基于胶体探针AFM的微塑料-气泡相互作用纳米力学机理研究

气浮在去除水体微塑料方面具有巨大的应用潜力，研发高效的微塑料气浮技术对于缓解其对生态环境和人类健康的危害具有重要意义。微塑料与气泡之间的相互作用决定了气浮过程中微塑料在气液界面吸附的难易程度和结合强度，从而影响气浮效率。本项目采用胶体探针原子力显微镜技术，表征水溶液中微塑料与微米气泡之间相互作用的纳米力学特性，通过理论模拟计算对其中各种表面力（范德华力、双电层力、疏水力等）及非表面力（流水动力、毛细力等）进行精确量化分析，以建立相应的力-距离函数关系；考察水溶液条件、微塑料性质、碰撞速度等一系列因素的影响，以明晰微塑料-气泡相互作用的调控机制；结合共聚焦显微镜技术可视化分析固/液/气三相界面形貌的时空演化过程，以量化三相界面形貌与纳米力学数据的映射关系。本项目将从纳米力学尺度揭示水体中微塑料-气泡相互作用机理及其调控机制，为实现水体中微塑料的高效气浮提供可靠的理论指导和有力的数据支持。

Flotation has been considered as a potential approach to effectively remove microplastics from aqueous media. Developing advanced microplastic flotation techniques can alleviate the hazard of microplastic pollution to ecosystem and human health. During the flotation process, the interactions of microplastics with bubbles are crucial in determining their adsorption probability and intensity at the air/water interfaces, thus significantly affecting the flotation efficiency. In this project, firstly, colloidal probe atomic force microscopy (AFM) will be utilized to study the nanomechanical characteristics of the interactions between typical microplastic particles and air bubbles in aqueous media. Stokes-Reynolds-Young-Laplace (SRYL) theoretical model will be applied to precisely quantify the involved surface forces such as van der Waals (VDW), electrical double-layer (EDL) and hydrophobic (HB) forces and non-surface forces such as hydrodynamic and capillary forces, aiming to establish the corresponding force-distance profiles. Secondly, in order to clearly explicate the modulation mechanism of the microplastic-bubble interaction, the effects of various influencing parameters will be comprehensively investigated, including water conditions, microplastic properties, collision velocity, et al. Finally, confocal microscopy will be incorporated to visualize the spatiotemporal evolution of the solid/water/air three-phase interface to quantitatively explore its relationship with the nanomechanical data. This project will reveal the intrinsic mechanism of the microplastic-bubble interaction, which can provide important theoretical guidance on development of efficient flotation techniques for microplastics removal from aqueous media.