A new and efficient photopolymer for the recording of volume holograms is presented. The material comprises a mixture of UV‐sensitive acrylates and grafted titanium dioxide nanoparticles with an average size of 4 nm. We report the formation of holographic gratings with refractive‐index modulation amplitudes of up to 15.5 × 10–3—an improvement of more than a factor of four over the base material without nanoparticles—while maintaining a low level of scattering and a high transparency in the visible‐wavelength range. The influence of the composition of the acrylate system on the final properties of the holographic material is also investigated and discussed. The presence of multifunctional monomers favors the compositional segregation of the different components, while the addition of monofunctional acrylate, highly compatible with the grafting of the nanoparticles, favors the dilution of these nanoparticles.

This paper describes the development of so-called all-polypropylene composites, namely polypropylenes (PPs) reinforced with oriented polypropylene bres rather than glass or natural bres. These all-polypropylene composites have speci c economic and ecological advantages since, upon recycling, a polypropylene blend is obtained that can be reused to make all-PP composites again or, alternatively, be used for other PP-based applications. One of the main challenges in the development of all-PP composites is to create a processing window that is large enough to keep the oriented PP reinforcement intact while this is combined or impregnated with PP resin. The technological breakthrough in the processing of all-PP composite that has been established is based on the hot compaction (welding) of coextruded tapes. These coextruded tapes consist of an oriented polymer core, providing strength and stiffness, and a polymer skin with a lower melting temperature than the core material forming the matrix and bonding the tapes together. Consolidation is achieved by simply 'welding' the tapes together, thus avoiding typical impregnation problems encountered in traditional thermoplastic composite manufacturing. Pilot studies have already shown the potential of a wide range of manufacturing technologies including thermoforming and lament winding.

Bulk‐heterojunction photovoltaic cells consisting of a photoactive layer of poly[2‐methoxy‐5‐(3′,7′‐dimethyloctyloxy)‐1,4‐phenylenevinylene] (MDMO‐PPV) and a C60 derivative, (1‐(3‐methoxycarbonyl)propyl‐1‐phenyl‐[6,6]‐methanofullerene), (PCBM), sandwiched between an indium tin oxide (ITO) anode covered with poly(ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS), and an aluminum cathode have been analyzed using transmission electron microscopy (TEM) and cryogenic Rutherford backscattering spectrometry (RBS) to assess the structural and elemental composition of these devices. TEM of cross sections of fully processed photovoltaic cells, prepared using a focused ion beam, provide a clear view of the individual layers and their interfaces. RBS shows that during preparation diffusion of indium into the PEDOT:PSS occurs while the diffusion of aluminum into the polymer layers is negligible. An iodinated C60 derivative (I‐PCBM) was used to determine the concentration profile of this derivative in the vertical direction of a 100 nm active layer.