多壁碳纳米管/二氧化硅纳米复合材料的制备及其吸油性能

以羧化多壁碳纳米管为基体、纳米硅溶胶粒为增强相，通过一步液相共混方法制备多壁碳纳米管/二氧化硅纳米复合材料。利用傅里叶变换红外光谱（FTIR）、电子扫描电镜（SEM）、热重（TGA）、孔结构分析（BET/BJH）对其进行了表征。以水中柴油为研究对象考察了该样品对水中柴油的吸附脱除效果，并与纳米二氧化硅胶粒、原生碳纳米管以及活性炭进行对比。结果表明：硅溶胶粒表面修饰后的多壁碳纳米管的聚团行为得以改善，而且材料具有微孔-介孔双孔道结构。对水中直馏柴油的去除率高达97.79%，并于1 h达到吸附平衡。整个吸附过程遵循准二级动力学模型，吸附体系的表观活化能为11.37 kJ·mol^-1，吸附等温线与Freundlich模型较为吻合，吸附效果明显强于其他3种吸附剂。

Facile synthesis of MWCNT/SiO2 nano-composites as high-performance oil adsorbents

Multi-walled carbon nanotubes-silica (MWCNT/SiO₂) nano-composites were prepared from carboxylated MWCNTs and silica sol-gel nanoparticles via one-step scalable precipitation. Structure and physical properties of the nano-composite were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), thermogravimetric analysis (TGA), and porous surface area and pore size distribution analysis (BET & BJH). Adsorption removal of oil was evaluated in diesel water on the nano-composite in comparison with SiO₂ sol-gel nanoparticles, pristine MWCNTs, and activated carbon. The nano-composite improved MWCNT agglomeration after surface modification by silica nanoparticles and formed dual microporous and mesoporous structures. The diesel removal efficiency of the nano-composite could be up to 97.79% with adsorption equilibrium reached within 1 h. The adsorption process followed the pseudo second-order kinetics with the apparent activation energy at 11.37 kJ·mol^-1 and the adsorption isotherms were fitted well with the Freundlich model. Overall, the nano-composite MWCNT/SiO₂ showed stronger adsorption capacity than the other three adsorbents.