storage and Processing Systems. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/isps2019-7468.
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Abstract Porous materials typified by mesoporous silica and porous carbon are expected to be applied in various fields such as adsorption, ion exchange, and engineering. In this research, we focused on mesoporous silica thin films and porous carbon thin films. For the mesoporous silica thin film, mass creation method was established the by introducing the roll-to-roll fabrication method. In this method, the pore size could be controlled by changing the molar ratio of the precursor solution, and the thickness of mesoporous silica film is controlled by changing the peripheral speed ratio. In the development of porous carbon thin film, we succeeded to express pores by using 1,4-dihydroxyanthraquinone as a carbon source. X-ray analysis and arithmetic mean roughness measurements were made on the fabricated carbon thin film. As a result, it was confirmed that the porous carbon thin film prepared in this study has a higher specific surface area than the porous carbon thin film synthesized by the conventional manufacturing method.
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Coquil, Thomas, Laurent Pilon, Christian Reitz, Torsten Brezesinski, Joseph E. Nemanick, and Sarah H. Tolbert. "Thermal Conductivity of Highly Ordered Amorphous and Crystalline Mesoporous Titania Thin Films." In 2010 14th International Heat Transfer Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/ihtc14-23161.
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This paper reports the cross-plane thermal conductivity of amorphous and crystalline templated mesoporous titania thin films synthesized by evaporation-induced self-assembly. Both sol-gel and nanocrystal-based films were considered, with respective average porosities of 30% and 35%. The pore diameter ranged from 7 to 25 nm and film thickness from 60 to 370 nm while the average wall thickness varied from 3 to 25 nm. Nanocrystals in crystalline mesoporous films featured diameters between 9 and 13 nm. The thermal conductivity was measured at room temperature using the 3ω method. The experimental setup and the associated analysis were validated by comparing the thermal conductivity measurements with data reported in the literature for dense titania films with thickness ranging from 95 to 1000 nm. The cross-plane thermal conductivity of the amorphous mesoporous titania thin films did not show strong dependence on pore size, wall thickness, or film thickness. This can be attributed to the high atomic scale disorder of amorphous materials. Heat is thus mainly carried by localized non-propagating vibrational modes. The average thermal conductivity of the amorphous mesoporous titania films was identical to that of the nanocrystal-based films and equal to 0.37 W/m.K. Thermal conductivity of sol-gel crystalline mesoporous titania thin films was significantly larger than that of their amorphous counterparts. It also depended on the organic template used to make the films. The results indicated that the pore size was not an important factor. Instead thermal conductivity depended only on porosity, crystallinity, nanocrystal size and connectivity.
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Shin, Yun-Ha, Hong-Gyu Jeon, Jeong-Kuk Son, Ji-Man Kim, Tae-Sung Kim, and Young Ze Lee. "Frictional Characteristics of Mesoporous SiO2 Thin Film Formed by Sol-Gel and Self-Assembly Method." In ASME/STLE 2007 International Joint Tribology Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/ijtc2007-44046.
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Frictional characteristics of mesoporous SiO2 thin films were evaluated with different pore sizes. The films were manufactured by sol-gel and self-assembly methods to have a porous structure. The pores on the surface may play as the outlet of wear particle and the storage of lubricant so that the surface interactions could be improved. The pores were exposed on the surface by chemical mechanical polishing (CMP) or plasma-etching after forming the porous films. The ball-on-disk tests with mesoporous SiO2 thin films on glass specimen were conducted at sliding speed of 15rpm and a load of 0.26N. The results show considerable dependency of friction on pore size of mesoporous SiO2 thin films. The friction coefficient decreased as increasing the pore size. CMP process was very useful to expose the pores on the surface.
