纳米Cu分散稳定性能影响因素及作用机理研究

鉴于粉体分散对纳米流体强化传热具有重要意义,通过测定纳米Cu-水悬浮液的Zeta电位和吸光度,探讨了不同pH值、不同分散剂种类及质量分数对纳米Cu-水悬浮液分散稳定性的影响,并分析其作用机理。结果表明:Zeta电位绝对值与吸光度有良好的对应关系,Zeta电位绝对值越高,吸光度越大,则体系分散稳定性越好;pH值、分散剂种类及加入量是影响纳米Cu-水悬浮液分散稳定性的主要因素。pH值为9.5左右时,体系Zeta电位绝对值和吸光度较高,相应分散稳定性较好。CTAB和SDBS能显著提高水溶液中Cu表面Zeta电位绝对值,增大了颗粒间静电排斥力,改善了悬浮液稳定性,而TX-10通过空间位阻在颗粒表面形成良好的水化膜,提高了Cu在水溶液中的分散稳定性。在质量分数为0.1%的纳米Cu-水悬浮液中,TX-10,CTAB,SDBS 3种分散剂加入质量分数分别为0.43%,0.05%,0.07%时,均能得到分散稳定的悬浮液体系。

Effect factor and function mechanism on dispersion and stability of Cu nanoparticles

In view that the dispersion of nano-Cu is regarded as the guide of heat transfer enhancement,the dispersion and stability of Cu nanoparticles in water were studied under different pH values,different dispersant types and mass fraction by the method of Zeta potential and absorbency,and the function mechanism was analyzed.The results show that the absolute value of Zeta potential has very corresponding relation with absorbency,and the higher the absolute value of Zeta potential and the absorbency are,the better the dispersion and stability in system are.The absolute value of Zeta potential and the absorbency are higher at pH 9.5.CTAB and SDBS can significantly increase the absolute value of Zeta potential by electrostatic repulsions,and TX-10 can form a good hydrate layer on the particle surfaces by steric,which leads to the enhancement of the stability of the Cu suspensions.The optimizing mass fraction for TX-10,CTAB and SDBS in mass fraction 0.1% copper nano-suspensions are 0.43%,0.05%,0.07% respectively,which have the best disperse results.