Preparation Of Modified M(SA-CS) Bipolar Membrane And Its Application In Electro-generating Glyoxylic Acid

Modified m(SA-CS)bipolar membrane was prepared after chitosan(CS)and alginate(SA)were modified by glutaraldehyde and ferric chloride as linking reagents, respectively.The sectional structure of m(SA-CS)bipolar membrane were studied by SEM.IR spectrum indicated that the bipolar membrane contains -NRH₂⁺ and-COO^-functional groups in CS membrane and SA membrane respectively,m(SA-CS)bipolar membrane was quite stable in acid and alkali solution.The cylinder electrolytic cell was constituted by double anode,using m(SA-CS) bipolar membrane as septum in electrolysis cell for electro-generating glyoxylic acid. Under the function of electric field,water was dissociated to produce H⁺ and OH^- in the bipolar membrane.H⁺ transmit into the cathode chamber to supply the consuming of H⁺ in the process of electro-generating glyoxylic acid.When the current density was 38.4 mA/cm²,the yield was 92.5%,and the current efficiency reached to 97.3%,The electrolysis voltage was as low as 2.3 V.Using m(SA-CS)BPM as septum in electrolysis cell for electro-generating glyoxylic acid.The experiment results show that H⁺ generated by BPM moves into cathode chamber in time through mSA to supplement H⁺ consumed by electro-reduction of oxalic acid to generate glyoxylic acid;OH^- moves into anode chamber in time through mCS to combine with H⁺ produced by electro-oxygenation of glyoxal to generate glyoxylic acid and improves the reaction go along.The current efficiency was up to 87.53%,84.4%and 80.97%,76.15%,respectively at 20℃during the current density was 30 mA/cm².