Charges on the pore walls of microporous membranes

Journal Article · Thu Jan 01 00:00:00 EST 1987 · Sep. Sci. Technol.; (United States)

DOI:https://doi.org/10.1080/01496398708057177· OSTI ID:6014972

Hernandez, A; Ibanez, J A; Martinez-Diez, L; Tejerina, A F

A method of calculation of the distribution of charges on the pore surfaces of microporous membranes is shown. The membranes are Nuclepore filters separating two diluted NaCl water solutions (concentrations c/sub o/ and c/sub i/ greater than or equal to c/sub o/. The method is based on the integration in the steady state of the Nernst-Planck-Poisson equations by using Goldman's hypothesis of a linear gradient of electric potential. This integration permits the authors to obtain the volume charge density inside the pores as a function of the distance. In order to obtain the surface density of charges on the pore walls, the pore shape has to be known. It has been proven by them that the pores of their Nuclepore membranes can be described as bent revolution parabolas whose parameters can be determined by adjusting them in order to fit the experimental porosity data. These membranes have very low permselectivities and they are unaffected by the diffusion layers, but the ionic permeabilities are smaller if these diffusion layers exist. This effect on the ionic permeabilities can be related with the angle of bending and the ratio between mean surface charge densities inside and outside the pores when c/sub i/ = c/sub o/.

• Research Organization: Universidad de Valladolid, Spain
• OSTI ID: 6014972
• Journal Information: Sep. Sci. Technol.; (United States), Vol. 22:4
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
MEMBRANES
CHARGE DENSITY
EFFICIENCY
PERMEABILITY
POROSITY
SODIUM CHLORIDES
SEPARATION PROCESSES
WATER
DIFFUSION
EXPERIMENTAL DATA
SURFACES
VOLUME
ALKALI METAL COMPOUNDS
CHLORIDES
CHLORINE COMPOUNDS
DATA
HALIDES
HALOGEN COMPOUNDS
HYDROGEN COMPOUNDS
INFORMATION
NUMERICAL DATA
OXYGEN COMPOUNDS
SODIUM COMPOUNDS
400105* - Separation Procedures