Effect Of Liquid Additives On The Surface Tension And The Boiling Temperature Of LiBr Aqueous Solution Added Nano-particles

The effect of surfactants on the surface tension and boiling characteristics of LiBraqueous solution added nano-particles is included in this thesis. Firstly, a view that theexistence of a direct link between the surface tension and the boiling temperature is obtainedfrom the classic nucleation theory. Secondly, the mechanism of surfactants on boilingcharacteristics of nano-LiBr aqueous solution is explored by experimental results that includethe effects of different concentrations of different alcohol surfactants on the surface tensionand boiling temperatures of nano-LiBr aqueous solution.To follow the principle that the chosen surfactants are widely used in industry, safe,reliable and with a certain regularity, C8H18O, C9H20O, C10H22O are selected as liquidadditives in experiments.And the relationship between the changes of sufactant concentrationand the surface tension and boiling temperature of nano-LiBr aqueous solution is measuredwhen add three liquid additives respectively.Experimental results show that: the surface tension of nano-LiBr solution isdecreased as the concentration of surfactant is increased, the initial effect is particularlysignificant and the trend leveled off when the concentration is greater than a predeterminedvalue; The comparision of three surfactants shows that: as the number of alkyl groups isincreased, the factor of hydroxyl groups in molecule is decreased, so that hydrophobicityof system is increased, and Surface activity of system is increased.The experiments show that: the boiling temperature of nano-LiBr added CH8H18O is20~30degree lower than unadded, the boiling temperature of nano-LiBr added C9H20O orC10H22O is30~35degree lower than unadded. This experimental consequence is same withthe classic nucleation theory. However, additional factors such as the increase of the contentof the surfactant can also affect the boiling temperature in the experiment. On the one hand,the increase of the content of the surfactant leads to higher gravity of surfactant layer in thetube, then surface tension of the suface of water is increased, so boiling temperature also isincreased; On the other hand, according to the operation of experiments, the concentration ofnano-LiBr is increased as the increase of the content of the surfactant, and boiling temperaturealso is increased.The interaction between the nanoparticles and the surfactant: the nanoparticle will bewraped by the surfactants is included in this thesis.And the effective sizes of the nanoparticlesand the surface roughness of the heating part are changed, therefore the boiling superheat ofnano-LiBr aqueous solution added dispersant or not are different.For C9H20O, A significant issue is found that is when more than2%of C9H20O is addedin a solution containing dispersant, nanoparticles appear to be wrapped,and this situationundermine the nature of nanofluids, also hindered C9H20O as a function of surfactant, therebymaking nanofluids boiling temperature linear upward trend.