Stimuli-Responsive Polymeric Membranes through Graft Copolymerization of N-Isopropylacrylamide onto Polycarbonate Track Etched Membranes for Biomedical Applications

Stimuli-responsive polymeric membranes have attracted the attention of researchers all around the world owing to their potential applications in the fields of controlled drug delivery, bioseperation, water treatment, and chemical sensors. N-isopropylacrylamide (NIPAAM) is well known for its novel thermo-sensitive behavior in aqueous media, was successfully grafted on the surface and in the pores of polycarbonate track etched membrane (PCTE).The influence of reaction parameters such as monomer concentration, reaction time, reaction temperature and concentration of the initiator on the grafting yield was investigated in detail. Optimum conditions pertaining to maximum percentage of grafting were evaluated as a function of these parameters. Maximum percentage of grafting (92%) was obtained at benzoyl peroxide concentration = 0.08 M, NIPAAM concentration = 6 v/v, and reaction temperature at 600°C in a reaction time of 5 h. The microstructure and morphology of the PCTE-g-NIPAAM membranes were characterized through Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) studies. Water Contact Angle Measurement was used to study the hydrophilic behavior of the grafted membranes. These grafted membranes were investigated for their swelling behavior. The thermo-sensitive behavior of the PCTE-g-NIPAAM membranes was studied. The diffusion coefficient of the model drug salicylic acid through pristine PCTE and the PCTE-g-NIPAAM membranes was determined