Lei Gao - Layer-by-Layer Assembly of Polyoxometalates into Microcapsules

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      Publication Details (including relevant citation   information):

      J. Phys. Chem. B, 2005, 109(35), 16587-16592


      The polyoxometalate (POM) chemistry world has been experiencing   an unparalleled development of rapid synthesis of new compounds   and slow development of POM-based functional materials and   devices. Meanwhile, researchers in the microcapsule world,   encouraged by the introduction of the layer-by-layer method, are   pursuing good components for constructing functional capsule   devices. Here, in view of the versatile properties that POM-based   microcapsules may possess, various types of POM−polyelectrolyte   composite microcapsules were constructed using the layer-by-layer   method. Microscopy reveals that polyoxometalates form   nanoparticles on the shell in the presence of cationic   polyelectrolytes. These nanoparticles connected with   polyelectrolytes constitute the shell and support the   microcapsule from collapse after drying, and this is an   interesting characteristic different from those of common   composite and polyelectrolyte capsules. Fourier transform   infrared (FTIR), UV−vis absorption, and X-ray photoelectron   spectroscopy (XPS) were used to examine the properties of the   POMs in the microcapsules. The obtained microcapsules exhibit   higher thermal stability than polyelectrolyte microcapsules.   Furthermore, the functions of POMs were maintained when they were   assembled into microcapsules. It is proved that microcapsules   bearing POMs with redox activity can provide a reduction   environment, which can lead to the realization of in situ   synthesis of materials, and that microcapsules with   photoluminescent POMs as a component can also have a   photoluminescent property, providing a way to develop functional   capsule devices. This work may provide an opportunity to enrich   both the polyoxometalate chemistry and the capsule field.

      Address (URL): http://pubs.acs.org/doi/abs/10.1021/jp051818f?prevSearch=%255Bauthor%253A%2BLei% 2BGao%255D&searchHistoryKey=