This work is focused on analyzing the electrokinetic behavior and colloidal stability of latex dispersions having different amounts of adsorbed ionic surfactants. The effects of the surface charge sign and value, and the type of ionic surfactant were examined. The analysis of the electrophoretic mobility (mu(e)) versus the electrolyte concentration up to really high amounts of salt, much higher...

We utilize ion mobility mass spectrometry with an atmospheric pressure differential mobility analyzer coupled to a time-of-flight mass spectrometer (DMA-MS) to examine the formation of ion-vapor molecule complexes with seed ions of K+ , Rb+ , Cs+ , Br- , and I- exposed to n-butanol and n-nonane vapor under subsaturated conditions. Ion-vapor molecule complex formation is indicated by a shift in ...

Experiments are described on the electrophoretic mobility of a single isolated colloid and the electroosmotic response of the surrounding medium. For that optical tweezers are employed which enable one to trap a particle without any mechanical contact and to measure its position and the forces acting on it with high resolution (±2 nm, ±200 fN). In a custom-made microfluidic cell, the two effect...

A commercially available ion mobility spectrometer was interfaced to a custom-built linear time-of-flight (TOF) mass spectrometer for the purpose of examining electrospray-generated plumes. Ionic species that were separated in the ion mobility spectrometer could be selectively determined with the TOF mass spectrometer. Tetraalkylammonium salts, a peptide, and proteins were examined. Their ion m...

Previous investigators have reported a change in distribution of serum protein fractions, as measured by the areas subtending the conventional electrophoresis curves, as a result of a change in ionic strength of the buffer (1) or as a result of a change in total protein concentration (1, 2). A similar effect of total protein concentration on the electrophoretic analysis of ovalbumin has been sh...

Synaptic vesicles isolated from guinea-pig cerebral cortex had an electrophoretic mobility of -3.55mum.s(-1).V(-1).cm in saline-sorbitol, pH7.2, at 25 degrees C (ionic strength 0.015g-ions/1). The mobility was pH-dependent, varied with ionic strength and indicated that the vesicular surface contained weak acidic functions with a pK(a) in the range 3.0-3.8. Although the vesicular surface was det...

Ionmobility and ionic conductance in nanodevices are known todeviate frombulk behavior, a phenomenon often attributed to surface effects. We demonstrate that dielectric mismatch between the electrolyte and the surface can qualitatively alter ionic transport in a counterintuitive manner. Instead of following the polarization-induced modulation of the concentration profile, mobility is enhanced o...

Robert Schöllhorn* and Wolfgang Schramm Anorganisch-Chemisches Institut der Universität Münster, Gievenbecker Weg 9, D-4400 Münster Z. Naturforsch. 84b, 697-699 (1979); received February 19, 1979 Topotactic Reactions, Intercalation Compounds, Niobium Chalcogenides, Ionic Conductivity, Superconductivity Cathodic reduction of Nb3S4 and Nb3Se4 electrodes in electrolytes containing cations of appro...