自然光照下PEG/PAA凝胶在Fe^(3+)/CA溶液中的凝胶-溶胶转化行为

Conversion Behavior of PEG / PAA Gel in Fe^(3+)/ CA Solution under Irradiation of Sunlight

将PEG/PAA凝胶浸入铁/柠檬酸(Fe3+/CA)溶液中,自然光照一定时间可实现凝胶-溶胶的相互转化,而且转化行为受溶液的组成及其p H影响。只有当溶液中[Fe3+]0∶[CA]0≤1∶2,且溶液的p H在1~6之间,该转化才会发生,通过改变溶液中[Fe3+]0∶[CA]0的值或溶液的p H可以有效地控制其转化速率。此外,结果还表明,当凝胶转化为溶胶后,向其中加入高价金属阳离子,例如Fe3+、Al3+、Ce4+、Cu2+等,溶胶又会再次转化为凝胶。由于这种新颖的特性,该凝胶有望应用于药物释放、细胞培养等领域。

A novel phase transition behavior of PEG / PAA gel was firstly observed involving a controllable conversion from gel to sol when it was immersed in a solution containing Fe3 +ions and citric acid under sunlight radiation for a certain time. The transformation process could be controlled effectively by changing the concentration ratio of Fe3 +to citrate acid and p H of the solution. This phenomenon occurred only when the concentration ratio was less than 1∶ 2 and the value of p H was in the range of 1 ~ 6. In addition,the sol would change to gel again if metal cations,such as Fe3 +,Al3 +,Ce4 +and Cu2 +were added into the system. The new characteristics of the gel may make it become a potential material in the drug release,cell culture and so on.