Highly Flexible Yet Hard Transparent Omniphobic Coating Reinforced with an Electrospun Nylon Nanofiber Mat
Loading...
Authors
Tan, Chun Keat
Date
Type
thesis
Language
eng
Keyword
Flexible , Hard , Transparent , Omniphobic coating , Electrospinning , Electrospun nylon nanofiber , Nanofiber , Composite , Reinforced , Anti-smudge , GPOSS , GPOSS-FC6 , nanocomposite , Bendability , wear resistance , abrasion
Alternative Title
Abstract
Photocuring GPOSS-g-FC6, 3-glycidyloxypropyl polyhedral oligomeric silsesquioxane (GPOSS) bearing a grafted (g) tridecafluoroheptanoyl group (FC6), produces a transparent omniphobic coating with the highest 9H pencil hardness. Although this coating on a poly(ethylene terephthalate) (PET) film can undergo inward bending to a curvature radius < 1 mm, it has limited bendability on the outer surface of a bending PET film, which limits the application of this coating on the touchscreen of foldable smartphones. My thesis research is aimed at solving this bendability challenge, by reinforcing a GPOSS-g-FC6 coating with a nylon 6,6 electrospun nanofiber mat.
To produce a transparent nanocomposite sample, the electrospun nanofiber diameter must be sufficiently small for minimum light scattering. Thus, the commercial nylon 6,6 was fractionated to yield a higher molecular weight nylon 6,6 (108 ± 4kDa) that enables the production of smaller electrospun nanofibers. The fractionated sample molecular weight was determined via viscosity analysis.
To simplify the preparation of a GPOSS-g-FC6/PET bilayer, electrospinning was done on an ITO-coated PET film. After optimization, a voltage of 20.0 kV, nozzle-to-collector distance of 18.0 cm, a 7.0 wt% nylon 6,6 in formic acid solution, and syringe pump rate of 0.254 mL/h, were used to fabricate nanofiber mats.
GPOSS-g-FC6 was mixed with a photoinitiator to form infusion solutions depending on different thicknesses, and % infusions (by voids volume) of nanofiber mats. A series of nanocomposite samples with 100%, 150%, and 200% infusions at 20, 30, and 40 μm were prepared.
The nanocomposite sample was investigated for its transparency, nanoindentation, pencil hardness, static contact angles, dynamic de-wettability, and wear resistance. The study shows 20 μm 150% infused sample has the best transparency at 98.1 ± 1.1 %. The sample has comparable nanoindentation properties with pure GPOSS-FC6 coating on ITO-PET film, and pencil hardness between 5H and 6H. Nanocomposites with 150% and 200% infusion have comparable de-wetting properties with pure GPOSS-FC6. Higher % infusion and thicker samples have better wear resistance. The free-standing nanocomposites are bendable on both surfaces on the smallest 2.00 mm diameter mandrel in a bend tester. In addition, the nanocomposite retains its ink contraction property after 500 bending cycles.
Description
Citation
Publisher
License
Queen's University's Thesis/Dissertation Non-Exclusive License for Deposit to QSpace and Library and Archives Canada
ProQuest PhD and Master's Theses International Dissemination Agreement
Intellectual Property Guidelines at Queen's University
Copying and Preserving Your Thesis
This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.
ProQuest PhD and Master's Theses International Dissemination Agreement
Intellectual Property Guidelines at Queen's University
Copying and Preserving Your Thesis
This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.