Quantitative mapping of structured polymeric systems using singular value decomposition analysis of soft X-ray images

The distribution of poly(acrylic acid) in a microporous polypropylene support membrane has been measured quantitatively by scanning transmission X-ray microscopy (STXM). Singular value decomposition analysis of X-ray microscopy images recorded at carefully selected photon energies was used to obtain quantitative maps of the polypropylene membrane and the poly(acrylic acid) gel, the two components of this system. The sample was studied fully hydrated in order to perform the quantitative mapping when the membrane is the same as in its state of application. Optimum strategies of data acquisition for quantitative X-ray microscopy analysis of radiation sensitive materials are discussed, along with a brief comparison of this technique to alternative methods of mapping the chemical components of structured multicomponent polymeric systems.