Polymer Nanocomposites

A. Initial Solvent-Driven Nonequilibrium of PNCs

Processing conditions of PNC such as casting solvent can greatly impact the characteristics of interfacial polymer layer around nanoparticle surface, making PNCs be in nonequilibrium states. As a result, PNC properties can be significantly changed by initial solvent although it does not exist in the final state, thus, requiring a careful consideration of PNC preparation protocols. We aim to investigate such initial solvent-driven nonequilibrium of various PNC systems with variations in particle/polymer size or surface properties of particle.

Representative paper

1)  Intensified Nonequilibrium Effect of Polymer Nanocomposites with Decreasing Nanoparticle Size (ACS Appl. Mater. Interfaces, 2023)

2)  Processing Method Determines the Long-Term Stability of Particle Dispersions in Concentrated Nanoparticle/Polymer Suspensions (Soft Matter, 2022)

3)  Initial Solvent-Driven Nonequilibrium Effect on Structure, Properties, and Dynamics of Polymer Nanocomposites (Phys. Rev. Lett., 2019)

B. Effects of Polymer Matrix Characteristics on PNCs

In the PNC process, polymers can be physically adsorbed onto the nanoparticle surface, forming a interfacial layer, which affects the structures and properties of PNCs. Hence, basic characteristics of initial polymer matrix such as molecular weight, chain conformation, and rigidity can affect the interfacial layer. We focus on controlling the microstructure and physical properties of PNCs by changing basic characteristics of the polymer matrix and by analyzing the dynamics of interfacial layer in various ways.

Representative paper

1)  Gradual Solvent Quality Changes Induce Abrupt Changes in Interfacial Layer, Dispersion Structure, and Physical Properties of Polymer Nanocomposites (Macromolecules, 2024)

2)  Decoupling of Mechanical Properties and Ionic Conductivity in a Low Molecular Weight Polymer Nanocomposites with Highly Connected Particle Aggregates (Polymer, 2023)

3)  Control of Particle Dispersion with Autophobic Dewetting in Polymer Nanocomposites (Macromolecules, 2020)

4)  Enhanced Mechanical Properties of Polymer Nanocomposites Using Dopamine-Modified Polymers at Nanoparticle Surfaces in very Low Molecular Weight Polymers (ACS Macro Lett., 2018)

5)  Tunable Nanoparticle Stability in Concentrated Polymer Solutions on the Basis of the Temperature Dependent Solvent Quality (Macromolecules, 2016)

C. Polymer Nanocomposite with Bimodal Nanoparticles

Polymer nanocomposites with bimodal nanoparticles have enhanced packing of nanoparticles which is expected to give rise to reinforcement of mechanical property. Furthermore, their different curvature of particles can introduce complicated dynamics of polymer interfacial layer. Our group is interested in general understanding of structural and rheological properties of polymer nanocomposites with bimodal particle and verifying possibility of application of functional binary nanoparticles systems.