液間電位差、液界電位

WordNet

smooth and flowing in quality; entirely free of harshness; "the liquid song of a robin"
the state in which a substance exhibits a characteristic readiness to flow with little or no tendency to disperse and relatively high incompressibility (同)liquidness, liquidity, liquid state
a substance that is liquid at room temperature and pressure
fluid matter having no fixed shape but a fixed volume
a frictionless continuant that is not a nasal consonant (especially `l and `r'
clear and bright; "the liquid air of a spring morning"; "eyes shining with a liquid luster"; "limpid blue eyes" (同)limpid
filled or brimming with tears; "swimming eyes"; "sorrow made the eyes of many grow liquid" (同)swimming
existing as or having characteristics of a liquid; especially tending to flow; "water and milk and blood are liquid substances"
the state of being joined together (同)conjunction, conjugation, colligation
an act of joining or adjoining things (同)adjunction
something that joins or connects (同)conjunction
the place where two or more things come together
existing in possibility; "a potential problem"; "possible uses of nuclear power" (同)possible
the inherent capacity for coming into being (同)potentiality, potency

PrepTutorEJDIC

『液体』,流体 / 『液体の』,液状の / (空気・水などが)澄んだ,透明な / (音・調子などが)なめらかな,流れるような;(動作などが)なめらかな / (資産・証券・紙幣などが)流動性の(現金化しやすいこと)
〈U〉〈C〉連結すること(された状態),『結合』,連合,合体 / 〈C〉『結合点』,連結(接合,合流)点 / 〈C〉(鉄道の)『連絡駅』,接続駅
可能性のある,潜在的な / 可能性,潜在力 / 電位

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2015/03/17 06:28:33」(JST)

wiki en

Liquid junction potential occurs when two solutions of different concentrations are in contact with each other. The more concentrated solution will have a tendency to diffuse into the comparatively less concentrated one. The rate of diffusion of each ion will be roughly proportional to its speed in an electric field. If the anions diffuse more rapidly than the cations, they will diffuse ahead into the dilute solution, leaving the latter negatively charged and the concentrated solution positively charged. This will result in an electrical double layer of positive and negative charges at the junction of the two solutions. Thus at the point of junction, a potential difference will develop because of the ionic transfer. This potential is called liquid junction potential or diffusion potential. The magnitude of the potential depends on the relative speeds of the ions' movement.

Calculation

The liquid junction potential cannot be measured directly but calculated. The Electromotive force (EMF) of a concentration cell with transference includes the liquid junction potential.

E_{without transference} = RT/F . ln(a₂/a₁)

where a₁ and a₂ are activities of HCl in the two solutions, R is the Universal Gas Constant, T is the temperature and F is Faraday's Constant.

E_{with transference} = t_M RT/F . ln (a₂/a₁)

where a₂ and a₁ are activities of HCl solutions of right and left hand electrodes respectively and t_M be transport number of Cl⁻

Liquid Junction potential = E_{with transference}– E_{without transference} = (t_M – 1) RT/F . ln (a₂/a₁)

Elimination of liquid junction potential

The liquid junction potential interferes with the exact measurement of the electromotive force of a chemical cell, so its effect should be minimized as much as possible for accurate measurement. The most common method of eliminating the liquid junction potential is to place a salt bridge consisting of a saturated solution of potassium chloride (KCl) and ammonium nitrate (NH₄NO₃) with lithium acetate (CH₃COOLi) between the two solutions constituting the junction. When such a bridge is used, the ions in the bridge are present in large excess at the junction and they carry almost the whole of the current across the boundary. The efficiency of KCl/NH₄NO₃ is connected with the fact that in these salts, the transport numbers^{[clarification needed]} of anions and cations are the same.

External links

Open source Liquid Junction Potential calculator

Junction Potential Explanation Video

References

Advanced Physical Chemistry by Gurtu & Snehi
Principles of Physical Chemistry by Puri, Sharma, Pathania

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

1. 神経筋接合部の電気診断学的評価 electrodiagnostic evaluation of the neuromuscular junction
2. 心筋活動電位および抗不整脈剤の作用 myocardial action potential and action of antiarrhythmic drugs
3. 神経筋接合部に作用する毒素の概要 overview of neuromuscular junction toxins
4. 液体呼吸 liquid ventilation
5. 新生児および幼児における神経筋接合部障害 neuromuscular junction disorders in newborns and infants

English Journal

Single-molecule electrochemical gating in ionic liquids.

Kay NJ, Higgins SJ, Jeppesen JO, Leary E, Lycoops J, Ulstrup J, Nichols RJ.SourceDepartment of Chemistry, Donnan and Robert Robinson Laboratories, University of Liverpool , Liverpool L69 7ZD, U.K.
Journal of the American Chemical Society.J Am Chem Soc.2012 Oct 10;134(40):16817-26. doi: 10.1021/ja307407e. Epub 2012 Sep 28.
The single-molecular conductance of a redox active molecular bridge has been studied in an electrochemical single-molecule transistor configuration in a room-temperature ionic liquid (RTIL). The redox active pyrrolo-tetrathiafulvalene (pTTF) moiety was attached to gold contacts at both ends through
PMID 22985306

Advantages and limitations of reference electrodes with an ionic liquid junction and three-dimensionally ordered macroporous carbon as solid contact.

Zhang T, Lai CZ, Fierke MA, Stein A, Bühlmann P.SourceCollege of Chemical Engineering, Sichuan University , No. 24 South Section 1, Yihuan Road, Chengdu, Sichuan 610065, China.
Analytical chemistry.Anal Chem.2012 Sep 18;84(18):7771-8. Epub 2012 Aug 28.
Liquid-junction-free reference electrodes that contact the sample through an ionic-liquid-doped, hydrophobic polymer membrane have attracted attention because they offer an alternative to reference electrodes with conventional salt bridges. In this work, liquid-junction-free reference electrodes wer
PMID 22901027

Japanese Journal

Stability of a Ag/AgCl Reference Electrode Equipped with an Ionic Liquid Salt Bridge Composed of 1-Methyl-3-octylimidazolium Bis(trifluoromethanesulfonyl)amide in Potentiometry of pH Standard Buffers

SHIBATA Manabu,YAMANUKI Mikito,IWAMOTO Yasukazu,NOMURA Satoshi,KAKIUCHI Takashi
Analytical sciences : the international journal of the Japan Society for Analytical Chemistry 26(11), 1203-1206, 2010-11-10
… The stability of a Ag/AgCl reference electrode equipped with a gelled ionic liquid, 1-methyl-3-octylimidazolium bis(trifluoromethanesulfonyl)amide (C8mimC1C1N), as a salt bridge, was examined in the potentiometry of pH standard solutions. …
NAID 10027316323