光滑及粗糙表面纳米气泡成核与生长动力学行为  

Nucleation and growth dynamics of nanobubbles on smooth and rough surfaces

作　　者：杨海昌[1,2] 徐梦迪[1,2] 邢耀文[1,2] 桂夏辉[1,2] 曹亦俊[1,2,3] YANG Haichang;XU Mengdi;XING Yaowen;GUI Xiahui;CAO Yijun(State Key Laboratory of Coking Coal Resources Green Exploitation,China University of Mining and Technology,Xuzhou 221116,China;Chinese National Engineering Research Center of Coal Preparation and Purification,China University of Mining and Technology,Xuzhou 221116,China;Key Metals Henan Laboratory,Zhengzhou University,Zhengzhou 450001,China)

机构地区：[1]中国矿业大学,炼焦煤资源绿色开发全国重点实验室,徐州221116 [2]中国矿业大学,国家煤加工与洁净化工程技术研究中心,徐州221116 [3]郑州大学,关键金属河南实验室,郑州450001

出　　处：《物理学报》2025年第2期160-172,共13页Acta Physica Sinica

基　　金：国家重点研发计划(批准号:2023YFE0100600);国家自然科学基金(批准号:51920105007,52174265,52104277)资助的课题.

摘　　要：界面纳米气泡的存在已被证实,其在矿物浮选、水产养殖、废水处理等多个领域极具应用潜力,但纳米气泡微观成核过程仍未明晰.本研究基于气体扩散理论建立了纳米气泡生长动力学模型,并借助分子动力学模拟研究了表面粗糙度和气体过饱和对纳米气泡成核和生长动力学的影响机制.结果表明:光滑均质表面上,随着气体过饱和度从100增大至150,纳米气泡的成核时间逐渐缩短,生长速率逐渐加快,且理论模型可以较好地拟合纳米气泡的生长动力学过程.然而,当气体过饱和度降低至50时,纳米气泡在200 ns模拟时间内始终未成核,这是由于低气体过饱和度时纳米气泡临界成核尺寸较大导致成核难度增加.在凹坑宽度为1-10 nm的粗糙表面上,气体过饱和度为50时,表面凹坑均迅速生成气核,但凹坑宽度在2 nm以下时气核难以生长为纳米气泡.理论分析表明:只有凹坑尺寸所对应的最小气泡半径达到纳米气泡临界成核半径时,凹坑中的气核才能生长为纳米气泡.研究结果将进一步完善纳米气泡成核理论体系,同时为纳米气泡生成调控及应用提供理论支撑.The interfacial nanobubbles(INBs)have been confirmed to exist,and have significant potential for applications in fields such as mineral flotation,aquaculture,and wastewater treatment.However,the microscopic nucleation process of INBs is still poorly understood.This study investigates the nucleation process and growth dynamics of INBs on smooth and rough surfaces under different levels of gas supersaturation.Molecular dynamics(MD)simulations using GROMACS software package are conducted to observe the microscopic nucleation process and the temporal evolution of the geometric characteristics of the INBs.Additionally,a growth dynamics model for INBs is derived based on the Epstein-Plesset gas diffusion theory,and the predictions from the model are compared with the MD simulation data.The results indicate that on smooth homogeneous surfaces,the curvature radius and width of INBs increase progressively with time after nucleation.This growth process is well captured by the theoretical model,indicating that the gas diffusion theory provides an accurate description of INB growth dynamics.In addition,the contact angle(measured on the gas side)during INB growth is not constant but increases initially before stabilizing.This phenomenon is caused by reducing solid-gas interfacial tension due to higher Laplace pressure,thus leading the contact angle to increase as the INB radius grows.Furthermore,on smooth homogeneous surfaces,INBs are observed to nucleate at 81,17,6,and 1.3 ns under gas supersaturation levels of 100,120,150,and 200,respectively.This demonstrates that higher gas supersaturation significantly shortens the nucleation time.Additionally,as gas supersaturation increases,the growth rate of INBs after nucleation will also accelerate.However,at a gas supersaturation level of 50,no nucleation occurrs during the simulation period of 200 ns.Theoretical analysis reveals that the INBs can only nucleate and grow when the radius of gas aggregates exceeds the critical nucleation radius(R_(critical)=δ/(ζP_(0))whereσis the l

关 键 词：纳米气泡成核 光滑表面 粗糙表面 气体过饱和度 

分 类 号：TB383.1[一般工业技术—材料科学与工程]