Polymer blend functionalization of MnFe₂O₄ nanoparticles: magnetic, structural and photocatalytic impacts

• PMMA-PEG-MF NPs features excellent superparamagnetic properties (Ms =0.0056 emu/g), thermal stability (262°C), high crystallinity, and high biocompatibility. • Applications of PMMA-PEG-MF NPs in photocatalytic degradation of methylene blue in aqueous solution is successfully demonstrated. • MF and PMMA-PEG-MF photocatalyst exhibited 84% and 56% photodegradation under 15 mins of UV light irradiation, respectively. Superparamagnetic nanocomposites based on poly(methyl methacrylate) (PMMA) and polyethylene glycol (PEG), functionalized on manganese ferrite (MnFe 2 O 4 ), were synthesized via a facile chemical co-precipitation method to develop an efficient analytical platform for dye adsorption in aqueous systems. The synthesized PMMA-PEG-MF nanoparticles were systematically characterized using particle size analysis (PSA), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission and scanning electron microscopy (TEM, SEM), energy-dispersive X-ray spectroscopy (EDX), thermogravimetric analysis (TGA), and vibrating sample magnetometry (VSM) to confirm their morphology, crystallinity, thermal stability, and magnetic behaviour. The nanocomposites exhibited a plate-like morphology with an average particle size of ∼70 nm and retained superparamagnetic properties suitable for facile separation. Analytical evaluation of dye removal efficiency of methylene blue (MB) revealed a maximum adsorption efficiency of 77% for PMMA-PEG-MF NPs and 93% for bare MnFe 2 O 4 NPs. These results demonstrate the potential of the PMMA-PEG-MF system as an analytical tool for quantitative assessment and remediation of dye contaminants in water, contributing to environmentally focused analytical methodologies.