A controlled-release formulation (CRF) of the nematicide carbofuran (CAB) was prepared using ionically cross-linked chitosan (CHS). Four cross-linker agents were assessed, among which sulfate (SUL) obtained the highest encapsulation efficiency. Several parameters for the encapsulation of the pesticide were optimized, including pH, SUL/CHS molar ratio, stirring time, and stirring speed. The EE and the pesticide loading (PL) were 67% and 24%, respectively, in the optimized process. Scanning electron microscopy (SEM) images for empty microparticles (EMP) showed a rough and porous surface, with particle size of 1023 nm, whereas the CRF surface was found to be smoother, with a particle size of 1127 nm. The release kinetics of CAB from CRF and commercial carbofuran (CC) were evaluated in water under laboratory conditions, and the release data were fitted to the generalized Korsmeyer-Peppas model. The results indicated that the release of CAB was accomplished by a diffusion-controlled process. The CAB release from CRF was slower than that from CC, and required 6 days for 70% release, whereas CC required 5 days for 100% delivery of the pesticide. A diffusion coefficient (n) of 0.603 was determined, meaning that delivery was not governed by Fick’s laws of diffusion, but by an anomalous transport mechanism.

使用离子交联的壳聚糖（CHS）制备了杀线虫剂呋喃丹（CAB）的控释制剂（CRF）。评估了四种交联剂，其中硫酸盐（SUL）获得最高的包封效率。优化了农药包封的几个参数，包括pH，SUL / CHS摩尔比，搅拌时间和搅拌速度。在优化的过程中，EE和农药含量（PL）分别为67％和24％。空微粒（EMP）的扫描电子显微镜（SEM）图像显示粗糙且多孔的表面，粒径为1023 nm，而发现CRF表面更光滑，粒径为1127 nm。在实验室条件下，在水中评估了CRF和商用呋喃丹（CC）中CAB的释放动力学，释放数据与广义的Korsmeyer-Peppas模型拟合。结果表明，CAB的释放是通过扩散控制的过程完成的。CRF释放的CAB较CC释放慢，需要6天才能释放70％，而CC则需要5天才能100％释放农药。扩散系数（n）被确定为0.603，这意味着传递不受Fick扩散定律的约束，而是受异常传输机制的约束。