
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 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.