Engineering Lignocellulosic Surfaces for Adhesion

虽然加拿大拥有世界上10%的森林资源，但加拿大人必须为我们的木材找到新的、更高附加值的用途。 非常有前途的举措包括在复合材料和涂料中使用纳米纤维素晶体和纤维。 然而，任何拥有潮湿地下室或旧甲板的人都知道，水是许多纤维素材料的致命弱点。 这项研究的重点是开发设计规则（科学知识）和新方法（技术），以控制纤维素表面的粘附性能，特别是在潮湿时。三个博士学生将追求三个相互关联的主要目标：*1.为粘合剂调整的纤维素表面：关键思想是根据实验证据开发机械模型，预测醛、羧基和磺酸基团的表面分布对粘合剂粘合的影响。通过使纤维素表面更具反应性，可以使用更环保和更便宜的粘合剂。 目前缺乏的是预测纤维素表面官能团的最佳密度和类型所需的理解，从而提供最佳的耐水性。2.用于纤维素的超韧性水凝胶粘合剂：在这里，我们量化了用互穿聚合物网络（IPN）取代均匀粘合剂聚合物网络的效果。 水凝胶文献中报道的最新进展描述了基于IPN的超韧性水凝胶。 在这个项目中，我们探讨是否有价值，在使用这种异国情调的结构作为基础，促进湿纤维素粘合。3.基于不稳定纤维素粘合剂的农业纸：目标是开发粘合剂网络，编程为随着刺激或时间自毁。 这种材料可以有许多应用，例如作为载体带，用于将种子和控释肥料和/或杀虫剂输送到加拿大的田地。研究生将在麦克马斯特生物界面研究所使用最先进的表面表征和高通量设施-为我们提供纤维素表面的前所未有的化学知识以及它们如何与聚合物粘合剂相互作用 *

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***