Abstract：
Nanobubbles have been increasingly used in various applications involving porous media, such as groundwater remediation and irrigation. However, the fundamental scientific knowledge regarding the interactions between nanobubbles and the media is still limited. The interactions can be repulsive, attractive, or inert, and can involve reversible or irreversible attachment as well as destructive mechanisms. Specifically, the stability and mobility of nanobubbles in porous media is expected to be dependent on the dynamic conditions and the physicochemical properties of the porous media, solutions, and nanobubbles themselves. In this study, we investigated how changes in solution chemistry (pH, ionic strength, and valence) and media characteristics (size and wettability) affect the size and concentration of nanobubbles under dynamic conditions using column experiments. Quartz crystal microbalance with dissipation monitoring provided a deeper understanding of irreversible and elastic nanobubbles\' interactions with silica-coated surfaces. Our findings suggest that nanobubbles are less mobile in solutions of higher ionic strength and valence, acidic pH and smaller porous media sizes, while the wettability of porous media has a negligible influence on the retention of nanobubbles. Overall, our findings provide insights into the underlying mechanisms of nanobubble interactions and suggest potential strategies to optimize their delivery in various applications.
摘要：
纳米气泡已越来越多地用于涉及多孔介质的各种应用中，如地下水修复和灌溉。然而,关于纳米气泡和介质之间的相互作用的基本科学知识仍然有限。相互作用可能是令人厌恶的，有吸引力,或惰性，并且可能涉及可逆或不可逆的附着以及破坏性机制。具体来说,纳米气泡在多孔介质中的稳定性和迁移率预计将取决于多孔介质的动态条件和物理化学性质，解决方案,和纳米气泡本身。在这项研究中,我们调查了溶液化学(pH，离子强度,和价态）和介质特性（尺寸和润湿性）在动态条件下使用柱实验影响纳米气泡的尺寸和浓度。具有耗散监测功能的石英晶体微天平更深入地了解了不可逆和弹性纳米气泡与二氧化硅涂层表面的相互作用。我们的研究结果表明，纳米气泡在离子强度和化合价较高的溶液中流动性较小，酸性pH值和较小的多孔介质尺寸，而多孔介质的润湿性对纳米气泡的保留具有可忽略的影响。总的来说,我们的研究结果为纳米气泡相互作用的潜在机制提供了见解，并提出了在各种应用中优化其递送的潜在策略。
