Development of active and intelligent packaging materials from low-value biomass for waste reduction

食物浪费和塑料污染是两个全球性问题。一方面，饥饿和营养不良是全球头号健康风险。在另一种情况下，每年约有40%的人工食品变成垃圾。与此同时，不可降解的塑料包装材料也带来了严重的处置和污染问题，威胁着人类的健康和发展。新颖的食品包装能帮助解决这些问题吗？由天然聚合物制成的活性和智能包装是创新材料，具有更好的保护和沟通能力，同时保持生物降解性。然而，像森林这样的自然资源不能过度开发。因此，我的研究计划(长期目标)旨在利用加拿大从废物和副产品中获得的低价值生物质(纤维素、淀粉、蛋白质和甲壳素)来生产可生物降解的功能性包装材料，以减少食品和塑料垃圾。这些材料将基于对分子结构及其相互作用的了解而设计，以实现所需的机械和阻隔性能，并将用于部分取代不可降解的塑料。通过加入活性化合物，新的包装材料还将能够延长保质期和/或指示食物的新鲜度，从而减少食物浪费。未来五年的短期目标是利用来自废旧纺织品的纤维素材料开发主动和智能的食品包装。北美每年产生超过1500万吨的废旧纺织品，但回收利用的不到五分之一。通过填埋或焚烧的方式处理废纺织品会造成环境问题，也是对有用资源的浪费。我打算使用绿色的水溶液来溶解废弃的纤维织物，并将其转化为具有良好的机械性能、阻隔性和抗微生物性能的功能性薄膜(目标1)。废弃纺织品也是纤维素纳米晶的潜在来源，它将用于稳定水中的疏水传感化合物，以开发用于监测食品腐败的活性视觉墨水(目标2)。各种纤维素衍生物将从废旧纺织品中获得，用于生产电纺织物。这些高渗透性的织物将是很有希望的基质，用于负载传感化合物，用于监测包装中的大气变化(目标3)。这项拟议的研究有三个预期的重大结果。首先，它将产生高附加值的产品(抗菌膜、活性视觉油墨和织物指示剂)，这些产品具有在商业产品中应用的高潜力，以减少食品和塑料垃圾。其次，它将进一步有助于我们从根本上理解纤维素的溶解。第三，它将培训新一代HQP，以解决围绕天然聚合物材料的环境可持续性问题和技术挑战。

Food waste and plastic pollution are two global issues. In one aspect, hunger and malnutrition are the number one health risks worldwide. In another, about 40% of manufactured food becomes waste each year. Meanwhile, the non-degradable plastic packaging materials have created significant disposal and pollution issues threatening human health and development. Can novel food packaging help address these issues? Active and intelligent packaging made by natural polymers are innovative materials with improved protection and communication at the same time retaining biodegradability. However, the natural resources like forest cannot be over-developed. Therefore, my research program (long-term objective) aims to utilize Canadian low-value biomass (cellulose, starch, protein, and chitin) obtained from waste and by-products to produce biodegradable functional packaging materials for the reduction of food and plastic wastes. These materials will be designed based on the understanding of molecular structures and their interactions to achieve desired mechanical and barrier properties, and will be used to partially replace the non-degradable plastics. By incorporating active compounds, the new packaging materials will also be able to extend the shelf life and/or indicate the food freshness, so as to decrease food waste. The short-term objectives for the next five years are to develop active and intelligent food packaging from cellulosic materials originating from waste textile. More than 15 million tons of waste textile are generated every year in North America, but less than one fifth are recycled. The disposal of waste textile via landfill or incineration causes environmental problem and also represents a waste of useful resources. I intend to use green' aqueous solvents to dissolve the cellulosic waste textile and convert it into functional films with good mechanical, barrier, and anti-microbial properties (Objective 1). Waste textile is also a potential source of cellulose nanocrystals which will be used to stabilize the hydrophobic sensing compounds in water to develop active visual ink for monitoring food spoilage (Objective 2). Various cellulose derivatives will be obtained from waste textile for the production of electrospun fabrics. These highly porous fabrics will be promising matrices to load sensing compounds for monitoring atmosphere change in package (Objective 3). This proposed research has three anticipated significant outcomes. Firstly, it will generate value-added products (antimicrobial films, active visual ink, and fabric indicator) which have high potential to be applied in commercial products to reduce food and plastic wastes. Secondly, it will further contribute to our fundamental understanding of dissolution of cellulose. Thirdly, it will train a new generation of HQP to address the environmental sustainability issues and technical challenges surrounding the natural polymer based materials.