A hydrophobic porous silica material was successfully synthesized using sodium silicate as silica source, hydrochloric acid as catalyst, and trimethylchlorosilane (TMCS) as a surface modifying agent, through sol-gel and surface modification processes. The structure and properties of the fabricated porous silica were analyzed by Fourier-transform infrared (FTIR) spectroscopy, contact-angle analyzer, liquid N2 adsorption, and scanning electron microscopy (SEM). The porous silica displayed a hierarchical porous structure and was super-hydrophobic, with contact angle as high as 156°. Specific surface area and pore volume were determined to be 566 m2·g-1 and 2.28 cm3·g-1, respectively. Moreover, the porous silica could adsorb up to 14 times its own mass of toluene, gasoline, diesel, and lube oil. The abundant mesopores and macropores allowed adsorption saturation to be reached within several minutes. In addition, the porous silica was extremely hydrophobic in gasoline-water mixture and thus preferentially adsorbed organic compounds other than water. This is an important requisite of good recyclability. It was verified that, following extraction with n-hexane. the regenerated porous silica retained its initial adsorption capacity. This porous silica, with good selectivity and excellent regeneration capability for oil removal, could find novel applications in the adsorption and separation of organics from polluted water.%以硅酸钠为硅源,盐酸为催化剂,三甲基氯硅烷(TMCS)为表面改性剂,经溶胶-凝胶和表面改性过程制备出一种疏水性多孔硅材料.采用傅里叶变换红外(FTIR)光谱仪、接触角分析仪、氮气物理吸附仪和扫描电子显微镜(SEM)对其结构和性质进行表征.结果表明:所制备的多孔硅具有分等级孔道结构(中孔-大孔),比表面积为566 m2·g-1,孔体积高达2.28 cm3· g-1,多孔硅与水的接触角为156°,显示出超疏水特征.对甲苯、汽油、柴油和润滑油的吸附量均可高达自身质量的14倍,丰富的孔道使其在几分钟内即可达到饱和吸附.这种多孔硅在汽油/水混合体系中对汽油具有较高的选择性,同时具有良好的再生能力.经正己烷萃取再生后,多孔硅仍能基本保持初始吸附容量.此方法制备的多孔硅材料在吸附分离污水中的有机物和溢油处理方面具有很好的应用前景.
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