
PTFE
films are films of the polymer polytetrafluoroethane.
Polytetrafluoroethylene is one of the most important high insulating organic
polymer electret materials, which have been applied in many fields such as
sensors, generators and motors, dose-meters, and air-filters at high
temperature.
PTFE films are ultimate in durability, low stretch, high strength, high
temperature, non-stick protection for lamination lay ups and roll end wraps.
PTFE have several advantages related to both orienting properties and
processibility. They are easy to prepare, chemically inert, thermally
stable, optically transparent and of low cost.
Preparation of the PTFE Film
Thin films of PTFE are prepared by pulsed laser deposition from bulk PTFE
targets using 157 nm F2-laser radiation. The Teflon films are analyzed by
means of optical polymerization microscopy, stylus profilometry, XPS, XRD,
FTIR spectroscopy and by capacitance measurements. The effect of substrate
temperature on the morphology and crystallinity is studied. Films treated at
sufficiently high temperature consist mainly of spherulite like
crystallites. Films with a thickness of more than about 155 nm are
continuous, pinhole free, well adherent to the substrate and have a
composition which is similar to that of the target material. The minimum
film thickness and deposition rates are much lower than achieved with
pressed PTFE powder targets using 248 nm KrF- laser ablation. This is
related to different deposition mechanisms. Correspondingly, the morphology,
crystallinity, and the optical and dielectric properties of films
significantly differ from each other.