活性炭对聚丙烯酸水凝胶pH敏感性的影响

摘要

The polyacrylic acid/activated carbon(PAA/AC)composite hydrogels were synthesized via free radical solution polymerization with acrylic acid(AA)as monomer,AC as pore forming agent,N,N-methylene bisacrylamide(NNMBA)as crosslinking agent,and ammonium persulfate(APS)as initiator. The impact of the introduction of AC on pH sensitivity of PAA hydrogels were observed as well as swelling kinetics of hydrogels in buffer at different pH values. The results showed that the introduction of AC does not change the chemical composition and thermo stability of PAA hydrogels,but increases the pore size of gels. Moreover,the introduction of AC improved the pH sensitivity of PAA hydrogels.The freeze-dried PAA/AC hydrogels reached swelling equilibrium faster in a bigger equilibrium swelling ratio than the oven-dried ones.%以丙烯酸(AA)为单体、活性炭(AC)为惰性致孔剂、N,N-亚甲基双丙烯酰胺为交联剂、过硫酸铵为引发剂,采用自由基溶液聚合法制备了聚丙烯酸(PAA)/AC复合水凝胶,并研究了AC的引入对PAA水凝胶pH敏感性的影响以及不同pH值的缓冲液中水凝胶的溶胀动力学.结果表明:AC的引入并未影响PAA水凝胶的化学组成和热稳定性,但增大了其孔隙尺寸;AC的引入提高了PAA水凝胶的pH敏感性;冻干的PAA/AC复合水凝胶比烘干的PAA/AC复合水凝胶达到溶胀平衡的速率更快、平衡溶胀比更大.