Porous 'Ouzo-effect' silica-ceria composite colloids and their application to aluminium corrosion protection.

By exploiting spontaneous emulsification to prepare porous SiO(2) particles, we report the formation of porous CeO(2)@SiO(2) hybrid colloids and their incorporation into a silica-zirconia coating to improve the corrosion protection of aluminium

Nanocontainers for Self-Healing Coatings

This progress report covers recent achievements in the development of nanocontainers for self‐healing corrosion protection coatings. The functionality and design of Layer‐by‐Layer‐assembled, polymer, and inorganic nanocontainers are demonstrated in the coatings for protection of steel and aluminium alloys. The release of the corrosion inhibitors from nanocontainers occurs only when triggered by local pH changes or other internal or external stimuli, which prevents leakage of the corrosion inhibitor out of the coating and increases coating durability. This leads to the self‐healing ability of the coating and terminates corrosion propagation.</jats:p

Nonclassical Moments and their Measurement

Practically applicable criteria for the nonclassicality of quantum states are formulated in terms of different types of moments. For this purpose the moments of the creation and annihilation operators, of two quadratures, and of a quadrature and the photon number operator turn out to be useful. It is shown that all the required moments can be determined by homodyne correlation measurements. An example of a nonclassical effect that is easily characterized by our methods is amplitude-squared squeezing.Comment: 12 pages, 6 figure

Non-uniform growth of composite layer-by-layer assembled coatings via three-dimensional expansion of hydrophobic magnetite nanoparticles

Nanocomposite coatings are promising for a range of practical applications and layer-by-layer assembly (LbL) is a versatile tool for nanocomposite formation. However, conventional LbL is a quite laborious procedure taking a lot of time to reach a sufficient thickness of the coatings required for practical applications. Herein, we proposed a novel variant of the LbL approach based on the deposition of hydrophilic polyelectrolyte molecules from a polar solvent and hydrophobic magnetite NP from a nonpolar dispersion medium with an intermediate washing in the same polar solvent. The composite multilayers formed in this way exhibit exponential growth of the thickness and mass. Based on QCM, FTIR, SEM, AFM, and surface profile measurements. We propose a model describing the driving force of multilayer formation and the factors leading to nonlinear growth of their mass and thickness. The re-sults allow to expand the understanding of the mechanism of the LbL assembly in order to form multifunctional nanocomposites in a more efficient way

Transmission electron microscopy investigation of segregation and critical floating-layer content of indium for island formation in InGaAs

We have investigated InGaAs layers grown by molecular-beam epitaxy on GaAs(001) by transmission electron microscopy (TEM) and photoluminescence spectroscopy. InGaAs layers with In-concentrations of 16, 25 and 28 % and respective thicknesses of 20, 22 and 23 monolayers were deposited at 535 C. The parameters were chosen to grow layers slightly above and below the transition between the two- and three-dimensional growth mode. In-concentration profiles were obtained from high-resolution TEM images by composition evaluation by lattice fringe analysis. The measured profiles can be well described applying the segregation model of Muraki et al. [Appl. Phys. Lett. 61 (1992) 557]. Calculated photoluminescence peak positions on the basis of the measured concentration profiles are in good agreement with the experimental ones. Evaluating experimental In-concentration profiles it is found that the transition from the two-dimensional to the three-dimensional growth mode occurs if the indium content in the In-floating layer exceeds 1.1+/-0.2 monolayers. The measured exponential decrease of the In-concentration within the cap layer on top of the islands reveals that the In-floating layer is not consumed during island formation. The segregation efficiency above the islands is increased compared to the quantum wells which is explained tentatively by strain-dependent lattice-site selection of In. In addition, In0.25Ga0.75As quantum wells were grown at different temperatures between 500 oC and 550 oC. The evaluation of concentration profiles shows that the segregation efficiency increases from R=0.65 to R=0.83.Comment: 16 pages, 6 figures, 1 table, sbmitted in Phys. Rev.

Nanocapsules containing salt hydrate phase change materials for thermal energy storage

Nanocapsules containing salt hydrate for latent heat storage were proven to be thermally and chemically stable over 100 cycles.</p

Crystallohydrate Loaded Halloysite Nanocontainers for Thermal Energy Storage

© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim The mixture of crystallohydrate phase change materials (PCMs) Na2HPO4· 12H2O and Na2SO4· 10H2O is loaded into halloysite nanotubes (HNTs) by water bath sonication and impregnation under vacuum at 40 °C. It is the first time HNTs are applied as nanocontainers for crystallohydrate PCMs for thermal energy storage. The PCM retains well in the nanocontainers over the solid–liquid phase change, due to the electrostatic interaction between PCM and the inner space of HNTs as well as the nanoconfinement effect. No new covalent bonding is formed between PCM and HNTs in the composite. The crystal structure of the hydrated salts mixture does not change after loading into HNTs. With 67 wt% effective loading of Na2HPO4· 12H2O and Na2SO4· 10H2O in 1:1 mass ratio, the nanocontainer composite exhibits the melting temperature of 35.8 °C and the melting enthalpy of 142 J g−1. During the thermal cycling tests, it shows no phase separation and the thermal stability is well kept for 50 cycles. The PCM/HNTs nanocontainers can be considered as efficient nanoscaled energy storage units with great potential in practical applications