Lakshmi Priya A, Subhapriya P, Jenisha S, Murali Krishnan M, Dhanapal V
Department of Chemistry, Nehru Institute of Engineering and Technology, Coimbatore 641105, Tamil Nadu, India.
Department of Chemistry, Bannari Amman Institute of Technology, Sathyamangalam 638 401, Erode Dt., Tamil Nadu, India.
Int J Biol Macromol. 2025 Feb;289:138814. doi: 10.1016/j.ijbiomac.2024.138814. Epub 2024 Dec 16.
Smart polymer hydrogels with superior dye adsorption (brilliant green) characteristics were synthesized via free-radical polymerization by grafting acrylic acid segments onto allylated chitosan and inducing crosslinking with a trimethylolpropane triacrylate crosslinker. The synthesized adsorbents were characterized for their chemical structure (FT-IR and H NMR), thermal stability (TG/DTG), and morphological features (SEM). The adsorption capacity for brilliant green (934 mg/g) and water uptake (712 g/g) were determined using spectrophotometric and gravimetric methods, respectively. The interaction between the synthesized adsorbent and brilliant green, including potential dye orientation on the adsorbent and hydrogen bond formation was analyzed using Density Functional Theory. The maximum adsorption of brilliant green (934 mg/g) and water uptake was achieved by optimizing the monomer feed compositions. Adsorption studies revealed that dye uptake followed Fickian diffusion and the Langmuir isotherm model, with pseudo-second-order kinetics. Thermodynamic analysis demonstrated that the adsorption process was spontaneous and exothermic, as evidenced by changes in free energy, enthalpy, and entropy under varying temperatures. Theoretical investigations confirmed the excellent affinity of the synthesized adsorbent toward brilliant green. Furthermore, reusability studies showed that the adsorbent retained its dye-holding capability over 20 adsorption-desorption cycles, highlighting its potential for sustainable and efficient dye removal applications.
通过自由基聚合反应，将丙烯酸链段接枝到烯丙基化壳聚糖上，并与三羟甲基丙烷三丙烯酸酯交联剂进行交联，合成了具有优异染料吸附（亮绿）特性的智能聚合物水凝胶。对合成的吸附剂进行了化学结构（傅里叶变换红外光谱和核磁共振氢谱）、热稳定性（热重/微商热重）和形态特征（扫描电子显微镜）表征。分别采用分光光度法和重量法测定了对亮绿的吸附容量（934 mg/g）和吸水量（712 g/g）。利用密度泛函理论分析了合成吸附剂与亮绿之间的相互作用，包括吸附剂上潜在的染料取向和氢键形成。通过优化单体进料组成，实现了亮绿的最大吸附量（934 mg/g）和吸水量。吸附研究表明，染料吸附遵循菲克扩散和朗缪尔等温线模型，动力学符合准二级动力学。热力学分析表明，吸附过程是自发的且放热的，不同温度下自由能、焓和熵的变化证明了这一点。理论研究证实了合成吸附剂对亮绿具有优异的亲和力。此外，可重复使用性研究表明，该吸附剂在20次吸附-解吸循环中保持了其染料吸附能力，突出了其在可持续高效染料去除应用中的潜力。
