Investigation of the pore structure and morphology of cellulose acetate membranes using small-angle neutron scattering. 2: Ultrafiltration and reverse-osmosis membranes

Journal Article · Mon Nov 07 04:00:00 EST 1994 · Macromolecules; (United States)

DOI:https://doi.org/10.1021/ma00101a017· OSTI ID:6949844

Kulkarni, S; Krause, S ^[1]; Wignall, G D ^[2]

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1. Rensselaer Polytechnic Inst., Troy, NY (United States)
2. Oak Ridge National Lab., TN (United States). Solid State Div.

Pore structure in cellulose acetate ultrafiltration (UF) and reverse-osmosis (RO) membranes has been studied using small-angle neutron scattering. Scattering experiments were carried out on dry membranes as well as on membranes swollen with deuterated solvents (D[sub 2]O and CD[sub 3]OD). In addition, the RO membranes were studied both before and after annealing (a process of heating a membrane in a water bath at [approximately]75 C to improve its separation properties). The pore surface in UF membranes was found to be smooth and nonfractal, as evidenced by the fourth power law behavior at high Q. Values of average pore sizes obtained for dry and solvent swollen membranes agree well with pore sizes obtained by other methods. For cellulose acetate RO membranes in their dry state, the unannealed membrane appears to consist of two discrete pore size distributions in the intermediate and high Q region while the annealed membrane contains a much wider distribution of pore sizes. These results give a good account of the changes occurring in the structure of RO membranes as a result of annealing, and agree well with the prediction of other authors.

• DOE Contract Number: AC05-84OR21400
• OSTI ID: 6949844
• Journal Information: Macromolecules; (United States), Journal Name: Macromolecules; (United States) Vol. 27:23; ISSN MAMOBX; ISSN 0024-9297
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360602* -- Other Materials-- Structure & Phase Studies
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400105 -- Separation Procedures
ACETATES
ALCOHOLS
CARBOXYLIC ACID SALTS
CELLULOSE ESTERS
COMPARATIVE EVALUATIONS
DIFFUSION
ESTERS
EVALUATION
FILTRATION
HEAVY WATER
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
LABELLED COMPOUNDS
MEMBRANES
METHANOL
MICROSTRUCTURE
ORGANIC COMPOUNDS
OSMOSIS
OXYGEN COMPOUNDS
PORE STRUCTURE
SCATTERING
SEPARATION EQUIPMENT
SEPARATION PROCESSES
SMALL ANGLE SCATTERING
SWELLING
ULTRAFILTRATION
WATER