Engineering Lignocellulosic Surfaces for Adhesion

尽管加拿大拥有世界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。非常有希望的举措包括在复合材料和涂层中使用纳米纤维素晶体和纤维。然而，任何地下室潮湿或甲板陈旧的人都知道，水是许多以纤维素为基础的材料的致命弱点。这项研究的重点是开发设计规则(科学知识)和新的方法(技术)来控制纤维素表面的粘合性能，特别是在潮湿时。 三名博士生将追求三个相互关联的关键目标： 1.针对胶粘剂的纤维素表面调整：其关键思想是基于实验证据开发机理模型，以预测醛、羧基和磺酸基团的表面分布对胶粘剂粘接的影响。通过使纤维素表面更具活性，可以使用更环保、更便宜的粘合剂。目前缺乏对预测具有最佳耐水性的纤维素表面官能团的最佳密度和类型所需的了解。 2.用于纤维素的超韧水凝胶粘合剂：在这里，我们量化了用互穿聚合物网络(IPN)取代均匀粘合聚合物网络的效果。水凝胶文献报道的最新进展描述了基于互穿网络的超韧性水凝胶。在这个项目中，我们探索是否有价值使用这种奇异的结构作为促进湿纤维粘附性的基础。 3.基于不稳定的纤维素粘合剂的农业用纸：目标是进一步开发粘合剂网络，通过编程在刺激或时间的作用下自毁。这种材料可以有许多用途，例如用作向加拿大田地运送种子和控释化肥和/或杀虫剂的载体胶带。 研究生将在麦克马斯特生物接口研究所使用最先进的表面表征和高通量设施-给我们前所未有的纤维素表面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