کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1483847 | 1510513 | 2009 | 7 صفحه PDF | دانلود رایگان |
Organic and carbon aerogels were prepared by sol–gel polymerization of phenol, melamine and formaldehyde, followed by supercritical drying and pyrolysis. The effect of the mole ratio of melamine/phenol (M/P) on microstructure of organic and carbon aerogels was investigated by N2 adsorption, SEM and TEM. Coordination M/P could change the hydrophilicity and cross-linking density of polymer framework, thereby affecting polymer colloid nanoparticle nucleation and growth, and ultimately determine the 3-dimensional network of the gels. The bulk densities of organic and carbon aerogels have maxima at M/P of 0.1, which are inversely proportional to volume shrinkage of gels during drying and pyrolysis. The size of the nanoparticles could be adjusted by varying M/P in the range from 10 to 22 nm. The mesopore volumes of organic and carbon aerogels are tailored in the range of 1.4–2.9 and 0.8–2.5 cm3/g, respectively. The average mesopore diameter has experienced a decreasing first and increasing afterward tendency with the increase of M/P, and exhibit a minimum at M/P of 0.1.
Journal: Journal of Non-Crystalline Solids - Volume 355, Issues 22–23, 15 July 2009, Pages 1252–1258