Yuanchi Ma

Postdoctoral Research, NIST

• Studied the phase diagram and structure evolution of potassium poly(styrene sulfonate)-poly(diallyldimethylammonium bromide) (KPSS-PDADMAB) complexes in water with respect to temperature, polymer concentration and salt concentration.
• Studied the effect of dielectric constant on the phase behavior of KPSS-PDADMAB.

Postdoc Research, University of Pennsylvania

• Synthesized two series of macromolecules: dextran methacrylate (dexMA) and tetra-arm poly(ethylene glycol) (TPEG), and used them individually as the building blocks for hydrogels.
• Characterized the structure of these hydrogels using small-angle neutron scattering (SANS) and scanning electron microscopy (SEM).
• Studied the diffusion of fluorescence probe particles (e.g. quantum dots) in these hydrogels by total internal reflection fluorescence (TIRF) microscopy, and investigated the dependence of diffusion coefficients on nano-confinement.

Graduate Research, University of Minnesota

• Synthesized multiple pairs of PMMA-b-(d9-)PnBMA diblock copolymers with narrow molecular weight distributions; characterized the size and dispersity of these PMMA-b-PnBMA micelles using dynamic light scattering (DLS) and small-angle X-ray scattering (SAXS).
• Investigated chain exchange kinetics of these micelles as a function of multiple parameters (T, χ, core length and corona length, etc.) using time-resolved small-angle neutron scattering (TR-SANS), and demonstrated their underlying relationships.

Publications

1. Zhao, D.; Ma, Y.; Wang, E.; Lodge, T. P.; Micellization of Binary Diblock Co-polymer Mixtures in an Ionic Liquid. Macromolecules 2019, 52, 4729-4738.
2. Zhao, D.; Ma, Y.; Lodge, T. P.; Exchange Kinetics for a Single Block Copolymer in Micelles of Two Different Sizes. Macromolecules 2018, 51, 2312-2320.
3. Ma, Y.; Lodge, T. P.; Chain Exchange Kinetics in Diblock Copolymer Micelles in Ionic Liquids: The Role of χ. Macromolecules 2016, 49, 9542-9552.
4. Ma, Y.; Lodge, T. P.; Poly(methyl methacrylate)-block-(Poly-n-butyl methacrylate) Diblock Copolymer Micelles in an Ionic Liquid: Scaling of Core and Corona Size with Core Block Length. Macromolecules 2016, 49, 3639-3646.