Atmospheric Plasma Deposited Dense Silica Coatings on Plastics

Abstract

We explore the application of a high-temperature precursor delivery system for depositing high boiling point organosilicate precursors on plastics using atmospheric plasma. Dense silica coatings were deposited on stretched poly(methyl methacrylate), polycarbonate and silicon substrates from the high boiling temperature precursor, 1, 2-bis(triethoxysilyl)ethane, and from two widely used low boiling temperature precursors, tetraethoxysilane and tetramethylcyclotetrasiloxane. The coating deposition rate, molecular network structure, density, Young's modulus and adhesion to plastics exhibited a strong dependence on the precursor delivery temperature and rate, and the functionality and number of silicon atoms in the precursor molecules. The Young's modulus of the coatings ranged from 6 to 34 GPa, depending strongly on the coating density. The adhesion of the coatings to plastics was affected by both the chemical structure of the precursor and the extent of exposure of the plastic substrate to the plasma during the initial stage of deposition. The optimum combinations of Young's modulus and adhesion were achieved with the high boiling point precursor which produced coatings with high Young's modulus and good adhesion compared to commercial polysiloxane hard coatings on plastics.

Improved Adhesion of Dense Silica Coatings on Polymers by Atmospheric Plasma Pretreatment

“…An atmospheric pressure plasma system [Surfx Technologies LLC, Redondo Beach, CA] integrated with a hightemperature precursor delivery system was employed to pretreat the plastic substrates and deposit the coating. 16 The area of the plasma showerhead was 5.1 cm 2 . A total of 99.995% purity quality helium and oxygen [Praxair Inc., Santa Clara, CA] were mixed and fed into the capacitive discharge plasma.…”

Mechanical properties of sol–gel coatings on polycarbonate: a review

“…It permits to measure the adhesion in J.m -2 (G c ) by applying loads/unloads at a controlled displacement rate to produce coating cracks growth [50]. G c is then calculated using the Kanninen corrected equation [51]:…”

Reverse osmosis performance of layered-hybrid membranes consisting of an organosilica separation layer on polymer supports

“…This membrane also showed high H 2 /CH 4 (10.5) and H 2 /N 2 (12.4) selectivities in a separation test of gas mixtures [25]. However, the deposition of a more promising organosilica layer between rigid inorganic and flexible polymeric materials on polymer has been demonstrated [26,27]. Ngamou et al proposed the use of an expanding thermal plasma chemical vapor deposition (ETP-CVD) technique in order to fabricate a BTESE-derived silica layer on a porous polyamide-imide substrate for n-butanol dehydration [28].…”