分子间弱相互作用调控下的抗污染超滤膜制备与性能研究

发布时间：2018-04-24 17:22

本文选题：超滤 + 表面偏析　；参考：《天津大学》2015年硕士论文

【摘要】：制备高性能超滤膜(高通量、抗污染及强稳定性)是解决超滤膜污染、成本高等问题的根本途径。表面偏析法是一种在相转化过程中对膜进行原位改性的方法,其在相转化过程中兼具表面改性和致孔双重功能,通过改变膜改性材料的化学组成可构建抗污染、温度响应等多种功能膜表面。然而,表面偏析法制备的超滤膜仍存在渗透通量较低、改性基团易流失等不足,严重限制了表面偏析法的广泛应用。本论文针对上述问题,以聚氯乙烯(PVC)和聚醚砜(PES)为膜主体材料,聚乙烯醇缩甲醛(PVF)和间苯三酚(MTB)为膜改性材料,分别制备了PVC/PVF、PES/PEG-MTB和PES/PVF超滤膜,研究了膜主体材料与膜改性材料间的分子间弱相互作用(疏水相互作用、氢键相互作用及疏水和氢键协同相互作用等)对相转化过程中膜主体材料的链运动行为、表面偏析过程中膜改性材料的表面偏析行为及超滤膜表面膜改性材料的驻留稳定性的影响,具体概述如下:在相转化过程中,膜主体材料与膜改性材料间的疏水相互作用显著干扰膜主体材料的结晶、凝胶化和玻璃化等固化行为,提高膜渗透通量;氢键相互作用则因其作用长度过短对膜渗透通量几乎无影响;当疏水和氢键相互作用共存时,疏水相互作用与氢键相互作用将产生协同效应,强化膜改性材料对膜主体材料链运动行为的干扰,大幅提升膜渗透通量。在表面偏析过程中,膜主体材料与膜改性材料间的相互作用将显著影响膜改性材料的偏析行为:当两者相互作用低于表面偏析阈值时,膜改性材料将发生过偏析而无表面改性效果;当两者相互作用高于表面偏析阈值时,膜改性材料将发生欠偏析使得需要更多的膜改性材料才能达到表面改性效果,制膜成本增加。此外,膜主体材料与膜改性材料间的相互作用越强,则表面膜改性材料的驻留稳定性越强,可避免表面功能性基团流失,提高膜的使用寿命。综上,通过对膜改性材料的理性设计,调控膜主体材料与膜改性材料间的相互作用,实现具有高通量、抗污染和强稳定性的高性能超滤膜的可控制备。
[Abstract]:The preparation of high performance ultrafiltration membrane (high throughput, anti-fouling and strong stability) is the fundamental way to solve the problem of high cost and fouling of ultrafiltration membrane. The surface segregation method is a method of in-situ modification of the membrane in the process of phase transformation. It has the functions of both surface modification and pore formation in the process of phase transformation. It can be constructed to resist pollution by changing the chemical composition of the membrane modified material. Temperature response and other functional film surface. However, the ultrafiltration membrane prepared by surface segregation method still has some shortcomings such as low permeation flux and easy loss of modified groups, which seriously limits the wide application of surface segregation method. In order to solve the above problems, PVC / PVF / PEG-MTB and PES/PVF ultrafiltration membranes were prepared using PVC and PES as main membrane materials, PVF and MTB) as membrane modified materials, respectively. The chain motion behavior of the membrane host material in the phase transformation process was studied by the weak intermolecular interaction (hydrophobic interaction, hydrogen bond interaction and hydrophobic and hydrogen bond synergistic interaction) between the membrane host material and the membrane modified material. In the process of surface segregation, the influence of the surface segregation behavior of membrane modified materials and the residence stability of ultrafiltration membrane surface modified materials are summarized as follows: in the process of phase transformation, The hydrophobic interaction between the membrane host material and the membrane modified material significantly interferes with the solidification behavior of the membrane main material such as crystallization gelation and vitrification so as to increase the permeation flux of the membrane. When hydrophobic and hydrogen bond interactions coexist, hydrophobic interaction and hydrogen bond interaction will produce synergistic effect, while hydrogen bond interaction has little effect on membrane permeation flux due to its short interaction length, and when hydrophobic and hydrogen bond interaction coexists, hydrophobic interaction and hydrogen bond interaction will produce synergistic effect. The disturbance of membrane modified material to the chain movement of the membrane body material was strengthened, and the permeation flux was greatly increased. In the process of surface segregation, the interaction between the film host material and the membrane modified material will significantly affect the segregation behavior of the membrane modified material: when the interaction between the two materials is lower than the surface segregation threshold, When the interaction between the two materials is higher than the surface segregation threshold, the membrane modified material will be undersegregated, and more membrane modified materials will be needed to achieve the surface modification effect. The cost of film preparation is increased. In addition, the stronger the interaction between the main membrane material and the membrane modified material, the stronger the residence stability of the surface membrane modified material, which can avoid the loss of the surface functional group and improve the service life of the membrane. In conclusion, through the rational design of the membrane modified material, the interaction between the main membrane material and the membrane modified material is regulated, and the controllable preparation of the high performance ultrafiltration membrane with high throughput, anti-fouling and strong stability is realized.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ051.893

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