Surface modification of polytetrafluoroethylene film by argon cold atmospheric pressure plasmas for enhancing bonding with graphene‐filled polyimide adhesives.
Significantly enhanced adhesion of polytetrafluoroethylene (PTFE) films to graphene‐filled polyimide (PI) adhesives by argon (Ar) cold atmospheric pressure plasmas (CAPPs) at the exposure durations of 72–96 s was undertaken. Poor adhesion of PTFE film to PI adhesive with no bonding (100% delamination) was highly improved to good bonding (100% attachment) for PTFE film treated by Ar CAPPs. Hydrophobic PTFE surface (water contact angle up to 91.1°) was changed to hydrophilic PTFE surfaces (water contact angle up to 37.4°–66.0°) with Ar CAPPs treatment by formation of polar chemical bonds such as C–O and C=O. To realize how the chemical bonds of C–O and C=O were produced onto the PTFE surface by Ar CAPPs, the plasma active species of Ar CAPPs were detected by optical emission spectroscopy.