纤维素基球形多孔气凝胶的制备及吸附性能

Preparation and adsorption properties of spherical cellulose-based porous aerogels

基于生物质功能材料的研究是当前处理环境污染的热点之一。本研究以自然界储量最丰富的纤维素为基材,通过反相悬浮交联技术制备纤维素(CE)/羧甲基纤维素(CMC)球形多孔气凝胶,并以制备的气凝胶作为吸附剂处理染料废水;用傅里叶变换红外光谱仪(FTIR)、热重分析(TGA)和扫描电镜(SEM)技术对其进行表征;在研究吸附剂的吸附性能时,考察了吸附时间、p H、染料初始浓度、吸附剂用量对染料去除率的影响。研究结果表明:吸附动力学符合准二级动力学模型,平衡吸附等温线与Langmuir吸附等温方程拟合;吸附剂对亚甲基蓝(MB)的最大吸附量为312.5 mg/g,吸附过程是放热和自发进行的。

The research of the functional material of biomass has already become a hot issue to deal with environmental pollution. Cellulose（CE）/carboxymethyl cellulose（CMC） spherical porous aerogels were prepared by inverse suspension crosslinking technique as a novel adsorbent to dispose of dye waste water. It was characterized by the fourier transform infrared（FTIR）spectroscopy, thermogravimetric analysis（TGA） and scanning electron microscopy（SEM） technique. The absorption effects of contact time, pH, initial concentration, and adsorbent dose on the sorption were all investigated. Adsorption kinetics and the equilibrium adsorption isotherm were fitted by a pseudo-second-order kinetic model and Langmuir isotherm, respectively. Equilibrium data of CE/CMC aerogels fitted well with Langmuir isothermal model, and the maximum theoretical adsorption capacity of the aerogels for methylene blue（MB） was 312.5 mg/g. The thermodynamic studies show exothermic and spontaneous nature of adsorption process.