Liquid Membrane Electrodes
Liquid Membrane Electrodes - Related Videos
08:41
Ultrasound Velocity Measurement in a Liquid Metal Electrode
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Cited by 14 •
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Ultrasound velocimetry is used to study mixing by fluid flow in liquid metal electrodes. The focus of this manuscript is to illustrate the methods used for making precise, spatially-resolved ultrasound measurements while limiting oxidation and controlling and monitoring temperature, applied current, and the heater power being supplied.
01:15
Potentiometry: Membrane Electrodes
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2024
Membrane electrodes, also known as p-ion electrodes, use membranes that selectively interact with free analyte ions, generating a potential difference across the membrane. The resulting membrane potential, known as the asymmetry potential, is not zero even when analyte concentrations on both sides of the membrane are equal. The membrane's response is typically not selective to a single analyte but proportional to the concentration of all ions in the sample solution capable of interacting at the...
10:16
Targeted Plasma Membrane Delivery of a Hydrophobic Cargo Encapsulated in a Liquid Crystal Nanoparticle Carrier
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Cited by 3 •
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A liquid crystal nanoparticle (LCNP) nanocarrier is exploited as a vehicle for the controlled delivery of a hydrophobic cargo to the plasma membrane of living cells.
03:02
Standard Electrode Potentials
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2020
On comparing the reactivity of silver and lead, it is observed that the two ionic species, Ag+ (aq) and Pb2+ (aq), show a difference in their redox reactivity towards copper: the silver ion undergoes spontaneous reduction, while the lead ion does not. This relative redox activity can be easily quantified in electrochemical cells by a property called cell potential. This property is commonly known as cell voltage in electrochemistry, and it is a measure of the energy which accompanies the charge...
09:21
Efficiency of Liquid-liquid Extraction
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2023
Source: Kerry M. Dooley and Michael G. Benton, Department of Chemical Engineering, Louisiana State University, Baton Rouge, LA Liquid-liquid extraction (LLE) is a separation technique used instead of distillation when either: (a) the relative volatilities of the compounds to be separated are very similar; (b) one or more of the mixture components are temperature sensitive even near ambient conditions; (c) the distillation would require a very low pressure or a very high distillate/feed...
FAQs
The ion exchanger or ionophore dissolves in the water-immiscible membrane and selectively partitions the target ion from the aqueous sample. This selective partitioning produces a membrane potential, which is measured relative to a reference electrode. Under suitable conditions, the potential follows the Nernst equation, linking the electrical response to the target ion’s activity.
These dissolved membrane components provide the chemical selectivity needed to distinguish a target ion from other species in solution. Their interaction with the selected ion controls its partitioning into the liquid membrane and therefore influences the resulting membrane potential. Choosing the appropriate component allows electrodes to respond to ions such as calcium, potassium, or nitrate.
The measured potential depends on ion activity rather than simply on the nominal concentration of the target ion. Activity represents the effective chemical availability of the ion under the measurement conditions. Consequently, interpreting the electrode signal requires suitable conditions in which the potential follows the Nernst relationship, allowing the electrical response to reflect changes in the target ion.
The electrode response is obtained by measuring the membrane potential against a reference electrode while the sensing membrane contacts the aqueous sample. The reference provides the comparison needed to observe changes attributable to selective ion partitioning. This paired arrangement supports potentiometric analysis, in which the measured potential is related to the activity of the selected ion.
A measurement requires an aqueous sample, the liquid membrane containing the appropriate ion exchanger or ionophore, and a reference electrode. The sample must contact the sensing membrane so the target ion can partition into the water-immiscible phase. With suitable conditions, the resulting potential can be used for potentiometric analysis while requiring only a small sample.
Their selective ion response, small sample requirements, and compatibility with automated measurements support several analytical settings. Applications include environmental monitoring, clinical testing, process control, and general analytical chemistry. The same approach can measure ions such as calcium, potassium, and nitrate, making it relevant when laboratories need targeted information from aqueous samples.