Thermo-responsive Properties of Surface Layer of Poly(tetrafluoroethylene) Plates Grafted with N-Isopropylacrylamide by Oxygen Plasma-treatment and Photografting.

Abstract

Poly(tetratluomethylene) (PTFE) plates grafted with N-isopropylacrylamide (NIPAAm) as hydrophilic monomer were prepared by the combined use of the plasma treatment and photografting. Their surface compositions of the grafted PTFE plates were analyzed by ES CA and thermo-responsive properties were investigated contact angle measurements and ellipsometry. Since the contact angle values of grafted PTFE decreased with an increase in the grafted amount of PNIPAAm, it is considered that the wettabilities of grafted PTFE surfaces come from the hydrophilicity of the grafted polymer chains. At the temperatures above the LCST of PNIPAAm the wettabilities of the grafted PTFE plates were lowered due to the contraction of the grafted polymer chains through hydrophobic interaction. Further, the thickness of the grafted layers of PNIPAAm onto PTFE evaluated by ellipsometry increased with the grafted amount, thermo-msponslbrllty persisting.

Low pressure plasma‐based approaches to fluorocarbon polymer surface modification

“…To avoid the problems mentioned earlier, grafting techniques on plasma activated surfaces can be applied 21–27. As a result, layers with a thickness from a few nanometers up to a few micron are formed.…”

“…19,20 To avoid the problems mentioned earlier, grafting techniques on plasma activated surfaces can be applied. [21][22][23][24][25][26][27] As a result, layers with a thickness from a few nanometers up to a few micron are formed. Contrary to simple plasma treatments, grafting processes can provide swellable and soft surfaces.…”