Magnetic hyperthermia studies in magnetite ferrofluids based on bio-friendly oils extracted from Calophyllum inophyllum, Brassica juncea, Ricinus communis and Madhuca longifolia

摘要

We study the magnetic hyperthermia efficiency of magnetite ferrofluids based on bio-friendly oils extracted from Calophyllum inophyllum (punnaga), Brassica juncea (mustard), Ricinus communis (castor) and Madhuca longifolia (iluppai) seeds. Reported medicinal uses of these bio-friendly oils make them interesting candidates for hyperthermia from a perspective of topical skin applications. Magneto-caloric experiments are performed at a fixed frequency of 126 kHz and varying field amplitudes of 33.1-25.7 kA/m. Experimental findings show that field induced heating efficiency is the highest for the punnaga oil based ferrofluids (～170.0 ± 8.2 W/gFe) and the estimated intrinsic loss power of ～ 1.26 nHm~2kg~(-1) is found to be comparable to several commercially available ferrofluids. The obtained results further indicate that field induced heating efficiency increased by ～11 times on ～ 88% reduction in medium viscosity, which is due to the reduction in Brownian relaxation time of the dispersed magnetite nanoparticles at lower medium viscosity. Dynamic hysteresis loop simulations are carried out to theoretically estimate the heating efficiencies and the experimental and theoretical data are found to exhibit similar trends. The obtained results are beneficial for optimal design of bio-friendly oil based ferrofluids for possible topical hyperthermia applications over skin surfaces.