Preparation of a novel superabsorbent hydrogel based on polyacrylic acid/shellac using gamma irradiation for adsorption removal of malachite green dye

Abstract

The objective of this study is to prepare a super absorbent hydrogel based on polyacrylic acid and an environmentally friendly material such as shellac to remove malachite green dye from aqueous solution using gamma radiation. The adsorption of malachite green (MG) dyes using polyacrylic acid (PAA)/shellac (SH) hydrogels was studied. These hydrogels were prepared by mixing aqueous solutions of PAA and SH at differing molecular ratios (10%, 20%, and 30% SH content in the final reaction mixture) and varying doses of gamma radiation (10–50 kGy). The water absorption by the PAA/SH hydrogels prepared at a 30-kGy radiation dose increased with an increase in the SH content. The removal of the MG dyes from an aqueous solution using PAA and PAA/SH hydrogels was investigated at different values for selected parameters, such as pH, contact time, SH concentration, and adsorbent dosage. The highest MG adsorption percentage (95.5%) was obtained for the PAA/SH hydrogel with the highest SH content (30%). As the adsorbent dosage increased, the dye adsorption capacity increased, accordingly. The combination of SH and gamma radiation caused the PAA to undergo structural changes verified by X-ray diffraction and Fourier transform infrared spectroscopy. Scanning electron microscopy was employed to investigate the morphology of the PAA/SH hydrogel and revealed that the SH belonging to the PAA matrixes exhibited a homogeneous dispersion. The thermal stability of the hydrogels was investigated by thermogravimetric analysis. The amount of dye adsorbed by the PAA/SH hydrogel was calculated by subtraction based on the ultraviolet–visible (UV–VIS) spectroscopy determination of the concentration of leftover dye in solution using a UV–VIS spectrophotometer.

4D Printing of Body Temperature-Responsive Hydrogels Based on Poly(acrylic acid) with Shape-Memory and Self-Healing Abilities

“…39 The crystalline structure of the printed PAAc-C16A hydrogels was evaluated by XRD. As shown in Figure 2a, the XRD pattern of pure PAAc exhibits a typical broad band at 2θ in between10 and 50°, indicating its amorphous nature, 40 whereas a single sharp peak appeared at 2θ = 21.7°for the hydrogel with 30 mol % of C16A, corresponding to the hexagonal lattice of the side alkyl chains of C16A units. 2 The temperature-dependent phase transition behavior of the swollen hydrogels due to the presence of crystalline hydrophobic C16A domains was demonstrated by DSC.…”

Radiation-Induced Hydrogel for Water Treatment

“…These ions will interact with the positively charged MG dye molecules and help the MG dye stick to them. Nonetheless, it seemed that the primary intermolecular interaction in this technique was the electrostatic connection between the dye molecules and the hydrogel matrix [116]. novel superabsorbent polyacrylic acid/shellac hydrogel is used to remove malachite green (MG) dyes from a water solution.…”

“…Fe2O3 nanoparticles enhance the magnetic properties of the hydrogels, facilitating their easy sep-Figure 5. Probable mechanism of cationic malachite green dye adsorption by radiation-induced polyacrylic acid/shellac hydrogels [116].…”

A Comprehensive Review of Radiation-Induced Hydrogels: Synthesis, Properties, and Multidimensional Applications

“…Moreover, gamma ray irradiation is commonly utilized to sterilize biomedical devices for veterinary and medical purposes [49,50]. Hydrogels were developed by exposing them to gamma ray radiation at different doses (26,64,96, and 124 kGy) in the presence of air at room temperature. This was performed using a Gamma Cell 220 type 60Co g irradiator, with a constant dose rate of 0.40 kGy h1.…”

“…These hydrogels were synthesized by blending aqueous solutions of polyacrylic acid and shellac at various molecular ratios, with the shellac content ranging from 10% to 30% in the final reaction mixture (as shown in Figure 3 b,c). Additionally, different doses of gamma radiation, ranging from 10 to 50 kGy, were applied during the synthesis process [ 54 , 55 , 64 ].…”