Adhesion and Tribological Properties of Sputtered Polymer Thin Films with Thermally Stable Polymer Targets

Abstract

Polymer thinˆlms were sputtered with thermally stable polymer targets onto a copper and glass slide substrate with a conventional RF sputtering apparatus. Polymer structures and adhesion and tribological properties of these polymer thinˆlms were evaluated.The pull strength between evaporated metalˆlms and sputtered poly(tetra‰uoroethylene) (PTFE) thinˆlm was higher than that between evaporated metal thinˆlms and the bulk PTFE. This diŠerence was apparently due to diŠerences in chemical bonding states between the sputtered PTFE thinˆlm and the bulk PTFE. The PTFE thinˆlms were sputtered at various conditions. Surface free energy of the PTFE thinˆlms decreased with increase of ‰uorine content of the PTFE thinˆlms. Although dispersion force component of the surface free energy slightly decreased, dipole force component dramatically decreased with increase of temperature of the substrate.Polymer thinˆlms were sputtered onto copper substrate with two polyimide (Kapton-V TM and Upilex-S TM ) targets. Argon and nitrogen were introduced into the sputtering chamber for the sputtering gases. Sputtering rate of the polymer thinˆlm with argon gas showed highest value at a pressure of 0.67 Pa. However, the sputtering rate with nitrogen gas showed highest value at a pressure of 8 Pa. Nitrogen content in the thinˆlm sputtered with the nitrogen gas (N 2 sputtered thinˆlm) increased compared to that sputtered with argon gas (Ar sputtered thinˆlm) and target material. Friction coe‹cient and wear durability of the N 2 sputtered thinˆlm were higher than those of the thinˆlm sputtered with the Ar sputtered thinˆlm. The pull strength between the N 2 sputtered thinˆlm and copper substrate was higher than that between the Ar sputtered thinˆlm and copper substrate. In addition, the N 2 sputtered thinˆlm was introduced between the copper substrate and Ar sputtered thinˆlm (Ar/N 2 /Cu laminate). The pull strength of this laminate showed higher value than that between the Ar sputtered thinˆlm and copper substrate.

Fluorocarbon Thin Films Fabricated using Carbon Nanotube/Polytetrafluoroethylene Composite Polymer Targets via Mid-Frequency Sputtering

“…Figure 5(a) indicates that the intensities of the C-F and C-CF peaks increase as the CNT concentration increases from 1 to 15 wt%, while the fluorine contents decrease. These results indicate that a highly cross-linked structure is formed as the carbon contents are increased 38 , 42 , 50 . F-1s peaks appear near 689.2 eV, and the intensities of the F-1s peaks of all fluorocarbon thin films have similar values (Supplementary Figure S3 , Supplementary Information).…”

“…The F/C ratios of the thin films were calculated from the relative intensities of the deconvolution peaks in the C-1s spectra (Supplementary Table S2 , Supplementary Information). Many researchers have reported F/C ratios ranging from 0.78~1.60 18 , 29 , 31 , 38 , 42 , 47 . Among these researchers, Golub et al .…”

“…The Faupel group focused on nanocomposite thin films formed by the methods of metal-polymer co-sputtering and multilayer processes 40 , 45 , 47 , 51 , 52 . The Iwamori group reported many research outcomes focusing on the optical and mechanical properties of RF-sputtered fluorocarbon thin films 22 , 24 , 33 , 34 , 38 , 41 , 42 .…”

Fabrication of superhydrophobic nanostructured surface on aluminum alloy

“…On the other hand, a variety of CVD and PVD techniques have been used to deposit PTFE. The sputtering technique is widely used in electrical and mechanical applications because the process is simple, time saving, environmentally friendly, and the resulting coating has a uniform structure and excellent adhesion properties to most substrates [15][16]. In this work, a superhydrophobic surface with low contact angle hysteresis (CAH) was made by consecutive immersion in boiling water and sputtering of Teflon on the surface of aluminum alloys.…”

Superhydrophobic and icephobic surfaces prepared by RF-sputtered polytetrafluoroethylene coatings

“…On the other hand, a variety of CVD and PVD techniques have been used to deposit PTFE. The sputtering technique is widely used in electrical and mechanical industries; because the process is simple, time saving, and environmentally friendly, and the resulting coating has a uniform structure and excellent adhesion properties to most substrates [27][28]. Herein, a superhydrophobic surface with low contact angle hysteresis (CAH) was made by consecutive anodizing of aluminum and sputtering of PTFE to reduce ice accumulation on the surface of aluminum alloys.…”