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以正硅酸乙酯(TEOS)为硅源,盐酸、氨水为催化剂,采用两步法及常温干燥技术制备了纤维增强SiO2气凝胶隔热材料,研究了H2O、EtOH、pH值及温度等制备条件对溶胶-凝胶过程的影响。H2O对凝胶化过程的影响比较复杂,凝胶时间随其用量的增加先减后增,转折点处水硅摩尔比为4～6之间;溶剂EtOH对凝胶化过程有明显的抑制作用,凝胶时间随其用量的增加而增加;pH值对凝胶化过程也有比较明显的影响,pH值越高凝胶化过程越快;随着温度的升高凝胶化过程也越快。
The TEOS as silica source, hydrochloric acid and ammonia as catalyst, two-step method and room temperature drying technology were used to prepare fiber-reinforced SiO2 airgel insulation materials. The effects of H2O, EtOH, pH and temperature Effect of Preparation Conditions on Sol - Gel Process. The influence of H2O on the gelation process is rather complicated. The gel time decreases first and then increases with the increase of the dosage, and the mole ratio of water to silicon at the turning point is between 4 and 6. The solvent EtOH obviously inhibits the gelation process, Gel time increased with the increase of its dosage; pH also had obvious influence on the gelation process; the higher the pH value was, the faster the gelation process was; the faster the gelation process was as the temperature increased.