Position available:

A Research Fellow/Engineer is required for our membrane project for boron removal

Translocation of polymer through a nanopore

Dissipative particle dynamic simulation is employed to study the translocation time of polymers of various kinds through a nanopore of various shapes, where entropic barrier plays a significant role for the passage of the macromolecules. Our investigation is conducted on linear as well as star polymer of different arm number and length. The driving force for the translocation is either an external force such as electrical force for polyelectrolyte or imposed pressure driven flow for neutral polymer.

 

Variation of spatial monomer distribution with tn for N=73, aps=17.50 and f=2 (left) and f=12 (right).

Variation of bond tension with position and time for star polymers with m=18. From the top row to the bottom, the values of f are 2, 4 and 6, respectively. The plots in the left column are for leading arms and those on the right column are for trailing arms. The lower and upper black curves are the plots of sn and pn against tn. In all cases, aps=17.50.

MOF incorporated membranes and their applications

UiO66 is incorporated in the synthesis of thin film nanocomposite, mixed matrix or continuous membranes for treatment of salty water or separation of organic solutes.

 

Transport of macromolecules and particles in porous media and polymeric network

Dynamic simulation is employed to investigate dynamics, diffusion and migration of particles or macromolecules in interconnected pores or a crosslink polymer network. Obstruction effect as well as hydrodynamic interactions can be taken into account to explore diffusion/migration behavior in various regimes.

Kinetics of exchange of block copolymer between micelles

Dissipative particle dynamic simulation is conducted to construct micelles of block copolymer and then monitor the dynamic process for the chain exchange by labeling the chains with different colors.

Phase behavior and rheology of block copolymer solutions 

Pluronic F127, a triblock copolymer, forms micelles and undergoes a sol-gel transition when the temperature exceeds the critical value. Its interaction with other Pluronic species or other polymer can considerably affects the phase bebavior and rheology. Use of additives therefore provides an avenue to tune the material properties to meet various needs. The following are cryo TEM images: Pure F127  (left) , F127+PEO (Mw=35k, middle) and  F127+PEO(Mw=200, right).