title: Preparation of the porphyrin-functionalized cotton fiber for the chromogenic detection and efficient adsorption of Cd2+ions.
abstract: In this study, a porphyrin functionalized cotton fiber was prepared and investigated for the visual detection and efficient adsorption of cadmium (Cd2+) ions in aqueous solutions. The pristine cotton fiber was first grafted with poly (3-sulfopropyl methacrylate potassium salt) (PSMP) via the surface-initiated atom transfer radical polymerization (SI-ATRP), and subsequently immobilized with 5,10,15,20-tetrakis(1-methy-4-pyridinio)porphyrin tetra(p-toluenesulfonate) (TMPyP), to form the CPT (Cotton-PSMP-TMPyP) material. The CPT was characterized by SEM, FTIR, XPS and elemental analysis, and examined for the detection and adsorption of cadmium ions. The influencing factors such as pH and the initial cadmium ion concentrations on the adsorption performances were investigated. Results showed that the cadmium ion adsorption isotherm was best fitted with the Langmuir isotherm model, with the derived maximum adsorption capacity of 0.8638mmol/g. The thermodynamic study showed the endothermic nature of the adsorption process. In addition, the adsorption kinetics was fast with over 90% of the total cadmium ions adsorbed within 2min. Furthermore, the distinctive color response of the CPT to the cadmium ions in aqueous solutions was clearly displayed. A linear relationship between the light absorbance of CPT-Cd (CPT adsorbed with cadmium ions) and the initial concentrations of cadmium ions was successfully established, which could be used for the fast determination of the cadmium ion concentrations in aqueous solutions.
authors.affiliation: Shenzhen Key Laboratory of Environmental Chemistry and Ecological Remediation, College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, PR China. Electronic address: liuck@szu.edu.cn.
authors.forename: Changkun
authors.initials: C
authors.lastname: Liu
authors.affiliation: Shenzhen Key Laboratory of Environmental Chemistry and Ecological Remediation, College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, PR China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Liang
authors.affiliation: Shenzhen Key Laboratory of Environmental Chemistry and Ecological Remediation, College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, PR China.
authors.forename: Ji'an
authors.initials: J
authors.lastname: Liu
authors.affiliation: Shenzhen Key Laboratory of Environmental Chemistry and Ecological Remediation, College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, PR China.
authors.forename: Xiaobin
authors.initials: X
authors.lastname: Lei
authors.affiliation: Shenzhen Key Laboratory of Environmental Chemistry and Ecological Remediation, College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, PR China.
authors.forename: Xinzhen
authors.initials: X
authors.lastname: Zhao
keywords: Adsorption; Cadmium ion; Color response; Cotton fiber; Fast detection