Atmospheric Pressure Plasma Hydrophilic Modification of a Silicone Surface

Abstract

A b e n o j a r , M . A . M a r t í n e z , a n d M . P a n t o j a. A tm o s p h e r i c p r e s s u r e p l a sm a h y d r o p h i l i c m o d i f i c a t i o n o f a s i l i c o n e s u r f a c e , P r e s e n t e d i n p a r t a t t h e 1 s t I n t e r n a t i o n a l C o n f e r e n c e o n S t r u c t u r a l A d h e s i v e B o n d i n g ( A B 2 0 1 1 ) , P o r t o , P o r t u g a l , 7 -8 J u l y 2 0 1 1 .

Surface Treatment of Polydimethylsiloxane (PDMS) with Atmospheric Pressure Rotating Plasma Jet. Modeling and Optimization of the Surface Treatment Conditions

“…Although the APPJ is meant to be used as an in‐line process to improve the wettability and adhesive properties of 2D or three‐dimensional substrates to different coatings, we have compared the aging of our plasma‐treated PDMS by two different APPJ, namely a fixed nozzle and a rotative one by WCA measurements. The silica‐like layer created by APPJ treatment of PDMS at optimal conditions allowed to confer hydrophilic properties to the surface which were more stable than what reported in the literature . Indeed in the case of the rotative plasma torch, the WCA increased but the evolution was considerably smaller than reported values .…”

“…However, in both cases a more or less silica‐like structure is formed, on the PDMS surface, due to enhanced oxidation of the surface which could explain the slightly lower aging effect as compared to what reported in the literature. In any case, the hydrophobic recovery on the APPJ‐treated PDMS is relatively fast (10–24 h) for both nozzles, although it is much slower than the one reported in the literature in which complete hydrophobic recovery of PDMS was obtained in 1 h after APPJ treatment . Therefore, the time needed for reaching substantial hydrophobic recovery of the APPJ‐treated PDMS surface at optimal conditions would be sufficiently long for allowing an efficient adhesive or coating application in an in‐line process.…”

“…Hydrophobic recovery is probably the main limitation related to plasma treatment of PDMS, an amorphous polymer, caused by the reorientation and migration of the polymeric chains after treatment . Indeed the hydrophobic recovery is particularly fast in atmospheric pressure plasma treatments as the complete recovery of the initial surface energy values of the air plasma torch treated‐PDMS within 1 h after treatment has been reported …”

“…There are very few research studies dealing with the surface treatment of PDMS with atmospheric pressure plasma jet (APPJ). Very recent studies analyzed the effects of the APPJ treatment on the adhesion properties of PDMS to different adhesives . In these studies, the influence of the experimental parameters of the APPJ treatment on the surface modification of PDMS was not analyzed but the treatment conditions were set arbitrarily.…”

“…In these studies, the influence of the experimental parameters of the APPJ treatment on the surface modification of PDMS was not analyzed but the treatment conditions were set arbitrarily. Moreover, the monitoring of surface energy obtained from different calculation methods using contact angles measurements showed an extremely fast hydrophobic recovery of APPJ‐treated PDMS surface, since it achieved the 100% of hydrophobic recovery in less than 1 h after APPJ treatment at not optimized conditions …”