Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology, School of Physics Science and Engineering, Tongji University , Shanghai 200092, P. R. China.
Langmuir. 2013 Sep 10;29(36):11208-16. doi: 10.1021/la401579z. Epub 2013 Aug 26.
Rigid and stable networks composed of litchi-shaped microspheres were formed via hierarchical self-assembly (SA) of oxide-based nanoparticles (NPs). The phenomenon of the apparent changes from NPs networks to microspheres networks after the gelation was similar to normal microsyneresis. However, in-situ composition evolution results indicate that the SA is driven by interparticle dehydration, but not affinity difference between the network for itself and for the solvent. In-situ small-angle X-ray scattering (SAXS), UV-vis-NIR, and electric conductivity were used to study the microsyneresis process. To further demonstrate the mechanism, extra complexant was added and successfully restrained the NPs-microsphere transition by inactivating the surface hydroxyl of the NPs. Considering the structural similarity, this work may provide a new approach to control the assemblies of diverse oxide-based NPs.
通过氧化物基纳米粒子（NPs）的分级自组装（SA）形成了由荔枝状微球组成的刚性和稳定的网络。凝胶化后从 NPs 网络到微球网络的明显变化现象类似于正常的微收缩。然而，原位组成演化结果表明，SA 是由颗粒间脱水驱动的，而不是网络本身与其溶剂之间的亲和力差异。原位小角 X 射线散射（SAXS）、紫外可见近红外（UV-vis-NIR）和电导率用于研究微收缩过程。为了进一步证明该机制，添加了额外的络合剂，并通过使 NPs 的表面羟基失活成功抑制了 NPs-微球的转变。考虑到结构的相似性，这项工作可能为控制不同氧化物基 NPs 的组装提供了一种新方法。
