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Novel nanocomposites consisting of a water-soluble acrylamide-based photopolymer and colloidal zeolite nanoparticles of zeolite Beta and zeolite A were prepared. The interactions between the photopolymer components and zeolite nanoparticles in the photopolymerizable nanocomposites were characterized for the first time by [sup.13]C nuclear magnetic resonance and visible spectroscopy. It was found that the zeolite Beta nanoparticles (up to 5 wt. %) behave as a noninert additive, resulting in an effective increase in layer thickness, which causes doubling of the diffraction efficiency of the nanocomposite in comparison to that of the undoped photopolymer. On the other hand, the nanocomposite containing zeolite A nanoparticles showed no evidence of interaction with the polymer matrix, had similar values of diffraction efficiency, and--up to a small addition of nanoparticles (up to 2.5 wt. %)--showed slightly higher light-induced refractive index modulation of the grating when compared to the undoped photopolymer. The good optical compatibility between the zeolite nanoparticles and the polymer allows a versatile design of photopolymerizable nanocomposites with different properties by selecting the adequate type of zeolite. The nanocomposite containing zeolite Beta nanoparticles demonstrates selective sensing behavior toward toluene and can be coated in either glass or plastic substrates and exposed directly to the environmental conditions. [c] 2010 Optical Society of America OCIS codes: 090.7330, 160.5335.

The formation and growth of crystal nuclei of zeolite A from dear solutions at room temperature were studied with low-dose, high-resolution transmission electron microscopy in field emission mode and with in situ dynamic tight scattering. Single zeolite A crystals nucleated in amorphous get particles of 40 to 80 nanometers within 3 days at room temperature. The resulting nanoscale single crystals (10 to 30 nanometers) were embedded in the amorphous gel particles. The get particles were consumed during further crystal growth at room temperature, forming a colloidal suspension of zeolite A nanocrystals of 40 to 80 nanometers. On heating this suspension at 80 ° C, solution-mediated transport resulted in additional substantial crystal growth., Zeolite molecular sieves are crystalline porous solids whose intricate pore and channel systems in the molecular size range of 0.3 to ~3 nm are the basis for their immense importance [...]