碳纳米管改性复合纳滤膜的制备及性能研究

Preparation and property of CNT modified composite nanofiltration membrane

为获得分离性能良好的复合纳滤膜,利用无机纳米颗粒碳纳米管(CNT)对纳滤膜进行改性,并在传统界面聚合反应的基础上增加了水相反应次数。以哌嗪(PIP)、均苯三甲酰氯(TMC)为反应单体,CNT为水相添加剂,磷酸钠(Na_(3)PO_(4))为酸接收剂,聚砜(PSF)超滤膜作为支撑层成功制备了CNT改性复合纳滤膜。利用正交试验较系统地得到了改性纳滤膜的最佳制备条件:第一次水相、有机相、第二次水相、热处理的反应时间分别为2.0min、1.0min、1.0min、10min,Na_(3)PO_(4)、PIP、TMC、CNT添加量分别为1.5%(质量分数,下同)、1.0%、0.25%、2.0%。在此条件下复合纳滤膜0.6MPa压力下纯水通量为35.35L/(m^(2)·h),对MgSO_(4)的截留率为94.1%,膜的亲水性能得到大幅度提高。

In order to obtain a composite nanofiltration membrane with good separation performance,the inorganic nanoparticle carbon nanotubes(CNT)were used to modify the nanofiltration membrane,and the number of aqueous phase reactions was increased on the basis of traditional interfacial polymerization(IP)reaction.Piperazine(PIP)and trimesoyl chloride(TMC)were used as the reactive monomer,CNT as the additive of water phase,and sodium phosphate(Na_(3)PO_(4))as acid acceptor,and polysulfone(PSF)ultrafiltration membrane was used as support layer to prepare CNT modified composite NF membrane successfully.The best preparation conditions were obtained systematically as follows by using orthogonal experiments:the reaction time of the first aqueous phase,organic phase,second aqueous phase,and heat treatment were 2.0 min,1.0 min,1.0 min snd 10 min,respectively.The amount of Na_(3)PO_(4),PIP,TMC and CNT addition were 1.5%,1.0%,0.25%,and 2.0%,respectively.The pure water flux of the membrane reached 35.35 L/(m^(2)·h),and the rejection for magnesium sulfate was 94.1%.At the same time,the hydrophilic properties of the membrane were improved greatly.