Author: Harshit Agarwal

Publisher:

Published: 2021

Total Pages:

ISBN-13:

The work reported in this thesis focuses broadly on advancing new design principles, developing new fabrication approaches, and characterizing the physical properties and functional behaviors of liquid impregnated surfaces (LIS) or slippery liquid infused porous surfaces (SLIPS). LIS or SLIPS are an emerging class of anti-fouling materials that are fabricated by the infusion of lubricating liquids into chemically compatible porous or textured solid surfaces, resulting in a thin and mobile film that allows a broad range of chemically complex liquids, microorganisms, and other contaminants to readily slide off. In the first half of this thesis, we demonstrate new fabrication approaches that allow liquid-infused materials to be formed on or applied to objects of arbitrary shape and size and, in many cases, using processes that have the potential to be integrated into industrial manufacturing processes. This involves approaches for the fabrication of polymer-based SLIPS in the confined luminal spaces of flexible tubing of arbitrary length and diameter, useful for reducing or preventing biofouling, process fouling, and the clogging or occlusion of tubing in a wide range of consumer, industrial, and healthcare-oriented applications. We further demonstrate a proof of concept demonstration of a continuous approach to SLIPS fabrication using a benchtop roll-to-roll setup to coat meter-scale lengths of flexible plastic film. SLIPS-coated film produced using this roll-to-roll approach was then used to design models of flexible food packaging (e.g., transparent bags or sachets) and containers. The second half of this thesis focuses on design principles that expand the range of building blocks that can be used to fabricate these anti-fouling materials and enable the incorporation of new behaviors and functions, such as controlled release, environmental responsiveness, biodegradability, and sustainability. We demonstrate that infusion of oils into porous nanofiber-based meshes fabricated by electrospinning or blow spinning of poly(caprolactone), a biodegradable polymer commonly used in biomedical implants and drug delivery devices, can lead to surfaces with robust anti-fouling performance. We further demonstrate that new functions and behaviors of controlled-release and environmental responsiveness can be introduced into these materials by using complex fluids such as water-in-oil (w/o) nanoemulsions or thermotropic liquid crystals, respectively, as the infused liquid phase instead of conventional oils.