Biomedical subjects

Hyun-joong Chung

Publications and source records attributed to Hyun-joong Chung.

2 recordsLinked to original sources

PubMed2005

Self-regulated structures in nanocomposites by directed nanoparticle assembly.

Adding surface-modified silica nanoparticles (NPs) to polymer blend films, we demonstrate that directed interfacial segregation of NPs stabilize either three-dimensional (3D) interpenetrating or 2D discrete structures at high and low volume fractions of NPs, respectively. A simple interfacial energy argument provides a general guideline for predicting whether the NPs are directed to the interface between phases or into one phase. The final morphology and domain size can be predicted from the volume fraction of NPs, film thickness, and NP size.

Journal Article↗

PubMed2004

Breakdown of dynamic scaling in thin film binary liquids undergoing phase separation.

The kinetics of phase separation in thin polymer blend films displaying discrete and bicontinuous domain morphologies are examined. For discrete domains, the correlation length xi grows as t(1/3), in agreement with a coalescence model. By plotting xi/d vs t/t(i) (initiation time), universal growth behavior is obtained for thickness values (d) from 1000 to 190 nm. In contrast, bicontinuous domains grow with a decreasing exponent, 0.62 to 0.28, as d decreases from 900 to 90 nm (i.e., no universal growth). This slowing down with reduced dimensionality suggests suppression of lateral hydrodynamic pumping.

Journal Article↗