Journal ArticleDOI
Infrared and thermogravimetric study of high pressure consolidation in alkoxide silica gel powders
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In this paper, high density, transparent, crack-free and hard compacts of silica gel were produced by compaction under nearly hydrostatic environment at 4.5 GPa, at room temperature.Abstract:
High density, transparent, crack-free and hard compacts of silica gel were produced by compaction under nearly hydrostatic environment at 4.5 GPa, at room temperature. The starting material was used three days after synthesis by hydrolysis of alkoxides without additional treatment. Fourier transform infrared spectroscopy (FTIR), using the KBr technique and a high vacuum cell at temperatures up to 450°C, and thermogravimetric analysis (TGA) up to 900°C was conducted. A reduction up to 60% in the adsorbed water content of the compacted silica gel was observed. Changes in the 3000 to 3800 cm−1 region indicate that the surface silanol groups became bridged, which promotes condensation reactions of dehydroxylation. Those results suggest that the mechanism for consolidation under high-pressure, is ‘cold sintering’ process, where silanol groups at the surface of the nanoparticles condense to form siloxane bonds between the particles and water, resulting in a stiff body with closed nanopores containing trapped water.read more
Citations
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Phd by thesis
TL;DR: In this paper, a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) is presented.
Journal ArticleDOI
OH Surface Density of SiO2 and TiO2 by Thermogravimetric Analysis
TL;DR: In this article, the authors used thermogravimetric analysis (TGA) for determination of the surface density (OH/nm2) and carbon content of silica and titania powders made by flame aerosol and sol−gel processes.
Journal ArticleDOI
Removal of Congo red from aqueous solution by anilinepropylsilica xerogel
TL;DR: The hybrid anilinepropylsilica xerogel (SiAn) was synthesized by sol-gel method and it was used as adsorbent for removing Congo red from aqueous solutions as mentioned in this paper.
Journal ArticleDOI
Rice husk ash as an adsorbent for purifying biodiesel from waste frying oil
Márcia Cardoso Manique,Candice Schmitt Faccini,Bruna Onorevoli,Edilson Valmir Benvenutti,Elina Bastos Caramão +4 more
TL;DR: In this article, the authors used rice husk ash (RHA) for the purification of biodiesel from waste frying oil (WFO) using RHA at concentrations of 1, 2, 3, 4, and 5% and compared it with two other different purification methods, the traditional acid solution (1% aqueous H3PO4) and with the commercial adsorbent Magnesol® 1% (w/w).
Journal ArticleDOI
A review of cold sintering processes
Salvatore Grasso,Mattia Biesuz,Luca Zoli,Gianmarco Taveri,Andrew Ian Duff,Daoyao Ke,Anna Jiang,Michael J. Reece +7 more
TL;DR: The need to reduce the energy consumed and the carbon footprint generated by firing ceramics has stimulated research to develop consolidation techniques operating at lower temperatures as discussed by the authors, ideally not at higher temperatures.
References
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Journal ArticleDOI
Phd by thesis
TL;DR: In this paper, a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) is presented.
Sol-gel science
TL;DR: In this article, the authors present and understand the sol-gel processing sequence from beginning to end, including discussions on the chemistry of hydrolysis and condensation of metal-organics and inorganic salts, the growth of polymeric or particulate species in sols, gelation, aging of gels, drying, structure of Gels, and sintering.
Journal ArticleDOI
Structural investigation of silica gel films by infrared spectroscopy
Rui M. Almeida,Carlo G. Pantano +1 more
TL;DR: In this article, Fourier transform infrared absorption spectroscopy has been used to characterize the structure of porous silica gel films, both deposited on c-Si substrates and free standing.
Book
Ceramic Processing before Firing
George Y. Onoda,Larry L. Hench +1 more
TL;DR: In this paper, a wide range of analytical tools for characterizing agglomerate features throughout the processing steps is presented, including electron and optical micrographs and discusses the improvement of product reliability, reduction of costs, and energy and environmental concerns.
Journal ArticleDOI
Slow fracture model based on strained silicate structures
T. A. Michalske,B. C. Bunker +1 more
TL;DR: In this paper, a model is developed based on chemically active bond defects generated by the strain field of the crack tip of the Si-O-Si bond, and a two-dimensional fracture model involving kink site nucleation and motion is developed.
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