Singh Baljit, Sharma D K, Gupta Atul
Department of Chemistry, Himachal Pradesh University, Shimla 171005, India.
J Hazard Mater. 2008 Jun 15;154(1-3):278-86. doi: 10.1016/j.jhazmat.2007.10.024. Epub 2007 Oct 13.
In order to make the judicious use of pesticide/fungicide and to maintain the environment and ecosystem we have developed the starch and poly(methacrylic acid)-based agrochemical delivery system for their controlled and sustained release. The delivery device was prepared by using N,N'-methylenebisacrylamide (N,N'-MBAAm) as crosslinker and was characterized with FTIR, TGA and with swelling studies as a function of time and crosslinker concentration. This article discusses the swelling kinetics of polymer matrix and release dynamics of thiram (fungicide) from hydrogels for the evaluation of the diffusion mechanism and diffusion coefficients. The values of the diffusion exponent 'n' for both cases, that is the swelling of hydrogels and for the release of thiram from the hydrogels have been observed between 0.7 and 0.9 when the concentration of the crosslinker in the polymers were varied from 6.49x10(-3) to 32.43x10(-3) moles/L. It is inferred from the values of the 'n' that Non-Fickian diffusion mechanism has occurred in both the cases.
为了合理使用农药/杀菌剂并维护环境和生态系统，我们开发了基于淀粉和聚（甲基丙烯酸）的农用化学品递送系统，用于其控制释放和持续释放。该递送装置采用N，N'-亚甲基双丙烯酰胺（N，N'-MBAAm）作为交联剂制备，并通过傅里叶变换红外光谱（FTIR）、热重分析（TGA）以及作为时间和交联剂浓度函数的溶胀研究进行表征。本文讨论了聚合物基质的溶胀动力学以及福美双（杀菌剂）从水凝胶中的释放动力学，以评估扩散机制和扩散系数。当聚合物中交联剂的浓度从6.49×10⁻³ 变化到32.43×10⁻³ 摩尔/升时，水凝胶溶胀和福美双从水凝胶中释放这两种情况下的扩散指数“n”值均在0.7至0.9之间。从“n”值推断，两种情况下均发生了非菲克扩散机制。
