Gellan gum/graphene oxide aerogels for methylene blue purification

Kunqi Cai; Meixia Zheng; Hui Xu; Yujing Zhu; Longtao Zhang; Baodong Zheng

doi:10.1016/j.carbpol.2021.117624

Gellan gum/graphene oxide aerogels for methylene blue purification

Carbohydr Polym. 2021 Apr 1:257:117624. doi: 10.1016/j.carbpol.2021.117624. Epub 2021 Jan 10.

Authors

Kunqi Cai¹, Meixia Zheng², Hui Xu³, Yujing Zhu⁴, Longtao Zhang⁵, Baodong Zheng¹

Affiliations

¹ College of Food Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, PR China; China-Ireland International Cooperation Laboratory of Foods Material Science and Structural Design, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, PR China; Fujian Provincial Key Laboratory of Quality Science and Processing Technology in Special Starch, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, PR China.
² Agricultural Bio-Resources Research Institute, Fujian Academy of Agricultural Sciences, Fuzhou, Fujian 350003, PR China. Electronic address: zhengmeixia2005@163.com.
³ College of Food Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, PR China; Fujian Provincial Key Laboratory of Quality Science and Processing Technology in Special Starch, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, PR China.
⁴ Agricultural Bio-Resources Research Institute, Fujian Academy of Agricultural Sciences, Fuzhou, Fujian 350003, PR China.
⁵ College of Food Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, PR China; China-Ireland International Cooperation Laboratory of Foods Material Science and Structural Design, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, PR China; Fujian Provincial Key Laboratory of Quality Science and Processing Technology in Special Starch, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, PR China. Electronic address: zlongtao@fafu.edu.cn.

PMID: 33541651
DOI: 10.1016/j.carbpol.2021.117624

Abstract

Stable gellan gum (GG)/graphene oxide (GO) aerogels were prepared by freeze-drying a mixture of GG and GO. On introduction of GO, the GG/GO aerogels had different level pore structures due to the different freezing temperatures. The volume per gram (1/ρ) of GG/GO aerogels ranges from 76.80 ± 1.54-158.30 ± 2.30 cm³/g. The porosity of GG/GO-3 (-80 °C) and GG/GO-6 (-20 °C) was 45.53 % and 61.30 %, respectively. The resulting three-dimensional GG/GO aerogels exhibited excellent performance in methylene blue (MB) adsorption. The pseudo-first-order and Freundlich isotherm models produced the best fits for the adsorption kinetics and adsorption equilibrium, respectively. The Gibbs free energy, enthalpy, and entropy of adsorption indicated that the adsorption was a spontaneous, exothermic, and entropy-increasing process. It is illustrated that the GG/GO aerogels exhibited faster adsorption kinetics and adsorption capacity. These GG/GO aerogels can remove MB from aqueous solutions.

Keywords: Adsorption; Aerogel; Gellan gum; Graphene oxide; Methylene blue.