Photoswitchable magnetic nanoparticles of Prussian blue with amphiphilic azobenzene

A novel type of photocontrollable Prussian blue (PB) magnetic nanoparticle has been designed and prepared by using the reverse micelle technique. These magnetic nanoparticles possess a well-organized nanoscale structure. Reversible photoisomerization of azobenzene chromophores realized photoswitching of the magnetization. The photoisomerization of the composite materials was accompanied by a geometrically confined structural change within the reverse micelles, as reflected by changes in the dipole moment and the electrostatic field. As a result, the magnetization values could be switched reversibly by using alternating UV and visible light illumination.