PREPARATION AND CHARACTERIZATION OF mCMC-PEG/mCS-PEG BIPOLAR MEMBRANE
mCMC-PEG/mCS-PEG双极膜的制备与表征

A bipolar membrane is a polymeric layered structure composed of a cation ion-exchange layer and an anion ion-exchange layer.With respect to commercial applications,a bipolar membrane has high selectivity,low potential drop,acid and base resistance,solvent resistance,a wide pH range and good mechanical strength.mCMC-PEG/mCS-PEG bipolar membrane was prepared by a paste method,which was prepared by a blend of sodium carboxymethyl cellubse-plyethylene glycol(CMC-PEG) and a blend of chitosan-plyethylene glycol(CS-PEG),which were modified by Fe3 and glutaraldehyde(GA) as linking reagents,respectively.FTIR was applied to analysis the function groups of the bipolar membrane.Furthermore,the cross-section SEM photographs of the bipolar membrane illustrated a structure that consists of anion layer(mCS-PEG membrane) and cation layer(mCMC-PEG membrane).The charge densities of mCMC-PEG and mCS-PEG solutions were determined by the colloid titration.The water ratio,ion exchange capacity and swelling degree of mCMC-PEG membrane and mCS-PEG membrane were investigated.The current-voltage(I-V) curve across mCMC-PEG/mCS-PEG bipolar membrane was measured.The experiment results showed that CS-PEG and CMC-PEG blends appeared better compatibility and the introduction of PEG was beneficial to enhance the ionic exchange capacity and decrease the swelling degree of membrane.When mass ratio of CMC/PEG was 10/1 and CS/PEG was 2/1,mCMC-PEG layer and mCS-PEG layer were agglutinated tightly.The mCMC-PEG/mCS-PEG bipolar membrane appeared excellent electrochemical properties and high mechanical strength in acid and alkali solution.Meanwhile TG analysis of mCMC-PEG/mCS-PEG bipolar membranes exhibited a good thermal stability.mCMC-PEG/mCS-PEG bipolar membranes were used as the separator in the electrolysis cell for electro-generation organic acid.