Determination of ligament size distribution of nanoporous gold by scanning electron microscopy and image analysis

A new method to quantitatively analyze the sponge-like structure of nanoporous gold (NPG) was developed. Images of NPG, acquired by a field emission scanning electron microscope (FESEM), were first binarized based on a gray threshold, and then ligaments were separated into a string of nanometer particles by an image split technique. In this way, the size distribution of these nanometer particles is equivalent to ligament size distribution. With similar approach, two addition parameters, pore width distribution and pore/ligament width ratio, were determined. And our results show a clear temperature dependence of the structure evolution of NPG.