Phase Separation of 5CB Liquid Crystal Droplets in the Self-assembling Protein Drops via Evaporative Drying

This presentation aims to show how a series of simple experiments can easily track the complex physical behavior. These experiments present new insights on the self-assembly of bio-colloidal structures in a symmetric drop driven by evaporative drying. Our findings uncover the self-assembly of the globular proteins, bovine serum albumin (BSA), myoglobin (Myo), and lysozyme (Lys), and the phase separation of the nematic liquid crystal, 5CB. The drying evolution and the resulting morphology of these drying drops with and without 5CB droplets are compared through the bright-field and cross-polarizing microscopy. Different regimes of intensity in the presence of 5CB droplets are shown under cross-polarizing configuration, whereas no such variation is observed in its absence in these protein drops. Interestingly, BSA shows a striking result by an umbilical defect in every domain near the periphery of the drop. On the other hand, Myo and Lys exhibit a central dark region in every domain surrounded by a bright region. Finally, under the bright-field configuration, the crack spacing is reduced in the dried Myo and Lys drops with 5CB droplets, whereas no significant difference is found in the dried BSA drop.