Design of Chitosan-Grafted Carbon Nanotubes: Evaluation of How the –OH Functional Group Affects Cs+ Adsorption

Abstract

In order to explore the effect of –OH functional groups in Cs+ adsorption, we herein used the low temperature plasma-induced grafting method to graft chitosan onto carbon nanotubes (denoted as CTS-g-CNTs), as raw-CNTs have few functional groups and chitosan has a large number of –OH functional groups. The synthesized CTS-g-CNT composites were characterized using different techniques. The effect of –OH functional groups in the Cs+ adsorption process was evaluated by comparison of the adsorption properties of raw-CNTs with and without grafting chitosan. The variation of environmental conditions such as pH and contact time was investigated. A comparison of contaminated seawater and simulated groundwater was also evaluated. The results indicated that: (1) the adsorption of Cs+ ions was strongly dependent on pH and the competitive cations; (2) for CNT-based material, the –OH functional groups have a positive effect on Cs+ removal; (3) simulated contaminated groundwater can be used to model contaminated seawater to evaluate the adsorption property of CNTs-based material. These results showed direct observational evidence on the effect of –OH functional groups for Cs+ adsorption. Our findings are important in providing future directions to design and to choose effective material to remedy the removal of radioactive cesium from contaminated groundwater and seawater, crucial for public health and the human social environment.

Preparation and Research Into Functional Properties of Nanostructured Titanates of Lithium and Sodium

“…Promising for the adsorption and safe disposal of 137 Cs + radioactive ions from an aqueous solution are nanotubes and Na 2 Ti 3 O 7 nanofibres. In [66], nanofibres and nanotubes of Na 2 Ti 3 O 7 were synthesized under hydrothermal conditions. The materials obtained have a layered structure where the TiO 6 octahedra are basic structural units [67].…”

“…Na + ions are located between the layers and can be exchanged with other cations. In [66], nanofibres (T3NF) and nanotubes (T3NT) were used to remove 137 Cs + radioactive ions from an aqueous solution by exchanging cations. This process with a structural change (Fig.…”

“…This property is an advantage for the safe disposal of immobilized radioactive ions. The structure evolution from the initial titanate NF to Ag 2 O-T3NF was also studied in [66] (Fig. 8).…”

“…Fig.7. Evolution of the structure of T3NF-layered nanofibers into a microporous T6NF tunnel structure [66].…”

Amino-functionalized magnetic chitosan beads to enhance immobilization of potassium copper hexacyanoferrate for selective Cs+ removal and facile recovery

“…Among these polymer matrices, chitosan-based adsorbents have strong advantages of cost-effectiveness, resource abundance, and many functional groups for desalination by ion adsorption. [25][26][27] Particularly, numerous amino functional groups in chitosan contribute to the coordination of various metal ions. 28,29 This unique property enables copper ions to be well dispersed, and thus, potassium copper hexacyanoferrate (KCuHCF) can be immobilized by precipitation on the surface of chitosan-based adsorbents for effective Cs + removal.…”