Surface tension of lithium bromide aqueous solution/ammonia with additives and nano-particles

CAI Wei-hua(蔡伟华)^{1, 2}, KONG Wei-wei(孔伟伟)³, WANG Yue(王悦)^{1, 2}, ZHU Meng-sheng(朱蒙生)³, WANG Xin-lei(王新雷)²

(1. School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001, China;
2. Department of Agricultural and Biological Engineering, University of Illinois at Urbana-Champaign,
Urbana 61801, USA;
3. School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China)

Abstract:In order to investigate the effect of additives and nano-particle on the surface tensions of lithium bromide (LiBr) aqueous solution/ammonia, many experiments were carried out based on Wilhelmy plate method. Firstly, the surface tension of LiBr aqueous solution with 1-octanol was measured and then the comparison between the measured results and previous experimental results was given to verify the measuring accuracy. Some new additives, such as cationic surfactants cetyltrimethyl ammonium chloride (CTAC), and cetyltrimethyl ammonium bromide (CTAB) were chosen in the experiments. The experimental results show that CTAC and CTAB can obviously reduce the surface tension of LiBr aqueous solution/ammonia. In addition, it is found that nano-particles cannot remarkably decrease the surface tension of LiBr aqueous solution/ammonia. However, the mixed addition of additives and nano-particles can remarkably affect the surface tension of LiBr aqueous solution/ammonia. That is to say, additives play more important role in reducing the surface tension of LiBr aqueous solution/ammonia. But nano-particles may enhance the heat transfer in the absorption refrigeration process.

Key words:lithium bromide; ammonia; additives; nano-particles; surface tension