非水相泡沫的形成及其稳定性机理研究

In spite of having wide technical importance in petroleum, chemical engineering and other areas, non-aqueous foams involving basic principles of formation, interfacial and stability are poorly understood relative to aqueous systems. Such understandings encumber its applications and controls in various industrial processes. For our research group, we concentrated on the evolution theory of foam dispersions from aqueous, mixture of oil and water, to non-aqueous systems in recent years. On the basis of the finished NSFC 21073140 entitled "Study on the stability mechanism of aqueous foams in the presence of crude oil", as a extending issue, the objective of this project is to investigate on the formation and stabilization mechanisms of non-aqueous foams. With the series of experiments on the properties of non-aqueous solutions and foaming behavior, the impact effects of the physical properties such as surface tension, viscosity of the non-aqueous solutions and solvent polarity on their foaming performance are studied in details. Coupled with the microstructures of the adsorbed layer at the bubble interface determined here, the amphiphilic molecular aggregation and alignment are analyzed with attempt to explore the driving sources for the formation of non-aqueous bubbles. Experimental studies on the bubble rupture mechanisms are carried out utilizing two self-designed apparatus including microscopic high-speed imaging and optical setup. An equation is proposed and calculated by a nonlinear least squares iteration procedure so as to uncover the dominated mechanisms (drainage or coalescence) in the foam breaking process. With serious determinations on the dilational rheologies of gas-oil interface incorporation using Foamscan tests, we can establish the correlations between surface dilational viscoelasticity and bubble life-time. Based on above researches, the stabilization mechanisms of non-aqueous foams will be revealed clearly. The investigation of this project will make the fundamental contributions to the theories and applications of non-aqueous foams in many industries, and also provide a primary basis for the foam evolution theory.

非水相泡沫在石油、化工等领域有着广泛的应用，但其发泡成因和稳定性等基础理论的匮乏，严重影响此类体系在工程中的应用与调控。本项目组致力于水相泡沫→油/水混相泡沫→非水相泡沫的泡沫体系演变理论研究，在前一个国家自然基金“原油对水相泡沫的稳定性作用机理研究”基础上，延伸拓展以探索非水相泡沫的形成及其稳定机理为目标。通过不同系列非水相溶液特性及其发泡性能实验，探索表面张力、粘性和溶剂极性对其发泡行为的影响规律，结合气泡界面微观结构测试，揭示气泡界面吸附层的分子排列及聚集状态，以探究非水相泡沫的形成机制。采用自行设计组装的显微高速成像和泡沫稳定性光学测试装置，结合数值模拟分析非水相泡沫破裂过程中的主导机制；通过油-气界面扩张粘弹性测试，分析气泡界面粘弹性各参数对泡沫稳定性的影响程度，进而揭示非水相泡沫的稳定性机理。项目成果将为非水相泡沫理论发展及工程应用奠定基础，还将为泡沫体系演变理论提供重要依据。

非水相泡沫在石油、化工等领域有着广泛的应用，但其发泡成因和稳定性等基础理论的匮乏，严重影响此类体系在工程中的应用与调控。本项目以探索非水相泡沫的形成及其稳定机理为目标。主要涉及三个方面的研究：非水相泡沫的形成机制、界面层微观结构和稳定性机理。开展这一具有前沿性的主题研究，可为泡沫体系理论增添新的篇章。通过系统的实验计划实施，取得了如下的理论成果：.(1) 揭示了表面活性剂在非水相溶剂中的溶剂极性、表面张力和粘性等参数对其发泡行为的影响机制。非水相溶剂极性越强，其表面张力越大，发泡能力愈强，反之亦然。发泡溶液表面张力的降低量是决定其发泡性能的关键。而溶液粘性仅与泡沫稳定性有关。.(2) 揭示反向溶致液晶对于非水相泡沫的形成与稳定性的影响机制。随着层状液晶含量的增加，泡沫量呈先增加后下降的趋势，但泡沫的寿命却越来愈长。层状液晶结构相较于表面活性剂分子，具有较低表面张力，提高溶液的体相粘度，有利于非水相泡沫的形成与稳定。.(3) 探明纳米SiO2表面润湿性对于非水相泡沫的形成、界面结构和稳定性的调控机制。不同非水相溶剂起泡所需的纳米颗粒接触角范围不同，其接触角范围均在38.3°~96.9°之间。非水相溶剂的变面张力越大，其要求的纳米颗粒接触角也越大。.(4) 提出CaCO3纳米晶体对于非水相泡沫的形成及稳定性影响机制。不同形貌、不同润湿性的CaCO3纳米晶体对与非水相溶剂的发泡性能不同。片状晶体颗粒的发泡性能最佳，所形成的非水相泡沫含气率在10%~56.9%。在强极性有机溶剂中，晶体颗粒接触角范围为53.5°~73.9°，在弱极性和非极性有机溶剂中，晶体颗粒接触角范围为47.5°~66°。.该项目完成了计划要求的研究目标，取得了预期的研究成果。发表学术论文12篇，其中国际主流期刊SCI收录6篇，中文核心6篇；申请发明专利16项，获授权4项；培养硕士研究生15名；参加国内学术会议18人次。