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以三聚氰胺(M)和甲醛(F)为原料,经溶胶-凝胶和超临界干燥过程成功制备出MF气凝胶。实验详细研究了反应物总浓度、溶液pH值、温度等对凝胶化时间及其结构的影响,实验结果表明:在一定的浓度和pH值范围内,凝胶化时间随反应物总浓度增加而减少,随pH值的降低而减少;只有在一定的pH值范围内(1.4～1.8)才能制得透明的MF气凝胶,反应物总浓度增大,孔径分布较窄且均匀(1～3 nm)。
The melamine (M) and formaldehyde (F) as raw materials, the successful preparation of aerogels by sol-gel and supercritical drying process. The effects of the total concentration of reactants, the pH value and the temperature of the solution on the gelation time and the structure of the gel were studied in detail. The experimental results show that the gelation time increases with the total concentration of the reactants at a certain concentration and pH range But decreased with the decrease of pH value. Transparent MF airgel could be obtained only in a certain pH range (1.4 ~ 1.8), the total concentration of reactants increased, the pore size distribution was narrow and uniform (1 ~ 3 nm).