Adsorption of malachite green onto Styrene-Methacrylate based molecularly imprinted polymer

Abstract

The adsorption of malachite green (MG) from aqueous medium by non-imprinted and molecularly imprinted styrene/methacrylate polymers was studied. The synthesized materials were characterized by powder X-ray diffraction, Fourier transform infra-red spectroscopy, scanning electron microscopy, and energy dispersive Xray spectroscopy. The effects of initial dye concentration, contact time and temperature on the adsorption-1 capacity for malachite green were investigated and found to be about 200 g kg for the imprinted polymer and 44-1 g kg for the non-imprinted polymer. The X-ray diffraction peaks at 2θ = 18°, 30° and 42° indicate the crystalline nature of the polymers. Uptake of malachite green increased with rise in contact time and concentration, for both polymers, while decrease in uptake was observed with rise in temperature. The kinetics of the adsorption 2 of the dye on the imprinted polymer followed the pseudo-second order (R = 0.97), while that of the non-2 imprinted polymer followed the pseudo-first order (R = 0.87). Equilibrium study showed that the Freundlich isotherm better describes the adsorption of the dye on both polymers, indicating a multilayer adsorption. The values of ΔG° indicate the spontaneity and non-spontaneity of the dye removal by the imprinted and nonimprinted polymers respectively. The negative ΔH° and ΔS° for the imprinted polymer signify that the process is exothermic and occurred with decrease in the degree of randomness. Thus, the high quantity of MG adsorbed onto the imprinted polymer indicates the high potential of the use of the imprinting technology in the removal of toxic waste from water.

Selective Removal of the Emerging Dye Basic Blue 3 via Molecularly Imprinting Technique

“…Therefore, the MIPs show a clear bend of the ester group at 1720 cm −1 and 1256 cm −1 due to the carbonyl C=O and C-O stretching. Additionally, the peaks at ~1400 cm −1 and ~1300 cm −1 are due to the presence of -CH 2 , and -CH 3 , respectively, while the strong peaks at 1159 cm −1 and 1046 cm −1 are due to the presence of the C-O functional group [ 21 ]. The FT-IR analysis of the MIPs and NIPs show that the MAA and EGDMA C=C double bond signal at 1637 cm −1 was absent, indicating that the polymer is successfully synthesized.…”

Preparation of styrene-based imprinted polymer for the adsorption of hazardous bromocresol green dye: Equilibrium, kinetics and thermodynamics study

“…Few of the adsorbent materials so far explored for adsorption purpose include sugarcane bagasse, chitin, maize cob, hazelnut shell, microorganisms such as fungus and yeasts, zeolites, lignin-based hydrogels and activated carbon (Jiang et al, 2020;Li et al, 2021;Wang et al, 2021;Sterenzon et al, 2022). However, as promising as these adsorbents are, many failed in their selectivity towards particular analytes, while others suffer from attrition, rendering them non-reusable (Awokoya et al, 2019(Awokoya et al, , 2021; hence the need for the development of alternative adsorbents that are capable of overcoming the deficiencies of common adsorbents.…”