Role of adsorbed water on PEEK surfaces prior to − and after − atmospheric plasma activation

Abstract

Poly‐ether‐ether‐ketone (PEEK) surfaces have been treated by atmospheric pressure plasma to increase their surface free energies − and hence, their adhesion potential towards metallic coatings as assessed by pull‐off test. Firstly, we show that adsorbed water on the polymer surface prior to plasma treatment acts as a shielding barrier against activation of the surface. This shielding effect is annealed by either a second plasma scan or by drying the surface before activation. Secondly, the relative humidity rate seems to be the main aging parameter on plasma‐treated surfaces. Our study reveals that high values of surface energies, and thus adhesion potential, can be assured and maintained for months by storing the material in a dry atmosphere before and after treatment.

Correlation between the surface chemistry, the surface free energy and the adhesion of metallic coatings onto plasma-treated Poly(ether ether ketone)

“…Two plasma treatments were used to compare their respective efficiencies and to verify the possible functionalization mechanisms they could have in common: an atmospheric pressure plasma treatment and a low pressure plasma treatment.Ageing of PEEK surfaces was already highlighted and characterized in our previous work [8]; for this current study, experimental precautions were thus taken to avoid surface properties degradation between plasma treatment and surface characterization due to surface ageing.…”

Investigating the effect of water‐mixing nitrogen atmospheric pressure plasma jet on polyether‐ether‐ketone and time stability under different conditions

“…However, the relatively poor wettability and low adhesion of PEEK have limited its further applications. To date, a lot of modification methods have been proposed to adjust PEEK properties, such as, chemical etching 12,13 , polymerization grafting [14][15][16] , laser texturing [17][18][19] , coating, [20][21][22] and plasma treatment [23][24][25][26][27][28][29][30] . Among these methods, plasma treatment can effectively improve wettability and adhesion strength of PEEK surface while does not involve chemical agents.…”

“…The increased contact angles indicate lower surface energy, which is mainly contributed by structural rearrangement and chain migration to minimize surface energy, and may restrain practical application of plasma-treated surfaces (for the plasma-induced effect gradually losses). To date, a lot of studies have been dedicated to investigate the wettability change of plasma-treated surfaces under different ambient conditions 24,[33][34][35][36] . Gravis et al 24 found that a dry atmosphere was relatively more favorable for maintaining the higher surface energy and adhesion potential of plasma-treated PEEK.…”

“…To date, a lot of studies have been dedicated to investigate the wettability change of plasma-treated surfaces under different ambient conditions 24,[33][34][35][36] . Gravis et al 24 found that a dry atmosphere was relatively more favorable for maintaining the higher surface energy and adhesion potential of plasma-treated PEEK. In addition to relative humidity, other factors like temperature and vacuum have also been found to have significant influences on the wettability recovery.…”

“…Rymuszka et al 23 studied the effect of air plasma treatment on surface wettability of PEEK, and observed that 180 s plasma treatment led to an obvious decrease of water contact angles. Gravis et al 24 found that atmospheric pressure plasma treatment could effectively improve wettability and surface energy of PEEK. Awaja et al 25–27 claimed that bond strength, surface wettability, and surface energy of PEEK were all efficiently improved after atmospheric pressure plasma treatment.…”