Research

We have a wide range of research area and interests in the space of colloidal science and emulsion polymer. Here we list a subset of research thrusts.
 
 
  • Synthesizing large-sized polystyrene colloidal particles

    Highly monodisperse polystyrene (PS) microspheres in the size range of 1 to 10 μm were synthesized. The particle size distribution (PSD) of the these microspheres obtained was investigated. The PS microspheres with coefficient of variation (CV) values all less than 10% analyzed by scanning electron microscopy. 

     

  • Synthesizing sub-micron colloidal particles by emulsion polimerization

    Uniform polymer particles are synthesized by emulsion polimerization. This technique is able to adjust particle diameters (50 - 300 nm), glass transition temperatures (-50 to 100 degree Celsius), and volume fractions (< 50%).  Part of EPI's latex library is listed here.

 

Drying-Inhomogeinity

During drying of latex, particles distribute inhomogeneously in space, compromising the final quality of the coating. To understand the mechanism of drying inhomogeneity, we integrate Optical Coherence Tomography (OCT) with gravimetric and video analysis (called “OCT-Gravimetry-Video” method) to monitor the internal structure, the water evaporation rate and the appearance of a latex coating simultaneously. Read more.

Stress relaxation of drying colloids attracts our interest because the final mechanical properties of materials depend on colloidal structure. We use oil droplets as probes to visualize how local stress develops in the colloids near close packing. Read more.  
 

 
Active matter systems are made up of units that transfer other type of energy into mechanical work. Many new collective behaviors were found in these system, such as swarming, clustering, and motility induced phase separation. Read More.

 

 

Probing stress and strain distribution in drying latex films