Effect of an “in situ” hydrous strain on the ionic exchange process of dioctahedral smectite: Case of solution containing (Cu2+, Co2+) cations

► The applied hydrous strain affects the interlamellar space configuration. ► Stressed Swy-Na sample, lose her homogeneous hydration character for %RH < 60. ► The selective exchange process is started for both stressed and unstressed materials. ► For 10−2 N solution, CEC of SWy-2N-S exhibit a partial saturation due to Co2+ cations.