  This study describes a new approach for material decomposition in x-ray
imaging, utilising phase contrast to both increase sensitivity to
weakly-attenuating samples and to act as a complementary measurement to
attenuation, therefore allowing two overlaid materials to be separated. The
measurements are captured using the single-exposure, single-grid x-ray phase
contrast imaging technique, with a novel correction that aims to remove
propagation-based phase effects seen at sharp edges in the attenuation image.
The use of a single-exposure technique means that images could be collected in
a high-speed sequence. Results are shown for both a known two-material sample
and for a biological specimen.
