Ulker Zeynep, Bozbay Rabia, Buyuk Sebnem Duygu, Orakdogen Nermin
Istanbul Technical University, Faculty of Science and Letters, Department of Chemistry, Soft Materials Research Laboratory, 34469 Maslak, Istanbul, Turkey.
Istanbul Technical University, Faculty of Science and Letters, Department of Chemistry, Soft Materials Research Laboratory, 34469 Maslak, Istanbul, Turkey; Graduate School of Science Engineering and Technology, Department of Chemistry, Istanbul Technical University, 34469 Maslak, Istanbul, Turkey.
Int J Biol Macromol. 2024 Dec;282(Pt 4):137199. doi: 10.1016/j.ijbiomac.2024.137199. Epub 2024 Nov 1.
Anionic polysaccharide-based gels enable the design of biobased materials with biochemical properties, non-toxic and natural origin. A new set of cationic gels was prepared from carboxymethylcellulose (CMC)-doped tertiary amino functional cationic monomers 2-(dimethylamino)ethyl methacrylate and N-(3-(dimethylamino)propyl) methacrylamide via the formation of semi-interpenetrated network (semi-IPN) at different polymerization temperatures, T. A detailed understanding of the temperature-dependent synthesis and physicochemical response is required for the design of interpenetrating networks with CMC as an adsorbent that provides effective sources for the removal of azo-food dyes such as tartrazine and carmoisine from aqueous solutions. The variation of elasticity and swelling properties with respect to polymerization temperature was investigated. CMC-integration and polymerization temperature played a decisive role in the compressive elasticity. Incorporation of CMC into copolymer matrix led to a significant increase in elasticity of semi-IPNs, while mechanically weaker gels were obtained with increasing T. Addition of CMC increased the swelling modulus of semi-IPNs formed at -18 °C by 2.6-fold. While the transparency changed depending on T and microstructure, addition of CMC decreased the swelling rate of gels at all polymerization temperatures. The compressive modulus decreased with the swelling process in accordance with the Rubber elasticity theory. Semi-IPN gels showed stable swelling against pH-change in aqueous solutions and exhibited excellent pH-sensitivity significantly in low pH. A 4 to 12 fold decrease in maximum volume was observed by varying the pH between 2.1 and 9.8. The correlation between polymerization temperature and removal of azo-food dyes; tartrazine and carmoisine from contaminated wastewater with CMC-based gels was studied. Dynamic adsorption equilibrium was reached in 30 min, and tartrazine and carmoisine removal performances varied between 92.8 % and 98.4 %. respectively. The adsorption data for azo-dyes were evaluated by Langmuir, Freundlich, Temkin, Dubinin-Radushkevich, Redlich-Patterson, Sips, and Tooth isotherm models, but were best described by Langmuir and Redlich-Patterson models as they gave the highest correlation. Pseudo-first order, pseudo-second order, Elovich, Avrami kinetic and intra-particle diffusion models were investigated and dye adsorption was represented by pseudo-second-order model. After the adsorption process, semi-IPNs can easily be regenerated and effectively reused over five cycles. The study provided new insights towards the facile and sustainable synthesis of eco-friendly multifunctional CMC-based gels carrying tertiary amino groups for effective removal of azo-based food colorants.
基于阴离子多糖的凝胶能够设计出具有生化特性、无毒且源于天然的生物基材料。通过在不同聚合温度T下形成半互穿网络（semi-IPN），由掺杂羧甲基纤维素（CMC）的叔胺官能阳离子单体甲基丙烯酸2-（二甲氨基）乙酯和N-（3-（二甲氨基）丙基）甲基丙烯酰胺制备了一组新型阳离子凝胶。对于以CMC作为吸附剂来设计互穿网络而言，需要详细了解温度依赖性合成及物理化学响应，该吸附剂可为从水溶液中去除偶氮食用染料（如柠檬黄和胭脂红）提供有效来源。研究了弹性和溶胀性能随聚合温度的变化。CMC整合和聚合温度在压缩弹性方面起决定性作用。将CMC掺入共聚物基体中导致半互穿网络的弹性显著增加，而随着T升高得到的凝胶机械性能较弱。添加CMC使在-18°C下形成的半互穿网络的溶胀模量提高了2.6倍。虽然透明度随T和微观结构而变化，但添加CMC降低了所有聚合温度下凝胶的溶胀速率。根据橡胶弹性理论，压缩模量随溶胀过程而降低。半互穿网络凝胶在水溶液中对pH变化表现出稳定的溶胀，并且在低pH下显著表现出优异的pH敏感性。通过将pH在2.1和9.8之间变化，观察到最大体积降低了4至12倍。研究了聚合温度与用基于CMC的凝胶从受污染废水中去除偶氮食用染料（柠檬黄和胭脂红）之间的相关性。在30分钟内达到动态吸附平衡，柠檬黄和胭脂红的去除性能分别在92.8%和98.4%之间变化。通过Langmuir、Freundlich、Temkin、Dubinin-Radushkevich、Redlich-Patterson、Sips和Tooth等温线模型评估偶氮染料的吸附数据，但Langmuir和Redlich-Patterson模型对其描述最佳，因为它们具有最高的相关性。研究了伪一级、伪二级、Elovich、Avrami动力学和颗粒内扩散模型，染料吸附由伪二级模型表示。吸附过程后，半互穿网络可以很容易地再生，并在五个循环中有效重复使用。该研究为简便且可持续地合成携带叔胺基团的环保型多功能CMC基凝胶以有效去除偶氮基食用色素提供了新的见解。
