Photopolymers are playing an ever more important role in diverse areas of research such as holographic data storage, hybrid photonic circuits, and solitary waves. In each of these applications, the production of primary radicals is the driving force of the polymerization processes. Therefore an understanding of the production, removal, and scavenging processes of free radicals in a photopolymer system is crucial in determining a material's response to a given exposure. One such scavenging process is inhibition. In this paper the non-local photo-polymerization driven diffusion model is extended to more accurately model the effects of (i) time varying primary radical production, (ii) the rate of removal of photosensitizer, and (iii) inhibition. The model is presented to specifically analyze the effects of inhibition, which occur most predominantly at the start of grating growth, and comparisons between theory and experiment are performed which quantify these effects.

In this paper, Cu 2+ doped ceria nanospheres were produced from a one-step hydrothermal synthesis. The products were characterized in detail at the structural and electronic level by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy, high-resolution transmission electron microscopy (HRTEM) and X-ray photoelectron spectroscopy (XPS). XRD results revealed that the doped ceria was free of other crystallographic phases, such as CeOHCO 3 , CuO or Cu 2 O. By introducing various reactant molar ratios of Cu : Ce, the composition can be freely manipulated. The H 2 -TPR measurement shows the improved reduction behaviour of the doped ceria samples prepared by us. A preliminary CO catalytic oxidation experiment indicated that the Cu 2+ doped ceria samples showed strikingly higher catalytic activity, due to the intrinsic surface defects of the samples. In addition ceria doped with other transition metal ions (M 2+ ), such Co 2+ , Ni 2+ and Mn 2+ , has also been successfully prepared. Considering this one-step synthesis as a versatile approach, it can be further extended to other binary metal oxide systems.

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