| abstract |
The present invention involves compositions having variable permeation and/or porosity and objects made therefrom. The compositions are prepared by dispersing a pore-forming agent in a polymer matrix by agitation. The composition is density developed resulting in a variable concentration in pore-forming agent throughout the mixture through application of an external force on the mixture with or without continued agitation. The pore-forming agent is then leached from the mixture to form a polymer matrix having variable permeability and/or porosity. |