Institute of Chemical Industry of Forest Products, CAF, Key Lab. of Biomass Energy and Material, Jiangsu Province, National Engineering Research Center of Low-Carbon Processing and Utilization of Forest Biomass, Key Lab. of Chemical Engineering of Forest Products, National Forestry and Grassland Administration, Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing 210042, China.
Institute of Chemical Industry of Forest Products, CAF, Key Lab. of Biomass Energy and Material, Jiangsu Province, National Engineering Research Center of Low-Carbon Processing and Utilization of Forest Biomass, Key Lab. of Chemical Engineering of Forest Products, National Forestry and Grassland Administration, Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing 210042, China.
Int J Biol Macromol. 2023 May 31;238:124132. doi: 10.1016/j.ijbiomac.2023.124132. Epub 2023 Mar 22.
As dye adsorbents with great potential, polysaccharide-based hydrogels are significantly hampered in practical application owing to intricate preparation methods, low absorption, and bad degradability. Salecan is a water-soluble extracellular polysaccharide with excellent physicochemical and biological properties. Here, salecan and xanthan gum were first used as a dual-precursors system, their mixed solution was crosslinked by Fe to assemble a photo-degradable ionic gel for malachite green (MG) adsorption. Photo-degradation was done using visible light under very mild conditions, which gave rise to gel network dissolution and homogeneous solution formation. Extensive dynamic coordinate interactions between Fe and polysaccharides maintained gel matrix stability and were systematically investigated. The control of water uptake, micro-structure, and rheology can be facilely implemented by tuning salecan/xanthan gum ratios. Furthermore, various parameters such as polysaccharide ratios, pHs, MG concentrations, and contact time affecting adsorption were optimized using batch experiments. Adsorption process accurately adhered to pseudo-second-order kinetic and Langmuir isotherm model, with the maximum adsorption capacity of 463.0 mg/g. Such mechanism implied monolayer chemisorptive characteristics. The gel exhibited satisfactory reusability and was recycled five times without apparent decrease in adsorption capacity. From these results, the photo-degradable Fe-induced salecan/xanthan gum ionic gel is an alternative and sustainable absorbent for MG removal.
作为具有巨大潜力的染料吸附剂，多糖基水凝胶由于其复杂的制备方法、低吸收性和差的可降解性，在实际应用中受到严重阻碍。沙莱聚糖是一种具有优异物理化学和生物特性的水溶性胞外多糖。在这里，沙莱聚糖和黄原胶首次被用作双前体体系，它们的混合溶液通过 Fe 交联形成光降解离子凝胶，用于孔雀石绿（MG）吸附。在非常温和的条件下，使用可见光进行光降解，导致凝胶网络溶解和均相溶液形成。Fe 和多糖之间广泛的动态配位相互作用保持了凝胶基质的稳定性，并进行了系统研究。通过调整沙莱聚糖/黄原胶的比例，可以轻松控制水吸收、微观结构和流变学。此外，使用批量实验优化了各种参数，如多糖比、pH 值、MG 浓度和接触时间对吸附的影响。吸附过程准确符合拟二级动力学和 Langmuir 等温线模型，最大吸附容量为 463.0mg/g。这种机制暗示了单层化学吸附特性。该凝胶表现出令人满意的可重复使用性，经过五次回收，吸附容量没有明显下降。从这些结果可以看出，光降解 Fe 诱导的沙莱聚糖/黄原胶离子凝胶是一种替代和可持续的 MG 去除吸收剂。
