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Silicalite nanoparticles and starch gel templates have been used to fabricate zeolite materials with a hierarchical micro/meso/macropore organization. Two methods were investigated. First, macroporous monoliths consisting of a continuous mesoporous framework of microporous silicalite were prepared by incorporating 50-nm-sized zeolite nanoparticles into freshly prepared viscous starch gels, followed by air-drying and calcination. Macropore sizes between 0.5 and 50 μm were achieved by varying the amount of starch and the starch/silicalite weight ratio. Mesoporous thin films of microporous silicalite, 2−15 μm in thickness, were also prepared by using gels containing low concentrations (2 wt %) of starch. Second, starch sponges with high internal macroporosities were prepared by freezing and thawing of starch gels and were then infiltrated with colloidal suspensions of silicalite nanoparticles and air-dried to produce silicalite−starch foams with pores up to 100 μm across depending on the starch concentration...

There are a number of strategies available for extending the length scale of structural organization in inorganic materials. Those that involve the assembly of inorganic nanoparticles into materials with higher-order architecture are collectively termed nanotectonics. In this review, we highlight one possible approach that involves the template-directed assembly of preformed nanoparticle building blocks. The inspiration for the use of preformed particles arises in part from studies of certain biomineral structures, some general aspects of which are summarized. Several synthetic examples of the use of template-directed approaches in nanotectonics are described in detail.