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Preparation of Phase‐Inversion Cellulose Acetate Membranes on Electrodes with Resolvation of the Polymer by Acetone Vapor Prior to the Gelation Step
Author(s) -
Hoyer Boy,
Sørensen Gunnar,
Jensen Nina,
Christensen Mikkel K.
Publication year - 1999
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/(sici)1521-4109(199909)11:13<940::aid-elan940>3.0.co;2-r
Subject(s) - membrane , cellulose acetate , polymer , anodic stripping voltammetry , electrode , ethylene glycol , acetone , phase inversion , solvent , chemical engineering , chemistry , materials science , analytical chemistry (journal) , inorganic chemistry , chromatography , electrochemistry , organic chemistry , biochemistry , engineering
An improved procedure for the preparation of antifouling cellulose acetate (CA) membranes on electrodes has been developed. Ultrathin (ca. 0.45 μm) CA coatings were deposited on glassy carbon electrodes by electrostatic spraying of a solution consisting of CA, acetone and aqueous magnesium perchlorate as pore former. After conditioning in constant relative humidity, the CA deposit was resolvated in a chamber containing saturated acetone vapor, and the membrane structure was formed by applying ice water (nonsolvent) to the coating while it remained in the acetone chamber. The membrane polymer is therefore in a well‐defined, solvated state at the moment of gelation which is a key requirement in the wet phase‐inversion process. It is shown that any mechanical transfer of the coated electrode from the resolvation chamber to a gelation bath is accompanied by rapid evaporation of solvent which strongly affects the properties of the resulting membrane and the reproducibility thereof. By using cadmium and lead as test analytes and differential pulse anodic stripping voltammetry as detection method, it was found that the membrane eliminated the interference from poly(ethylene glycol) (PEG) 6000 which represents a major improvement in comparison with the previous preparation method. The interference from PEG 2000 and PEG 1500 was also significantly reduced. The sensitivity of the coated electrodes towards the test analytes was the same as that obtained with the previous preparation method.