Composite structure, discriminating layer

An alternative to the asymmetric structure is the composite structure illustrated in Figure 1 which compares the two. Like the asymmetric structure, the composite structure consists of a discriminating layer supported by an underlying support. In contrast to the asymmetric structure, the support generally is not made of the same material as the discriminating layer and hence is not integrally attached to it. 

Ramakrishnan S., McDonald C.J., Carbeck J.D., Prudhomme R.K. Latex composite membranes Structure and properties of the discriminating layer. J. Mem. Sci. 2004 231 57-70 Romero-Cano M.S., Martin-Rodriguez A., Nieves F.J.D.L. Electrosteric stabilization of polymer colloids with different functionality. Langmuir 2001 17(11) 3505-3511 Rau D.C., Parsegian V.A. Direct Measurement of the intermolecular forces between counterion-condensed DNA double helices— Evidence for long-range attractive hydration forces. Biophys. J. 1992 61(1) 246-259... 

An alternative approach to using interferometers for imaging is to use another source that provides spectral discrimination directly. One such source is an infrared diode laser. A laser coupled to an infrared microscope provides a means to rapidly obtain spatial resolution approaching the diffraction limit (142 ]. A multi-layer polymer composite contaminated by migration of a volatile additive from an exogenous source was imaged using this system. The distribution of this additive in the layered structure was shown to correlate with specific layers (Fig. 21). A con-... 

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