纳米SiO_2改性海藻酸钠/壳聚糖双极膜的制备与表征  

Preparation and Characterization of Bipolar Membrane Modified by Nano-SiO_2

作　　者：陈日耀[1] 

机构地区：[1]福建师范大学化学与材料学院,福建福州350007

出　　处：《高校化学工程学报》2012年第1期160-164,共5页Journal of Chemical Engineering of Chinese Universities

基　　金：福建省自然科学基金资助项目(D0710009)

摘　　要：在壳聚糖(CS)阴离子交换膜层中添加纳米SiO2,制备了PVA-SA/SiO2-CS双极膜(其中,PVA:聚乙烯醇;SA:海藻酸钠),并用扫描电镜、热重、电子万能试验机、接触角测定仪、J-V关系和交流阻抗谱等对其进行了表征。研究结果表明,双极膜经纳米SiO2改性后,亲水性得以提高,壳聚糖膜的接触角从104.01°下降到78.39°。膜亲水性的提高增强了膜与水分子间的作用,减弱了水的键合力,促进了中间界面层水的解离,降低了双极膜电阻压降(IR降)和槽电压,当电流密度为45 mA.cm.2时,槽电压从9.0 V下降到6.2 V。此外,添加纳米SiO2还可提高双极膜热稳定性和机械性能,双极膜的断裂伸长率从81.29%提高到87.67%,杨氏模量从30.68 MPa提高到79.59 MPa。The nano-SiO2 was added into chitosan（CS） anion layer to prepare the PVA-SA/SiO2-CS（Here,PVA： polyvinyl alcohol;SA： sodium alginate） bipolar membrane（BPM）.The prepared BPM was characterized by using SEM,TG,electric universal testing machine,contact angle measurer,J-V investigation and AC impedance spectroscopy,respectively.Experimental results show that the hydrophilicity of the BPM modified with nano-SiO2 is increased,the contact angle of CS membrane with water drops from 104.01° to 78.39°.The increase of the hydrophilicity improves the interaction force between the membrane and water molecule,weakens the bond force of the water molecule,promotes the water splitting in the interlayer and reduces the IR drop and cell voltage of the BPM.When the current density is 45 mA？cm？2,the cell voltage is decreased from 9.0V to 6.2 V.Furthermore,the thermal stability and mechanical properties of the modified BPM are also increased.The elongation at break of the BPM is improved from 81.29% to 87.67%,and the Young＇s modulus rises from 30.68 MPa to 79.59 MPa.

关 键 词：海藻酸钠 壳聚糖 双极膜 纳米SIO2 

分 类 号：TB383[一般工业技术—材料科学与工程] O636.9[理学—高分子化学]