Stimuli-Chromic Polymer Nanoparticles for Smart Inks, Encryption, Visualization of LatentFingerprints, Sensors, and OLEDs

In this study, amine-functionalized polymer nanoparticles were synthesized by emulsioncopolymerization of methyl methacrylate (MMA) and ۲-(dimethylamino)ethyl methacrylate (DMAEMA). The sizeof the latex nanoparticles was increased as a function of poly(dimethylaminoethyl acrylate) (PDMAEMA)contents, and also a decrease of particle size was obtained in response to an increase of temperature from ۲۵to ۷۰ °C, above the lower critical solution temperature (LCST) of PDMAEMA. Afterward, prepared polymernanoparticles were physically modified with spiropyran and oxazolidine to form photoswitchable polymernanoparticles that display photochromism (color change) and photoluminescence (red fluorescence emission)in response to UV-light irradiation (۳۶۵ nm). Photoswitchable polymer nanoparticles were used in two forms oflatex solution and polymer powder for different applications such as anticounterfeiting inks, encryption ofinformation, visualization of latent fingerprints, sensing of pH, and development of organic light-emitting diodes(OLEDs).

Keywords:

Spiropyran , Oxazolidine , Photochromic , Fluorescence , Smart Ink , Latent Fingerprint