The objective of this project is to explore layer-by-layer self-assembly of temperature and pH-responsive block copolymer micelles with polyelectrolytes at surfaces. Future applications of such films include controlled delivery of active components from surfaces. A combined theoretical and experimental approach is being built through international collaboration between our group and groups of Dr. Kramarenko and Dr. Potemkin at Moscow State University in Russia. Publications: one paper submitted to Macromolecules, two conference proceedings papers accepted to Polymer Materials: Science and Engineering, and two manuscripts are in preparation. Materials World Network: US-Russia Collaboration on Respon sive Micelles at Surfaces -- A Combined Experimental and T heoretical Approach Svetlana Sukhishvili, Stevens Institute of Technology, DMR 0710591 pH-triggered release of active compounds from micelles in solution (A) and from surface multilayer films (B). pH 8 pH 5 pH A B Self-assembly of PDMAEMA 50 -b-PNIPAM 50 in 0.3M Na 2 SO 4 solutions 3 4 5 6 7 0 20 40 60 80 100 H ydrodynam ic size,n m pH 7 μ m 4 5 6 7 8 9 10 11 20 40 60 80 100 H ydrodynam ic S ize (n m ) pH unim er micel le Self-assembly of PDEA 50 -b- PNIPAM 50 in low-salt solutions as a function of B - HO + OH + + OH OH HO OH OH + - - - 0.38μm Self-assembly of PDEA 50 -b- PNIPAM 50 micelles at surfaces We have also synthesized poly-(2- diethylamino)ethylmethacrylate-b-poly-N- isopropylacrylamide (PDEA-b-PNIPAM) copolymers by ATRP technique. Self-assembly of such polymer in aqueous solutions at room temperature is induced by deprotonation of PDEA block at high pH values, resulting in formation of PDEA-core/PNIPAM-corona micelles (left). These responsive micelles were also deposited at surfaces (right). Theoretical treatment of these transition is being developed by Russian collaborators. We have synthesized amphiphilic pH- and temperature reposnive poly[2(dimethylamino)ethyl methacrylate)-b-poly(N- isopropylacrylamide)] (PDMAEMA-b- PNIPAM) block copolymers, and found a new type of phase transitions and restructuring in pH-responsive polymeric micelles. This is first experimental observation of the phase transition between small, strongly charged and big neutral polymer micelles. Practical consequences of such findings are significant, as such transitions present novel ways for controlled