Dual-network design to enhance the properties of agar aerogel adsorbent by incorporating in situ ion cross-linked alginate

• Published in: Environmental chemistry letters Vol. 18; no. 1; pp. 251 - 255
• Main Authors: Huang, Dajian, Quan, Qiling, Zheng, Yuting, Tang, Wenjie, Zhang, Zhuo, Qiang, Xiaohu
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 2020; Springer Nature B.V
• Subjects: Adsorbents; Adsorption; Aerogels; Alginic acid; Analytical Chemistry; Aqueous solutions; Calcium alginate; Calcium ions; Contaminants; Cosmetics industry; Crosslinking; Dimensional stability; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Geochemistry; Methylene blue; Morphology; Network design; Original Paper; Pollution; Polymers; Seaweed meal; Sodium; Sodium alginate; Stability; Agar; Double network aerogel; Alginate; Adsorbent; Ionic cross-linked
• ISSN: 1610-3653; 1610-3661
• DOI: 10.1007/s10311-019-00932-7

Natural and synthetic adsorbents are used to remove contaminants from polluted waters. In particular, polymer-based aerogels are promising but their adsorption capacity and dimensional stability should be improved. Here we propose a new design strategy to prepare a dual-network aerogel, consisting of physical cross-linked agar and Ca 2+ cross-linked sodium alginate as the first and second networks, respectively. After introducing cross-linked sodium alginate into the agar matrix, the morphology of the agar aerogel transformed from a distinct layered structure to a co-continuous network. The swelling degree ratio of the agar aerogel is reduced, and the dimensional stability was  improved by introducing ion cross-linked sodium alginate into the agar matrix. The aerogels were used as adsorbents to remove methylene blue from aqueous solutions. The adsorption capacity of the agar aerogel was remarkably improved by adding sodium alginate due to the increase in electrostatic attraction and adsorption site.