Unique pattern of close-packed colloid film observed by polarized light microscopy

Abstract

Polarized light microscopy has been extensively used in the research of anisotropic material such as liquid crystal, but not often in the study of the close-packed colloid film. Here, we show that the polarized microscopy can be much more effective than the bright-field or the dark-field microscopy in identifying domain orientation and boundary as well as in distinguishing regions of the different number of layers in the close-packed microsphere colloid film due to its unique pattern and enhanced contrast. Origins for these unique properties could be well explained by the simple model based on the polarization rotation at the microsphere edges and the possible close-packed multilayer structures. These findings will renew the use of the polarized microscopy in the study of the close-packed colloid film. (C) 2013 AIP Publishing LLC.