Replacing traditional surfactants in the preparation of polymer nanoparticles

一些重要的、大批量的商业产品，包括汽车轮胎、油漆、涂料、密封剂和粘合剂，在制造过程中需要使用大量的表面活性剂，也就是通常所说的洗涤剂、乳化剂或肥皂。它们的作用是稳定分散在水中的小聚合物（塑料、橡胶）颗粒，防止它们凝固。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，造成严重的毒性和环境问题，要么在产品使用寿命期间从产品中浸出，要么在产品最终被填埋。此外，它们以石油为基础，因此是不可再生的。认识到这些问题，工业界正在积极寻找传统表面活性剂的替代品，然而，尽管他们进行了大量的研究，但尚未出现有希望的候选产品。理想的替代品是无毒且可再生的。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，消除环境和毒性问题，并且是可再生来源或生物基的。大约一个世纪以前，人们首次认识到纳米级的固体二氧化硅颗粒（很像沙子，只是小得多）能够稳定水包油乳液。然而，直到最近，人们对这些主要用于食品工业、高端化妆品和个人护理产品的“皮克林乳化剂”越来越感兴趣，这一发现才引起了人们的好奇心。这些应用包括稳定较大的油滴或蜡质颗粒。鉴于最近人们对皮克林乳化剂的兴趣，一个有趣的问题是，在上述基于聚合物的工艺中，是否有可能和/或实际使用类似的方法来取代传统的表面活性剂。最近在女王学院和其他地方取得的进展让人们相信，这样的事业是可能实现的。因此，拟议的研究计划将努力开发一种新的生物基替代品，以取代由纤维素、淀粉、几丁质或壳聚糖制成的纳米颗粒制成的传统表面活性剂。以前很少有研究使用生物纳米颗粒来制造聚合物颗粒，这提供了一个产生重大科学和商业影响的机会。其好处将是全球性的。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效益外，还包括作为生物基皮克林乳化剂的全球领导者所带来的经济效益，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.