| Abstract |
With the increased availability of sophisticated synthesis methods, it appears that the role of architecture on the rheological properties of polymers has received renewed attention, mainly due to dendrimer synthesis. Hyperbranched polymers represent materials of high branching complexity. Some previous studies have suggested that hyperbranched polymers may behave like unentangled polymers, while others have suggested that may behave like soft colloids. The unusual solution properties and molecular architecture of hyperbranched polymers have made them attractive candidates for use as rheology modifiers. So, in an effort to compare the response of hyperbranched polymers to other more familiar materials, such as star polymers, micelles etc. we used dendritically branched polystyrenes and our goal was to bridge the gap between colloids and polymers. So, rheological properties of the hyperbranched polymers are compared to those of polymers and colloids. Also mixtures of linear and hyperbranched polymers, the two ends of branching complexity, are compared to bare linear polymer and hyperbranched polymer solutions. On the practical side, combining the distinct colloidal and polymeric hallmarks in a single mesoscopic system may lead the way for the molecular design of new marerials. In the second part of this research we are working on star polymers with high functionality, which have emerged as a novel class of ultrasoft colloidal particles. In an effort to continue a previous research, we are tying to study the effect of adding low functionalitys star polymers to star polymers with a large number of arms. The great challenge is to find a way to achieve molecular control of these mixtures by tuning the dynamic response to external stimuli. This will have a significant scientific and technological impact, as it will open the route for the rational design of soft materials with desired properties in a variety of situations.
|
Δυναμική διαλυμάτων διακλαδωμένων πολυμερών
