The application of polarized fluorescence spectroscopy in the characterization of molecular orientation in cellulose acetate reverse osmosis membranes

Abstract

In this work the probable effects of orientation of the amorphous phase of cellulose acetate, CA, reverse osmosis RO, membranes are discussed. It is concluded that these effects are more than likely substantial and that the polarized fluorescence technique as applied to probed films would appear to be a fruitful method for gaining valuable insight into this area of the problem in as much as the probes selectively monitor the structure of the amorphous phase. Preliminary data is presented which shows correlations between the orientational parameters and both: 1) the parameters of the RO membrane casting and 2) the RO membrane transport characteristics. Sufficient problems arose, however, during the course of this study, such that the results presented here can only be interpreted as the encouraging beginnings of a feasibility study. While much effort in recent years has been expended in the general area of polarized fluorescence spectroscopy, little has been done to implement the results of these promising findings to the realm of applied engineering problems. This investigation, thus represents a step in that direction.