Selfassembly of zeolite L crystals on biological self-cleaning surfaces

An interesting phenomenon was observed when the petals of different flowers were immersed into a suspension containing dye-loaded zeolite L crystals. The zeolites align into patterns which are distinct for each flower species. On the petal of a horned pansy, for example, they align into hexagons. Polarised fluorescence microscope images show that the zeolites, to a remarkable extent, are aligned along the hexagonal pattern. We have investigated this in detail and we found that the alignment observed on the flower petals is not due to topological forces. In places which exhibit self-cleaning properties, zeolites are not adsorbed. These observations are new and intriguing. Visualisation of surface patterns by means of optical microscopy methods, which are less destructive than other tools such as electron microscopy, are attractive and may also be applied to living organisms. The phenomenon may also contribute to the application of drugs at specific places, and we can learn from these observations how to pattern a surface in order to realise self-organisation of micro or nano objects.