Surface Modification Of Polymer By Atmospheric Non-thermal Plasmas And Plasma-Assisted Atomic Layer Deposition

Ultrahigh molecular weight polyethylene (UHMWPE) fibers were modified by an aluminum 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 were employed. It demonstrates that the aluminum oxide layer was successfully deposited on the fiber surface by scanning electron microscopy measurements. The significant enhancement of interfacial shear strength (up to435%) was achieved between the fiber surface and the resin epoxy with the coating the aluminum oxide layer, which was attributed to both the absorbance of free-OH functional group on the UHMWPE fiber surface.Polyethyleneterephthalate (PET) film with and without plasma pre-treatment were modified 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 plasma regime. It demonstrates that the Al2O3films were successfully deposited onto the surface of PET films. The cracks with various characteristics have been found in the ALD with and without plasma pre-treatment and PA-ALD with substrate at the inside of plasma regime Evaluation on the wettability by contact angle measurement shows Al2O3layers can be used to enhance the wetting property of the surfaces. Further characterizations of FTIR and X-ray diffraction show the improvement of hydroxyl OH group with Al2O3coating was consistently amorphous phase. Chemical composition of the Al2O3coated PET film has been characterized by X-ray Photoelectron Spectroscopy that has shown the content of C1s was decrease with increasing of O1s in all various coated PET Al3O3films.Polyethylene terephthalate films that modified by dielectric barrier discharge (DBD) plasma treatment have shown the helium and helium-oxygen can be functionalized on the roughness improvement of the polyethylene terephthalate surfaces. The wetting property increases significantly by plasma treatment. Further enhancement can be achieved by increasing of the oxygen content and the treatment time. It reveals the oxygen intensity increased with increasing of the oxygen flow rate that has contribution on the surface modification. Infrared spectra show the plasma treatment leads to change the chemical structure of the PET surfaces.