Non-aqueous Solution Of Surfactant Calorimetry Study Of Thermodynamic Properties

Surfactants are a class of very important fine chemical products which has wetting, dispersion, emulsification, solubilization, foaming, defoaming, washing, dyeing, lubrication, penetration, anti-static, anti-corrosion, disinfection and other aspects the function and role, is vividly called "the industry monosodium glutamate".A lot of effort has been put into research on the properties of Surfactants in aqueous solutions from home and abroad. However, such research in non-aqueous solvents has received only limited attention.critical micelle concentration and thermodynamic properties in non-aqueous solvents is a new topic on Surfactants' property research.With the rapid development of biotechnology and wider applications of the reverse micelle extraction technology, The micellar and microemulsion in non-aqueous mediums attract more attention.The research of surfactant in non-aqueous solution can provides theoretical foundations to further study of these reacts. This has important theoretical significance,and broad application prospects.This paper determined the CMC of non-ionic surfactants tween80 and span80 in nonaqueous solvents by microcalorimetric method, and then obtained its Thermodynamic functions with the power-time curves of the micelle formation process.The main contents are as follows:1. The determination and regularity of CMC and Thermodynamic functionsThe power-time curves of the micelle formation process were determined for non-ionic Surfactant (tween80 and span80) under different temperatures and different alcohols of different concentrations by microcalorimetric method, then the CMC values were obtained from the lowest point of the curves. The conclusions are as follows:Tween80 and span80 in DMF systems, Under the condition of same alcohol and same alcohol concentration, the CMC values decreased with the increment of temperature; under the condition of same temperature and same alcohol, the CMC values decreased with increasing concentration of alcohol. Under the condition of same temperature and same alcohol concentration, the CMC of surfactants decreased with an increase in the carbon number of the alcohol.2. Thermodynamic function acquisition and regularity discussionThe area of the curve which represents the thermal effect was obtained. The standard enthalpy changes (ΔHθm) of the micellization process of tween80 and span 80 in DMF under different conditions were calculated.ΔGθm andΔSθm can also be obtained by thermodynamic theory. The conclusions are as follows: Tween80 and span80 in DMF systems, theΔHθm andΔSθm increased whileΔGθm decreased with the increment of temperature at the presence of same alcohol and same alcohol concentration; theΔHθmΔGθm andΔSθm all decreased with the increment of alcohol's carbon number at the presence of same temperature and same alcohol's concentration; theΔHθm,ΔGθm andΔSθm all decreased with the increment of alcohol's concentration at the presence of same temperature and same alcohol.The innovation of this paper1. The study on CMC and thermodynamic function acquisition and regularity of Non-ionic surfactant Tween80 and Span80 with cosurfactant that different alcohols and alcohols in different concentrations in the presence of DMF system is a new topic on surfactants research.2. Titration Microcalorimetry was used to study the interactivity of surfactants, cosurfactants and solvents in non-aqueous solution. The CMC andΔHθm were determined by power-time curve. TheΔGθm andΔSθm were calculated by thermodynamic equations. This is a new method to gain CMC and thermodynamic functions.