羧甲基纤维素凝胶对乙草胺的控制释放研究

羧甲基纤维素(CMC)经Fe3 交联得到的凝胶载体可以有效延缓除草剂乙草胺的释放速率,有助于减轻农药污染.采用50%乙草胺被释放所需时间(t50)衡量乙草胺的释放速率,结果表明乙草胺由水凝胶中释放的t50值不足8h.将CMC水凝胶干燥处理可以使t50值提高到100h以上,同时制剂中的载药量越少释放速度越慢.采用控制释放模型对释放动力学数据进行分析得到,乙草胺从干凝胶中的释放主要由扩散机理控制.红外光谱分析证实了乙草胺与CMC之间主要通过氢键结合.

Controlled Release of Acetochlor from Carboxylmethylcellulose Gels

Release of the herbicide acetochlor was controlled by encapsulating it into the gel carrier that was obtained from the crosslinking of carboxylmethylcellulose(CMC) with Fe3 ions,which is beneficial for reducing contamination of herbicides.The required time for 50 % of acetochlor released into water(t50) was used to compare the release rate.The results indicated that,the t50 values from CMC hydrogels were below 8 h,but the values from dried gels were improved to 100 h.The less amount of herbicide loading in gel formulations resulted in a slower release rate.The release data were analyzed with a controlled release model,and the results indicated that the release of herbicide from dried gels was dominated by a diffusion mechanism.IR spectrum confirmed the interaction between CMC macromolecules and acetochlor through hydrogen bonding.