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

淀粉纳米颗粒(SNPs)是一种有趣的新型亲水水分散材料，由我们的支持组织EcoSynthetix以EcoSynthetix®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，通过将溶液温度提高到临界温度T_c以上，可以诱导SNPs聚集甚至析出水溶液。实际上，修改后的SNPs会对热触发做出反应，并对温度做出响应。这项建议旨在优化化学修饰的SNPs的热响应性，以用作采油应用中的添加剂。经修饰的SNPs可以在高于Tc的温度下与油砂中的石油相互作用。油和改性的SNPs之间的这些相互作用将产生稳定的乳状液，在去除沙子后，可以通过将温度降低到TC以下来破坏乳状液的稳定性。在这样做的过程中，修饰后的SNPs重新分散在水中，而乳化液中的油向空气-水界面扩散，在那里积累。然后，石油可以被撇除，而装载了改良SNPs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，这将使尾矿库的形成降至最低。该提案中将进行的任务包括：用丁烯或环氧苯乙烷等疏水小分子对SNPs进行系统修饰，使其具有温度响应性，并用聚乙二醇等大分子水溶性聚合物使其在水中稳定；评估其在不同有机稀释剂(如辛醇或甲苯)存在下从油砂中萃取石油的效率；以及放大萃取以模拟萃取过程。SNPs的化学修饰将在ECO借给我们的Brabender搅拌机中在干燥状态下进行，这样实验条件就可以很容易地转移到ECO操作的挤出机上，以生产改性的SNPs。该项目将产生具有令人兴奋的特性的新材料，这应该会引起加拿大石油行业的高度兴趣。

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.