Figure 4.

Small-angle X-ray scattering (SAXS) sample geometry. (a) Dispersions were prepared by drying in narrow Hele–Shaw cells. One end of the cell was raised by a few millimetres, to allow the dispersion (cloudy intermediate region) to drain to the other edge, where evaporation occurred. A solid deposit (clear, right-hand side) then slowly grew in from this edge. After several hours cells were raised vertically, and SAXS spectra were collected at a series of scan points along the midline of the cell. (b) The sample geometry is idealized as a receding meniscus moving at a velocity , to balance evaporation at rate from one end, and a solid deposit growing in the opposite direction at velocity w.