Water uptake behavior of tyrosine-derived carbonates and copolymers

We measure the total water uptake and water flux in homopolymer tyrosine-derived carbonates (DTE) as well as in copolymers of DTE-PEG. We study total water uptake by /sup 3/H-labeled radioactive water, and we observe that PEG substantially increases the absorbed amount compared with the homopolymers. Likewise, flux studies reveal that flux is higher in the PEG-containing carbonates. To assess the high spatial distribution of water in these copolymers we use spatially-resolved electron energy-loss spectroscopy. For the case of DTE-8% PEG we find no statistically significant variations in water content greater than 100 nm length scales.