再生竹纤维球形介孔气凝胶的表征

Characterization of Spherical Mesoporous Aerogels from Regenerated Bamboo Fiber

为获得均一稳定的纤维素气凝胶,以再生竹纤维为原料,采用滴定悬浮和真空冷冻干燥的方法制备球形纤维素气凝胶。傅里叶变换红外光谱仪(FTIR)、X射线衍射仪(XRD)、扫描电镜(SEM)分析结果表明,球形纤维素气凝胶为纤维素II型结构,内部为疏松多孔的网络状结构。球形纤维素气凝胶的比表面积均在240 m2/g以上,且孔径均在15 nm以下,最小密度可达37 mg/cm3,这表明球形纤维素气凝胶具有较高的比表面积、较小的孔径。热重分析(TG)结果表明,纤维素气凝胶大球的最大热失重温度为364.4℃,纤维素气凝胶中球的最大热失重温度为357.3℃,纤维素气凝胶小球的最大热失重温度为354.2℃,而再生竹纤维的最大热失重温度为354.0℃。球形纤维素气凝胶在污水处理、海水除油、重金属离子吸附等领域具有开发价值。

To obtain uniform and stable cellulose aerogels, spherical cellulose aerogels were prepared by titration suspension and vacuum freeze drying method using regenerated bamboo fiber as the raw material. The results of Fourier transform infrared spectroscopy （FTIR）, X-ray diffraction （XRD） and scanning electron microscopy （SEM） show that spherical cellulose aerogels are typical cellulose II structure, and the internal structure was a porous network-like one. The specific surface areas of all spherical cellulose aerogels exceed 240 m2/g. Besides, the pore sizes of spherical cellulose aerogels are below 15 nm, and the minimum density of spherical cellulose aerogels is up to 37 mg/cm3. These data indicate that spherical cellulose aerogels have high specific surface areas and small pore sizes. The results of thermal gravimetric （TG） analysis show that the maximum heat loss temperatures of large, middle and small cellulose aerogels are 364.4, 357.3 and 354.2℃, respectively, while the maximum heat loss temperature of regenerated bamboo fiber is 354.0℃. Spherical cellulose aerogels have potential applications in sewage treatment, sea oil removal and heavy metal ion adsorption.