Effect of cross-linker and dopant concentrations on the magnetic properties of poly(vinyl alcohol)-borax ferrogels

Abstract

Here, Vibrating Sample Magnetometry (VSM) measurements on two sets of poly(vinyl alcohol) ferrogels are reported. The ferrogel matrices are cross-linked with borax and possess micron-sized carbonyl iron (CI) particles as the magnetically-sensitive dopant. The matrices exhibit soft magnetic behaviour owing to the presence of the dopant. For the set with borax concentration 30 mg/mL, the ferrogel with CI concentration 20 mg/mL shows the highest saturation magnetization and magnetic susceptibility values. Among the ferrogels having borax proportions 40 mg/mL, the matrix with CI concentration 20 mg/mL exhibits lowest saturation magnetization and magnetic susceptibility, while the other samples have nearly-equal values of the parameters. The observed magnetic parameters are explained on the basis of modifications of local network structure which arise from the variations in borax and CI concentrations. The findings will be useful in the development of improved and fine-tuned applications.