Ordered mesoporous polymers have been prepared by replication of colloidal crystals made from silica spheres 35 nanometers in diameter. The pores in the colloidal crystals were filled with divinylbenzene (DVB), ethyleneglycol dimethacrylate (EDMA), or a mixture of the two. Polymerization and subsequent dissolution of the silica template leaves a polycrystalline network of interconnected pores. When mixtures of DVB and EDMA are used, the pore size of the polymer replicas can be varied continuously between 35 and 15 nanometers because the polymer shrinks when the silica template is removed.

Zeolites were used as templates to prepare microporous polymer replicas. Phenolformaldehyde polymers were synthesized and cured within the channel networks of zeolites Y, β, and L. Dissolution of the aluminosilicate framework in aqueous HF yields an organic replica that contains <2% aluminosilicate. The zeolite template exerts important topological effects on the structure and physical properties of the replica. Using zeolites Y and β, which have three-dimensionally interconnected channel structures, the microporosity of the template is reflected in the replica polymer. Pore size distributions are consistent with the predominance of 5-6 Å walls in the parent zeolite. In contrast, complete collapse of the replica, to a give nonporous material, occurs upon removal of the zeolite L template, since the latter has a one-dimensional channel structure. TEM and SEM micrographs also show evidence of collapse in the latter case. Pyrolysis of the zeolite-resin composites at 900 °C, and subsequent etching, produces very high surface area, electronically conducting replicas. Under these conditions the zeolite Y replica has markedly lower conductivity than those obtained from β and L, which have straight channels.

The intercalation and exfoliation reactions of α-zirconium phosphate, Zr(HPO4)2·H2O (α-ZrP), were studied microscopically by atomic force microscopy (AFM) and transmission electron microscopy (TEM). The reaction of α-ZrP with tetra(n-butylammonium) hydroxide (TBA+OH-) initially produces intercalation compounds, which then transform to unilamellar colloids. The rate-determining step in intercalation is the opening of the interlamellar galleries. Subsequent diffusion of TBA+ ions into the opened galleries is rapid. The hydrolysis reaction of α-ZrP colloids proceeds from the edges inward, forming ∼4-nm hydrated zirconia particles that decorate the edges of the sheets. The reaction does not go to completion, as it is limited by equilibrium associated with the release of phosphate into the solution. The hydrolysis reaction is negligible at 0 °C, which permits the synthesis of hydrolysis-free unilamellar colloids. Remarkably, these colloids form monolayer films on amine-derivatized silicon surfaces with a high density that suggests significant surface mobility during the adsorption process. Addition of appropriate phosphonic acids to colloidal α-ZrP suspensions enables modification of the sheet edges, illustrated here by the anchoring of osmium oxide particles to the sheet edges by a vinylphosphonate linker.

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