Study on swelling of poly[2-(N,N-dimethyl amino)ethyl methacrylate]-1-polyisobutylene (PDMAEMA-1-PIB) amphiphilic co-network

The swelling behavior of the PDMAEMA-l-PIB conetwork in hydrophobic (n-heptane) and hydrophilic (water and n-propanol) solvents were investigated simultaneously by conventional swelling and positron annihilation measurements wich is an unusual experimental technique in the field of swelling studies. It was found that the solvent transport is "non-Fickian" in each of the three cases. Our measurements demonstrate that the positron lifetime spectroscopy is a suitable technique for obtaining information on the changes of the free volume and for following the swelling dynamics of APCNs.