White light emission from polystyrene under pulsed ultra violet laser irradiation

Abstract

This paper reports for the first time the luminescent property of polystyrene (PS), produced by pulsed ultra violet laser irradiation. We have discovered that, in air, ultra-violet (UV) irradiated PS nanospheres emit bright white light with the dominant peak at 510 nm, while in vacuum they emit in the near-blue region. From the comparison of PS nanospheres irradiated in vacuum and air, we suggest that the white luminescence is due to the formation of carbonyl groups on the surface of PS by photochemical oxidation. Our results potentially offer a new route and strategy for white light sources.

Optical Trapping Dynamics of a Single Polystyrene Sphere: Continuous Wave versus Femtosecond Lasers

“…In this range of laser power, the immobilization time of fs pulse mode is slightly longer than that of cw laser mode. We should note that at a laser power of 30 mW, a few trapping events under fs-mode accompanied by white photoluminescence were clearly observed by the CCD camera after the particle is immobilized in the trapping site for more than 10 s. The luminescence could be assigned to the photoluminescence of polystyrene induced by the fs laser pulse train, and such photoluminescence of polystyrene induced by UV pulsed laser irradiation for several minutes has been reported . This phenomenon has been ascribed to the formation of carbonyl groups on the surface of polystyrene particles due to fs laser-induced photochemical oxidation .…”

“…We should note that at a laser power of 30 mW, a few trapping events under fs-mode accompanied by white photoluminescence were clearly observed by the CCD camera after the particle is immobilized in the trapping site for more than 10 s. The luminescence could be assigned to the photoluminescence of polystyrene induced by the fs laser pulse train, and such photoluminescence of polystyrene induced by UV pulsed laser irradiation for several minutes has been reported. 55 This phenomenon has been ascribed to the formation of carbonyl groups on the surface of polystyrene particles due to fs laserinduced photochemical oxidation. 55 As the photoluminescence is successive processes of photoexcitation, photoreaction, and generation of photoproducts, 55 detectable photoluminescence spectrum of accumulated photoproducts during the laser trapping was observed after long irradiation time.…”

Size-Dependent Charge Storage Behavior of Mesoporous Hollow Carbon Spheres for High-Performance Li–Se Batteries

“…From the figure, it is evident that polystyrene shows photoluminescencerelated bands in the range of 350−550 cm −1 , which are found to be absent in the precursor and in the HCS, thereby indicating the formation of hollow carbon spheres as the final product without any polystyrene moiety. 42 Figure 1 presents the bright-field transmission electron microscopy images of PS-templated hollow carbon spheres with 500 and 1000 nm hollow interiors. These images demonstrate the formation of homogenous hollow spherical structures consisting of a distinct interior with a diameter exactly same as that of the PS template.…”

“…PL spectra recorded for polystyrene, carbon-coated precursor, and hollow carbon spheres are displayed in Figure S2. From the figure, it is evident that polystyrene shows photoluminescence-related bands in the range of 350–550 cm –1 , which are found to be absent in the precursor and in the HCS, thereby indicating the formation of hollow carbon spheres as the final product without any polystyrene moiety …”

Two-dimensional organic cathode materials for alkali-metal-ion batteries

“…Polycyclic aromatic hydrocarbons (PAHs) with extended π -delocalized structure have been represented as typical twodimensional graphene segments [77] . Because of their unique optoelectronic and electrochemical properties, these 2D polyaromatic molecules have gained increasing interest in the application of optoelectronic devices, such as organic field transistors (OFETs) [78] , organic solar cells (OPVs) [79] , and organic light-emitting devices (OLEDs) [80,81] . Concerning their facile synthetic protocols, incorporation of various redox functional groups into the aromatic frameworks of 2D polyaromatic molecules is an efficient strategy to endow their excellent electrochemical performance for energy storage and conversion.…”