Unzipping oyster shell

Abstract

A novel technique to extract nacre tablets (bricks) from molluskan shells using ‘soft energy’ ionic liquid based dissolution of the organic material (mortar) between the tablets rather than using high energy and potentially tablet-damaging ball milling processing has been developed. The tablets isolated from this ‘unzipping’ of the shell in the ionic liquid n-butyl-3-methylimidazolium hexafluorophosphate were structurally characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and atomic force microscopy (AFM). High resolution AFM combined with in situ SEM shows nanoparticles of calcium carbonate approximately 4–5 nm in diameter present at the interface between multiple tablets of pearl nacre where there is incomplete dissolution of the mortar in the ionic liquid.