Design of nanocomposite polymer coatings for MEMS applications

Julthongpiput, Duangrut

doi:10.31274/rtd-180814-177

Cited by 1 publication

(1 citation statement)

References 83 publications

(110 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The concept of utilizing the mobile PFPE to enhance wear durability of SAMs with different functional groups or polymer films has not been tried in view of MEMS lubrication. Julthongpiput [25] proposed this concept of PFPE overcoating to enhance the wear resistance of epoxy nanocomposite bilayers, however, the results are not available.…”

Section: Introductionmentioning

confidence: 99%

Tribology of PFPE overcoated self-assembled monolayers deposited on Si surface

Satyanarayana¹,

Sinha²

2005

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

Friction and wear characteristics of monomolecular layers of self-assembled monolayers (SAMs) with and without perfluoropolyether (PFPE) overcoat were studied using ball-on-disk experiments. Ultra-thin layer of PFPE was dip-coated onto two different SAMs, one with non-reactive terminal group (octadecyltrichlorosilane (OTS)) and the other with reactive terminal group (3-aminopropyltrimethoxysilane (APTMS)), which were formed on Si substrate by self-assembly. The effects of PFPE overcoating on physical and chemical properties were evaluated using contact angle measurement and x-ray photoelectron spectroscopy. For a comparison, PFPE was also coated onto the Si surface and their properties were evaluated. All PFPE modified surfaces were baked at 150°C for 2 h, to investigate the effect of thermal treatment on tribological properties. PFPE coating has shown higher water contact angles irrespective of the SAM surface. Coating of PFPE on both SAM surfaces has lowered their coefficients of friction. PFPE overcoating has shown remarkable increase in the wear resistance when it was coated on reactive APTMS SAM and little increase on OTS SAM. Thermal treatment after PFPE coating onto SAMs further reduced the coefficient of friction to a smaller extent. Moreover, thermal treatment has shown an additional increase in wear-life by approximately 30% in the case of PFPE coated APTMS SAM surface and a decrease in the wear-life in the case of PFPE coated OTS SAM. The reasons for these observed phenomena are explained in terms of the amounts of PFPE bonded or mobile, surface energies of SAMs, uniformity and molecular packing of SAM surfaces.

show abstract

Section: Introductionmentioning

confidence: 99%