SHG Active Fe(IO3)3 Particles: From Spherical Nanocrystals to Urchin-Like Microstructures through the Additive-Mediated Microemulsion Route
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- 作者：Rachid Ladj ; Moustafa El Kass ; Yannick Mugnier ; Ronan Le Dantec ; Hatem Fessi ; Christine Galez ; Abdelhamid Elaissari
- 刊名：Crystal Growth & Design
- 出版年：2012
- 出版时间：November 7, 2012
- 年：2012
- 卷：12
- 期：11
- 页码：5387-5395
- 全文大小：476K
- 年卷期：v.12,no.11(November 7, 2012)
- ISSN：1528-7505
文摘
Spherical nanocrystals of iron iodate (Fe(IO3)3) as well as different hierarchically organized hybrid superstructures are synthesized at 80 掳C from AOT-based water-in-oil microemulsions. For a fixed reaction time of 2 h, initial addition of PEG molecules and changes in the water/surfactant molar ratio w allow modification of the interactions between surfactant and PEG molecules at the surface of amorphous precursor particles. At low water content (w = 5.8), adsorption of AOT molecules inhibits the formation of crystallized nanoparticles if the amount of added PEG is too low, whereas spherical nanocrystals are obtained otherwise. In contrast, at a high water content (w = 12.2), SEM and TEM imaging reveal that the aggregation-induced crystallization of amorphous precursors induces the formation of higher-order complex forms. Aggregates of elongated cone-shaped bundles of nanofilaments and, subsequently, quasi-spherical urchin-like microstructures as long as the PEG amount is raised are observed. Significantly, lattice parameter refinements originally demonstrate the key role of AOT in the self-assembly and a homogeneous nucleation, leading to the formation of primary bouquet-like structures, is suggested before further self-assembly results in urchin-like structures. In terms of potential applications, spherical nanocrystals are promising exogenous labels for multiphoton microscopy, whereas higher-order architectures give perspectives in the morphogenesis of new functional materials.