Preparation Of Zwitterionic Modified Intermediate Layer Of Bipoalr Membrane

A bipolar membrane is a new type of composite membrane.Usually,a BPM is consist of an anion exchange layer,a cation exchange layer and an intermediate layer between two layers.It is well-known that water splitting occurred in the interface layer.Under a reverse bias condition,water at the intermediate layer of a bipolar membrane can be split into H+ and OH-,which migrate from interface layer towards cathode and anode,respectively.Since the water splitting capability depends on the interface characteristics,it is important to studythe potential catalysts for water splitting.In this study,an ultrasonic-sprayed assembly technique was proposed to modify thee bipolar membrane with different zwitterions,such as[3-(methacryloylamino)propyl]dimethyl(3-(sulfopropyl)ammonium hydroxide,sulfobetaine methacrylate and carboxybetaine methacrylate.The results indicated that,among these bipolar membranes,the CBMA-modified bipolar membranes showed the best performance.The water splitting voltage across CBMA-modified bipolar membranewas 1.00 V at 100 mA·cm-2.The electro-dialysis tests showed that the acid and alkali concentration were 0.0389 mol·l-1 and 0.0550 mol·l-1,respectively.Compared with heterogeneous-homogeneous composite bipolar membranes,homogeneous bipolar membranes offered better long-term stability,higher current efficiency,and higher product purity.