Jonghwi Lee
Chung-Ang University, South Korea
Title: Bio-inspired, microchanneled materials prepared by crystallization of solvents
Biography
Biography: Jonghwi Lee
Abstract
Microporous polymeric materials in nature have well-controlled structures of skeletal walls and pores for their functions. The structures of man-made microporous polymers are commonly limited to isolated porous architecture, although they have continually been developed for the critical roles in various industries. The directional melt crystallization of solvent, a relatively new versatile preparation method to produce aligned pores in the forms of 3D patterns, has produced porous structures of Voronoi and honeycomb-like architecture morphology. By applying this technique to polymers, we have produced various materials having ordered microchannels. Crystallization rate and direction have been carefully controlled in a home-made apparatus to prepare defect-free materials having well-ordered through-thickness microchannels. From polymer solutions or dispersions, solutes become skeletal portion and crystallized solvents become pores after sublimation. The free-standing membranes of 60-90 vol% through-thickness porosity could be prepared without having internal microcracks. With the support of nanotemplates, nanospheres, nanorods, and nanomembranes could be prepared too. Controlling pore morphology by directional freezing offers a versatile route to prepare unique porous polymer and composites for future biomedical, electronics and environmental applications.