Surface Modification of Polymer by Atospheric Non-thermal Plasmas and Plasma-Assisted Atomic Layer Deposition

摘要

Ultrahigh molecular weight polyethylene (UHMWPE) fibers were modified by analuminum oxide thin film deposited with plasma assisted atomic layer deposition (PA-ALD),in which the precursors of Al(CH3)3 [Trimethylaluminum (TMA)] and water vapor wereemployed.It demonstrates that the aluminum oxide layer was successfully deposited on thefiber surface by scanning electron microscopy measurements.The significant enhancement ofinterfacial shear strength (up to 435 ％) was achieved between the fiber surface and the resinepoxy with the coating the aluminum oxide layer, which was attributed to both theabsorbance of free-OH functional group on the UHMWPE fiber surface.、
　　 Polyethyleneterephthalate (PET) film with and without plasma pre-treatment weremodified by atomic layer deposition (ALD) and plasma-assisted atomic layer deposition(PA-ALD) with PET substrates were positioned on the inside and the outside of Ar plasmaregime.It demonstrates that the Al2O3 films were successfully deposited onto the surface ofPET films.The cracks with various characteristics have been found in the ALD with andwithout plasma pre-treatment and PA-ALD with substrate at the inside of plas(m)a regime.Evaluation on the wettability by contact angle measurement shows Al2O3 layers can be usedto enhance the wetting property of the surfaces.Further characterizations of FTIR and X-raydiffraction show the improvement of hydroxyl-OH group with Al2O3 coating wasconsistently amorphous phase.Chemical composition of the Al2O3 coated PET film has beencharacterized by X-ray Photoelectron Spectroscopy that has shown the content of C ls wasdecrease with increasing of O ls in all various coated PET Al2O3 films.
　　 Polyethylene terephthalate films that modified by dielectric barrier discharge (DBD)plasma treatment have shown the helium and helium-oxygen can be functionalized on theroughness improvement of the polyethylene terephthalate surfaces.The wetting propertyincreases significantly by plasma treatment.Further enhancement can be achieved byincreasing of the oxygen content and the treatment time.It reveals the oxygen intensityincreased with increasing of the oxygen flow rate that has contribution on the surfacemodification.Infrared spectra show the plasma treatment leads to change the chemicalstructure of the PET surfaces.