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In order to prepare porous silica that is mesoporous or microporous, the sol-gel process is recommended. Unlike methods that require high temperatures, the sol-gel process produces porous silica more or less at room temperature. T...
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In order to prepare porous silica that is mesoporous or microporous, the sol-gel process is recommended. Unlike methods that require high temperatures, the sol-gel process produces porous silica more or less at room temperature. The process involves the hydrolysis and polycondensation of silicon alkoxides in the majority of cases. Colloidal silica and soluble silicates may be used as well. The processing parameters that influence the porosity are primarily the pH and aging. Applications using porous silica to encapsulate sensor molecules and enzymes are developing rapidly.
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Using the porosity of a binary exotemplate, with mesoporous core-shell structure (SiO2@ZrO2), opens a new pathway to produce hybrid core-shell spheres, composite hollow spheres, and porous hollow spheres - all monodisperse in size.
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The synthesis of a novel anion-exchangeable nanostructured aminophenyl silica with a well-ordered layer geometry was demonstrated by utilizing the sol-gel reaction of rho-aminophenyltrimethoxysilane in the presence of an anionic s...
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The synthesis of a novel anion-exchangeable nanostructured aminophenyl silica with a well-ordered layer geometry was demonstrated by utilizing the sol-gel reaction of rho-aminophenyltrimethoxysilane in the presence of an anionic surfactant micelle under acidic conditions.
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The condensation of 4-oxo-4H-1-benzopyran-3-carbaldehydes with 3-methyl-1-phenylpyrazolin-5-(4H)-ones in dioxane to afford 3-methyl-4-[(chromon-3-yl)methylene]-1-phenylpyrazolin-5-(4H)-ones was performed using MCM-41-SO3H as a cat...
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The condensation of 4-oxo-4H-1-benzopyran-3-carbaldehydes with 3-methyl-1-phenylpyrazolin-5-(4H)-ones in dioxane to afford 3-methyl-4-[(chromon-3-yl)methylene]-1-phenylpyrazolin-5-(4H)-ones was performed using MCM-41-SO3H as a catalyst. [References: 15]
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Morphology-controllable silica-based nanostructures (MC SiO(2)Ns) have been comprehensively studied because of their potential practical applications in various fields, such as biological chemistry. The superior properties of thes...
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Morphology-controllable silica-based nanostructures (MC SiO(2)Ns) have been comprehensively studied because of their potential practical applications in various fields, such as biological chemistry. The superior properties of these nanostructures, including low density, biocompatibility, thermal stability, and high mechanical strength, have been the focus of research to improve their current performance. In this review, experimental parameters, morphology, and formation mechanism of MC SiO(2)Ns (including vesicle-like mesoporous silica, rod-like mesoporous silica, and silica mesoporous nanospheres) are discussed. Moreover, current progress in functionalization and performance improvement of MC SiO(2)Ns is presented. Applications of MC SiO(2)Ns in immobilization techniques, biological catalysis, and drug delivery are also provided. (C) 2016 Elsevier Ltd. All rights reserved.
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In the present work, boron-acrylate/Santa Barbara Amorphous (SBA)-15 polymer composite was synthesized using free radical polymerization method. Firstly, SBA-15 was functionalized with 3-(trimethoxysilyl)propyl methacrylate to obt...
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In the present work, boron-acrylate/Santa Barbara Amorphous (SBA)-15 polymer composite was synthesized using free radical polymerization method. Firstly, SBA-15 was functionalized with 3-(trimethoxysilyl)propyl methacrylate to obtain chemically bonded boron acrylate (BAc) polymer on the SBA-15 surface. The structural analysis was evaluated via Fourier-transform infrared spectroscopy and solid-state nuclear magnetic resonance C-13. Samples were also characterized by using scanning electron microscopy, X-ray powder diffraction, N-2 adsorption/desorption and thermogravimetric analysis. In order to examine the BAc polymers in the mesopores, the silica framework was removed via hydrofluoric acid etching process. The results indicated that the synthesis of boron-acrylate/SBA-15 polymer composite was performed successfully. Thermal stabilities of the composites were higher with greater amounts of BAc polymer in mesopores under oxidative conditions.
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An acidichromic silyl spiropyran was synthesized and covalently immobilized on the surface of mesoporous silica (SBA-15) through either post-modification or a co-condensation route. The integration of the spiropyran into the porou...
