An interaction between the incident light and the structural architecture, i.e. stratified bilayers of aragonite calcium carbonate and organic matrix, of Asian green mussel (Perna viridis) induces visually observable pearlescent colors. In this work, we investigate the influence of the structure on the color expression and exploit it in several innovative applications. The developed treatment technique for disintegrating nacre to pearlescent flakes enables us to gain the insight understanding of structure-color relationship as only the organic binder was disintegrated without destroying the structural assembly of nacre of shells. Moreover, the pearlescent flakes were further disintegrated to transparent aragonite plates with unique structure. The modified transfer matrix method was employed to verify the structural colors of virgin nacre (aragonite/organic matrix) and pearlescent flakes (aragonite/air gap). Due to a unique optical characteristic of pearlescent flakes, we can be used it as a color-shifting pigment for decorative applications as well as a pigment for products identification or forgery prevention purpose. The individual aragonite plates disintegrated from pearlescent flakes can be used as a solid support in several applications (e.g. catalysis, surface enhance Raman spectroscopy), transparent filler for coating polymer, pearlescent pigment, and art clay for decorative applications.

Thesis (Ph.D.)--Chulalongkorn University, 2014