Investigation of dialysis membranes with atomic force microscopy

AFM was used to investigate dialysis membranes made of regenerated cellulose by the cuoxam process. The membranes were either Cuprophan or experimental samples, modified with different amounts of diethylaminoethylcellulose (DEAE). Atomic force microscopes with optical-lever detection systems were used to image the dry membranes in air as received from the manufacturer as well as wet membranes in a swollen state under water. Differences could be observed between modified and unmodified as well as between dry and wet membranes.