摘要
与传统炭气凝胶制备不同,在室温条件下以乙腈为溶剂,间苯二酚和甲醛为前驱体,盐酸为催化剂,采用溶胶-凝胶、超临界干燥结合高温炭化工艺制备炭气凝胶(密度低至约50 mg.cm-3)。红外光谱、比表面积和孔径分布、扫描电子显微镜(SEM)和X射线衍射等测试表明,所制炭气凝胶是一种类石墨结构的非晶态材料,具有纳米骨架网络结构,比表面积达1 300 m2.g-1。对比不同配比气凝胶的SEM发现,气凝胶的颗粒尺寸为40 nm～70 nm。分析溶胶-凝胶过程中的温度变化和乙腈在凝胶化中作用得知,由于盐酸的催化和反应放热共同作用,实现了室温下间苯二酚和甲醛的加成和缩聚反应,并最终形成凝胶;乙腈在反应中起着一种分散剂的作用。
Carbon aerogels were synthesized at room temperature by a sol-gel polymerization route using resor- cinol and formaldehyde as precursors, acetonitrile as solvent and hydrochloric acid as catalyst, followed by CO2 supercritical drying and carbonization. FT-IR, SEM, XRD and nitrogen adsorption were used to characterize the microstructure of the aerogels. Results showed that the carbon aerogels are graphite-like amorphous materials with nano-skeleton networks formed by nanoparticles around 40-70 nm in diameter, whose specific surface area is up to 1 300 m2 ~ g-~ and lowest density about 0. 050 g/cm3. The heat of condensation and the catalytic action of hydrochloric acid made it possible to form gels at room temperature. The high surface area and low density of the as-prepared carbon aerogels were ascribed to a strong interaction between acetonitrile and --OH groups by hydro- gen bonding.
出处
《新型炭材料》
SCIE
EI
CAS
CSCD
北大核心
2012年第6期462-468,共7页
New Carbon Materials
基金
国家自然科学基金(51102184
51172163)
国家科技支撑计划(2009BAC62B02)
同济大学青年优秀人才培养行动计划(2010KJ068)
教育部博士点基金(20090072110047
20100072110054)~~
关键词
炭气凝胶
室温
乙腈
反应热
Carbon aerogels
Room temperature
Acetonitrile
Heat
