膜电渗透装置分离戊二醛-水及电场对聚砜膜的影响

Separation of glutaraldehyde-water by membrane electroosmosis andeffect of electric field on polysulfone membrane

为了发掘电场作为膜分离过程推动力的巨大潜力,强化近似匀强电场下的膜分离传质过程,采用自主设计的膜电渗透装置对具有极性差异的戊二醛-水物系进行无相变的分离。结果表明:在膜的两侧施加电场后,纯水和戊二醛-纯水物系的膜通量均有所增加;戊二醛-纯水物系的膜通量相较于单一纯水的膜通量有所减少,从而证明电场对极性大的物质的作用力较强;随着电压的增大、电场强度不断增强,电场对体系中极性分子的作用力也不断增大;施加电场后,渗透液中戊二醛的含量扩大了1.6~2.5倍;对渗透膜本身而言,电场的存在使聚砜膜的亲水性降低,并且聚砜膜的表面结构没有因为弱化匀强电场的存在而发生显著的变化,但是电场的施加能够产生与强吸电子基团存在时同样的效果,从而出现醛基中C=O伸缩振动强吸收峰,该极性共价键的突出说明了在电场对物质极性的增强具有明显的作用。

In order to explore the potential of electric field as the driving force of membrane separation process and to strengthen the membrane separation and mass transfer process under an approximately uniform electric field,a self-designed membrane electroosmosis device was used to separate glutaraldehyde water system with different polarities.The results show that after applying electric fields on both sides of the membrane,the membrane fluxes of pure water and glutaraldehyde-pure water systems both increase.The membrane fluxes of glutaraldehyde-pure water system is reduced compared with that of single pure water system,which proves that the electric field exerts a greater effect on the polar substances.As the voltage increases and the electric field strength continues to increase,the electric field exerts an increasing force on the polar molecules in the system.After applying electric field,the content of glutaraldehyde in the permeate increases by about 1.6-2.5 times.For the osmotic membrane itself,the existence of electric field reduces the hydrophilicity of polysulfone membrane.The surface structure of polysulfone film has no significant change because of weakening the existence of uniform electric field,but the application of electric field can produce the same effect as that of strong electron absorption group,which makes the contraction vibration of C=O bond appear absorption peak in aldehyde group.The prominent of the polar covalent bond shows that the enhancement of material polarity in electric field has obvious effect.