Molecular-based objects: Nanoscopic control of physical and mechanical properties, Craig J. Hawker (U.C.-Santa Barbara)

and Karen L. Wooley (Washington University), DMR-0301833

In an international collaboration with Anders Hult and Eva Malmström (Royal Institute of Technology, Sweden)

Supramolecular (self) assembly of macromolecules in solution is a powerful method by which to produce discrete nanoscale objects with numerous commercial applications. In this international collaborative work, our goals have been to develop (1) templating strategies and (2) facile synthetic strategies (e.g. Click chemistry and RAFT procedures) for the production of well-defined nanostructures. One recent advance, as highlighted here, has employed reversible-addition fragmentation-termination (RAFT) copolymerization of maleic anhydride (Man) with styrene (S) and in situ assembly to afford a new rosette morphology rapidly and in large scale. Further work continues to investigate the physical and mechanical properties of these materials.

Amphiphilic diblock copolymers of PMAn-alt-PS-b-PS can be synthesized by RAFT copolymerization and then assembled into well-defined nanostructures having a unique rosette internal morphology, all in one step. In this figure (Chem. Commun. cover art), the central diagonal illustrates the general approach, which is surrounded by several TEM images of the resulting nanostructures, each collected on carbon-coated copper grids with uranyl acetate negative staining.Chem. Commun., 2005, 3259-3261

Education

Under this grant, two graduate students are pursuing their Ph.D. degrees. One undergraduate student and two postdoctoral research associates have also been supported. In Sweden, three graduate students are pursuing their Ph.D. degrees and one postdoctoral associate supported.

Outreach

• During June 2004 in Stockholm, Sweden, a course in polymer chemistry was taught by the PI’s from the US and Sweden

• A similar course will be taught at UCSB from October 3-7, 2005.

• In February 2005, two graduate students from Sweden visited Washington University in St Louis, USA, for 2 months to conduct extended experiments.

• In April 2005, 8 students from Sweden visited UCSB for 1 week to discuss research progress and future directions.

• Each student involved in this NSF-Europe program has given at least two presentations at external scientific conferences.

US and Swedish participants in Polymer Chemistry course taught by all 4 PI’s in Stockholm, June 2004, ca. 30 students from both Sweden and the US including an under-represented undergraduate student (Jasmine Hunt).

Molecular-based objects: Nanoscopic control of physical and mechanical properties, Craig J. Hawker (U.C.-Santa Barbara)

and Karen L. Wooley (Washington University), DMR-0301833

In an international collaboration with Anders Hult and Eva Malmström (Royal Institute of Technology, Sweden)