This work reports on the effect of substituting Al2O3 for P2O5 and substituting CaO for (Na2O+K2O) in the ternary 0,46 (K2O + Na2O) 0,54 P2O5 glass system, certain of these compositions being eventually of interest for bio-medical applications. Different properties are analysed here. When CaO replaces (Na2O+K2O) (constant O/P ratio) or when Al2O3 replaces P2O5 (increasing O/P ratio), it is shown that the density of the glasses increased, the coefficient of thermal expansion decreased and the glass transition temperature increased. A partial and limited study of dissolution behaviour in water indicates that the dissolution rates decreased by orders of magnitude with the introduction of CaO or Al2O3, in agreement with the trends reported in the literature. The pH values of the dissolution solutions were also measured. The pH quickly decreased and saturated to around 2.5 for glasses with no alumina, i.e with the highest P2O5 content. On another hand, when Al2O3 was substituted for P2O5 (i.e. when P2O5 content decreased and O/P increased), the pH initially increased to more basic values (around 7) and always remained above 5. Some interpretation of the structural role of CaO and Al2O3 are proposed to explain these properties change with composition.

We report on the comparison between temperature-dependent magneto-absorption and magnetotransport spectroscopy of HgTe/CdHgTe quantum wells in terms of the detection of the phase transition between the topological insulator and band insulator states. Our results demonstrate that temperature-dependent magnetospectroscopy is a powerful tool to discriminate trivial and topological insulator phases, yet the magnetotransport method is shown to have advantages for the clear manifestation of the phase transition with accurate quantitative values of the transition parameter (i.e., critical magnetic field B c).

A comprehensive characterization of physical-chemical properties and biological interactions of ca. 200-nm-thick hybrid films based on silylated (inorganic part) castor oil (organic part) is proposed. A series of such nanofilms was fabricated and cross-linked by a sol-gel procedure, and their properties such as hydrophilicity, hardness and water vapour transmission rate were systematically studied as a function of the ratio of silylated agent to castor oil. It was found that the nanofilms have contact angles always below 90°, tunable Young modulus and hardness in the MPa range. Moreover, their water vapour transmission rates are increased by decreasing the silica ratio. The protein adsorption and cytocompatibility were evaluated using model proteins and cells. The adsorption of the proteins bovine serum albumin (BSA) and lysozyme was characterized using a quartz crystal microbalance in energy dissipation mode (QCM-D), and atomic force microscopy (AFM). The combination of the latter provided evidence for the different affinities of the proteins with the films. It was found that BSA and lysozyme form rigid layers on the surface with surface coverage close to 30%, and that both protein layers decrease their thickness after their dehydration. Finally, cell culture experiments exhibited a good viability of the fibroblasts compared to ultra-low adhesion surfaces, which makes them potential candidates for biomedical applications.

le M-TEGFET, est un nouveau type de transistor, sans grille, fonctionnant grâce à un effet magnétique.