A simple procedure to elaborate robust ultraflat gold surface without clean room facilities is presented. Self-assembled 3-mercaptopropytriethoxysilane (MPTMS) on silicon was used as a buffer layer on which gold was sputtered using a common sputter-coating apparatus. The optimization of the sample position into the chamber of the sputtering machine yielded the formation of a thin (approximately 8 nm) gold layer. The characterization of the resulting gold surface (i.e., AFM, X-ray reflectivity, and diffraction) has demonstrated its high smoothness (<0.7 nm) over a large scale with a preferred (111) orientation. The robustness of the substrate toward organic solvents and thermal treatment was also tested. The ability of these surfaces to be used as substrates for high-resolution surface modification was confirmed by functionalizing the gold surface using the dip pen nanolithography process.

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EPR investigations of the photoreduction of Ti(4+) into Ti(3+) under UV irradiation were carried out on three titanium-based materials for which the initial concentration of Ti(4+) was defined in the ternary phase diagram (TiOCl(2), H(2)O, DMF). The kinetics of this photoreduction was monitored at 200 K and related to the initial concentration of Ti(4+) in the solution. This study was complemented by a multi-approach EPR method (pulsed electron paramagnetic resonance (EPR), pulsed electron nuclear double resonance, and hyperfine sublevel correlation spectroscopy (HYSCORE)) with the aim of probing the proton environment of the Ti(3+) ions. Indeed, many species such as H(2)O, OH(-), HCOO(-) are located in the immediate vicinity of Ti(3+). Although we found that a distribution of g tensors was involved, for simplicity, two types of g tensor were used to describe the main features of the EPR signal related to the paramagnetic ions. Additionally, we have evidenced that two kinds of protons are identified next to Ti(3+) species, with specific distances determined from the hyperfine coupling parameters obtained by the HYSCORE method.

The phase diagram of the binary water/Brij58 system has been studied at constant temperature T = 20• C first by simple optical observation and then by small angle X-ray scattering. The small angle X-ray scattering patterns in the isotropic diluted phase are analyzed in a quantitative way by refining the experimental measurements with a model assuming hard spherical micelles in interaction. The micelles are described by a poly dispersed core-shell model and the interaction by the Perkus-Yevick hard-sphere model. The fitted parameters are analyzed in detail to determine the way polyoxyethylene blocks are hydrated with respect to the volumic fraction of water. In the more concentrated regime, the crystalline phases that are identified are the F m3m cubic, the 2D hexagonal and the lamellar phases. The structural parameters that describe each phases are analyzed and commented. The small angle X-ray scattering study is complemented by the determination of the temperature dependent liquid-solid transition by rheology.PACS: 81.30.−t, 61.05.C−, 64.70.dg IntroductionThe full understanding of the properties of surfactants when added to oil and water is of considerable interest given their tremendous applications in many scientific fields such as the design of hybrid mesoporous materials, drug delivery, or more prosaically industrial applications of detergents. Among widely used surfactants one finds the non-ionic surfactant of the Brij family characterized by a hydrophilic head made of polyoxyethylene (PEO) and a hydrophobic tail made of an alkyl chain. Quite surprisingly very little information is found in the literature about the phase diagram of the Brij58 (polyoxyethylene(20) cetyl ether). Apart from a neutron study of Brij58 micelles made by Sheffer et al. [1] by small angle neutron scattering and the study done by Mitchell on the phase behavior of polyoxyethylene surfactants with water, no real analysis of the phase diagram is available to the best of our knowledge [1][2][3].Our objective in this paper is to present the small angle X-ray scattering (SAXS) determination of the structures developed by the Brij58 when mixed with water from 5% to 95% in weight at a constant temperature of 20

Transparent gels prepared from an acid solution of TiOCl(2) in N,N-dimethylformamide (DMF) and water have been studied by small-angle X-ray scattering (SAXS). The sol-gel transformation of the titanium inorganic polymer was studied as a function of chemical composition of the sol and of the annealing time. Quantitative information was obtained by modeling the SAXS data with the Burford and Beaucage models. From the fits to the data, the radius of gyration of the primary particles, the so-called building blocks, the size xi of the homogeneous objects forming a fractal network in the gel, and the fractal dimension of the gel were obtained. We found fractal dimensions varying between D(f) = 1.75 and 2.2 and a radius of gyration of the building blocks equal to R(g) = 0.46 nm, which remained almost constant for all studied samples. The analysis of the homogeneous domain size xi as a function of the annealing time shows the existence of an incubation time preceding the rapid growth of the aggregates at high titanium concentration.

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The response of a photosensitive TiO 2 -based gel to UV light is described. Upon irradiation, the gel adsorbs light at 365 nm and becomes dark blue due to the transformation of the Ti 4+ centers into Ti 3+ . This behavior is revealed using electron paramagnetic resonance spectroscopy as a function of the gel chemical composition. The structure of the TiO 2 network is studied by small angle x-ray scattering.