# Research Interests

I mainly work in the field of soft matter physics, dedicating efforts to understand the physics of polymers and biological macromolecules.

## Polymer Field-Theoretic Study

The self-consistent field theory (SCFT), as the most accurate theory at the mean-field level, has become a standard technique in practice for studying microphase separations of block copolymers. Composition fluctuations become more and more important with the derease of the invariant degree of polymerization or invariant polymer concentration. While mean-field theories, such as SCFT, breaks down in this circumstance, beyond mean-field theories, such as Gaussian approximation, one-loop theory and complex Langevin simulation, are developed to study the fluctuation corrections to the mean-field theory.

### Topics

• The microphase-separated nanostructures in confined polymer systems
• Directed self-assembly and defect removal processes.
• Beyond mean-field theories for polymer solutions and block copolymers
• The phase behavior of weakly charged polymer solutions

## Ultrathin Film Polymer Crystallization

Ordering and crystallization of polymeric chains with regular chemistry structure is one of the most striking phenomena in con-densed matter physics. The process of polymer crystallization is a transition from a randomly coiled state to a perfectly ordered state. During this process a hierarchy of ordered structure develops, which in turn controls the physical properties of the polymer materials. In bulk, spherulites are the most common superstruc-tures observed when crystallizing from melt, while single crystals and dendrites can be grown from dilute solutions. Recently, polymer crystallization under spatial confinement, especially in thin (thickness less than 1000 nm) and ultrathin (thickness less than 100 nm) films on solid substrates, has attracted increasing attention. The objective to study polymer crystal-lization confined in ultrathin films is twofold:

1. to develop new technologies and to enhance device performance;
2. to provide new evidence to better understand the nature of polymer crystal-lization.

### Topics

• Pattern formation of ultrathin film polymer crystallization.
• Thickening behavior of thin monolayer crystals.

## Scientific Software Development

As an important part of my research, I have developed several computational software packages and implemented numerical algorithms to perform computational tasks encountered along research.

Programming languages involved: C/C++ and Python. Transition to Julia Planned.

### Numerical Algorithms

• Chebyshev collocation method for SCFT calculations of confined polymers.
• Pseudo-spectral method for SCFT calculations.
• Multigrid method for SCFT calculations of charged polymers.
• Off-lattice Monte-Carlo simulation of polymer crystal growth.
• Phase-field simulations of thin film polymer crystal growth.

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