氧化前处理对炭气凝胶孔结构的影响

氧化前处理对炭气凝胶孔结构的影响

  • 摘要: 在110℃~170℃范围内对糠醛酚醛基有机气凝胶进行氧化处理1h~7h,考察了氧化对有机气凝胶热裂解产生的炭气凝胶孔结构的影响。结果表明:氧化可避免有机气凝胶纳米骨架在裂解过程中的塑性阶段发生,有机气凝胶的适度氧化有利于纳米结构的稳定化;由于空气在大、中、微孔中扩散的差别,氧化前处理对炭气凝胶的大、中、微孔有不同的影响,尤其对接近中孔的大孔影响最大。在所考察的氧化温度和时间内,130℃/7h时或150℃/3h时的适度氧化条件下,可显著提高中孔孔容、中孔比表面和BET比表面。

     

    Abstract: Organic aerogels, prepared by solgel polymerization of phenolic and furfural, were oxidized at 110 to 170℃ for 1 to 7h in air. The effect of oxidation temperature and time on the pore structure of the carbon aerogels was investigated. It is found that oxidation under appropriate conditions can stabilize a nanonetwork of organic aerogels during pyrolysis by preventing plasticity. However, the oxidative effect on micro, meso and macropores is quite different. A mild condition is appropriate for macropores while a severe condition is needed for meso and micropores due to a faster diffusion of air into macropores than into meso and micropores. The appropriate oxidation parameters for an improved mesopore volume and surface area are 130℃ for 7h or 150℃ for 3h in air.

     

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