Morphological Control of Hydrothermal Ni(OH)2 in the Presence of Polymers and Surfactants: Nanocrystals, Mesocrystals, and Superstructures
International audience; Polymers with different hydrophilic groups [polyvinylpyrrolidone (PVP), ammonium polyacrylate (APA), and hydroxypropylmethyl cellulose (HPMC)] and surfactants [cetyltrimethylammonium bromide (CTAB) and sodium dodecylbenzensulfonate (SDBS)] were used as additives to modify the crystallization of β-Ni(OH)2 in hydrothermal conditions. Marked morphological changes in the β-Ni(OH)2 particles were observed depending on the additive concentration and on the duration of the hydrothermal treatment. The final morphology is the result of a complex, time-dependent self-assembly and growth process. Well-defined particles with sizes from submicrometer range to a few micrometers co…
Growth of polycrystalline nickel hydroxide films from aqueous solution. Solution chemistry, deposition methods, film morphology and texture
Abstract Deposition of functional ceramic films on different substrates by using soft aqueous solution processing can represent a cheap, low- energy and environmental friendly alternative to other film technologies. In this study β-Ni(OH)2 polycrystalline films were grown on polytetrafluoroethylene, NiO, glass, copper, and Y:ZrO2 substrates from Ni2 +–NH4OH aqueous solutions. A careful control of solution supersaturation was essential to induce heterogeneous nucleation on the substrate and film growth. This was realized through the gradual decomposition of the nickel amino complexes Ni(NH3)n2 + using two different methods. Thermodynamic modeling of the Ni–NH4OH–H2O system was used to provid…