4种阴离子表面活性剂在煤沥青表面的润湿规律

Effects of four kinds of anionic surfactants on wetting of coal tar pitch surfaces

为了探讨分散剂溶液对煤沥青表面的润湿性能,通过表面张力与接触角的测定研究了SDS,SDBS,NA和SN四种结构互异的阴离子表面活性剂溶液在煤沥青表面的润湿规律,并探讨了表面活性剂溶液在煤沥青表面的临界表面张力、铺展系数、黏附功和吸附机理。结果表明,SDS和SDBS溶液的表面张力和接触角均低于NA和SN,且计算得出的铺展系数高于NA和SN,而黏附功则低于NA和SN,说明SDS和SDBS溶液在煤沥青表面的润湿性强于NA和SN,而黏附性则低于NA和SN。4种表面活性剂的γlg-cosθ曲线均符合Zisman理论。SDS和SDBS的黏附张力(γ1gcosθ)与表面张力(γ1g)的曲线呈线性关系,可推测这两种表面活性剂分子在煤沥青表面的范德华吸附是润湿过程的主导因素。

In order to investigate wetting of surfactant solution on coal pitch surface in preparing the coal pitch water slurry （CPWS） , the wetting behavior of coal pitch surface by solutions of four kinds of anionic surfactants with different structures, sodium dodecyl sulfate （ SDS ）, dodecyl benzene sulfonic acid sodium （ SDBS ）, anthraquinone - 2 - sodium sulfonate（NA） and Naphthalene-l-sulphonie acid sodium（SN）,were investigated by measuring surface tension and contact angle. The critical surface tension, spreading coefficient, adhesion work and adsorption mechanism of surfac- tants solutions on coal pitch surface were discussed, too. It turned out that the surface tension and contact angle of SDS and SDBS were lower than that of NA and SN,and the spreading coefficients of SDS and SDBS are greater than that of NA and SN,while the adhesion works of SDS and SDBS are lower than that of NA and SN. This shows that the wetta- bility of SDS and SDBS on coal pitch surface is better than that of NA and SN, while adhesion of SDS and SDBS on coal pitch surface is poorer. Moreover, the Zisman theory is well agree with the wetting of four kinds of surfactants solu- tions on coal pitch surface. There is a liner relationship between adhesion tension（ γ1gcosθ） and surface tension（γ1g） of SDS and SDBS, so it can be speculated that Lifshitz-van der Waals adsorption lead the wetting process.