聚乙烯醇硫酸钾水凝胶电机械化学行为研究

通过将交联聚乙烯醇硫酸酯化的方法制备了一种新型电刺激响应性聚乙烯醇硫酸钾(PVSK)智能水凝胶,并探讨了溶液离子强度和pH对PVSK水凝胶的溶胀吸水率、机械性能以及电机械化学行为的影响.结果表明,制备的PVSK水凝胶的平衡溶胀比随NaCl溶液离子强度的增大而减小,在pH2.39～10.83范围内基本不受溶液pH的影响;经不同离子强度和pH的NaCl溶液充分溶胀的PVSK水凝胶具有良好的机械性能,在非接触的直流电场作用下,该水凝胶向电场负极弯曲,凝胶的弯曲速度和弯曲偏转量随外加电场强度的增加而增大,随NaCl溶液离子强度的增大出现临界最大值,但不随溶液pH(2.08～10.53)的改变而改变;在循环电场作用下,PVSK水凝胶的电机械化学行为具有良好的可逆性.

STUDIES ON THE ELECTROMECHANOCHEMICAL BEHAVIOR OF POLYVINYL SULFATE POTASSIUM HYDROGELS

A novel electroresponse intelligent hydrogel of crosslinked polyvinyl sulfate potassium(PVSK)was prepared by the sulfating reaction of crosslinked polyvinyalcohol,and the effect of the ionic strength and pH on the swelling ratio at equilibrium,mechanical properties and electromechanochemical behavior of the PVSK hydrogel were studied.The experimental results indicated that the swelling ratios at equilibrium of PVSK hydrogels decreased with increasing the ionic strength of NaCl solutions and were almost invariable in the pH range of 2.39～10.83.The PVSK hydrogels swollen in NaCl solutions of different pH and ionic strength presented excellent mechanical properties.The PVSK hydrogel bended toward the cathode under non-contact D.C.electric field in NaCl aqueous solutions,the bending speed and bending strain of the PVSK hydrogel increased with increasing the applied voltage and were almost invariable in the pH range of 2.08～10.53.The electroresponsive behavior of the PVSK hydrogel was also affected by the electrolyte concentration of the external NaCl solution,and there was a critical ionic strength of 0.1 at which its bending speed and equilibrium strain reached their maximum values.Under a cyclically varying electric field the hydrogel exhibited a good reversible electromechanochemical behavior.