有机-无机氧化硅空心球的合成及VOCs吸附应用

介孔有机-无机复合氧化硅空心球(MOSs)在碱性条件下以反向胶束为模板经过正硅酸乙酯(TEOS)和1,2-双(三乙氧基甲硅烷基)乙烷(BTSE)共缩合被成功合成, 并通过不同手段对样品的结构和性能进行表征。MOSs用于去除挥发性有机物(VOCs), 研究其对水蒸气、正己烷、甲苯和92#汽油的静态吸附性能, 并以商业硅胶(SG)和活性炭(AC)为参考。实验结果发现, 初始BTSE/(BTSE+TEOS) 摩尔比为10%时, (MOS-10%)的样品具有均匀的中空介观结构和最大的VOCs吸附容量(1.28 g·g^-1正己烷, 1.25 g·g^-1甲苯和1.14 g·g^-1 92#汽油), 静态水蒸气吸附量最小(0.630 g·g^-1)。通过穿透曲线评估单一组分VOC(正己烷或甲苯)在MOS-10%上的动态吸附行为, 动态正己烷和甲苯吸附结果以及高湿度条件下的正己烷吸附性能表明, 与商业吸附剂相比, MOS-10%具有最佳的穿透时间、吸附能力和疏水性。对于二元组分同时吸附(正己烷和甲苯), MOS-10%的正己烷吸附性能优于甲苯。介孔有机-无机复合氧化硅空心球的动态VOCs吸附容量较大归因于有机基团、表面积和孔体积的共同作用。MOSs的VOCs去除能力强和可回收性优良, 显示出巨大的VOCs捕获潜力。

Mesoporous Organic-inorganic Hybrid Siliceous Hollow Spheres: Synthesis and VOCs Adsorption

Mesoporous organic-inorganic hybrid siliceous hollow spheres (MOSs) were successfully synthesized by co-condensation of tetraethylorthosilicate (TEOS) and 1, 2-bis(triethoxysilyl)ethane (BTSE) with reverse micelle as template under basic condition. Structure and property of the prepared samples were characterized by different methods. The MOSs was used for VOCs removal with commercial silica gel (SG) and activated carbon (AC) as references. It is found that the sample with initial BTSE/(BTSE+TEOS) molar ratio of 10% (MOS-10%) displays uniform hollow mesostructure with the highest static VOCs adsorption capacities (1.28 g·g^-1 n-hexane, 1.25 g·g^-1 toluene and 1.14 g·g^-1 92# gasoline), and the lowest water vapor adsorption capacity of 0.630 g·g^-1. Dynamic single component (n-hexane, toluene adsorption under dry condition or n-hexane adsorption under high humidity condition, 95% RH) adsorption results show that MOS-10% has the best breakthrough times, adsorption capacities, and hydrophobicity. For binary component (n-hexane and toluene) adsorption, MOS-10% preferred to adsorb n-hexane rather than adsorb toluene. The higher dynamic VOCs capacity of MOS is attributed to the cooperation of the introduced organic groups, surface area and pore volume. The MOSs with high VOCs removal capacity and excellent recyclability show great potential for VOCs adsorption.