Effect of sodium chloride on gelatinization of silicic acid and the formation of novel polysilicic acid crystals

Zhou, Zhong Shi; Li, Chun Sheng; Jin, Jian Zhong; He, Xue Han

doi:10.1016/j.jnoncrysol.2007.05.026

Cited by 8 publications

(2 citation statements)

References 12 publications

(13 reference statements)

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“…The percentage weight losses were found to be 8.43 and 11.94% for PFS1M after SPP in pH 3 and pH 11 solutions, respectively. This decrease can be considered as the loss of silanol groups, which is clearly observed at a temperature of over 200 C. 29,30) Nevertheless, the decrease is significant in the case of PFS1M after SPP in pH 7 solution [Fig. 6B(c)].…”

Section: Resultsmentioning

confidence: 99%

Solution Plasma Process for Template Removal in Mesoporous Silica Synthesis

Pootawang

Saito

Takai

2010

Jpn. J. Appl. Phys.

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The plasma discharge in aqueous solution was scientifically studied and applied to template removal in mesoporous silica synthesis. Highly dispersed spherical mesoporous silica particles were synthesized by the ternary surfactant system containing the Pluronic P123 copolymer (EO20PO69EO20), sodium dodecylbenzene sulfonate, and 1,1,2,2,3,3,4,4,4-nonafluoro-1-butane sulfonate, via the sol–gel method in acid solutions. The solution plasma process (SPP), instead of conventional thermal calcinations, was used to remove the template. The mechanism of the removal of the organic template occurred via oxidation by the hydroxyl radicals generated during discharge. The transformation of a mesopore structure from a disordered wormlike structure to a hexagonally arranged structure was observed by X-ray diffraction analysis and was confirmed by transmission electron microscopy. The results of the thermal analysis and functional group identification of mesoporous silica after SPP showed evidence of organic template removal. The surface area calculated using the Brunauer–Emmett–Teller (BET) theory and the mean pore diameter results could be used to evaluate the plasma efficiency, demonstrating that this method does not affect the pore size in the case of discharge in a solution of pH 3 compared with the results of thermal calcination. Hence, SPP was proved to be highly efficient for organic template removal, exhibiting short consumption time and less contamination.

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Section: Resultsmentioning

confidence: 99%

Solution Plasma Process for Template Removal in Mesoporous Silica Synthesis

Pootawang

Saito

Takai

2010

Jpn. J. Appl. Phys.

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“…Silicic acid with high purity can be obtained by passing sodium silicate through ion exchange resin. 24 However, the use of ion exchange resin is a costly and time-consuming process. Aerogels were also prepared without prior ion exchange to produce silica aerogel powders via fluidized bed drying, possessing properties such as a tapping density value as low as 0.05 g cc −1 , high specific surface area of 783 m 2 g −1 and cumulative pore volume of 1.79 cm 3 g −1 .…”

Section: Silica Aerogels From Sodium Silicatementioning

confidence: 99%