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Fleetwood, Sara Kaitlin

University of British Columbia

Waterproof, breathable materials (WBMs) serve various purposes, ranging from water filtration to food packaging, with a familiar application being rain jackets. The primary function of rain jackets is to keep a user dry by blocking liquid water while allowing the transmission of water vapour. WBMs achieve this with two key components: an external hydrophobic coating and an internal membrane. However, coatings often contain perfluorinated compounds (PFCs) that are hazardous to human health, and the membranes have a water vapour transmission rate (WVTR) too low to match the body’s sweat rate. This work introduces PFC-free, superhydrophobic coatings that are both biodegradable and bio-sourced. Water-repellent coatings were prepared from commercially unavailable plant waxes. A plant survey was conducted, and the bulk extraction of waxes from conifer trees yielded a mixture of hydrophobic and hydrophilic compounds. Therefore, a purification process was tested, and it was determined that, although the wax extract outperformed commercial products, removing noncrystallizing wax components did not significantly enhance the coating's performance. It was shown that, using less coating material than commercial coatings, high-performing petroleum-free coatings could be made and applied onto textiles of various polarities without a costly purification step. Additionally, to enhance the WVTR of existing membranes, we developed intracellularly hydrogelated isolated guard cells (iGCs), intended for future incorporation into microporous membranes. Through this work, guard cells (GCs) were successfully isolated with their cell walls intact from the leaves of Vicia faba, allowing further in-depth analyses into the cell wall composition of GCs. Additionally, we intracellularly infused the hydrogel polymer PEG-DA into the iGCs through photoactivated crosslinking. By incorporating a hydrogel intracellularly within iGCs, this work aided in the preservation of GCs with minimal compositional loss, offering potential future insights into their composition and plant actuation mechanisms. In conclusion, this work overcomes the human health hazards of existing coatings through the development of plant-based alternatives. Furthermore, it tackles the WVTR challenges of existing membranes through the successful isolation and modification of GCs, with the hope of future developments resulting in responsively breathable membranes.

Text

2024-10-24

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/89503

Chemical and Biological Engineering

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/