Synthesis and functionalization of cross-linked molecularly imprinted polymer (MIP) microwave-assisted for recognition and selective extraction of lead (II) and arsenic (V) from water: Isotherms modeling and integrative mechanisms

Abstract

A cross-linked molecularly imprinted polymer (MIP) was synthesized and functionalized by metal oxide nanoparticles (TiO2 and SiO2) to form a potential cross-linked (MIP) nanocomposite via binding of Nano-TiO2 and Nano-SiO2 to cross-linked chitosan. Where chitosan acted as a functional monomer, glutaraldehyde (Glu) acted as an organic cross-linker with bifunctional reactive groups, and lead (II) and arsenic (V) acted as templates. This work is composed of a binary of promising ideas: (a) a facile preparation of cross-inked molecularly imprinted polymer (MIP) via bulk polymerization method, and (b) the functionalization of newly fabricated cross-linked (MIP) using metal oxide nanoparticles. The fabricated cross-linked biopolymer nanocomposite was used for simultaneous and selective recovery of toxic metal ions from water. Microwave irradiation was applied as an assisted technique to estimate the performance of the synthesized material. The properties and structure of the fabricated Nano-TiO2@Cross-linked Chitosan@Nano-SiO2 were characterized by FT-IR, XRD, TG/DTA, BETs, SEM-EDX, TEM, and XPS. The results indicated that Pb(II) at pH 5.0 ± 0.15 and at time varied from 5 sec to 25 sec exhibited recoveries capacity 97.99–99.81% and Qmax 81.97 mg/g, while As(V) at pH 4.0 ± 0.15 and at 5 sec to 20 sec, exhibited recoveries capacity 96.38–99.72 % and Qmax 625.00 mg/g. The cross-linked MIP nanocomposite exhibited an improved specific surface (388.0 m2/g) and mesopore size (15.18 nm) compared to its precursors. Freundlich and pseudo-second-order equation well-fitted the experimental data. Pb(II) and As(V) recoveries were exothermic, spontaneous, and governed by entropy change. Solvents subjected to eliminate the templates, interfering ions, selectivity, and reusability experiments were carried out. Newly integrative mechanisms for implementing cross-linked (MIP) nanocomposite for recognizing and recovering metal ions were adequately explained.