ENTEG guest seminar by Dr Ranjita K. Bose, entitled "Polymer thin films and interfaces: vapor deposition vs. solution polymerization methods towards devices and applications"
|When:||Tu 05-07-2016 13:00 - 14:00|
In this talk, wide-ranging applications using well-defined polymer thin films will be presented. These polymer thin films were synthesized using two approaches: (i) initiated chemical vapor deposition (iCVD), a vapor based deposition polymerization and (ii) atom transfer radical polymerization (ATRP), a solution based controlled polymerization technique. The process of iCVD uses a chemical vapor deposition environment to first activate an initiator in the gas phase by a resistively heated filament array to form active free radicals. In the second step, monomer units and the generated radicals adsorb onto a substrate, and finally, the adsorbed initiator radicals initiate surface polymerization by linking monomer units. By eliminating the need to dissolve macromolecules, iCVD enables insoluble polymers to be coated and prevents solvent damage to the substrate. Room temperature modification with functional polymers can be achieved on virtually any substrate: organic, inorganic, rigid, flexible, planar, three-dimensional, dense, or porous. These iCVD polymers were used for biocompatible implants, encapsulation and controlled release, and superhydrophobic coatings. The structure and properties of the polymer films were tuned as required by the application conditions. Additionally, ATRP was used to develop well-defined, surface grafted polymer brushes. The properties of these films were studied for understanding interfacial self-healing in polymers. Thus, a combination of surface chemistry, solvent based and vapor based polymer deposition techniques is a powerful means to produce structures and devices with unique properties for varied applications