Carn Florent, Saadaoui Hassan, Massé Pascal, Ravaine Serge, Julian-Lopez Beatriz, Sanchez Clément, Deleuze Hervé, Talham Daniel R, Backov Rénal
Centre de Recherche Paul Pascal, UPR 8641-CNRS, 115 Avenue Albert Schweitzer, 33600 Pessac, France.
Langmuir. 2006 Jun 6;22(12):5469-75. doi: 10.1021/la060220b.
The synthesis of novel meso-/macroporous SiO2 monoliths by combining a nano-building-blocks-based approach with the confined geometry of a tailored air-liquid foam structure is described. The resulting macrostructure in which ordered close-packed colloidal silica nanoparticles constitute the monolith's scaffolds very closely resembles the tailored periodic air-liquid foam template. The void spaces between adjacent particles create textural mesoporosity; therefore, the as-prepared silica networks are characterized by hierarchical porosity at the macroscopic and mesoscopic length scales. The fine-tuning of both the liquid foam's fraction and the bubble size allows a rational design over the macroscopic cell morphologies (shape, Plateau border's length, and width). Striking results of this approach are the weak shrinkage of the as-synthesized opal-like scaffolds during the thermally induced sintering process and, in contrast with previous studies, the formation of closed-cell structures. Particle organization and the foam film surface roughness are investigated by atomic force microscopy (AFM), showing the influence of the liquid flow, within the foams' Plateau borders and films, on the final assemblies.
本文描述了通过将基于纳米构建块的方法与定制的气液泡沫结构的受限几何形状相结合来合成新型介孔/大孔二氧化硅整体材料。所得的宏观结构中，有序密堆积的胶体二氧化硅纳米颗粒构成了整体材料的支架，与定制的周期性气液泡沫模板非常相似。相邻颗粒之间的空隙形成了结构介孔；因此，所制备的二氧化硅网络在宏观和介观长度尺度上具有分级孔隙率。对液体泡沫的分数和气泡尺寸进行微调，可以合理设计宏观孔结构形态（形状、Plateau边界的长度和宽度）。这种方法的显著成果是，在热诱导烧结过程中，合成的类蛋白石支架收缩较弱，并且与先前的研究相比，形成了闭孔结构。通过原子力显微镜（AFM）研究了颗粒组织和泡沫膜表面粗糙度，显示了泡沫Plateau边界和膜内的液体流动对最终组装体的影响。
