Effets du dodécylsulfate sur la précipitation d'hydroxydes de nickel

ST ETIENNE-ENS des Mines (422182304) / SudocSudocFranceF

Precipitation of nickel hydroxides from nickel dodecylsulphate.

6 pages Comptes-rendus du colloque EMRS Fall meeting, Varsovie september 6th - 7th 200

Surfactant effects on pH-controlled synthesis of nickel hydroxides

International audienceThe aim of the present work is to determine at 60 °C, the influence of the specific nature of nickel salt and pH on nickel hydroxide features such as crystallographic structure and morphology. Within the range 8 ≤ pH ≤ 11.5, a home-made nickel functionalized surfactant, nickel di-dodecylsulfate Ni(C12H25SO4)2 is compared to usual salts (nickel nitrate Ni(NO3)2 and nickel sulfate NiSO4). In both cases, a sharp transition appears for pH about 10. In the classic salt case, the transition mainly affects morphology, that could be evidenced by the crosschecking of complementary techniques as SEM and nitrogen gas adsorption. For pH < 10, β-Ni(OH)2 platelets are yielded, whereas more basic conditions lead to randomly aggregated nano-grains of badly crystallized β hydroxide. Inversely, by employing the functionalized surfactant, 2D morphology is maintained in the whole pH-range, but the crystal structure is pH-controlled (α phase with interlamellar dodecylsulfate for pH ≤ 9.5, and β phase for pH ≥ 10.5)

Nanostructured particles by controlled precipitation techniques Example of nickel and cobalt hydroxides.

Numéro spécial suite au congrès EMRS Fall meeting, Warsaw, Poland, 4 -8 septembre 2006. disponible en ligne