甘蔗渣纤维素基碳气凝胶的制备及吸附性能研究

通过对甘蔗渣进行碱/酸处理提取甘蔗渣纤维素，采用氢氧化钠/脲溶液将纤维素溶解，并通过在水中再生、冷冻干燥及在不同温度下碳化，制备具有优异疏水吸油性能的甘蔗渣纤维素基碳气凝胶。采用扫描电镜（SEM）、红外光谱（FT-IR）、X射线衍射（XRD）、BET法比表面积、水接触角（WCA）等测试方法对制备的甘蔗渣纤维素基碳气凝胶进行分析表征，并进行不同油类和有机溶剂的吸附、解吸实验。结果表明，制备的甘蔗渣纤维素基碳气凝胶拥有不规则的片-孔式网络状三维结构，具有轻质、高疏水、高比表面积等特性。高温碳化不仅可以改善碳气凝胶的轻质抗压性能、比表面积和孔径，还可以增强其疏水性及吸附性能。当碳化温度为800 ℃时，制备的CA-2-800表现出较好的轻质性（密度为33.4 mg/cm³）、高疏水性（水接触角为136°）和高比表面积（468.24 m²/g）。CA-2-800对柴油、汽油、泵油、正己烷、甲苯、三氯甲烷具有较好的吸附能力（20.2~66.3 g/g）。吸附动力学研究表明，CA-2-800在30 s内对汽油、柴油均能达到吸附平衡，且对三氯甲烷进行10次吸附-解吸循环吸附实验仍保留97%的吸附性能。

Study on preparation of bagasse cellulose based carbon aerogels and their adsorption properties

Cellulose was extracted from bagasse by alkali/acid treatment of bagasse，dissolved by sodium hydroxide/urea solution，regenerated，freeze?dried and carbonized at different temperature to prepare bagasse cellulose based carbon aerogel with excellent hydrophobic and oil?absorbing properties.Scanning electron microscopy（SEM），infrared spectroscopy（FT-IR），X-ray diffraction（XRD），BET specific surface area，water contact angle（WCA） and other test methods were used to analyze and characterize the prepared bagasse cellulose based carbon aerogel，and the adsorption and desorption experiments of different oils and organic solvents were carried out.The results showed that the bagasse cellulose carbon aerogel had irregular split?pore network structure and had the characteristics of light weight，high hydrophobic and high specific surface area.High temperature carbonization could not only improve the light compressive properties，specific surface area and pore diameter of carbon aerogel，but also enhance its hydrophobicity and adsorption properties.When the carbonization temperature was 800 ℃，the prepared product CA-2-800 showed good lightness（density:33.4 mg/cm³），high hydrophobicity（water contact angle:136°） and high specific surface area（468.24 m²/g）.CA-2-800 had a good adsorption capacity（20.2~66.3 g/g） for diesel，gasoline，pump oil，n-hexane，toluene and chloroform.Adsorption kinetics showed that CA-2-800 could reach adsorption equilibrium for gasoline and diesel within 30 s，and after 10 cycles of adsorption and desorption for chloroform，CA-2-800 still retained 97% of the adsorption capacity.