Physico-chemical characterization of a polycarbonate (PC) surface modified by exposure to dc glow discharge in air

Autor: Subrata Ray, S. K. Barthwal, Amrish K. Panwar, S. M. Shivaprasad
Rok vydání: 2008
Předmět:
Zdroj: Journal of Physics D: Applied Physics. 41:135305
ISSN: 1361-6463
0022-3727
DOI: 10.1088/0022-3727/41/13/135305
Popis: The present investigation describes the changes in the wetting characteristics of a polycarbonate (PC) surface modified by exposure to dc glow discharge at 2.04 W, as observed by contact angle measurement. The contact angle of droplets of test liquids of deionized water and formamide on PC surface decreases rapidly with increasing time of exposure to dc glow discharge and attains a minimum. Thereafter, the contact angle increases slightly to show a small hump before saturating finally at longer times of exposure. The lowering of contact angle is primarily due to the increasing polar component of surface energy. Fourier transform infrared spectroscopy and electron spectroscopy for chemical analysis indicate that increasing polar surface energy is accompanied by increased oxidized functional groups such as C–O and C=O, thus showing increasing O/C ratio with increasing exposure time. Atomic force microscopy shows increasing adhesion force with increasing exposure time, consistent with the observed adhesion energy estimated from 2.04 W contact angle measurement.
Databáze: OpenAIRE