Duty cycle dependent wettability of pulsed plasma copolymers
Octafluorocyclobutane and acrylic acid (C4F8-co-AA) plasma copolymer coatings are deposited using a pulsed wave (PW) radio frequency (RF) plasma on low density polyethylene (LDPE). The influence of duty cycle in pulsed process with the monomer feed rate on the surface chemistry and wettability of C4F8-co-AA plasma polymer coatings is studied. The concentration of the carboxylic acid (hydrophilic) groups increase, and that of fluorocarbon (hydrophobic) groups decrease by lowering the duty cycle. The combined effect of surface chemistry and surface morphology of the RF pulsed plasma copolymer coatings causes tunable surface wettability and surface adhesion. The gradual emergence of hydrophilic contents leads to surface heterogeneity by lowering duty cycle causing an increased surface adhesion in hydrophobic coatings. The C4F8-co-AA plasma polymer coatings on the nanotextured surfaces are tuned from repulsive superhydrophobicity to adhesive superhydrophobicity, and further to superhydrophilicity by adjusting the duty cycles with the monomer feed rates.
Further details can be found in the article by I. Muzammil et al. from the Dalian University of Technology.
Tunable water adhesiveness from repulsive to adhesivesuperhydrophobicity was demonstrated.
Controllable wettability was confirmed from superhydrophobicity to superhydrophilicity.
Further details can be found in the article by I. Muzammil et al. from the Dalian University of Technology. 
- Muzammil Iqbal; Y.P. Li; X.Y. Li; M.K. Lei; Duty cycle dependent chemical structure and wettability of RF pulsed plasma copolymers of acrylic acid and octafluorocyclobutane. Applied Surface Science 2018, 436, 411-418, 10.1016/j.apsusc.2017.11.261.