空气纳米气泡的稳定性及理化特性

Stability and physicochemical properties of air nanobubbles

空气纳米气泡(Air-NBs)的理化特性是其广泛应用的基础。本文利用纳米粒度-zeta电位分析仪研究了水力空化原理产生的Air-NBs的理化特性,即粒径分布和zeta电位,考察了装置运行压力、电解质浓度、pH和温度对Air-NBs理化特性的影响;同时考察了去离子水和CaCl_(2)溶液中Air-NBs稳定性。结果表明:纳米气泡发生器的压力越大,其产生的Air-NBs的小粒径比例更大,且电解质的加入有助于气泡粒径的缩小。随着溶液中电解质浓度、pH和温度的升高,溶液中Air-NBs的平均粒径逐渐减小,但气泡间的聚结作用会导致其粒径随时间逐渐增大;通过对两种溶液中Air-NBs粒径的实时监测发现其能在溶液中存在5天之久。胶体稳定(DLVO)理论和zeta电位效应可以合理阐释溶液中Air-NBs的稳定性。

The physicochemical properties of air nanobubbles(Air-NBs)are the basis of their wide application.In this study,the physicochemical properties of Air-NBs produced by the principle of hydrodynamic cavitation,including the particle size distribution and zeta potential,were studied on the nanoparticle size-zeta potential analyzer.The effects of operating pressure,electrolyte concentration,pH and temperature on the physicochemical properties of Air-NBs were investigated,as well as the stability of Air-NBs respectively in deionized water and CaCl_(2)solution.The results showed that the higher the pressure of the nano bubble generator,the larger the proportion of small particle size of Air-NBs,and the addition of electrolyte helped to reduce the particle size of bubbles.The average particle size distribution of Air-NBs decreased with the increase of electrolyte concentration,pH and temperature.However,the coalescence between bubbles was ascribed to the gradual increase of the particle size with time going.The Air-NBs particle size in the two solutions was monitored online.It was found that the Air-NBs could exist in the solutions for 5 days.The stability of Air-NBs in solution can be explained reasonably through DLVO theory and zeta potential effect.