![]() Liu, The measuring and analyzing of polymerization degree of silicic acid in the course of gelation of water glass. Yu, The measurement of average degree of polymerization of silicate ions in water glass. Debye, Light-scattering investigations of carefully filtered sodium silicate solutions. Wang, Studies on silicic acid and its salt(IX). Dai, Studies on silicic acid and its salt(XIV). Abil’Magzhanov, Evaluation of the significance of the factors influencing the microstructure of silicic acid gels. Li, Integration of fossil energy systems with CO 2 sequestration through NH 4HCO 3 production. Chen, Preparation of white carbon black with lime-kiln gas by carbonization. Wei, Synthesis of silica powders by pressured carbonation. Yang, A simple and inexpensive route to synthesize porous silica microflowers by supercritical CO 2. Gupta, Supercritical CO 2-based formation of silica nanoparticles using water-in-oil microemulsions. ![]() Rao, Physico-chemical properties of ambiently dried sodium silicate based aerogels catalyzed with various acids. Tarutani, Polymerization of silicic acid. Roque-Malherbe, Synthesis and characterization of large specific surface area nanostructured amorphous silica materials. Zhao, Amorphous silica nanohybrids: synthesis, properties and applications. The growth kinetics of hydrated silica was investigated and the apparent activation energy of particle growth of hydrated SiO 2 was 43.377 kJ/mol in the first polymerization stage. Higher the reaction temperature, shorter the gelation time of silicic acid. In alkaline system, the polymerization rate of silicic acid decreased with the increase of pH value. The effects of pH value, temperature on polymerization rate of silicic acid were studied as well. TEM images revealed that the white carbon black powders were spherical particles resulted from homogeneous polymerization of ring nucleus. After completion of polymerization, the 29SiNMR signal presented a single peak at −113 ppm with two shoulder at −98 and −93 ppm, indicating that the silicic acid polymerized to form homogeneous Q 4 configuration. In the fast polymerization phase, 29SiNMR signal was split into 5 peaks which indicated there were a complex configuration resulted from silicon atom in different chemical environment including monomers, multimers and hydrated ions. The signals of 29SiNMR demonstrated that the silicate of raw material was in a ring multimer. The polymerization process was divided into three stages which include slow polymerization, fast polymerization and the end of polymerization. The results indicated that the luminousness decreased as the reaction progress. The UV-vis spectra and 29SiNMR were used to characterize the configuration of silicon atoms before and after polymerization of silicic acid. ![]() The white carbon black powders were prepared through carbonation of water glass. ![]()
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