多巴胺接枝的GO-Al2O3膜对Na^+/Mg^2+的分离性能

Separation of Na^+/Mg^(2+) with dopamine grafted GO-Al_2O_3 membrane

以Al_2O_3管式膜为载体,采用简单的浸浆法制备氧化石墨烯-三氧化二铝(GO-Al_2O_3)复合膜,考察了用多巴胺接枝和未接枝的GO-Al_2O_3膜对纯水渗透性能和一二价离子截留性能的影响.结果表明,GO成功地涂覆在Al_2O_3管式膜表面.用多巴胺接枝的GO-Al_2O_3膜的纯水通量为330L/(m2·h·MPa),比未用多巴胺接枝的GO-Al_2O_3膜下降了45%,相比于Al_2O_3膜降低了83%.在压力为0.3MPa,盐溶液浓度为10mmol/L,膜面流速为1.3m/s的条件下,Al_2O_3管式膜对4种无机盐均无截留性能;多巴胺接枝GO-Al_2O_3膜和GO-Al_2O_3膜对4种盐的截留顺序为R(Na2SO4)>R(NaCl)>R(MgSO4)>R(MgCl2),并且多巴胺接枝GO-Al_2O_3膜对4种盐的截留率,相比于GO-Al_2O_3膜,有了明显的提高.

GO Al 2O 3 membrane was fabricated on Al 2O 3 tubular support via dip-coating method.The effects of dopamine-grafted GO Al 2O 3 membrane and GO Al 2O 3 membrane on the permeation of pure water and rejection of monovalent and divalent ion were investigated.The results showed that GO were successfully coated on the inner surface of Al 2O 3 tubular support.The pure water flux of dopamine-grafted GO Al 2O 3 membrane was 330 L/(m 2·h·MPa),which was decreased by 45%and 83%from GO Al 2O 3 membrane and Al 2O 3 tubular support,respectively.At the pressure of 0.3 MPa,solution concentration of 10 mmol/L and membrane surface velocity of 1.3 m/s,Al 2O 3 tubular support had no rejection to four inorganic salts.Dopamine-grafted GO Al 2O 3 and GO Al 2O 3 membrane exhibited a decreasing rejection rate in the sequence as follow:R(Na 2SO 4)>R(NaCl)>R(MgSO 4)>R(MgCl 2).Compared to GO Al 2O 3 membrane,the rejection to four inorganic salts with dopamine-grafted GO Al 2O 3 membrane had significant increase.