颗粒气泡黏附科学——微纳尺度下颗粒气泡黏附试验研究进展

自20世纪30年代始,微纳尺度下的颗粒气泡黏附就引起了学者的广泛关注并逐渐涌现出一系列试验技术探索颗粒气泡黏附机理。在宏观尺度下颗粒气泡黏附研究进展的基础上,系统的对微纳尺度下颗粒气泡间相互作用力及液膜薄化破裂动力学试验技术研究进展进行综述。技术总体上可以分为两类:力测量法及排液法。排液法是通过光学显微干涉技术直接获得气液界面变形及排液动力学数据,通过耦合扩展DLVO理论及排液方程求解作用力信息,如单气泡撞板显微干涉技术、薄膜压力平衡技术及表面力分析仪等。力测量法则主要是借助胶体探针原子力显微镜(AFM)测试颗粒气泡间表面力及流体阻力,通过流体力学排液模型模拟液膜薄化破裂动力学行为。排液法和力测量法均发现疏水力是颗粒气泡间液膜快速薄化并破裂的根本原因,其中排液法所获得的疏水力倾向于一种长程作用力,而力测量法得到的疏水力为短程作用力,造成这种差异的原因仍不明确。随着AFM-反射干涉对比显微镜联用、变形体系力分析仪和薄液膜力分析仪等技术的问世,作用力和液膜排液的同步测试已经成为一种技术趋势,充分助力了浮选颗粒气泡黏附基础研究。基于现有研究进展应进一步开展颗粒气泡间疏水力的系统研究,通过借助不同检测技术的优势互补及分子动力学模拟等手段,有望从根本上阐明这一科学问题。

Bubble-particle attachment science:Experimental advances in bubble-particle attachment on a micro-nano scale

Since the 1930s,bubble-particle attachment on a micro-nano scale has attracted the widespread attention of scholars.A series of experimental techniques have emerged to explore the mechanism of bubble-particle attachment.Based on the advances in bubble-particle attachment on a macroscopic scale,advances in the experimental techniques focus on the measurement of bubble-particle interaction force and film drainage on a micro-nano scale were reviewed.Techniques are generally classified into two categories:force measurement method and film drainage approach.For film drainage approach,such as bubble against plate assisted by micro-interference technique,thin film balance,and surface force apparatus,the deformation of gas-water interface and film thinning dynamics data were directly obtained by microscopic interference.The force information was further solved by the combination of extended DLVO theory and drainage equation.For force measurement method,colloidal probe atomic force microscopy (AFM) was used to measure surface and hydrodynamic forces,the film thinning rupture behavior was modeled by using hydrodynamic drainage models.Hydrophobic force was found to be the reason for the rapid thinning and rupture of thin liquid film between bubble and particle through both force measurement method and film drainage approach.The hydrophobic force obtained by film drainage approach tends to be a long-ranged force,while the hydrophobic force obtained by force measurement is a short-ranged force.The reason for this difference is still unclear.With the development of the combination of AFM and reflection interference contrast microscopy,force apparatus for deformable surfaces and integrated thin film drainage apparatus and integrated thin liquid film force apparatus,the synchronous measurement of the interaction force and the spatiotemporal evolution of the confined thin liquid film is a general trend,and it is expected to clarify the scientific mechanism of bubble-particle attachment.in the following research work.