In this work the physicochemical characterization of liposomes loaded with a newly synthesised carboranyl porphyrazine (H2HECASPz) is described. This molecule represents a potential drug for different anticancer therapies, such as Boron Neutron Capture Therapy, Photodynamic Therapy and Photothermal Therapy. Different loading methods and different lipid mixtures were tested. The corresponding loaded vectors were studied by Small Angle Scattering (SANS and SAXS), light scattering and zeta potential. The combined analysis of structural data at various length scales and the measurement of the surface charge allowed to obtain a detailed characterization of the investigated systems. The mechanisms underlying the onset of differences in relevant physicochemical parameters (size, polydispersity and charge) were also critically discussed.

Reinforcement of elastomers by colloidal nanoparticles is an important application where microstructure needs to be understood - and if possible controlled - if one wishes to tune macroscopic mechanical properties. Here the three-dimensional structure of big aggregates of nanometric silica particles embedded in a soft polymeric matrix is determined by Small Angle Neutron Scattering. Experimentally, the crowded environment leading to strong reinforcement induces a strong interaction between aggregates, which generates a prominent interaction peak in the scattering. We propose to analyze the total signal by means of a decomposition in a classical colloidal structure factor describing aggregate interaction and an aggregate form factor determined by a Reverse Monte Carlo technique. The result gives new insights in the shape of aggregates and their complex interaction in elastomers. For comparison, fractal models for aggregate scattering are also discussed.

The adsorption of polymer and surfactant molecules onto colloidal particles or droplets in solution can be characterized non-destructively by scattering techniques. In a first part, the general framework of Dynamic Light Scattering, Small Angle Neutron and X-ray Scattering for the determination of the structure of adsorbed layers, and namely of the density profile, is presented. We then review recent studies of layers of the model polymer poly(ethylene oxide), as homopolymer or part of a block copolymer. In this field, scattering with contrast variation has been shown to be a powerful tool to obtain a detailed description of the layer structure. Adsorption of chemically more complex systems, including polyelectrolytes, polymer complexes, grafted chains and biomacromolecules are also discussed in this review, as well as surfactant adsorption.

The design and characteristics of the new very small angle neutron scattering spectrometer under construction at the Laboratoire Leon Brillouin is described. Its goal is to extend the range of scattering vectors magnitudes towards 2E−4 /A. The unique feature of this new spectrometer is a high resolution two dimensional image plate detector sensitive to neutrons. The wavelength selection is achieved by a double reflection supermirror monochromator and the collimator uses a novel multibeam design.

The design and characteristics of a double supermirror monochromator for neutron instrumentation at the Laboratoire Leon Brillouin is described. The aim of this monochromator is to reduce the intense gamma-radiation produced by conventional velocity selectors and to avoid a direct view of the guide while keeping a comparable neutron transmission (higher than 70%). The monochromator offers a continuous choice of wavelength selection in the range 0.5 to 2 nm.