Interfacial curvature of surfactants

这个界面曲率计划的长期目标是开发一个框架来预测表面活性剂-油-水(SOW)体系的相行为和动力学。这一知识将使人们能够使用化学工程方法(质量和能量平衡、热力学、反应动力学和传输现象)来设计涉及表面活性剂的工艺和产品，包括微乳液、乳液、悬浮液、泡沫和其他。该程序的核心是亲水亲油差分(HLD)+净平均曲率(NAC)模型，这是SOW系统的半经验状态方程。这项赠款申请寻求在以下优先领域推动HLD-NAC框架的支持：超临界流体、三元相图(包括聚合物和液晶)的预测以及动态界面现象(增溶、界面张力和润湿)的预测。这些优先领域是在与学术界和工业界合作者协商后确定的。有关超临界流体的工作部分是由新型二氧化碳微乳液对枯竭油层的模拟、基于二氧化碳的干洗以及用于制药应用的纳米颗粒的二氧化碳微乳液合成的令人鼓舞的数据推动的。这些系统的行为是高度非线性的，并且在狭窄的温度和压力间隔内发生相变，导致这些技术的性能发生实质性变化。原来的HLD方程没有考虑压力的变化，因此需要一种基于分子相互作用的替代HLD，这种分子相互作用可以解释压力和温度的变化，并有助于设计这些二氧化碳微乳液过程。三元相图的工作是由石油和天然气行业、制药和食品行业、涂料/涂料行业以及表面活性剂和洗涤剂行业的同事推动的。实验获得的三元相图是高度资源密集型的，但它们是所有这些行业的最终制定工具。研究动态现象的目的是为了预测基于表面活性剂的采油过程(自乳化溶剂注入、萃取剂增溶、增溶摆动、萃取剂自乳化和用于三次采油的碱性表面活性剂聚合物驱)的效率。我们最近在乳液方面的工作表明，只需改变表面活性剂的类型，分离时间就可以变化多达四个数量级。我们假设，这种剧烈的变化也可以转化为其他分离过程，对它们的理解和管理将导致更有效的过程。关于HLD的分子基础及其在超临界系统中的应用的工作将由Boza-TronCoso先生(博士生)负责，他引入并验证了用于预测SOW系统行为的综合自由能模型(IFEM)。三元相图的工作将是Zarate夫人(博士生)和Nouraei先生(博士生)之间的团队努力。界面动力学方面的工作将由Stamitti先生(博士申请者)承担。根据这一研究计划以前的结果，我们预计，这些研究的结果和经过培训的高素质人员(4名博士和10名或更多本科生)将受到涉及以下行业的公司的需求：营养食品生产(加拿大行业年收入40亿美元)、化妆品和个人护理产品(加拿大行业年收入90亿美元)、制药行业(加拿大行业年收入200亿美元)以及石油和天然气行业(加拿大行业年收入800亿美元)。

The long-term goal of this interfacial curvature program is to develop a framework to predict the phase behaviour and dynamics of surfactant-oil-water (SOW) systems. This knowledge would enable using a chemical engineering approach (mass and energy balances, thermodynamics, reaction kinetics and transport phenomena) to design process and products that involve surfactants, including microemulsions, emulsions, suspensions, foams, and others. At the core of this program is the hydrophilic-lipophilic-difference (HLD) + net-average curvature (NAC) model, a semi-empirical equation of state for SOW systems. This grant application seeks support to advance the HLD-NAC framework in the following priority areas: supercriticial fluids, prediction of ternary phase diagrams (including polymers and liquid crystals), and the prediction of dynamic interfacial phenomena (solubilisation, interfacial tension and wetting). These priorities areas were identified in consultation with academic and industrial collaborators. The work on supercritical fluids is motivated in part by encouraging data from novel CO2 microemulsion stimulation of depleted oil reservoirs, CO2-based dry cleaning, and CO2 microemulsion synthesis of nanoparticles used in pharmaceutical applications. The behavior of these systems is highly non-linear and there are phase inversion changes that take place within narrow temperature and pressure intervals, leading to substantial changes in the performance of these technologies. The original HLD equation does not account for changes in pressure, thus the need for an alternative HLD based on molecular interactions that can account for changes in pressure and temperature and that could help engineer these CO2 microemulsion processes. The work on ternary phase diagrams was motivated by colleagues in the oil and gas industry, in the pharmaceutical and food industries, in the paint/coatings industry, and in the surfactant and detergents industry. Experimentally-obtained ternary phase diagrams are highly resource-intensive but they are the ultimate formulation tool for all these industries. The work on dynamic phenomena is motivated by the need to predict the efficiency of surfactant-based extraction processes (self-emulsified solvent injection, extractive solubilisation, solubilisation swings, extractive self-emulsification, and alkaline surfactant polymer flooding for tertiary oil recovery). Our recent work on emulsions showed that separation times could vary by as much as four orders of magnitude by simply changing the type of surfactant. We hypothesize that such drastic changes could also translate to other separation process, and their understanding and management will lead to more efficient processes. The work on the molecular basis of HLD and its application to supercritical systems will be undertaken by Mr. Boza-Troncoso (PhD candidate) who introduced and validated the integrated free energy model (IFEM) to predict the behaviour SOW systems. The work on ternary phase diagrams will be a team effort between Mrs. Zarate (PhD candidate) and Mr. Nouraei (PhD student). The work on interfacial dynamics will be undertaken by Mr. Stamitti (PhD applicant). Based on previous outcomes of this research program, we expect that the findings from these studies and the highly qualified personnel trained (4 PhDs and 10 or more undergraduates) will be in demand by companies involved in the production of nutraceuticals ($4 billion/year industry in Canada), in cosmetics and personal care products ($9 billion/year industry in Canada), in the pharmaceutical industry($20 billion/year industry in Canada), and in the oil and gas industry ($80 billion/year industry in Canada).