Soft Materials Laboratory
Akcora Research Group
- Understanding mechanical and structural relationships of ordered-disordered polymeric nanocomposites
- Developing new strategies for self-assembly of nanoparticles
- Synthesis and characterization of biocompatible functionalized surfaces
Multi-functional Particle Assemblies in Polymer Nanocomposites
We aim to design multi-functional magnetic-polymer hybrids with tunable mechanical and electrical properties. Polymer decorated iron oxide nanoparticles (magnetic brushes) are a comprehensive model system offering both anisotropic and isotropic interactions which can be controlled with particle size, particle functionality (e.g. length and density of grafted chains or ions) and external magnetic fields. In this project, we will explain the role of various attractive and repulsive interactions and elucidate the formation of thermodynamically equilibrium self-assembled structures of magnetic brushes through non-linear rheology, scattering and microscopy. The magnetic nanostructures in equilibrium offers a new approach of magnetic-field induced reversible self-assembly of particles. Cluster organization kinetics and transition from disordered to ordered structures are measured insitu to underpin the transition from equilibrium to nonequilibrium states and reversibility of complex architectures
Bioengineered Surfaces of Varying Hydrophilicity
In this project, we investigate the formation of hierarchical structures of iron oxide nanoparticles with protein and polymer patches. Our purpose is to control the density, coverage of hydrophilic patches to understand protein adhesion on these surfaces that can be used for applications in therapeutics and clinical diagnosis. We utilize “click chemistry” to functionalize the planar and particle surfaces with proteins and hydrophobic polymers. We are developing a novel heterogeneous surface consisting of the protein, streptavidin, and poly(methyl methacrylate) (PMMA) grafted to a silicon substrate. We are fabricating our unique surfaces in a stepwise fashion by first taking the “click chemistry” approach to graft biotin and PMMA to the substrate and then utilizing the strong affinity between biotin and streptavidin to facilitate protein adsorption.
Deformation of Polymers & Nanocomposites under LAOS
Deformation of homopolymers in the presence and absence of nanoparticles under large stresses are being investigated. We examine the reversibility of nanostructures exposed to large strains which is critical for high-strength materials. We show that periodic deformation process results in unusual stiffening of attractive polymer composites. We developed deformation protocols to understand the role of polymer-particle interfaces on the mechanical and adaptive behavior of polymer composites.