We have used single-walled carbon nanotube transistors to measure changes in the chemical potential of a solution due to redox-active transition-metal complexes. The interaction of the molecules with a gold electrolyte-gate wire changes the electrostatic potential sensed by the nanotube, which in turn shifts the gate-voltage dependence of the nanotube conductance. As predicted by the Nernst equ...

In this paper we present parallel adaptive finite element algorithms for solving the 3D electro-diffusion equations such as the Poisson-Nernst-Planck equations and the size-modified Poisson-Nernst-Planck equations in simulations of biomolecular systems in ionic liquid. A set of transformation methods based on the generalized Slotboom variables is used to solve the coupled equations. Calculation...

By application of matched asymptotic expansions, a simplified partial differential equation (PDE) model for the dynamic electrochemical processes occurring in the vicinity of a membrane, as ions selectively permeate across it, is formally derived from the Poisson-Nernst-Planck equations of electrochemistry. It is demonstrated that this simplified model reduces itself, in the limit of a long thi...

Ionic liquids are liquids comprised totally of ions. However, not all of the ions present appear to be available to participate in conduction processes, to a degree that is dependent on the nature of the ionic liquid and its structure. There is much interest in quantifying and understanding this 'degree of ionicity' phenomenon. In this paper we present transport data for a range of ionic liquid...

T H E chemical composition of the foetal fluids in the rabbit was studied by Davies & Routh (1957). These investigators showed that the amniotic and exocoelomic fluids resembled extracellular fluid in their ionic composition whereas the allantoic fluid more closely resembled intracellular fluid. These findings were confirmed by Dickerson & McCance (1957). An experimental study of the trans-memb...

A calibration procedure is presented for the use of a Y2O3-stabilized zirconia (YSZ) oxygen sensor in 1 atm gas-mixing furnaces in the temperature range 1200–1500°C and 0–8 orders of magnitude below the iron-wüstite (IW) buffer. Corrections to the Nernst equation were obtained by measuring apparent oxygen fugacities of gases in equilibrium with graphite (equilibrated with pure CO vapor), Cr 1 C...

Membrane potential, conductance, and intracellular potassium concentration were measured in oligodendrocytes in 3- to 10-week-old cultures of embryonic mouse spinal cord. After intracellular recording the cells were first injected with Lucifer Yellow and then stained by immunofluorescence using rhodamine-labeled monoclonal antibody 01 specific for oligodendrocyte cell surfaces. The membrane pot...

The membrane potential, arising from uneven distribution of ions across cell membranes containing selectively permeable ion channels, is of fundamental importance to cell signaling. The necessity of maintaining the membrane potential may be appreciated by expressing Ohm's law as current = voltage/resistance and recognizing that no current flows when voltage = 0, i.e., transmembrane voltage grad...

in this paper, numerical investigation of a flat passive micromixer with heterogeneous surface properties that the flow through it, is driven by the electroosmotic flow have been presented. the governing equations, which consist of a laplace equation for the distribution of external electric potential, a poisson equation for the distribution of electric double layer potential, modified navier-s...

The Nernst formulation of the third law of ordinary thermody-namics (often referred to as the \Nernst theorem") asserts that the entropy, S, of a system must go to zero (or a \universal constant") as its temperature, T , goes to zero. This assertion is commonly considered to be a fundamental law of thermodynamics. As such, it seems to spoil the otherwise perfect analogy between the ordinary law...