Pulsed plasma discharge polymer coatings

Area of Science:

• Materials Science
• Polymer Chemistry
• Plasma Physics

Background:

• Controlling film uniformity and homogeneity is crucial for plasma-deposited polymers.
• Pulsed radiofrequency glow discharge (pRFGD) offers a method to modulate plasma parameters.

Purpose of the Study:

• To investigate the effect of RF duty cycle on the molecular structure of plasma-deposited polymer films.
• To explore the deposition of fluorocarbon, silane, and acrylonitrile monomers using pRFGD.

Main Methods:

• Utilized a pulsed radiofrequency glow discharge (pRFGD) system with varying duty cycles.
• Deposited polymer films on polyethylene terephthalate (PET), silicon (Si), and potassium chloride (KCl) substrates.
• Characterized film composition using electron spectroscopy for chemical analysis (ESCA) and fourier transform infrared (FTIR) analysis.

Main Results:

• Decreasing RF duty cycle in fluorocarbon films enhanced CF2/CF3 content and reduced cross-linking, yielding Teflon-like structures.
• Silane experiments showed an increasing Si-H/Si-CH3 ratio with decreasing RF duty cycle.
• Acrylonitrile experiments revealed an increasing surface density of -CN groups as RF duty cycle decreased.

Conclusions:

• The RF duty cycle is a critical parameter for controlling the molecular structure and properties of plasma-deposited polymer films.
• pRFGD provides a versatile method for tailoring polymer film characteristics for specific applications.
• Systematic variations in RF duty cycle allow for predictable modifications in film chemistry and morphology.