In Situ Observation of Laser-Induced Convection of Water in High Magnetic Fields Using a Photochromic Reaction

The effects of vertical magnetic fields on laser-induced convection of water were studied using a photochromic reaction of a water-soluble 1,2-diarylethene (WSD). A thin blue disk of its photoisomer (PI) solution was formed on the bottom surface; it moved upward when the WSD aqueous solution was irradiated using a 355 nm laser from the bottom of the vessel. The lift speeds of the PI solution were about 2.5 (11 T, +1200 T2 m−1), 1.2 (11 T, −1500 T2 m−1), and 1.6 mm min−1 (15 T, −100 T2 m−1). All results are described in terms of the magnetic force acting on the PI solution.