Abstract: 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.

Key words: Superhydrophobic cotton, modified cotton, silica hydrosol, contact angle, oil-water mixture