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THE VARIATION OF ELECTRICAL RESISTANCE WITH APPLIED POTENTIAL : II. THIN COLLODION FILMS
1Laboratories of The Rockefeller Institute for Medical Research.
The Journal of General Physiology
|October 30, 2009
Summary
Collodion membrane resistance to direct current mimics living cells by varying with applied voltage. This electrical property is influenced by ion mobility and direction of current flow, showing unique ohmic behavior.
Area of Science:
- Physical Chemistry
- Membrane Science
- Electrochemistry
Background:
- Thin collodion membranes exhibit electrical resistance.
- Living cells also show voltage-dependent resistance.
- Understanding membrane electrical properties is crucial for various applications.
Purpose of the Study:
- To investigate the direct current resistance of thin collodion membranes.
- To compare the electrical behavior of collodion membranes to living cells.
- To elucidate the relationship between ion mobility, potential, and membrane resistance.
Main Methods:
- Applying direct current potentials across collodion membranes.
- Measuring membrane resistance under varying voltage conditions.
- Analyzing the influence of different ionic solutions on resistance.
Main Results:
- Collodion membrane resistance varies with applied potential, similar to living cells.
- Resistance changes with current direction, dependent on ion mobility.
- A hysteretic effect of prior current flow was observed.
- The resistance increase was largely ohmic, with minimal polarization potential.
Conclusions:
- Collodion membranes serve as a model for studying voltage-dependent electrical resistance in biological systems.
- Ion mobility and directionality significantly impact membrane electrical characteristics.
- The ohmic nature of resistance changes distinguishes these membranes from certain biological cells like Valonia.
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