Nov 17, 2009

Amphiphillic Organic Crystals

J. J. Segura, A. Verdaguer and  J. Fraxedas, members and leader of the Small Molecules on surfaces in ambient and pristine conditions group at CIN2 (CSIC-ICN) published 'Amphiphillic Organic Crystals' on Journal of American Chemical Society, together with M. Cobián and E. R. Hernández, from the ICMAB. 

The amphiphillic character, that is, the capacity to simultaneously attract and repel water, has been traditionally reserved to organic molecules such as phospholipids and surfactants, containing both hydrophilic and hydrophobic groups within the same molecule. However, this general concept can be extended to artificial structures such as micrometer-sized particles, the so-called Janus particles, and patterned surfaces. Here we provide an example of an amphiphillic crystalline solid, l-alanine, by combining atomic force microscopy measurements performed on two different cleavage surfaces showing contrasting behaviors when exposed to water vapor, with computer simulations that allow us to clarify the dipolar origin of this behavior. Although we take l-alanine as an example, our results should apply quite generally to dipolar molecular crystals.

+ DOI: 10.1021/ja905961h