Relationship between topology and hydrodynamics of cyclic polymers
Cyclic polymers move differently in solutions according to their topology. This finding of Dr. Mohammad Reza Ejtehadi, Professor of the Faculty of Physics of Sharif University of Technology, is the result of the master's project of the student of Sharif Faculty of Physics, Rehane Frimani. Ijtihadi along with his former students Rihane Freemani and Zahra Ahmadian Dehaqani, who are currently doing research at the Faculty of Physics of the University of Vienna and SISSA International School of Advanced Studies in Italy respectively, and also with their international colleague Christos N. Likos From the Faculty of Physics of the University of Vienna, in their new research, which has been published in the prestigious journal Physical Review Letters, they have investigated the relationship between the dynamics of interconnected cyclic polymers and their topology.
Mohammad Reza Ejtihadi, Professor of Physics Faculty of Sharif University of Technology
In this research, Ejtihadi and his colleagues have performed a computer simulation for two types of self-avoiding ring polymers. The first type, polymers that are mechanically bound together are called poly(2) catenanes, abbreviated PCs, and polymers that are chemically bound together are called bonded rings or BRs.
Both of these simulations have been performed under the same static shear conditions.
This research group has found that bound loops of BRs have created a new movement pattern which they call gradient tumbling. A movement that has a rotation around the axis of the gradient. For PCs, polymer rings are stretched and create a new pattern of movement called slip tumbling. Another difference is that in BR rings, the dynamic is continuous and fluctuating, while in PC polymers, discontinuous movement and sliding occurs in the interval between their rolling.
The findings of this research group show a deep connection between the topology of interconnected polymers and their hydrodynamics in dilute solutions.
This research, which is included in the suggested list of the editor of PRL magazine, will open a new window to the physics of continuous polymers and the role of topology in their hydrodynamics.