Engineering Lignocellulosic Surfaces for Adhesion

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Although blessed with 10% of the world's forests resources, Canadians must find new, higher value-added uses for our wood. Very promising initiatives include the use of nanocellulose crystals and fibers in composites and coatings. However, anyone with a wet basement or an old deck knows that water is the Achilles heal of many cellulose-based materials. This research focuses on the development of design rules (scientific knowledge) and new approaches (technologies) for controlling adhesion properties of cellulose surfaces particularly when wet.****Three Ph.D. students will pursue three key objectives, which are inter-related:****1. Cellulose Surfaces Tuned For Adhesives: The key idea is to develop mechanistic models, based on experimental evidence, that will predict the influence of the surface distribution of aldehyde, carboxyl and sulfonic acid groups on bonding to adhesives. By making the cellulose surface more reactive, greener and less expensive adhesives can be employed. Currently lacking is the understanding required to predict the optimum density and types of cellulose surface functional groups giving the best water resistance.****2. Ultra-tough Hydrogel Adhesives for Cellulose: Here we quantify the effects of replacing the homogenous adhesive polymer networks with interpenetrating polymer networks (IPNs). Recent developments reported in the hydrogel literature describe ultra-tough hydrogels based on IPNs. In this project we explore whether or not there is value in using such exotic structures as a basis for promoting wet cellulose adhesion.****3. Towards Agricultural Papers Based on Labile Cellulose Adhesives: The goal is to develop adhesive networks, programed to self-destruct with a stimulus or time. Such a material could have many applications, for example as carrier tapes for delivering seeds and controlled release fertilizers and/or pesticides to Canadian fields.****The graduate students will employ state-of-the-art surface characterization and high throughput facilities in the McMaster Biointerfaces Institute - giving us unprecedented chemical knowledge of cellulose surfaces and how they interact with polymeric adhesives***