2018 Volume 49 Pages 25-51
The formation of precipitation bands in gels, such as Liesegang bands, is regarded as a self-assembling phenomenon. Although X-ray spectroscopic methods, including X-ray fluorescence and XANES spectroscopy, have not been employed for such band formation phenomena until recently, the situation changed from 2011. This paper surveys basic properties of Liesegang bands, theoretical aspects of periodic precipitation, and several effects to change the band morphology, comments points to note for applications of X-ray spectroscopies to the periodic precipitation systems, refers some previous studies by using related X-ray methods, and reviews recent X-ray spectroscopic studies on periodic and non-periodic precipitation bands of Prussian blue analogs (PBAs) in water-glass gels, after outlining the interesting properties of PBAs.
