Solvent and cosolute dependence of Mg surface enrichment in submicron aerosol particles

The formation of multicomponent aerosol particles from precursor solution droplets often involves segregation and surface enrichment of the different solutes, resulting in non-homogeneous particle structures and diverse morphologies. In particular,...

Determination of bulk and surface properties of liquid Bi-Sn alloys using an improved quasi-lattice theory

The thermodynamic properties of Bi-Sn were studied at 600 and 900 K using a quasi-lattice theory. After successful fitting of Gibbs free energies of mixing and thermodynamic activities, the fitting parameters were used to investigate the enthalpy of mixing, the entropy of mixing, concentration fluctuations, Warren-Cowley short-range-order parameter, surface concentrations and surface tensions of the binary systems. Positive and symmetrically shaped enthalpies of mixing were observed in all composition range, while negative excess entropies of mixing were observed. Bi-Sn showed a slight preference for like-atoms as nearest neighbours in all composition range. The nature of atomic order in Bi-Sn at 600 and 900 K appeared similar. The highest tendency for homocoordination exists at composition where mole fraction of Bi is about 40%. It was also observed that Bi (whose surface tension is lower than that of Sn) has the highest surface enrichment in the Bi-Sn systems. Unlike many previous applications of the quasi-lattice theory where constant values were used to approximate coordination numbers, temperature and composition-dependent coordination numbers were applied in this work.

Quantifying Oxygen Induced Surface Enrichment of a Dilute PdAu Alloy Catalyst

Dilute PdAu alloys are promising catalysts for selective oxidation and hydrogenation reactions. However, the surface composition and active site density of the minority metal, Pd, is unknown. In this study,...

Получение атомарно-чистых и структурно-упорядоченных поверхностей эпитаксиальных пленок CdTe для последующей эпитаксии

In this work, atomically clean and structurally ordered surface of CdTe epitaxial layer after storage in air by treatment in isopropyl alcohol saturated with vapors of hydrochloric acid, and further temperature heating in an ultrahigh vacuum, was obtained. CdTe surface chemical treatment results in the removal of native oxides and surface enrichment with elemental tellurium. Heating in vacuum leads to the tellurium desorption and the appearance of a Te-stabilized CdTe surface. During heating in vacuum, two stages of surface state change are observed (~125°С and ≤250°С). At Т>250°С, elemental tellurium is desorbed and a Te-stabilized structure (1x1) CdTe(013) is formed.

Understanding interfacial segregation in polymer blend films with random and mixed side chain bottlebrush copolymer additives

We show that side-chain microstructure does not significantly impact surface enrichment of bottlebrush additives in blends with linear polymers.

Surface enrichment of iridium on IrCo alloy for boosting hydrogen production

We report facile synthesis of Ir surface-enriched IrCo alloy catalyst and its excellent activity which outperforms commercial Pt/C for hydrogen evolution reaction (HER) in acidic media showing fast kinetics. The...