Preparation of multisensitive poly (N-isopropylacrylamide-co-acrylic acid)/TiO2 composites for degradation of methyl orange

Composites of poly (N-isopropylacrylamide-co-acrylic acid)/titanium dioxide (TiO₂) have been prepared via UV-initiated free radical polymerization. Fourier transform infrared spectra (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), environmental scanning electron microscope (ESEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) are used to study the composition, structure, and morphology of the as-prepared composites. TiO₂ is found to be successfully encapsulated in the copolymer in spherical shapes with size of 2.5 μm. The thermo- and pH-responsive properties of the composites are observed using dynamic light scattering (DLS). The photocatalytic property of the composites is studied using UV–vis spectrophotometer on the degradation of methyl orange (MO) solution under various pHs and temperatures. Degradation ratio is higher at low pH and increases with increasing temperature above volume phase transition temperature (VPTT).