Interfacial curvature of surfactant systems

界面曲率计划的目标是使用化学工程原理来设计涉及表面活性剂-油水（SOW）系统的产品和工艺。我们已经使用亲水-亲脂-差(HLD) +净平均曲率（NAC）作为SOW系统的状态方程（EOS）来配制产品，例如用于制药和食品成分的自微乳化输送系统（SMEDS），以及用于沥青回收的靶向乳化溶剂注射（TESI）。我们的食品级卵磷脂SMEDS与分散体相比，将普通药物的生物利用度提高了约4倍。TESI有可能减少80%的能源消耗和蒸汽辅助重力排水（SAGD）的温室气体排放。由于其通用性和在实际应用中的应用，HLD-NAC已成为表面活性剂行业的基准EOS。过去的发现为我们指明了新的机会。第一种是综合自由能模型（IFEM）中的固定电荷。IFEM是HLD-NAC的竞争对手，但我们是从分子热力学发展而来的。探索电荷将使IFEM适用于离子表面活性剂（约占所有表面活性剂的60%），将使探索极性油（在食品和制药中常见）成为可能，并回答长期存在的霍夫迈斯特盐效应问题。我们了解到HLD-NAC还描述了非离子表面活性剂的云点，甚至是溶致液晶（LLC）行为的特征。第二个目标是了解为什么HLD-NAC可以预测LLC特征，以及我们如何使用它们来设计结构材料（聚合物）。初步研究表明，我们可以制备纳米聚合物-纳米颗粒复合材料和纳米聚合物凝胶，在催化和水处理方面具有潜在的应用前景。第三个目标源于一个令人惊讶的观察，我们的卵磷脂- smeds，由HLD-NAC设计，延长了药物的循环时间，这表明脂质和脂蛋白与组织交换物质的方式可能发生改变。通过探索脂蛋白与SMEDS的相互作用，我们希望了解SMEDS是否以及如何改变脂质分布，以及其在脂质管理（包括肠外营养）中的潜在应用。第四个目标是引入输运现象原理，HLD-NAC作为状态方程，并将其纳入可用于自乳化溶剂过程的流动模拟器，特别是TESI。该集成系统有望帮助我们设计最佳的流体动力学，以确保TESI能够在二维油砂油藏模型中保持或提高其采收率（~80%，优于SAGD的60%）。在该项目中接受培训的校友已经成为加拿大公司研发部门的负责人，其中一位正在创办自己的公司，以实施该项目获得的技术。大多数工程师在SOW系统方面缺乏专业知识，这表明4名博士和5名本科生学员将在各自的职业生涯中做出重大贡献。

The goal of the interfacial curvature program is to use chemical engineering principles to design products and processes involving Surfactant-Oil-Water (SOW) systems. We have used the hydrophilic-lipophilic-difference (HLD) + net-average curvature (NAC) as equation of state (EOS) for SOW systems to formulate products such as self-microemulsifying delivery systems (SMEDS) for pharma and food ingredients, and Targeted Emulsified Solvent Injection (TESI) for bitumen recovery. Our food-grade, lecithin SMEDS improves the bioavailabity of common drugs by about 4 times compared to dispersions. TESI has the potential to reduce by 80% the energy consumption and green house gasses of Steam Assisted Gravity Drainage (SAGD). Because of its versatility and use in real applications, the HLD-NAC has become a benchmark EOS for the surfactant industry. Past findings pointed us to new opportunities. The first one involves fixed charges in the Integrated Free Energy Model (IFEM). IFEM rivals HLD-NAC, but we developed IFEM from molecular thermodynamics. Exploring charges will make IFEM suitable for ionic surfactants (~60% of all surfactants), will enable exploring polar oils (common in food and pharma) and answer the long-standing question of Hoffmeister salt effects. We learned that HLD-NAC also describes the cloud point of nonionic surfactants, and surprisingly, even features of lyotropic liquid crystal (LLC) behavior. The second aim is to understand why HLD-NAC can predict LLC features and how we can use them to design structured materials (polymers). Preliminary work shows that we can produce nanostructured polymer-nanoparticle composites and nanostructured polymer gels with potential use in catalysis and water treatment. The third aim was born out of a surprising observation that our lecithin-SMEDS, designed with HLD-NAC, extended the circulation times of a drug, suggesting a potential modification in the way lipids and lipoproteins exchange material with tissue. By exploring the lipoprotein-SMEDS interaction we hope to understand if and how SMEDS can alter lipid distribution, and its potential use in lipid management, including parenteral nutrition. The fourth aim is to bring in transport phenomena principles, HLD-NAC as equation of state, and incorporate them in flow simulators that could work with self-emulsified solvent processes, particularly TESI. This integrated system is expected to help us design optimal hydrodynamics that would ensure that TESI can maintain or increase its oil recovery capacity (~80%, better than 60% for SAGD) in 2D models of oil sand reservoirs. Alumni trained in the program have gone on to lead R&D divisions for Canadian companies, and one is starting his own company to implement technologies from the program. The lack of expertise in SOW systems, in most engineers, suggest that the 4 PHDs and 5 undergrad trainees will be well positioned to make significant contributions in their respective careers.