表面活性剂改性碳气凝胶吸附亚甲基蓝性能的研究

Adsorption Performance of Carbon Aerogels on Methylene Blue Modified by Surfactant

以间苯二酚和甲醛为碳前体,分别以十二烷基苯磺酸钠、十二烷基硫酸钠、十六烷基三甲基溴化铵为模板剂,采用溶胶凝胶法制备碳气凝胶材料。采用TG、XRD、SEM、N2吸脱附法等技术手段对其结构、形貌及热稳定性进行表征,探讨了吸附时间、染料初始浓度等因素对亚甲基蓝吸附性能的影响。结果表明,表面活性剂改性后的碳气凝胶孔结构较原生的碳气凝胶丰富;以十二烷基苯磺酸钠作模板剂所制得的样品吸附性能最佳,吸附条件为:样品用量为25mg、染料浓度为300mg/mL、吸附时间为5h。对吸附机理研究表明,吸附剂去除亚甲基蓝符合Langmuir吸附模型,吸附动力学研究表明吸附行为符合二级动力学模型。

Carbon aerogels were synthesized through sol-gel process by polycondensation of resorcinol and formaldehyde,using SDBS,SDS and CTAB as template,respectively. Structure,morphology and thermal stability of carbon aerogels were characterized by TG,XRD,SEM,and nitrogen adsorption,respectively. The effect of factors including the initial dye concentration and contact time were studied. The results show that the pore structure of modified carbon aerogel were more abundant than that of the original carbon aerogel,and the optimal adsorption efficiency were reached under the adsorbent dosage of 25 mg,initial dye concentration of 300 mg/mL,and contact time of 5 h by using SDBS as the template. Isotherm study showed that the experimental data can be well fitted by Langmuir adsorption modes. Kinetic study indicated that the adsorption process followed pseudo-second order kinetic model.