Effect of interstitial media on segregation in vertically vibrated granular mixtures

Vertically vibrated segregation behaviors of binary granular mixtures with different interstitial media are experimentally investigated. To study the role of interstitial media on the segregation, two types of interstitial fluids are adopted and the resulting phase diagrams are compared. The water-immersed granular mixture exhibits two kinds of complete segregation behaviors: Brazil nut effect and sandwich patterns, at least the latter is absent in the same air-immersed mixture. Additionally, the segregation extent is improved remarkably for the water-immersed mixture. The experimental observation further confirms that the effect of interstitial media on the relative motion of grains is one of the predominant mechanisms for granular segregation.