旧报纸碳基气凝胶的制备及其吸附性能的研究

Study on the Preparation of Carbon-based Aerogels from Old Newspaper and Its Adsorption Performance

中文关键词:  碳基气凝胶  旧报纸  吸附能力  疏水性

Key Words:carbon-based aerogels  old newspaper  absorption ability  hydrophobic

中文摘要:

      将富含纤维素的旧报纸先进行润胀、打浆，然后冷冻干燥，得到旧报纸气凝胶（WNA），利用高温热分解的方式处理WNA制得旧报纸碳基气凝胶（CA）。采用傅里叶变换红外光谱（FT-IR）、扫描电子显微镜（SEM）、X射线衍射仪（XRD）对CA的性能进行表征。结果表明，CA的密度（0.0348 g/cm³）较低，动态接触角为129.8°，表明CA的疏水性能优异。FT-IR结果表明，与WNA相比，CA中羟基、烷基及糖苷键等官能团含量减少。SEM分析表明，CA的纤维宽度在8～10 μm范围内，其具有连续纳米多孔三维网络结构。XRD分析表明，纤维素的结晶区受到破坏，导致无定形碳的形成。CA能高效、快速地吸附有机溶剂和石油化工产品，吸附量可达自身质量的21～37倍。利用燃烧的方法可将吸附的物质从CA中分离出来并对CA进行回收。经过6个吸附/燃烧循环过程，CA对甲醇和硅油的吸附能力分别是原吸附能力的83.9%和86.4%，表明CA可实现多次循环利用。

Abstract:

      The carbon-based aerogels （CA） were prepared by freeze-drying and carbonization process using old newspaper as raw material. The structures and properties of the obtained CA were characterized by FT-IR， scanning electron microscopy （SEM）， X-ray diffraction （XRD）. The results showed that CA had a low density of 0.0348 g/cm³， excellent hydrophobicity with a water contact angle of 129.8°. The results of FT-IR analysis showed that the content of hydroxyl， alkyl， glycosidic bonds were decreased. The results of SEM showed that CA had a favorable porous structure with three-dimensional network and the width of fibers was about 8～10 μm. The results of XRD confirmed that the crystalline structure of CA was destroyed during the pyrolysis process and amorphous carbon was formed. The adsorption capacity of CA for organic solvents and oil was about 21～37 g/g. The CA adsorbed organic solvent or oil could be recycled by combustion and the recycled CA also exhibited excellent adsorption ability to hydrophobic solvents. After six cycles of adsorption/combustion process， the adsorption abilities of recycled CA for methanol and silicon oil were 83.9% and 86.4% of original adsorption abilities， respectively.