When solid surfaces are immersed in aqueous solutions, some of their charges can dissociate and leave behind charged patches on the surface. Although the charges are distributed heterogeneously on the surface, most of the theoretical models treat them as homogeneous. For overall non-neutral surfaces, the assumption of surface charge homogeneity is rather reasonable since the leading terms of tw...

In the current study, we have examined the possibility to improve the biocompatibility of the (TiZrNbTaHf)C through replacement of either Ti or Ta by Si. The coatings were deposited on Si and 316L stainless steel substrates by magnetron sputtering in an Ar+CH4 mixed atmosphere and were examined for elemental composition, chemical bonds, surface topography, surface electrical charge and biocompa...

A mixed bilayer of cholesterol and dimyristoylphosphatidylcholine has been formed on a gold-coated block of quartz by fusion of small unilamellar vesicles. The formation of this bilayer lipid membrane on a conductive surface allowed us to study the influence of the support's surface charge on the structure and hydration of the bilayer lipid membrane. We have employed electrochemical measurement...

Ferroelectric vortex domain structure which exists in low-dimensional ferroelectrics is being intensively researched for future applications in functional nanodevices. Here we demonstrate that adjusting surface charge screening in combination with temperature can provide an efficient way to gain control of vortex domain structure in ferroelectric nanodot. Systematical simulating experiments hav...

Due to double-layer forces a charged colloid suspended in an electrolyte is repelled from a like-charged planar wall. We demonstrate that and how a precise measurement of these double-layer forces acting on a colloid near a glass surface can be used to determine surface charge densities. The effective wall–colloid potentials are measured using the total internal reflection microscopy technique,...

Streptococcus pneumoniae (pneumococcus) frequently colonizes the human nasopharynx and is an important cause of pneumonia, meningitis, sinusitis, and otitis media. The outer cell surface of pneumococcus may assume various degrees of negative charge depending on the polysaccharide capsule, of which more than 90 serotypes have been identified. The negative charge of capsular polysaccharides has b...

Fermentor-stabilized activated sludge from an industrial beverage bottling plant was grown on three different food sources: normal plant wastewater, plant wastewater containing high sucrose concentrations, and a synthetic glucose-based feed stock. Surface charge, hydrophobicity, and exopolysaccharide composition were measured on the stabilized bacterial flocs. Cell surface charge was measured b...

In this paper, the interaction between an oscillating dipole moment and a Silver nanoparticle has been studied. Our calculations are based on Mie scattering theory and discrete dipole approximation(DDA) method.At first, the resonance frequency due to excitingthe localized surface plasmons has been obtained using Mie scattering theory and then by exciting a dipole moment in theclose proximity of...

In this paper, we attempt to reveal the nature of the chemical and electromagnetic mechanisms of tip-enhanced Raman scattering (TERS). Direct visual evidence regarding the chemical mechanism via charge transfer was obtained with charge difference density. It is found that there are several kinds of charge transfer: (1) tip to molecule, (2) surface to molecule, (3) tip and surface to molecule si...

in the current study, pure tio2 and cr-doped tio2 (cr@tio2) nanoparticles were synthesized via sol-gel method and the resulting materials were applied to prepare the porous tio2 electrodes for dye-sensitized solar cells (dsscs). it is hypothesized that the advantages of the doping of the metal ions into tio2 lattice are the temporary rapping of the photogenerated electron-hole (charge carriers)...