Influence of CATB on Stability of Copper Nano-Suspensions

Dispersion and stability of Cu nano-suspensions with dispersant is the important base for the study of rheology and heat transfer enhancement of the suspensions. This paper presented a procedure for preparing a nanofluid which was a suspension consisting of nanophase powders and a base liquids. By means of the procedure, Cu-H₂O nanofluids with and without dispersant were prepared, whose sedimentation photographs were given to illustrate the stability and evenness of suspension with dispersant. Dispersion and stability of Cu nanoparticles in water were studied under different pH values and the concentration of hexadecyl trimethyl ammonium bromide (CATB) dispersant by the method of zeta potential and absorbency. The results show that zeta potential has very corresponding relation with absorbency, and the higher absolute value of zeta potential and absorbency are, the better dispersion and stability in system is. The absolute value of zeta potential is higher at pH 9.5. CATB can significantly increase the absolute value of the zeta potential of the particle surfaces by electrostatic repulsions, which leads to the enhancement of the stability of the Cu suspensions. The optimizing concentration for CATB in the 0.1% copper nano-suspensions is 0.05%, which has the best disperse results.