RHEOLOGY AND PIPELINE FLOW BEHAVIOUR OF NANOPARTICLE-STABILIZED PICKERING EMULSIONS: MODELLING AND EXPERIMENTS

最近对纳米颗粒在Pickering乳剂中用作乳化剂的研究表明，在生产新的食品、化妆品和药品方面前景广阔，仅举几例。然而，这些Pickering乳剂在大规模生产系统中的行为方式尚不清楚。这项研究建议提供所需的模型来预测他们的行为，以便制造商能够相应地设计工厂和工艺。这项研究将帮助加拿大工业利用这些乳剂的优势生产增强产品，从而在全球市场上成功竞争。许多产品都含有使用表面活性剂将一种液体悬浮在另一种不相容液体(如油和水)中的乳状液。表面活性剂通过制造、包装、运输和储存来稳定乳液产品，并有助于确保它们在购买后仍然安全。不幸的是，表面活性剂通常来自不可再生的来源，会导致健康问题，包括皮肤刺激和红细胞损伤。这在化妆品和药品中是有问题的，因为它们是作为面霜、擦剂和皮肤软膏生产的。在过去的十年里，科学家们开始使用无毒物质的固体纳米颗粒，如蛋白质和淀粉，来创造不含表面活性剂的乳状液。它们出色的特性使它们成为产品开发的理想选择，但人们对它们在大规模生产系统中的流动知之甚少。事实上，这些Pickering乳状液的油/水界面处的纳米颗粒层改变了它们的流变性和管道流动行为。因此，使用传统表面活性剂乳液的模型来生产Pickering乳液会导致工艺和质量控制问题。制造商需要充分了解Pickering乳液的流变学和泵送行为，然后才能设计、选择和操作通过管道系统处理、混合、存储和运输此类材料的设备。然而，还没有发表的研究充分描述皮克林乳剂的流变学和管道流动。这项研究的长期目标是对稀释和浓缩的Pickering乳液的流变学和管道流动进行建模和实验研究，这将导致预测它们在大规模生产系统中的行为的模型。加拿大工业可以使用这些模式为其创新的新产品设计具有成本效益、持久和节能的基础设施和流程。这项研究的大部分将由学生进行，他们将成为制造业一个鲜为人知的方面的专家，这可能会给加拿大公司带来巨大的优势。毕业后，学生将拥有强大的实验技能和流变学，以及与乳化液有关的界面和传输现象的理论理解。这种可转让的知识在加拿大的制造业和资源行业中至关重要，需求很大。

Recent research into the use of nanoparticles as emulsifiers in Pickering emulsions shows great promise for the production of new food, cosmetic and pharmaceutical products, to name a few. However, the way these Pickering emulsions behave in large-scale production systems is unknown. This research proposes to provide the models needed to predict their behavior, so that manufacturers can design plants and processes accordingly. This research will help Canadian industry capitalize on the advantages of these emulsions to produce enhanced products and so successfully compete in global markets. Many products incorporate emulsions that use surfactants to suspend one liquid in another immiscible liquid (e.g. oil and water). The surfactants stabilize emulsion products through manufacturing, packaging, transportation and storage, and help ensure they remain safe after purchase. Unfortunately, surfactants are commonly obtained from non-renewable sources and can cause health problems, including skin irritation and red blood cell damage. This is problematic in cosmetics and pharmaceuticals produced as creams, liniments and ointments for the skin. In the past decade, scientists began using solid nanoparticles of non-toxic substances, such as proteins and starches, to create surfactant-free emulsions. Their outstanding properties make them ideal for product development, but little is known about how they flow within a mass-production system. In fact, the layer of nanoparticles at the oil-/water interface of these Pickering emulsions changes their rheological and pipeline flow behaviours. Therefore, using the models for conventional surfactant-based emulsions to manufacture Pickering emulsions would cause process and quality control problems. Manufacturers need a solid understanding of the rheology and pumping behaviour of Pickering emulsions before they can design, select and operate equipment to handle, mix, store and transport such materials through a system of pipelines. And yet, no published studies adequately describe the rheology and pipeline flow of Pickering emulsions. The longterm goal of this research is to conduct modelling and experimental studies of the rheology and pipeline flow of dilute and concentrated Pickering emulsions, which will lead to models that predict how they will behave in a mass production system. Canadian industry can use these models to design cost-effective, long-lasting and energy efficient infrastructure and processes for their innovative new products. Much of this research will be conducted by students, who will become experts in a poorly understood aspect of manufacturing that could bestow a great advantage to Canadian companies. Upon graduation, the students will possess strong experimental skills and theoretical understanding of rheology, and interfacial and transport phenomena pertaining to emulsions. This transferrable knowledge, vital throughout Canada's manufacturing and resource industries, is in high demand.