The preparation of membrances

Carnell, Paul H.; Cassidy, Harold G.

doi:10.1002/pol.1961.1205516122

Cited by 29 publications

(11 citation statements)

References 79 publications

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“…When nitrocellulose supports are used, therefore, it is important to define their physical characteristics, since these affect the electrical signal recorded across the assembled membranes. The thickness of the polymeric film, for example, can be controlled in part by the concentration of nitrocellulose and the solvent used in casting (Carnell and Cassidy, 1961;Lackshminarayanaiah and Shanes 1965). The condition we selected, 1% in isoamyacetate, produced films that are thin yet sufficiently strong to support the pressure to which they are subjected throughout the assembly routine.…”

Section: Discussionmentioning

confidence: 99%

Proton transport by bacteriorhodopsin in planar membranes assembled from air-water interface films.

Korenbrot

Hwang

1980

The Journal of General Physiology

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Bacteriorhodopsin, in known amounts and controlled orientation, is incorporated into planar membrane films. These films are formed by the sequential transfer of two air-water interface films onto a thin, hydrophilic, electrically conductive support cast from nitrocellulose. The films are easily accessible to electrical measurements and to control of the ionic milieu on either side of the membrane. The area of the assembled membrane films can be varied between 2.3 x 10(-2) cm2 and 0.7 cm2. Illumination of these films produces photocurrents, photovoltages, and changes in the pH of the surrounding medium. The peak amplitude of the photocurrent increases linearly with light intensity for dim lights, and it approaches a saturating value for brighter lights. In the linear range, the stoichiometry of transport is 0.65 +/- 0.06 protons/absorbed photon. The rate of transport is linearly proportional to light at all intensities tested. The amplitude and kinetics of the photovoltage measured are accurately predicted by the photocurrent generated and the passive electrical features of the film. Parallel measurements of pH and photocurrent reveal that the light-induced changes in pH are fully accounted for by the rate and amount of charge transport across the membrane. Preceding the transport of protons, a transient photovoltage is detected that exhibits no detectable latency, reaches peak in about 80 microseconds, and probably arises from light-induced intramolecular charge displacements.

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Section: Discussionmentioning

confidence: 99%

Proton transport by bacteriorhodopsin in planar membranes assembled from air-water interface films.

Korenbrot

Hwang

1980

The Journal of General Physiology

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“…In addition, several deposition methods have been proposed. Dip coating [16,17], deposition by plasma polymerization [ 18,19 ] and interfacial polymerization [20 ] are frequently used methods. A particularly practical deposition method was proposed by Franken [21 ], who simply modified (hydrophobic) membranes by passing a suitable (water soluble) polymer solution over them.…”

Section: Na0hmentioning

confidence: 99%

Surfactant-induced wetting transitions: Role of surface hydrophobicity and effect on oil permeability of ultrafiltration membranes

Keurentjes

Stuart

Brinkman

et al. 1990

Colloids and Surfaces

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“…This decrease caused decrease in the rate of flow of Parlodion solution down the glass plate as the concentration of the solution was increased, and as a result the thickness of the material deposited with the evaporation of the solvent increased. Conclusion (2) is at variance with what was observed in the previous study.' The porosity of the membrane obviously depended on the amount of solvent evaporating from the Parlodion solution during the period of formation of the membrane.…”

Section: Resultsmentioning

confidence: 99%

Preparation and characterization of thin parlodion membranes

Lakshminarayanaiah

1965

J of Applied Polymer Sci

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synopsisParlodion membranes 95 to 500 A. thick have been prepared on a glass surface by dipping a clean glass plate into the Parlodion solution and subsequently evaporating the solvent under controlled conditions by keeping the glass plate vertical in a metallic frame and covered with an inverted beaker. The membrane may be floated off on to an aqueous surface. Capacitance measurement established the thicknew of the membrane. Electrical resistance and isothermal diffusion potentials arising across them when they separate different salt solutions have also been measured at room temperature.In a previous study,' it was found that the electrical resistance of Parlodion membranes and isothermal diffusion potentials arising across them when they separated different salt solutions, decreased with increase in membrane thickness which was built by transferring more of the Parlodion solution to cover a fixed area of the aqueous surface. It was suggested that the increase in porosity of the membrane and masking of the effect of some of the ionogenic carboxyl groups present as the thicker membranes were formed, were probably responsible for the observed decrease in the membrane resistance and the emf.In order to confirm these suggestions, thin membranes (95-500 A. thick) were prepared by a different technique. The thickness of the membrane was developed not by using larger volumes of the standard Parlodion solution but by increasing the concentration of the membrane-forming solution. This principle is inherent in the method of membrane formation developed by Carnell and Cassidy.2 In our previous attempt^,^ difliculty was experienced in floating the membrane off the glass plate on to an aqueous surface. Further, there was the uncertainty about membrane thickness and hence required another independent method to infer the thickness. But recent work' has shown that this uncertainty can be eliminated by measuring the membrane capacitance. Use of the General Radio impedance-admittance (2-Y) bridge to measure the resistance of the membrane gave also the required capacitance value from which the thickness of the membrane could be deduced. 1285

show abstract

The preparation of membrances

Cited by 29 publications

References 79 publications

Proton transport by bacteriorhodopsin in planar membranes assembled from air-water interface films.

Proton transport by bacteriorhodopsin in planar membranes assembled from air-water interface films.

Surfactant-induced wetting transitions: Role of surface hydrophobicity and effect on oil permeability of ultrafiltration membranes

Preparation and characterization of thin parlodion membranes

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