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Titinchi, Salam J. J., Waheed Saban, Leslie Petrik, and Hanna S. Abbo. "Synthesis, Characterization and Physiochemical Properties of Platinum Supported on Mesoporous Carbon." In ASME 2011 9th International Conference on Fuel Cell Science, Engineering and Technology collocated with ASME 2011 5th International Conference on Energy Sustainability. ASMEDC, 2011. http://dx.doi.org/10.1115/fuelcell2011-54670.
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Ordered mesoporous carbon (OMC) has been prepared by impregnating the pores of the silica template (SBA-15) with liquid petroleum gas (LPG) or sucrose. The desired support (OMC) was obtained after dissolution with NaOH. Platinum nanoparticles were dispersed on ordered mesoporous carbons using Chemical Vapour Deposition (CVD) method and Pt(acac)2 as metal source. The resulting ordered mesoporous carbon possess a large surface area with high microporosity, and a controlled pore size distribution, High-quality carbon replicas of SBA-15 show an X-ray diffraction peak at low angle, which indicates that the structural periodicity of the (111) planes has been maintained. Their pore volume and specific surface area are high and the pore volume is almost entirely microporous. The synthesized Pt/OMC was characterized by powder X-Ray diffraction, HR-TEM, HR-SEM, EDS, thermogravimetric analysis, and nitrogen adsorption. The performance of Pt catalyst supported OMC was evaluated by electrochemical studies, which shows almost similar activity to the commercial catalyst.
Reports on the topic "Mesoporou"
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Saunders, R. S., J. H. Small, R. R. Lagasse, J. L. Schroeder, and G. M. Jamison. Engineered monodisperse mesoporous materials. Office of Scientific and Technical Information (OSTI), August 1997. http://dx.doi.org/10.2172/527462.
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Brinker, C. Jeffrey, and Yunfeng Lu. Aligned mesoporous architectures and devices. Office of Scientific and Technical Information (OSTI), March 2011. http://dx.doi.org/10.2172/1010416.
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Kandel, Kapil. Multitasking mesoporous nanomaterials for biorefinery applications. Office of Scientific and Technical Information (OSTI), January 2013. http://dx.doi.org/10.2172/1082978.
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Parikh, Bosky. Synthesis, characterization and catalytic studies of N-doped ordered mesoporous carbons and functionalized periodic mesoporous organosilicas. Office of Scientific and Technical Information (OSTI), December 2017. http://dx.doi.org/10.2172/1505185.
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Fang, I.-Ju. Cellular membrane trafficking of mesoporous silica nanoparticles. Office of Scientific and Technical Information (OSTI), January 2012. http://dx.doi.org/10.2172/1048532.
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Shih, Wei-Heng, and Tejas Patil. DEVELOPMENT OF MESOPOROUS MEMBRANE MATERIALS FOR CO2 SEPARATION. Office of Scientific and Technical Information (OSTI), October 2002. http://dx.doi.org/10.2172/804177.
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Wei-Heng Shih, Tejas Patil, and Qiang Zhao. DEVELOPMENT OF MESOPOROUS MEMBRANE MATERIALS FOR CO2 SEPARATION. Office of Scientific and Technical Information (OSTI), March 2003. http://dx.doi.org/10.2172/812171.
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Shih, Wei-Heng, Qiang Zhao, and Nanlin Wang. DEVELOPMENT OF MESOPOROUS MEMBRANE MATERIALS FOR CO2 SEPARATION. Office of Scientific and Technical Information (OSTI), May 2002. http://dx.doi.org/10.2172/795760.
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Shih, Wei-Heng, Qiang Zhao, and Tejas Patil. DEVELOPMENT OF MESOPOROUS MEMBRANE MATERIALS FOR CO2 SEPARATION. Office of Scientific and Technical Information (OSTI), May 2002. http://dx.doi.org/10.2172/795762.
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Strosahl, Kasey Jean. Selective catalysis utilizing bifunctionalized MCM-41 mesoporous materials. Office of Scientific and Technical Information (OSTI), January 2005. http://dx.doi.org/10.2172/850044.
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