Electron diffraction studies of etched al leaf films

Anomalies occurring in electron diffraction patterns of etched An leaf films were studied. The anomalies were of two kinds, extra lines and orientation effects. The extra lines, in agreement with the report of Thomson and Cochrane, were attributed to contamination of the films by some long chain compound. The orientation effects consisted of a variation of the intensities of several of the lines of the An patterns obtained from the intensity of these same lines as observed in standard patterns of randomly-oriented Au. These abnormal intensities evidenced the existence of the [100] crystal direction as an axis of orientation perpendicular to the face of the film. A second orientation effect, the arcing of some of the lines of the Au patterns, indicated a second axis of orientation parallel to the face of the film but insufficient evidence prevented the identification of this axis of orientation.Results of the orientation study confirm the findings of other investigators, particularly those of Trillat and Hirsch.     

Stresses in thin films for hyperfiltration

An elastic and a viscoelastic analyses have been performed to determine the extent to which thin polymer films used in “hyperfiltration” process of desalination of brackish or sea water may be stressed. It was found that if pores of the size comparable to the thickness of the film exist in the rigid supporting material, stress of the order of magnitude comparable to the ultimate strength of the film may be induced.