文摘
RH-controlled XRD of selected illites reveals d(100) contraction upon wetting. Related phyllosilicates like smectite, chlorite, and celadonite show expansion. Muscovite and phengite contract negligibly; chlorite has the greatest expansion. The contrasting behavior is attributed to different interlayer occupancy and content. The presence of hydrous species in the interlayer is a crucial factor.