Hydrophobically Modified Thermoresponsive Starch Nanoparticles for Use in Oil Recovery of Oil Sands

淀粉纳米颗粒（SNP）代表了一种有趣的新型亲水性水分散性材料，其由我们的支持组织EcoSynthetix以EcoSphere®商业销售。SNP可以用疏水分子化学修饰。通过仔细调节疏水性和连接到SNP上的分子的数量，可以通过将溶液温度提高到临界温度Tc以上来诱导SNP聚集，甚至从水溶液中沉淀出来。实际上，修饰的SNP响应于热触发，并且它们已经变得热响应。该提议是为了优化化学修饰的SNP的热响应性，以用作采油应用中的添加剂。修饰的SNP可以在高于Tc的温度下与油砂中捕获的油相互作用。油和修饰的SNP之间的这些相互作用将产生稳定的乳液，在去除砂之后，可以通过将温度降低到Tc以下来使其不稳定。在这样做时，修饰的SNP重新分散在水中，而乳液液滴中的油朝向其积聚的空气-水界面扩散。然后可以撇去油，而负载有修饰的SNP的水可以在另一轮提取中重新使用。原则上，在提取过程中不应产生废水，这应尽量减少尾矿池的形成。该提案中将开展的任务包括用小疏水分子如丁烯或氧化苯乙烯对SNP进行系统修饰，使其具有热响应性，以及大的水溶性聚合物如聚（乙二醇）以使它们在水中稳定，评估它们在不同有机稀释剂如辛醇或甲苯存在下从油砂中提取油的效率，并放大提取过程来模拟提取过程。SNP的化学修饰将在ECO借给我们的Brabender混合器中以干燥状态进行，以便实验条件可以容易地转移到ECO操作的挤出机中以生产修饰的SNP。该项目将产生具有令人兴奋的特性的新材料，这些材料应该引起加拿大石油工业的高度兴趣。

Starch nanoparticles (SNPs) represent an interesting new hydrophilic water-dispersible material that is sold commercially as EcoSphere® by EcoSynthetix, our Supporting Organization. SNPs can be chemically modified with hydrophobic molecules. By careful adjustment of the hydrophobicity and number of molecules being attached onto SNPs, the SNPs can be induced to aggregate and even precipitate out of the aqueous solution by increasing the solution temperature above a critical temperature Tc. In effect, the modified SNPs respond to a thermal trigger and they have become thermo-responsive. This proposal is to optimize the thermo-responsiveness of the chemically modified SNPs for use as additives in oil recovery applications. The modified SNPs can interact with the oil trapped in oil sands at temperatures greater than Tc. These interactions between the oil and the modified SNPs will generate a stable emulsion which, after removal of the sand, can be destabilized by lowering the temperature below Tc. In so doing, the modified SNPs re-disperse in the water while the oil in the emulsion droplets diffuses toward the air-water interface where it accumulates. The oil can then be skimmed off while the water loaded with the modified SNPs can be re-used in another round of extractions. In principle, no waste water should be generated in the extraction which should minimize the formation of tailing ponds. The tasks that will be carried out in this proposal include the systematic modification of SNPs with small hydrophobic molecules such as butene or styrene oxide to make them thermo-responsive and large water-soluble polymers such as poly(ethylene glycol) to stabilize them in water, the assessment of their efficiency to extract oil from oil sands in the presence of different organic thinners such as octanol or toluene, and scale up extractions to model the extraction process. Chemical modifications of the SNPs will be conducted in the dry state in a Brabender mixer loaned to us by ECO so that experimental conditions can be easily transferred to the extruder operated by ECO to produce modified SNPs. This project will generate new materials with exciting properties that should be of high interest to the Canadian oil industry.