UV Light-Responsive Photo-rheological Fluids:As a New Class of Smart Fluids

초록

This research presents a state-of-art review on the photo-rheological (PR)fluid whose rheological behavior can be changed by ultraviolet (UV) light with a wavelength of 365 nm. When the PR fluid was exposed to UV light, the viscosity of PR fluid becomes decreased, while viscosity recovered its initial value when UV light was turned off, which implies that the viscosity of PR fluid can be reversible, and tunable by light. Contrary to conventional smart fluid such as ERFs, and MRFs, PR fluid does not suffer from phase splitting problem because it is single-phase solution. Additionally, PR fluid does not require any contact component such as electrodes, and electric wires that will be essential components for conventional smart fluids. The PR fluid also does not require any electro-magnetic interference (EMI) shielding. In this research, the PRFs were synthesized by doping lecithin/sodium deoxycholate (SDC) reverse micelles with a photochromic spiropyran (SP) compound. It is demonstrated that the viscosity changes of PR fluids can be induced by UV light, and their rheological properties are examined in detail. The potential applications using the PR fluids is also briefly discussed.