nnp FY2013 Annual Report 3.2 Figure 1

Figure 1: a) Top view of a tenuous solid of particle rafts formed by hydrophobic particles introduced at the air-water interface. At high particle density, when the inter-particle distance falls below the capillary length scale (approximately 2 mm for water), the particles are bound together through capillary interactions and collectively behave as a two-dimensional solid. (b) When this two-dimensional solid is subjected to a radially diverging stress, provided via a water-insoluble surfactact spreading across the interface, the solid ruptures and cracks emerge.