title: Photochemical interaction of polystyrene nanospheres with 193 nm pulsed laser light.
abstract: The photochemical interaction of 193 nm light with polystyrene nanospheres is used to produce particles with a controlled size and morphology. Laser fluences from 0 to 0.14 J/cm2 at 10 and 50 Hz photofragment nearly monodisperse 110 nm spherical polystyrene particles. The size distributions before and after irradiation are measured with a scanning mobility particle sizer (SMPS), and the morphology of the irradiated particles is examined with a transmission electron microscope (TEM). The results show that the irradiated particles have a smaller mean diameter ( approximately 25 nm) and a number concentration more than an order of magnitude higher than nonirradiated particles. The particles are formed by nucleation of gas-phase species produced by photolytic decomposition of nanospheres. A nondimensional parameter, the photon-to-atom ratio (PAR), is used to interpret the laser-particle interaction energetics.
authors.affiliation: Mechanical Engineering Department, University of California, Berkeley, California 94720, USA. jhyunc@me.berkeley.edu
authors.forename: Jong Hyun
authors.initials: JH
authors.lastname: Choi
authors.forename: Donald
authors.initials: D
authors.lastname: Lucas
authors.forename: Catherine P
authors.initials: CP
authors.lastname: Koshland
authors.forename: Robert F
authors.initials: RF
authors.lastname: Sawyer
mesh_terms: D007834:Lasers; D046529:Microscopy, Electron, Transmission / Q000379:methods; D049329:Nanostructures / Q000737:chemistry* / Q000528:radiation effects*; D010316:Particle Size; D010777:Photochemistry; D011137:Polystyrenes / Q000737:chemistry* / Q000528:radiation effects*; D012680:Sensitivity and Specificity; D013499:Surface Properties; D014466:Ultraviolet Rays
chemical_list: D011137:Polystyrenes