GENERIC PARAMETERS GOVERNING THE WETTABILITY CHARACTERISTICS OF LASER-MODIFIED NYLON 6,6

摘要

Wettability is an interesting subject which spans anyrndiscipline that takes into account any form of adhesion.rnAs such, it is imperative to identify generic parametersrnthat govern the wetting nature of materials. This paperrndetails the use of CO_2 and KrF excimer lasers tornmodify the surface of nylon 6,6 in order to modulaternthe wettability characteristics. White lightrninterferometery allowed one to establish that thernsurface roughness (Ra) was dramatically increased byrnup to 4.5 μm in comparison to the as-received sample.rnUsing a sessile drop device it was determined for allrnsamples that the polar component had a strong inversernrelationship with the contact angle, θ. For the patternedrnsamples an increase in θ indicated the likely formationrnof a mixed-state wetting regime and highlighted thernsignificant influence of surface topography on θ. X-rayrnphotoelectron spectroscopy determined that the surfacernoxygen content had increased by up to 5.7 %at. for allrnsamples. Due to the highly modulated nature of θ overrnall samples it was concluded that surface oxygenrncontent was not a dominant parameter; whereas thernpolar component and surface pattern were the mostrndominant parameters governing the wettabilityrncharacteristics of the laser-surface-modified nylon 6,6.