木质素/纤维素复合气凝胶的制备与表征

Preparation and characterization of lignin/cellulose composite aerogel

以木质素和纤维素为原料,以氢氧化钠/尿素水溶液作为溶解体系,采用真空冷冻干燥法制备出木质素/纤维素复合气凝胶。运用扫描电子显微镜、X射线衍射仪、傅里叶红外光谱仪和孔径分析仪等手段对复合气凝胶的内部结构进行表征,并探究了复合气凝胶对阳离子染料的吸附性能。结果表明:木质素/纤维素复合气凝胶内部呈空间网状结构,存在纤维素Ⅱ型的特征结构峰;孔径在15nm左右,且随着木质素添加量的增加,样品的比表面积与孔容逐渐下降;在常温下,样品CL-4对亚甲基蓝的去除率可达94.26%,且吸附亚甲基蓝的过程符合Langmuir等温吸附模型,为单分子层吸附,理论吸附饱和容量可达200.0mg/g。

Lignin/cellulose composite aerogels were prepared by vacuum freeze-drying with lignin and cellulose as raw materials and sodium hydroxide/urea aqueous solution as the solution system.The internal structure of the aerogel was characterized by scanning electron microscope,X-ray diffractometer,fourier infrared spectrometer and aperture analyzer,and the adsorption properties of the aerogel on cationic dyes were investigated.The results shown that the aerogel internal presented space mesh structure,and the characteristics of the structure peak of celluloseⅡ.The pore diameter was about 15 nm,and with the increase of lignin content,the specific surface area and pore volume of samples decreased gradually.At room temperature,the removal rate of sample CL-4 to methylene blue was up to 94.26%,and the adsorption process of methylene blue was consistent with the Langmuir isothermal adsorption model.The adsorption was monolayer,and the adsorption saturation capacity was up to 200.0 mg/g.