聚苯乙烯纳米球与193纳米脉冲激光的光化学相互作用。

Photochemical interaction of polystyrene nanospheres with 193 nm pulsed laser light.

作者信息

Choi Jong Hyun, Lucas Donald, Koshland Catherine P, Sawyer Robert F

机构信息

Mechanical Engineering Department, University of California, Berkeley, California 94720, USA.

出版信息

J Phys Chem B. 2005 Dec 22;109(50):23905-10. doi: 10.1021/jp0540611.

DOI:10.1021/jp0540611

PMID:16375376

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.

摘要

利用193纳米光与聚苯乙烯纳米球的光化学相互作用来制备尺寸和形态可控的颗粒。在10赫兹和50赫兹频率下，激光能量密度从0到0.14焦耳/平方厘米可使近乎单分散的110纳米球形聚苯乙烯颗粒发生光碎片化。用扫描迁移率颗粒大小分析仪（SMPS）测量辐照前后的尺寸分布，并用透射电子显微镜（TEM）检查辐照颗粒的形态。结果表明，辐照后的颗粒平均直径较小（约25纳米），且数浓度比未辐照颗粒高出一个数量级以上。这些颗粒是由纳米球光解产生的气相物种成核形成的。一个无量纲参数，即光子与原子比（PAR），用于解释激光与颗粒相互作用的能量学。