title: Adsorption and intercalation of low and medium molar mass chitosans on/in the sodium montmorillonite.
abstract: Chitosan-montmorillonite composites can provide hydrophobicity and amino groups to enhance the performances of montmorillonite in wastewater treatment. In this paper, low molar mass chitosan (LC) and medium molar mass chitosan (MC) were selected to intercalate a sodium montmorillonite (Mt). The adsorption isotherm of LC and MC on the Mt and the pH dependency were measured. Thermo X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) were used to characterize the chitosan-Mt composites. Results showed that with hydrochloric acid as the solvent of chitosans, increasing pH from 3 to 5.5 enhanced the adsorption of both LC and MC on the Mt, and when the equilibrium concentration of chitosans approached 300mg/L at pH 5.5, the amount of adsorbed chitosan reached the highest level of 0.203mg/mg for LC and 0.190mg/mg for MC, respectively. When the Mt was saturated with the chitosan, the amino groups on the chitosan were bonded with the Mt through electrostatic interaction and there was monolayer of the chitosan in the interlayer space of Mt, which were confirmed by FTIR spectra and XRD patterns, respectively.
authors: College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China; Department of Life Sciences and Technologies, Hubei Engineering University, Xiaogan 432000, China.
authors: Chao
authors: C
authors: Hu
authors: Department of Soil and Crop Sciences, Texas A&M University, College Station, TX 77843-2474, USA.
authors: Youjun
authors: Y
authors: Deng
authors: College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China. Electronic address: hqhu@mail.hzau.edu.cn.
authors: Hongqing
authors: H
authors: Hu
authors: Zachry Department of Civil Engineering, Texas A&M University, College Station, TX 77843-3136, USA.
authors: Yuhang
authors: Y
authors: Duan
authors: College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China.
authors: Kun
authors: K
authors: Zhai
mesh_terms: D000327:Adsorption; D001546:Bentonite / Q000737:chemistry*; D048271:Chitosan / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D007700:Kinetics; D055672:Static Electricity; D013816:Thermodynamics; D018508:Water Purification
chemical_list: D001546:Bentonite; D048271:Chitosan
keywords: Adsorption; Chitosan; Intercalation; Organoclay; Sodium montmorillonite