Preparation And Properties Researches Of Polyether Sulfone Charged Membrane

The polyether sulfone (PES) as the matrix polymer, the carboxyl polyethersulfone (CPES),the carboxymethylated polyether sulfone (CMPES) andchloromethylation polyether (CCPES) were synthesized by chemical modification.Carboxyl polyether sulfone negatively charged membrane (CPM), carboxymethylpolyether sulfone negatively charged membrane (CMPM), and the quaternizedpolyether sulfone positively charged membrane(QAPM) were prepared by the phaseinversion.Bovine serum albumin (BSA) as the object, according to the electricphenomenon and variation law of Zeta potential of the charged membrane, BSAadsorption of different PES charged membranes, the permeability and anti-pollutionbehavior were analysed. The results showed that:1.FT-IR confirmed that the carboxyl polyether sulfone and carboxymethylatedpolyether sulfone have carboxyl characteristic functional groups absorption. WithCPES, CMPES as additive, two series of negatively charged membranes (CPM andCMPM) were prepared by phase inversion. Morphology show that: CPM and CMPMcharged membranes with surface smooth and dense holes, which have typicalasymmetric membrane structure.Moreover, the CMPM negative charged membraneshave more pore structure. With the added amount of CPES and CMPES modifiedpolymer increasing in negatively charged membranes, the porosity and pore size ofCPM and CMPM are increased; the hydrophilic contact angle (WCA) and the ionexchange capacity were increasesd also. The results of Zeta potential and streamingpotential (ΔE) showed that: the streaming and Zeta potential of CMPM and CPM wereall negatively, with the negatively charged polymer amount in the membrane and thepH increasing, negatively charged enhanced. 2.BSA of CPM and CMPM filtration experiments showed that: after PESmembrane charged modification, the flux of BSA significantly increased,retentionbehavior was influenced by the solution environment. Negatively charged membranemodification improved the membrane flux ratio and the cleaning recovery rate, alsoincreasesd with membrane negative enhancement. When the pH higher than theisoelectric point of BSA solution, higher negatively load capacity of CPM-4, CMPM-4and CMPM-5have a better permeability and strong anti-pollution sexuality.3.Chloromethylated modified polyether sulfone (CCPES) as the membranematerial, quaternized ammonium polyether sulfone positively charged membrane(QAPM) were prepared by putting CCPM immersed in4.0mol/L trimethylaminesolution,which CCPM was prepared by phase inversion. With the degree ofquaternization increasing, the hydrophilic contact angle of the QAPM were reduced,the permeability performance were improved. Data of the streaming potential showthat: QAPM was positively charged membrane.And with the increasing degree ofquaternization, the trend was significant. QAPM of BSA adsorption behavior asdistinct from the change of solution pH. When in the low pH conditions, retention rateof QAPM to BSA solution and the cleaning recovery rate were higher, but the poreblocking resistance were small, so,the QAPM have a better pollution resistant effect.However, at high pH conditions, due to electrostatic attraction, although with highretention rate of QAPM to BSA solution, but the pore blocking resistance wasincreased, so, the cleaning recovery rates decreased and the ability to resist pollutionwere poor.