Replacing traditional surfactants in the preparation of polymer nanoparticles

包括汽车轮胎、油漆、涂料、密封剂和粘合剂在内的几种重要的大批量商业产品是在需要使用大量表面活性剂（通常也称为洗涤剂、乳化剂或肥皂）的制造工艺中制造的。它们的作用是稳定分散在水中的小聚合物（塑料，橡胶）颗粒，防止它们分散。这是一个每年价值超过500亿美元（CAD）的全球市场，每年使用约40万吨表面活性剂。表面活性剂是制造这些产品所必需的，但它们不能被去除或回收。因此，表面活性剂最终进入环境中，在使用寿命期间从产品中浸出，或者当产品最终进入垃圾填埋场时，它们会造成严重的毒性和环境问题。此外，它们是以石油为基础的，因此是不可再生的。认识到这些问题，工业界正在积极寻求传统表面活性剂的替代品，然而，尽管他们进行了深入的研究，但还没有出现有希望的候选物。一个理想的替代品是无毒和可再生的。这项研究计划将探索一种新型的聚合物颗粒稳定剂，能够取代现有的表面活性剂，但具有非常不同的设计，消除了环境和毒性问题，并且是可再生来源或生物基的。 大约在世纪前，人们首次认识到二氧化硅的纳米固体颗粒（很像沙子，只是小得多）能够稳定水包油乳液。然而，这一发现仅仅是一种好奇心，直到最近，人们对这些“皮克林乳化剂”表现出越来越大的兴趣，主要用于食品工业以及高端化妆品和个人护理产品。这些应用涉及稳定相对较大的油滴或蜡状颗粒。 考虑到最近对皮克林乳化剂的兴趣，一个有趣的问题是是否可能和/或实际地使用类似的方法来替代上述基于聚合物的方法中的常规表面活性剂。最近在皇后学院和其他地方取得的进展使人们感到鼓舞，认为这样的努力是可能的。因此，拟议的研究计划将奋进开发一类新的生物基替代品，以取代传统的表面活性剂，其基础是由纤维素、淀粉、甲壳素或壳聚糖制成的纳米颗粒。以前很少有研究使用生物基纳米颗粒来制造聚合物颗粒，这为产生重大的科学和商业影响提供了机会。好处将是全球性的。对加拿大的好处，除了由于减少使用表面活性剂而带来的健康和环境好处外，还包括成为生物基皮克林乳化剂的全球领导者所带来的经济好处，包括对几名高素质人员的高级培训。

Several important, large volume commercial products including automotive tires, paints, coatings, sealants and adhesives are made in manufacturing processes that require the use of large amounts of surfactants, also commonly known as detergents, emulsifiers or soaps. Their role is to stabilize the small polymer (plastic, rubber) particles which are dispersed in water by preventing them from coagulating. This is a global market worth over $50 billion (CAD) annually that uses approximately 400,000 tonnes of surfactant per year. The surfactants are essential to making these products, but they cannot be removed or recovered. Consequently the surfactants end up in the environment where they pose serious toxicity and environmental concerns, either by leaching out of the product during its service life, or when the product ends up in a landfill. Furthermore, they are petroleum-based and therefore non-renewable. Recognizing these problems, industry is actively seeking alternatives to conventional surfactants, however despite their intensive research efforts no promising candidates have emerged. An ideal replacement would be non-toxic and renewably sourced. This research proposal will explore a new type of stabilizer for polymer particles, capable of replacing existing surfactants but having a very different design, eliminating the environmental and toxicity concerns, and additionally being renewably sourced, or bio-based. Almost a century ago it was first recognized that nano-size solid particles of silica (much like sand, only much smaller) were able to stabilize oil-in-water emulsions. However this discovery remained little more than a curiosity until recently when increasing interest has been shown for these "Pickering emulsifiers", primarily for use in the food industry as well as higher end cosmetics and personal care products. These applications involve stabilizing relatively large oil droplets or waxy particles. Given the recent interest in Pickering emulsifiers, an intriguing question is whether it is possible, and/or practical, to use a similar approach to replace conventional surfactants in the polymer-based processes described above. Recent progress at Queen's and elsewhere has offered encouragement that such an undertaking may be possible. The proposed research program will therefore endeavor to develop a new class of bio-based alternatives to conventional surfactants based on nanoparticles made from cellulose, starch, chitin or chitosan. There are very few previous studies using bio-based nanoparticles to make polymer particles, presenting an opportunity to make significant scientific and commercial impacts. The benefits would be global. Benefits to Canada, in addition to health and environmental benefits due to reduced use of surfactants, would include economic benefits from being global leaders in bio-based Pickering emulsifiers including advanced training of several highly qualified personnel.