Patent ID: 8222306

Claim:
A method of modifying an elastic modulus of an article comprising a polyelectrolyte complex, the polyelectrolyte complex comprising an interior region and a surface region, wherein the interior region comprises an intermolecular blend of at least one interior positively charged polyelectrolyte polymer and at least one interior negatively charged polyelectrolyte polymer, the surface region comprises an intermolecular blend of at least one surface positively charged polyelectrolyte polymer and at least one surface negatively charged polyelectrolyte polymer, the surface region has a surface elastic modulus, and the interior region has an interior elastic modulus, the method comprising: applying a mechanical force to compact the article comprising the polyelectrolyte complex to thereby form a compacted article comprising the polyelectrolyte complex; contacting the compacted article comprising the polyelectrolyte complex with a solution comprising an osmolyte to thereby change a water concentration in the article from a first water concentration to a second water concentration, wherein the osmotic pressure of the solution is at least 10% greater than the internal osmotic pressure of the article comprising the polyelectrolyte complex and wherein contact with said solution changes the surface elastic modulus relative to the interior elastic modulus.