非水介质中有机土分散体系高温稳定性的影响因素和机理研究

To improve the high temperature stability of organoclay suspension has become a major subject in oil-based drilling fluids, which is beneficial for the development of deepwater drilling. In our research, the mechanism of organoclay suspension instability will be investigated based on the desorption behavior of modifier after aging at high temperature. The desorption process of modifier from particle surface will be investigated in terms of molecule/surface interaction and adsorption equilibrium by QCM-D. The adsorption mode of modifier will be determined according to TG-FTIR-GCMS characterization, and the desorption of modifier through each mode will be studied in details after aging at high temperature. Effect of adsorption site, hydration of ions and particle/particle interaction on the high temperature rheological properties will also be systematically studied. Ion exchange with gemini surfactants and covalent grafting will be applied for enhanced particle surface modification, respectively. The purpose of this study is to develop a novel kind of hydrophobically modified particle, which can remain its rheological properties unchanged or less changed at high temperature. The organoclay is expected to be applied in oil-based drilling fluid and polymer nanocomposites, which is of great significance to petroleum production and new materials development. This research will also promote the development of ceramics and electrophoretic inks.

有机土高温稳定性是油基钻井液领域亟待解决的重要问题，成为国内钻井技术发展的瓶颈。本项目将基于高温促进改性剂脱附来研究有机土分散体系高温失稳的机理。利用石英晶体微天平（QCM-D）研究改性剂从蒙脱土表面吸脱附的过程，同时改变溶剂介电常数，从吸脱附模式的角度增进对吸脱附行为的认识；进而通过热重-红外-气质联用确定改性剂在黏土表面的吸附方式和吸附位置，研究各种吸附方式的改性剂高温下脱附行为的差异。将吸附位点、金属离子的水化能力、颗粒的相互作用与黏土高温流变性能相结合，构建有机土分散体系高温失稳机理。针对改性剂的脱附问题，本项目将分别采取双子表面活性剂改性和共价接枝的方法制备有机土，期待得到一种新型耐高温有机改性颗粒，实现在较宽范围内保持流变性能稳定的目的。该项目的研究成果有望用于油基钻井液的配制和聚合物纳米复合材料的合成，对高端陶瓷材料的制备和电泳显示等领域也具有借鉴价值。

油包水Pickering乳液的应用温度范围较宽，由此带来的低温增稠和高温失稳问题亟待解决。本研究针对以上问题，利用低碳数烷基链改性的纳米颗粒制备油包水Pickering乳液。通过调整改性剂类型、改性程度、颗粒浓度、连续相类型、分散相盐浓度和体积等制备条件，利用显微镜观察乳液滴粒径和流变仪测定乳液流变学性能，以期制备出宽温度范围内稳定的油包水Pickering乳液。针对乳液稳定机理的探究，本研究采用低场核磁和耗散型石英微重力天平研究温度变化过程中颗粒表面溶剂化程度的变化规律，得到溶剂化程度的改变对乳液滴之间相互作用的影响规律，最终揭示溶剂化程度对乳液体系流变学性能的影响。该研究成果有望用于油基钻井液的配制，对高端陶瓷材料、电泳显示和润滑油等领域亦具有借鉴价值，对新材料的研发和石油资源的开采具有重要意义。