欢迎登录材料期刊网

材料期刊网

高级检索

通过溶胶-凝胶途径,将间苯二酚-甲醛预聚物和二氧化硅溶胶混合,在碱性溶液中制备出有机/无机杂化水凝胶.水凝胶经溶剂置换、超临界干燥、裂解和氢氟酸刻蚀制备得到炭气凝胶.采用氮气吸附法研究了水凝胶向炭气凝胶转化的结构演变规律.固定间苯二酚/甲醛摩尔比为0.5,二氧化硅溶胶浓度为15g/100mL,考察了二氧化硅胶体颗粒的尺寸及间苯二酚和甲醛浓度对炭气凝胶孔隙结构的影响.结果表明:无机二氧化硅溶胶骨架有效减少了有机物在超临界干燥和裂解过程中的体积收缩.中孔率随间苯二酚和甲醛浓度的升高而增加,孔隙率随二氧化硅溶胶粒子的增大而减小.当间苯二酚和甲醛质量分数之和的达到20%时,7nm二氧化硅溶胶体系的密度低达0.22g/cm3,中孔率达到96%,12nm二氧化硅溶胶体系的密度低达0.26g/cm3,中孔率达到98%.

参考文献

[1] Pekala R W .Organic aerogels from the polycondensation of resorcinol with formaldehyde[J].Journal of Materials Science,1989,24:3221-3227.
[2] Pekala R W;Schaefer D W .Structure of organic aerogels.1.morphology and scaling[J].Macromolecules,1993,26(20):5487-5493.
[3] Pekala R W;Alviso C T;Kong F M et al.Aerogels derived from multifunctional organic monomers[J].Journal of Non-Crystalline Solids,1992,145:90-98.
[4] Tran T D;Lenz D .Materials for electrochemical energy strorage and conversion-Ⅱ Batteries,Capacitors and Fuel Cells[J].Research Society Symposium Proceedings,1998,496:607-632.
[5] Biesmans G.;Francais E.;Perrut M.;Randall D. .Polyurethane-based organic aerogels' thermal performance[J].Journal of Non-Crystalline Solids: A Journal Devoted to Oxide, Halide, Chalcogenide and Metallic Glasses, Amorphous Semiconductors, Non-Crystalline Films, Glass-Ceramics and Glassy Composites,1998(1):36-40.
[6] J.Yamashita;T.Hirano;M.Shioya .Development of mesopores during activation of poly(vinylidene fluoride)-based carbon[J].Carbon: An International Journal Sponsored by the American Carbon Society,2002(9):1541-1548.
[7] Rui Zhang;Yonggen Lu;Liang Zhan .Monolithic carbon aerogels from sol-gel polymerization of phenolic resoles and methylolated melamine[J].Carbon: An International Journal Sponsored by the American Carbon Society,2003(8):1660-1663.
[8] Zhang R;Liang X Y;Wu G P et al.Effect of hydrophobic group in polymer matrix on meso-and macroporosity of organic and carbon aerogels from phenolic resole and methylolated melamine[J].Microporous and Mesoporous Materials,2003,62(1 -2):17-27.
[9] 张睿,徐耀,吕永根,李志宏,孟庆函,李开喜,吴东,凌立成,王俊,赵辉,荣利霞,董宝中.小角X射线散射研究制备炭气凝胶过程中凝胶的微结构演化[J].新型炭材料,2002(03):31-36.
[10] Gregg S J;Sing K S W.Adsorption,Surface Area and Porosity[M].London,UK:Academic Press,1982
上一张 下一张
上一张 下一张
计量
  • 下载量()
  • 访问量()
文章评分
  • 您的评分:
  • 1
    0%
  • 2
    0%
  • 3
    0%
  • 4
    0%
  • 5
    0%