Zou Wensheng, Ma Wei, Zhang Shufen
State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, School of Chemical Engineering, Dalian University of Technology, Dalian 116023, China.
State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, School of Chemical Engineering, Dalian University of Technology, Dalian 116023, China.
Int J Biol Macromol. 2024 Dec;282(Pt 5):136992. doi: 10.1016/j.ijbiomac.2024.136992. Epub 2024 Oct 31.
In this paper, we present the modification of cotton with glycidyltrimethylammonium chloride (GTA), demonstrating its capability not only for salt-free dye adsorption but also for achieving fixation reactions with monochlorotriazine-type reactive dyes under neutral conditions. The results of adsorption kinetics and isotherm experiments indicate that the adsorption of reactive dyes by modified cotton is chemisorption. Color-stripping experiments conducted on modified cotton dyed with different dyes revealed that GTA-modified cotton underwent fixation reactions with monochlorotriazine-type reactive dyes under neutral conditions. The reaction sites of modified cotton with reactive dyes were determined by measuring the H NMR of the model reaction products. Mechanism investigation using Density Functional Theory (DFT) on the fixation reaction revealed that the hydroxyl groups on the modification agent chain exhibit a lower pKa value and carry more negative charge, resulting in a lower reaction barrier with monochlorotriazine-type reactive dyes. Our research findings demonstrate that GTA-modified cotton fiber enhance the reactivity of cotton, providing significant guidance for the development of novel modifiers.
在本文中，我们展示了用缩水甘油基三甲基氯化铵（GTA）对棉进行改性，证明了其不仅具有无盐染料吸附能力，还能在中性条件下与一氯三嗪型活性染料发生固着反应。吸附动力学和等温线实验结果表明，改性棉对活性染料的吸附是化学吸附。对用不同染料染色的改性棉进行的褪色实验表明，GTA改性棉在中性条件下与一氯三嗪型活性染料发生了固着反应。通过测量模型反应产物的核磁共振氢谱（1H NMR）确定了改性棉与活性染料的反应位点。利用密度泛函理论（DFT）对固着反应进行的机理研究表明，改性剂链上的羟基具有较低的pKa值且带有更多负电荷，导致与一氯三嗪型活性染料的反应势垒较低。我们的研究结果表明，GTA改性棉纤维提高了棉的反应活性，为新型改性剂的开发提供了重要指导。
