Microwave preparation and properties of O‐crosslinked maleic acyl chitosan adsorbent for Pb²⁺ and Cu²⁺

Abstract

A novel chitosan-based adsorbent (CCTM) was prepared by the reaction of epichlorohydrin O-crosslinked chitosan with maleic anhydride under microwave irradiation. The chemical structure of this polymer was characterized by infrared spectroscopy and X-ray diffraction analyses. The effects of various variables such as degree of substitution, adsorption time, initial metal ion concentration, solution pH, and temperature, on the adsorption of Pb 2þ and Cu 2þ by CCTM were investigated. The results demonstrate that the microwave irradiation can remarkably enhance the reaction. CCTM has higher adsorption capacity than chitosan. The maximum adsorption capacities for Pb 2þ and Cu 2þ , with initial concentrations of 0.02 mol L À1 at pH 5, are 246.3 and 132.5 mg g À1 , respectively. The adsorbent can be recycled. These results have important implications for the design of effective chitosan-based adsorbents in the removal of heavy metal ions from wastewaters.

Synthesis, Characterization, and Antibacterial Activity of Cross-Linked Chitosan-Glutaraldehyde

“…The XRD pattern of chitosan in this study displayed two sharp diffraction peaks at 2 θ = 10° and 20°, revealing the high crystallinity of chitosan. This result is consistent with the result of a number of previous studies [22,32,33], which reported the typical X-ray diffraction pattern of chitosan. The high crystallinity is due to the chitosan structure while plenty of hydroxyl and amino groups could form strong intermolecular and intramolecular hydrogen bonds [33].…”

“…The XRD measurements of chitosan and CLCG were recorded as described by Ge et al [22] and Zhang et al [59] by using an XPert PRO diffractometer (Holland) with a detector operating under a voltage of 40.0 kV and a current of 30.0 mA using CuKo radiation. The recording range of 2 θ was 5° to 60°, and the scanning speed was 6°/min.…”

“…Interestingly, previous studies have revealed that the biological activities of chitosan and its derivatives could be affected by different environments [14,21] and improved by either combining chitosan with different metal ions [22,23,24,25] or cross-linking chitosan with other organic compounds [26,27,28]. Indeed, chitosan has been cross-linked with glutaraldehyde in several studies [27,29], while these cross-linked complexes have been found to play a key role in the uptake of heavy metals [30,31].…”

Design, characterization and in vitro evaluation of novel shell crosslinked poly(butylene adipate)-co-N-succinyl chitosan nanogels containing loteprednol etabonate: A new system for therapeutic effect enhancement via controlled drug delivery

“…The peak at 10 was assigned to the crystal form I and the strong peak at 20 was assigned to form II [51]. This is because the structure of chitosan molecules has certain regularity which can form crystalline regions very easily [52]. But, for succinated chitosan, the peak at 10 disappears and the reflection at 20 also significantly decreases [53].…”

Microwave preparation of triethylenetetramine modified graphene oxide/chitosan composite for adsorption of Cr(VI)

“…The linear forms of pseudo-first-order and the pseudo-second-order 226 equations are expressed as follows(Ge, Chen, & Huang, 2012):…”