Ion Exchange Reaction of Layered Double Hydroxide with Sodium Sulfate

Employing sodium sulfate solution in a concentration from 0.004 to 0.80 mol·L-1 as the exchange matter,ion exchange capacity and ion exchange reaction equilibrium constant of chloride anion style layered hydroxide [Mg4.7Al(OH)11.4]Cl0.96(OH)0.04·7.9H2O were determined under the ultrasonic wave experimental condition.It showed that the maximum exchange capacity of inner-laminar Cl-1 was 1.497 mmol·g-1,the maximum exchange capacity of inner-laminar OH-1 was 0.026 8 mmol·g-1 and the exchange equilibrium constant(pK) was 3.65.The solid samples were characterized by XRD,FT-IR and BET-N2.It showed that the lattice parameters c and gallery height h of hexagonal cell increased evidently after ion exchange reaction,the crystallinity of LDH and the Td symmetry of SO42-decreased separately,and the laminar feature of the product weakened and the micro-pore adsorption capacity decreased.