Cargando…

STUDIES ON PERMEABILITY OF MEMBRANES : V. THE DIFFUSION OF NON-ELECTROLYTES THROUGH THE DRIED COLLODION MEMBRANE.

A study has been made of the relative rates at which various organic non-electrolytes diffuse through the dried collodion membrane. It was found that acetone and urea pass through the membrane many times more rapidly than glycerine and that glycerine in its turn diffuses much faster than glucose. It...

Descripción completa

Detalles Bibliográficos
Autores principales: Weech, A. A., Michaelis, L.
Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 1928
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2323688/
https://www.ncbi.nlm.nih.gov/pubmed/19872448
_version_ 1782152677492260864
author Weech, A. A.
Michaelis, L.
author_facet Weech, A. A.
Michaelis, L.
author_sort Weech, A. A.
collection PubMed
description A study has been made of the relative rates at which various organic non-electrolytes diffuse through the dried collodion membrane. It was found that acetone and urea pass through the membrane many times more rapidly than glycerine and that glycerine in its turn diffuses much faster than glucose. It was also demonstrated that the rate of diffusion varies directly with the difference in concentration between the solutions on the two sides of the membrane. It was shown that the presence of glycerine on the two sides of the membrane did not appreciably affect the rate of diffusion of acetone. In a study of the changes going on during the establishment of the stationary diffusion gradient with glucose experiments were described which strongly suggested that many of the membrane channels may gradually become clogged up with glucose molecules so that the diffusion rate decreases from day to day until the stationary gradient is finally reached. In explaining the various experimental data the conception of the collodion membrane as a sieve with pores approximating in smallness the size of individual molecules was utilized. The large differences in the diffusion rates between different substances were then referred to differences in molecular size, the relatively large molecules of glycerine and glucose being unable to pass through many of the smaller pores available for urea and acetone. From the data available it was possible to estimate that 98 per cent of the pore area distributed among holes large enough for the diffusion of acetone was unavailable for the passage of glycerine and that only 0.3 per cent of the pore area available for acetone could be utilized by glucose. In trying to correlate the ratio between the diffusion rates of two different substances with the characteristic concentration potential (Co P) given by the same membrane it was found (1) that with the acetone-glycerine ratio there is no correspondence (2) that with the acetone-glucose ratio a suggestive relation exists and (3) that with the glycerine-glucose ratio a definite correspondence can be shown, the higher ratios being obtained only with membranes giving high CO P values. A rational explanation for these facts was proposed.
format Text
id pubmed-2323688
institution National Center for Biotechnology Information
language English
publishDate 1928
publisher The Rockefeller University Press
record_format MEDLINE/PubMed
spelling pubmed-23236882008-04-23 STUDIES ON PERMEABILITY OF MEMBRANES : V. THE DIFFUSION OF NON-ELECTROLYTES THROUGH THE DRIED COLLODION MEMBRANE. Weech, A. A. Michaelis, L. J Gen Physiol Article A study has been made of the relative rates at which various organic non-electrolytes diffuse through the dried collodion membrane. It was found that acetone and urea pass through the membrane many times more rapidly than glycerine and that glycerine in its turn diffuses much faster than glucose. It was also demonstrated that the rate of diffusion varies directly with the difference in concentration between the solutions on the two sides of the membrane. It was shown that the presence of glycerine on the two sides of the membrane did not appreciably affect the rate of diffusion of acetone. In a study of the changes going on during the establishment of the stationary diffusion gradient with glucose experiments were described which strongly suggested that many of the membrane channels may gradually become clogged up with glucose molecules so that the diffusion rate decreases from day to day until the stationary gradient is finally reached. In explaining the various experimental data the conception of the collodion membrane as a sieve with pores approximating in smallness the size of individual molecules was utilized. The large differences in the diffusion rates between different substances were then referred to differences in molecular size, the relatively large molecules of glycerine and glucose being unable to pass through many of the smaller pores available for urea and acetone. From the data available it was possible to estimate that 98 per cent of the pore area distributed among holes large enough for the diffusion of acetone was unavailable for the passage of glycerine and that only 0.3 per cent of the pore area available for acetone could be utilized by glucose. In trying to correlate the ratio between the diffusion rates of two different substances with the characteristic concentration potential (Co P) given by the same membrane it was found (1) that with the acetone-glycerine ratio there is no correspondence (2) that with the acetone-glucose ratio a suggestive relation exists and (3) that with the glycerine-glucose ratio a definite correspondence can be shown, the higher ratios being obtained only with membranes giving high CO P values. A rational explanation for these facts was proposed. The Rockefeller University Press 1928-09-20 /pmc/articles/PMC2323688/ /pubmed/19872448 Text en Copyright © Copyright, 1928, by The Rockefeller Institute for Medical Research This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/).
spellingShingle Article
Weech, A. A.
Michaelis, L.
STUDIES ON PERMEABILITY OF MEMBRANES : V. THE DIFFUSION OF NON-ELECTROLYTES THROUGH THE DRIED COLLODION MEMBRANE.
title STUDIES ON PERMEABILITY OF MEMBRANES : V. THE DIFFUSION OF NON-ELECTROLYTES THROUGH THE DRIED COLLODION MEMBRANE.
title_full STUDIES ON PERMEABILITY OF MEMBRANES : V. THE DIFFUSION OF NON-ELECTROLYTES THROUGH THE DRIED COLLODION MEMBRANE.
title_fullStr STUDIES ON PERMEABILITY OF MEMBRANES : V. THE DIFFUSION OF NON-ELECTROLYTES THROUGH THE DRIED COLLODION MEMBRANE.
title_full_unstemmed STUDIES ON PERMEABILITY OF MEMBRANES : V. THE DIFFUSION OF NON-ELECTROLYTES THROUGH THE DRIED COLLODION MEMBRANE.
title_short STUDIES ON PERMEABILITY OF MEMBRANES : V. THE DIFFUSION OF NON-ELECTROLYTES THROUGH THE DRIED COLLODION MEMBRANE.
title_sort studies on permeability of membranes : v. the diffusion of non-electrolytes through the dried collodion membrane.
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2323688/
https://www.ncbi.nlm.nih.gov/pubmed/19872448
work_keys_str_mv AT weechaa studiesonpermeabilityofmembranesvthediffusionofnonelectrolytesthroughthedriedcollodionmembrane
AT michaelisl studiesonpermeabilityofmembranesvthediffusionofnonelectrolytesthroughthedriedcollodionmembrane