Li Jianfa, Jiang Man, Wu Huan, Li Yimin
Department of Chemistry, Shaoxing University, Zhejiang 312000, China.
J Agric Food Chem. 2009 Apr 8;57(7):2868-74. doi: 10.1021/jf803744w.
Carboxymethylcellulose (CMC) gel was used for encapsulating anionic herbicide 2,4-D for its controlled release. The slower release rate of 2,4-D in water and soil was obtained by adding in the gel formulation some modified bentonites, which were prepared by intercalating inorganic or organic cations in interlayers of Na(+)-saturated bentonite. The higher encapsulation efficiencies of 2,4-D were observed on the bentonite/CMC gel formulations due to the sorption of 2,4-D on modified bentonites. The time taken for 50% of 2,4-D to be released in water, t(50), showed a variation (8.8-19.8 h) for these gel formulations, the largest value corresponding to the formulation incorporated with hydroxy-iron intercalated bentonite that has the highest sorption capacity to 2,4-D. The gel formulations could also control the release of 2,4-D when applied to a thin soil layer and demonstrated potential to reduce leaching of such anionic herbicides in soil.
羧甲基纤维素（CMC）凝胶被用于包封阴离子除草剂2,4-二氯苯氧乙酸（2,4-D）以实现其控释。通过在凝胶配方中添加一些改性膨润土，可使2,4-D在水和土壤中的释放速率变慢，这些改性膨润土是通过在钠饱和膨润土的层间插入无机或有机阳离子而制备的。由于2,4-D在改性膨润土上的吸附作用，在膨润土/CMC凝胶配方上观察到2,4-D具有更高的包封效率。这些凝胶配方中，2,4-D在水中释放50%所需的时间t(50)有所不同（8.8 - 19.8小时），最大值对应于含有羟基铁插层膨润土的配方，该膨润土对2,4-D具有最高的吸附能力。当将凝胶配方施用于薄土层时，也能控制2,4-D的释放，并显示出减少此类阴离子除草剂在土壤中淋溶的潜力。
