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该工作探讨利用TEOS前驱液及不同含量、不同分子量PEG制备出SiO2粉末的性质.SiO2粉末由溶胶-凝胶法制备,并结合退火前后烘干.TEOS前驱溶液的水解及缩合反应速率在pH=3时比在pH=5,7,9时进行得更彻底,且随温度及PEG分子量的升高而升高;粉末产率在TEOS前驱液pH=3时达到最大.与不加PEG的溶胶-凝胶法制备出的样品相比,加入PEG制备的粉末有更高的吸水能力.若粉末从高至500℃退火,则可发现乙醇浓度增加.依据液体和固体NMR、电子显微镜以及BET结果,对吸水及粉末表面积之间的关系进行了讨论.
This work explored the properties of SiO2 powders prepared by using TEOS precursors and different contents of PEG with different molecular weights.SiO2 powders were prepared by sol-gel method and combined with drying before and after annealing.The hydrolytic and condensation reaction rates of TEOS precursors at pH = 3 was more thorough than at pH = 5, 7, 9 and increased with increasing temperature and PEG molecular weight; the yield of powder reached its maximum at TEOS precursor pH = 3. Compared with PEG without sol Compared to the samples prepared by the gel method, the powders prepared by the addition of PEG have a higher water absorption capacity, and the ethanol concentration can be found to be increased if the powder is annealed up to 500 ° C. Based on liquid and solid NMR, electron microscopy and BET results , The relationship between water absorption and powder surface area was discussed.