We propose obtaining TiO₂ films by ICPCVD for the fabrication of low-loss waveguides. The challenge is to produce a dense and homogeneous layer with a high refractive index and low absorption in the visible range. Crystallized layers with features such as grains and amorphous layers have a rather low index for the application targeted, so we aimed for an intermediate state. We investigated the influence of plasma power, pressure, deposition time and annealing temperature on the structural, crystalline, and optical properties in order to tailor them. We showed that crystallization into rutile at the nanoscale occurred during deposition and under wisely chosen conditions, we reached a refractive index of 2.5 at 630 nm without creating interfaces or inhomogeneity in the layer depth. Annealing permits one to further increase the index, up to 2.6. TEM analysis on one sample before and after annealing confirmed the nano-polycrystallization and presence of both anatase and rutile phases and we considered that this intermediate state of crystallization was the best compromise for guided optics.

This work investigates the influence of spark plasma sintering (SPS) parameters on the microstructure and mechanical properties of consolidated aluminum powders processed by high-energy ball milling under an air atmosphere. Sintering was performed under vacuum at various temperatures ranging from 550 °C to 625 °C and under pressures between 50 and 100 MPa. The particle size, crystallite size, and microstructure of the powders and the consolidated pellets were analyzed using laser granulometry, X-ray diffraction (XRD), scanning electron microscopy (SEM), and Archimedes’ density measurements. Mechanical properties were evaluated via Vickers microhardness, nanoindentation, and tribological testing. For comparison, unmilled aluminum powders were also consolidated and characterized. After 46 h of milling, the aluminum crystallite size was reduced from 74 nm to 68 nm. The sample’s density increased with higher sintering temperature and pressure. The aluminum sintered at 600 °C and 100 MPa after 46 h of milling exhibited the highest microhardness (187.5 HV). Nanoindentation tests were conducted to characterize different microstructural regions formed after SPS, revealing two distinct zones: one hard and one soft. The tribology results revealed that the SPS-consolidated samples of milled powders exhibited a reduction of 50% in specific wear rate and a reduction of 20% in the coefficient of friction compared to the SPS-sintered samples of unmilled powders.

Mesoporous silica nanoparticles (MSNs) have attracted significant attention as a promising drug delivery platform for cancer treatment. However, their colloidal stability often remains overlooked, despite the numerous drawbacks associated with its absence. In this study, the enhancement of the colloidal stability of thoroughly characterised (TEM, DLS, zeta potential, TGA, XRD, N₂ physisorption) monodisperse MCM-41 MSNs in physiological conditions through the grafting a comb-like copolymer was successfully accomplished (preservation of the hydrodynamic diameter and the polydispersity index for at least 3 days). The loading of a therapeutic agent, cisplatin, was then achieved (12 wt%) without compromising their colloidal stability, and drug release kinetics were evaluated in cell culture medium, observing a complete release of the cargo after 48 h. Cytotoxicity studies conducted before and after drug loading confirmed the innocuousness of unloaded MSNs and demonstrated cytotoxic effects comparable to those of free cisplatin for the loaded nanoparticles (IC₅₀ = 23 and 13 μM CDDP for loaded MSNs versus 24 and 11 μM CDDP for free cisplatin in, respectively, SW480 and A549 cell lines). Particular emphasis was placed on ensuring the reproducibility of the results (e.g., hydrodynamic diameter and polydispersity index were measured across 49 independent synthesis) and on thoroughly evaluating the colloidal stability of the nanoparticles throughout the study, from synthesis to cytotoxicity assays. To the best of our knowledge, this work represents the first systematic study of the conditions required to develop stable colloidal suspensions of monodispersed mesoporous silica nanoparticles loaded with cisplatin, achieving high reproducibility, which constitutes a novel and robust contribution to the field.