Morphological Control of Hydrothermal Ni(OH)2 in the Presence of Polymers and Surfactants: Nanocrystals, Mesocrystals, and Superstructures

详细信息    查看全文

• 作者：Maria Teresa Buscaglia ; Vincenzo Buscaglia ; Carlo Bottino ; Massimo Viviani ; Roxane Fournier ; Mohamed Sennour ; Sabrina Presto ; Rinaldo Marazza ; Paolo Nanni
• 刊名：Crystal Growth & Design
• 出版年：2008
• 出版时间：October 1, 2008
• 年：2008
• 卷：8
• 期：10
• 页码：3847-3855
• 全文大小：740K
• 年卷期：v.8,no.10(October 1, 2008)
• ISSN：1528-7505

文摘

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 corresponding to hexagonal lamellae, hexagonal tabular mesocrystals, rosette- and flowerlike aggregates of lamellae, hexagonal prismatic mesocrystals, and acicular nanocrystals were easily obtained after a short time (2−24 h) aging at 150−200 °C. With PVP and CTAB, there is evidence of a growth process dominated by self-assembly of nanocrystals to produce mesocrystals. The formation of spherical superstructures (with SDBS, up to 70 μm in diameter) and hollow spheres (with PVP) is observed at long times (>24 h) as a result of solvent-mediated recrystallization processes, like Ostwald ripening. The overall results show that hydrothermal synthesis of β-Ni(OH)₂ in the presence of polymers with hydrophilic groups and surfactants is a versatile tool for crystal morphogenesis.