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

淀粉纳米颗粒（snp）是一种有趣的新型亲水性水分散材料，由我们的支持组织EcoSynthetix以EcoSphere®的名称进行商业销售。SNPs可以用疏水分子进行化学修饰。通过仔细调整SNPs的疏水性和附着在SNPs上的分子数量，将溶液温度提高到临界温度Tc以上，可以诱导SNPs聚集甚至析出水溶液。实际上，修改后的snp响应热触发，它们已经成为热响应。本研究旨在优化化学修饰的SNPs的热响应性，使其成为采油添加剂。修饰后的SNPs可以在高于Tc的温度下与油砂中的油相互作用。油与改性SNPs之间的相互作用将产生稳定的乳状液，在去除砂后，将温度降低到Tc以下即可使其不稳定。在这样做的过程中，经过修饰的snp重新分散在水中，而乳化液滴中的油则向空气-水界面扩散，并在此积聚。然后，油可以被撇去，而装有改性snp的水可以在另一轮提取中重复使用。原则上，在提取过程中不应产生废水，尽量减少尾矿库的形成。该提案将执行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；用大水溶性聚合物（如聚乙二醇）对snp进行系统修饰，使其在水中稳定；评估它们在不同有机稀释剂（如辛醇或甲苯）存在的情况下从油砂中提取石油的效率；SNPs的化学修饰将在干燥状态下在ECO借给我们的Brabender混合器中进行，这样实验条件可以很容易地转移到ECO操作的挤出机中以产生修饰的SNPs。该项目将产生具有令人兴奋的性能的新材料，这应该是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.