Enhanced thermal conductivity of nanoparticle aqueous suspensions by femtosecond laser irradiation
발표자
()
초록
내용
This work reports a significant increase in the thermal conductivity (k) of aqueous titanium dioxide (TiO2) nanoparticle suspensions achieved through ultrafast laser irradiation. At relatively low laser fluence , a laser stabilization process occurred, which did not reduce the primary particle size but resulted in an increase in the thermal-conductivity ratio from 1.04 to 1.12 in the aqueous TiO2 nanoparticle suspension. At relatively high laser fluence, laser fragmentation of the NPs reduced the primary particle size, leading to a further increase in the k ratio to 1.26. Theoretical models considering percolation effects of aggregates, Brownian motion, interfacial liquid layering, and the formation of an electric double layer were used to explain the observed increase in thermal conductivity. This work demonstrates that ultrafast laser irradiation provides an effective non-chemical method to enhance the thermal and colloidal properties of TiO2 nanofluids.