超疏水海绵和氧化硅的制备及复合油水分离性能研究

Fabrication and composite oil-water separation performance for superhydrophobic sponge and silica powder

以正硅酸乙酯和十六烷三甲氧基硅烷的水解和缩聚反应为基础,通过一步法可制备两种不同形态的超疏水材料,即超疏水海绵和超疏水氧化硅粉末。分别利用扫描电镜(SEM)和傅里叶变化红外光谱(FT-IR)表征两种超疏水材料的表面形貌和表面官能团,分析了材料具有超疏水特性的原理,利用接触角(CA)表征了两种材料的特殊浸润性能,说明制备的两种形态材料均具有良好的超疏水-超亲油特性。且通过控制反应溶液中催化剂的浓度可调控超疏水氧化硅粉末的粒径从纳米级到微米级进行变化。同时采用两种不同形态超疏水材料进行油水分离应用,可满足在不同环境下的多样化需求,达到油水分离的最佳效果。

Two forms of superhydrophobic materials, superhydrophobic polyurethane sponges and superhydrophobic silica powder, were both prepared by one step reaction based with hydrolysis and cross-linked tetraethyl orthosilioate （TEOS） and hexadeeyltrimethoxysilane in solution. The morphology and functional groups of the surface were characterized by SEM and FT-IR and the mechanism of superhydrophobicity was analyzed as well. The pretreatment for sponges produces hydrophilic group --OH in the surfaces which provided anchors for im- mobilization of silica particles. The immobilized particles on the sponge^s surface increased the roughness of skeleton of sponges. The cross-linked hexadecyltrimethyloxysilane provided long-chain alkyl for low surface energy. Hierarchical structure and low surface energy on the surface of sponges resulted special wettability. The contact angles investigated for special wettability showed that the prepared materials were both superhydrophobicity and superoleophilicity. Furthermore, diameters of the prepared superhydrophobic silica particles could be controlled from nanoscale to microscale under different catalyst concentrations in reacted solution. The two forms of superhydrophobic materials could be satisfied various needs in different environment for oil-water sepa- rations. The porous superhydrophobic sponge absorbed amount of oils from water surface in large area except in scattered region. Some oils which could not be cleaned by superhydrophobic sponges still leaved on water surface. However, the problem could be solved well by superhydrophobic silica powder which reached anywhere and absorbed residual oils on water surface. The two forms of superhydrophobic materials were used simultaneously and performed excellent in oil-water separation.