This study presents the development and evaluation of a novel class of multifunctional chitosan/glycidyl methacrylate (GMA) cryogels designed for simultaneous removal of cationic and anionic dyes and effective inhibition of pathogenic bacteria in aqueous environments. The cryogels were fabricated via a two-step process: first, chitosan was dissolved in glacial acetic acid and cross-linked with GMA to form a stable hydrogel network; second, functional monomers—3-sulfopropyl methacrylate potassium salt (SMA) for anionic functionality and [2-(methacryloyloxy)ethyl] trimethyl ammonium chloride (DMC) for cationic functionality—were introduced at controlled molar ratios (1/4, 1/3, 1/2 relative to chitosan). After thermal cross-linking at 80 °C for 3 hours, the hydrogels were subjected to freeze-drying under vacuum (40 Pa, trap temperature < −45 °C) for 48 hours, resulting in highly porous, lightweight cryogels. Comprehensive characterization confirmed successful chemical modification and structural integrity. FTIR spectra revealed the disappearance of characteristic O–H and N–H stretching vibrations from chitosan and the emergence of new C=O peaks at ~1715 cm⁻¹, indicating covalent cross-linking through epoxy ring opening. Additional absorption bands at 1037 cm⁻¹ (SO₃⁻) and 1482 cm⁻¹ (quaternary ammonium) confirmed the incorporation of SMA and DMC, respectively. SEM imaging showed that CS/GMA/SMA cryogels exhibited a heterogeneous, folded sheet-like morphology due to polyelectrolyte complex formation between protonated amino groups and sulfonate ions, while CS/GMA/DMC maintained a uniform, interconnected pore structure with enhanced surface roughness. EDX mapping clearly detected sulfur in CS/GMA/SMA and chlorine in CS/GMA/DMC, providing direct evidence of molecular integration. The cryogels demonstrated ultra-light weight with densities below 0.13 g/cm³ and porosities exceeding 91%, confirming the formation of a highly open three-dimensional network ideal for rapid mass transfer. Swelling studies indicated pH-responsive behavior: maximum swelling occurred at pH 3 due to full protonation of amino groups, while swelling decreased at higher pH values as deprotonation reduced osmotic pressure.Benzylhydrazine Inhibitor Despite this, all samples retained substantial water absorption capacity, essential for dye diffusion and interaction.Ethyl 6-bromohexanoate Protocol
Adsorption performance was assessed using Cationic Yellow X-8GL (CY) and Reactive Yellow B-4RFN (RY) as model pollutants.PMID:35048778 For CY removal, CS/GMA/SMA cryogels achieved 71.20% efficiency, following pseudo-second order kinetics and Freundlich isotherm models, indicating chemically driven, heterogeneous multilayer adsorption. For RY, CS/GMA/DMC cryogels removed 96.11% of dye with a maximum adsorption capacity of 224.6 mg/g, fitting well with pseudo-second order and Dubinin-Radushkevich models. The high performance was attributed to strong electrostatic attraction between the positively charged cryogel surface and the SO₃⁻ group in RY, supported by hydrogen bonding, van der Waals forces, and π–π interactions.
Zeta potential measurements revealed a clear charge gradient: CS/GMA/DMC (+32.16 mV) > CS/GMA (+18.73 mV) > CS/GMA/SMA (+7.17 mV), directly correlating with adsorption selectivity. Antibacterial assays against Escherichia coli and Staphylococcus aureus showed that CS/GMA/DMC induced up to 94.51% bacterial reduction, significantly outperforming CS/GMA (81.14%) and CS/GMA/SMA (73.57%). This enhanced activity stems from the dense positive charge density enabling membrane disruption and cell lysis.
In conclusion, the developed chitosan-based cryogels offer a sustainable, multifunctional solution for advanced wastewater treatment. Their ability to selectively remove diverse dyes based on tunable surface charge, combined with potent antibacterial activity, makes them highly suitable for real-world applications in industrial effluent remediation. These materials represent a significant step toward integrated, eco-friendly technologies for environmental protection.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com