超疏水棉花的制备及用于油水分离

采用溶胶-凝胶法制备了SiO2水溶胶，并用三甲基甲氧基硅烷进行疏水改性，通过一步浸泡法将改性后SiO2水溶胶修饰到棉花上制备出改性棉花，用接触角测定仪和扫描电子显微镜对制备的改性棉花进行了表征，二次蒸馏水及酸、碱液滴在改性棉花上的接触角均大于150°，表明制备的改性棉花具有超疏水性和耐酸碱性。 改性棉花对柴油展示了高达8.3 g/g的饱和吸附量，在5次重复使用中，吸附能力和接触角均可维持在4.0 g/g和大于150°水平。 在油水混合物吸附研究中，改性棉花吸水量仅是未改性棉花吸水量的1/45，表明改性棉花对油具有很好的选择性。 吸附了柴油后的改性棉花经过简单挤压，即可直接回收吸附的柴油和释放出改性棉花，从而实现了改性棉花的重复使用。

Preparation of Superhydrophobic Cotton and Its Application in Oil-Water Separation

A kind of novel modified cotton was prepared by immersing raw cotton into modified silica hydrosol. The modified silica hydrosol was prepared via slo-gel reaction and subsequent hydrophobization with methoxytrimethylsilane. The prepared modified cotton was characterized by water contact angle measurement(CA) and scanning electron microscopy(SEM), respectively. Contact angles of redistilled water, acidic solution, and alkaline solution are all over 150° on the as-prepared modified cotton, which indicates the superhydrophobicity and acid and alkali resistance of the modified cotton. The modified cotton showed 8.3 g/g and 4.0 g/g of saturated absorption capacity for diesel oil at the first time used and the sequent five times used, respectively. The contact angles of the recycled modified cotton kept above 150°. The water absorption capacity of the modified cotton is only 1/45 times of the raw cotton in removing diesel oil from oil-water mixture, suggesting the high selectivity of the modified cotton to diesel oil. The modified cotton can be recovered easily by extruding the absorbed diesel oil and then can be reused. This study would provide a fast, simple, cheap, and environment friendly approach to the oil recovery from oil-water mixture.