Evaluation of p(HEMA-co-NIPAM) hydrogels for removal of methylene blue from aqueous solution:isotherm, kinetic, and thermodynamic studies

Abstract

In this study, a novel adsorbent material, poly (2-hydroxyethyl methacrylate-co-N-isopropyl acrylamide) (p(HEMA-co-NIPAM) hydrogel, was synthesized for the purpose of removing methylene blue (MB) from aqueous media. The synthesis of hydrogel was carefully conducted, and its properties were thoroughly examined using techniques such as Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The adsorption experiments conducted revealed a remarkable affinity of p(HEMA-co-NIPAM) hydrogel towards MB. The highest adsorption was observed when 0.05 g of the adsorbent were utilized, with optimal conditions at a pH of 6.0 and a temperature of 15 °C. This underscores the importance of pH control and temperature regulation in optimizing the adsorption treatment. The adsorption behavior of MB on p(HEMA-co-NIPAM) hydrogel was best elucidated by the Langmuir isotherm model, which provided insights into the maximum adsorption capacity. Impressively, this capacity reached 126.6 mg/g, indicative of the adsorbent's robust capability to capture the MB molecules. The isotherm data further highlighted the strong affinity between p(HEMA-co-NIPAM) hydrogel and the MB dye, underscoring the effectiveness of the synthesized hydrogel as an adsorbent material. The successful application of p(HEMA-co-NIPAM) hydrogel for MB adsorption not only emphasizes its potential for wastewater treatment but also hints at its broader significance for environmental remediation. By harnessing the adsorption capabilities of this hydrogel, the removal of MB from industrial and domestic wastewater could be significantly enhanced, leading to cleaner water resources. This study presents p(HEMA-co-NIPAM) hydrogel as a promising adsorbent material with exceptional affinity for MB. This is demonstrated through a comprehensive analysis of its synthesis, characterization, and adsorption performance. The findings hold promise for addressing wastewater contamination issues and promoting sustainable water management practices.