Abstract

In this work, the use of carboxymethyl cellulose (CMC) is highlighted in enhancing the controlled release behaviour of zinc/aluminium layered double hydroxide-quinclorac (Zn/Al-LDH-QC). The Zn/Al-LDH-QC-CMC nanocomposite were characterised using powder x-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric and derivative thermogravimetric analysis and field emission scanning electron microscopy. The release study was carried out in an aqueous solution of Na₃PO₄, Na₂SO₄ and NaCl, so as to mimic the environmental condition where the QC is frequently used. The Zn/Al-LDH-QC-CMC nanocomposites showed better performance in releasing QC, with prolonged release time ranging from 163–6083 min, compared to 99–2639 min for the uncoated nanocomposites. The hygroscopic nature of the CMC play a critical role in enhancing the release behaviour of the Zn/Al-LDH-QC-CMC. The kinetic study shows that the Zn/Al-LDH-QC-CMC follows the pseudo-second order kinetic model; hence the release mechanism occurred via dissolution of the CMC matrix and the ion exchange process. These results, therefore, indicate the potential of Zn/Al-LDH-QC-CMC in dealing with the downside effect of the excessive usage of herbicide in paddy cultivation.

Graphic abstract

中文翻译：

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羧甲基纤维素包衣的锌/铝层状双氢氧化物-喹克洛酯的聚合纳米复合基除草剂：农药的控释目的

摘要

在这项工作中，突出强调了使用羧甲基纤维素（CMC）来增强锌/铝层状双氢氧化物-喹克拉克（Zn / Al-LDH-QC）的控释性能。Zn / Al-LDH-QC-CMC纳米复合材料的特征在于粉末X射线衍射，傅立叶变换红外光谱，热重和导数热重分析以及场发射扫描电子显微镜。在Na ₃ PO ₄，Na ₂ SO ₄的水溶液中进行释放研究和氯化钠，以模仿经常使用质量控制的环境条件。Zn / Al-LDH-QC-CMC纳米复合材料在释放QC方面表现出更好的性能，延长的释放时间为163–6083分钟，而未涂覆的纳米复合材料的释放时间为99–2639分钟。CMC的吸湿性在增强Zn / Al-LDH-QC-CMC的释放行为中起关键作用。动力学研究表明，Zn / Al-LDH-QC-CMC遵循伪二级动力学模型。因此，释放机理是通过CMC基质的溶解和离子交换过程发生的。因此，这些结果表明了Zn / Al-LDH-QC-CMC在解决水稻种植中过量使用除草剂带来的负面影响方面的潜力。

图形摘要