| Abstract
| - A highly ordered, porous nanoscale network structure of polyoxomolybdate was prepared from theslow decomposition of an unstable precursor compound MoO2(OH)(OOH) in the presence of PEO-containingtriblock copolymer gels or semidilute/concentrated poly(ethylene oxide) (PEO) homopolymer solutions. Small-angle X-ray scattering (SAXS) and wide-angle X-ray diffraction (WAXD) measurements of the 1-μm sizecrystals revealed an extremely ordered primitive cubic (pc) structure made of polyoxomolybdates. Scanningelectron microscopy (SEM) measurements showed that the overall size of these single crystals was close to 1μm, in agreement with estimates from the scattering peak widths. Evidence from both scattering measurementsand transmission electron microscope (TEM) measurements suggested that the system formed a highly porousprimitive cubic network similar to that of certain zeolite structures. However, the observed lattice constant of5 nm was much larger. The function of the PEO-containing polymer network was found to be very subtle andcomplex. Presumably, PEO acted simultaneously as a weak reducing agent and as a viscous matrix to ensuresufficient time for the formation of long-range ordered structures, resulting in the growth of extremely uniformbut probably hollow “nanospheres”. We suggest that this new material may find unique applications as ahigh-efficiency absorbent or catalyst. Furthermore, the current synthetic method may open up new pathwaysto prepare similar functional nanomaterials.
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