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An acidichromic silyl spiropyran was synthesized and covalently immobilized on the surface of mesoporous silica (SBA-15) through either post-modification or a co-condensation route. The integration of the spiropyran into the porous silica was probed by thermogravimetric analysis, nitrogen adsorption/ desorption studies and UV-Vis optical spectroscopy. While the co-condensation route provides the higher spiropyran loading levels, it also leads to two different states of attachment. Both synthetic procedures favor the formation of the open, merocyanine form of the spiropyran within the framework, but this form can be readily switched from a protonated to a deprotonated state by treatment with buffered aqueous solutions. Preliminary evaluation of the metal ion sorption capabilities of the spiro-functionalized SBA-15 for selected monovalent, divalent, and trivalent metal ions indicates that the spiropyran-modified materials show modestly improved cation exchange characteristics versus the unfunctionalized mesoporous framework.
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The study reports the effect of mesoporous silica nanoparticles (MSNs) on detoxifi cation of toxic organophorous compounds. Based on gravimetric sensing experiment with resonant microcantilever, rapid adsorption of the organophoro...
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The study reports the effect of mesoporous silica nanoparticles (MSNs) on detoxifi cation of toxic organophorous compounds. Based on gravimetric sensing experiment with resonant microcantilever, rapid adsorption of the organophorous simulant of dimethyl methylphosphonate (DMMP) onto MSNs is confi rmed. The experimentally observed irreversible gravimetric-signal implies that substitutionreaction possibly occurs at the nanomaterial surface. By exploring a method of gravimetric detection at different temperatures to obtain two isotherms, high reaction-heat of 97.1 kJ mol ?1 is extracted that indicates strong chemical interaction. Characterizations with solid-state NMR and FT-IR to the MSNs are performed during the adsorption/interaction process, revealing that substitution-reaction exactly occurs. GC-MS analysis to the post-reaction vapor exhaust indicates that one or two methyl groups in a DMMP molecule can be substituted by hydrogen atom(s) through substitution-reaction with silanol group(s) of MSNs, thereby, destructing DMMP into two sorts of new molecules. With such comprehensive analyses, the destruction/detoxifi cation mechanism is clearly identifi ed. To evaluate the detoxifi cation performance of the MSNs, real toxic of dichlorvos is experimentally examined, resulting in that organophosphate dichlorvos is detoxifi ed into nontoxic dimethylphosphate. The low-cost and producible MSNs are promising for detoxifi cation to organophorous compounds. Besides, the micro-gravimetric analysis method can be expanding for extensive researches on various functional materials
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Magnetic mesoporous silica (MMS) nanoparticles with controllable magnetization have been synthesized by encapsulating Fe_3O_4 nanoparticles in a mesoporous silica matrix. The structure, magnetic heating capacity and drug delivery ...
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Magnetic mesoporous silica (MMS) nanoparticles with controllable magnetization have been synthesized by encapsulating Fe_3O_4 nanoparticles in a mesoporous silica matrix. The structure, magnetic heating capacity and drug delivery ability of MMS nanoparticles were evaluated. The results showed that MMS nanoparticles had an average particle size of 150 nm and showed low cytotoxicity and efficient cell uptake ability. MMS nanoparticles exhibited a sustained drug release in the medium of pH 5.0, but a very slow release in the medium of pH 7.4. On the other hand, MMS nanoparticles could controllably generate heat to reach the hyperthermia temperature within a short time upon exposure to an alternating magnetic field due to the superparamagnetic behavior and controllable magnetization. Therefore, MMS nanoparticles could provide a promising multifunctional platform for the combination of chemotherapy and hyperthermia for cancer therapy.
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Aerogel-type silica has been synthesized via precipitation of a hydrogel from liquid glass in the presence of glycerol followed by an extraction treatment with ethanol. Isotherms of low-temperature nitrogen adsorption-desorption b...
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Aerogel-type silica has been synthesized via precipitation of a hydrogel from liquid glass in the presence of glycerol followed by an extraction treatment with ethanol. Isotherms of low-temperature nitrogen adsorption-desorption by the prepared samples have been measured. It has been shown that the mesopore size distribution becomes more uniform with an increase in the pH of precipitation and the amount of glyc- erol, as well as after the extraction treatment of both a liquid hydrogel and xerogels dried at 293 and 373 K.
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