添加纳米颗粒对溴化锂溶液表面张力的影响及其机理分析

纳米颗粒可以改变溴化锂溶液的表面张力,从而促进其传热传质效果。利用Wilhelmy平板法研究了温度、溶液浓度、分散剂和纳米颗粒添加量等因素对溴化锂溶液表面张力的影响。结果表明,溴化锂溶液表面张力随溶液浓度和纳米颗粒添加量的增加而增大,随温度和分散剂添加量的增加而减小。分散剂的添加量存在最佳值,此时溶液表面张力趋于稳定,且稳定纳米溴化锂溶液的表面张力是分散剂和纳米颗粒耦合作用的结果。并拟合出溶液温度25~60℃、溶液浓度50%~59%、分散剂质量分数0~5%、纳米颗粒质量分数0~0.2%时,稳定纳米溴化锂溶液的表面张力半经验模型。

Effect of adding nanoparticles on the surface tension of Lithium Bromide solution and its mechanism analysis

The nanoparticles adding into the Lithium Bromide (LiBr) aqueous solution can fairly influence on the surface tension of LiBr solution, and then enhance its heat and mass transfer performance. The influence of temperature, solution concentration, dispersant (Gum Arabic) and CuO nanoparticles addition on the surface tension of LiBr aqueous solution was analyzed by the Wilhelmy plate method. The results showed that the surface tension of the LiBr aqueous solution increases with increasing concentration of the solution and nanoparticles, and decreases with the increasing temperature and the amount of Gum Arabic. However, there is an optimal value for the amount of dispersant, as the surface tension of LiBr aqueous solution approaches a stable value once the optimal value of dispersant amount is reached, and the surface tension of stable nano-LiBr solution is affected by the coupled effect of dispersant and CuO nanoparticles. A semi-empirical model of the surface tension for stable nano-LiBr solution was fitted under the experimental conditions.