A new method for preparation of nanoplates of Zn-Al layered double hydroxides

Methods for preparation of nanoplates of layered double hydroxides (LDHs) have been intensively investigated for the purpose of making nanocomposites. The present study provides a new simple method of nanoplate preparation for Zn-Al LDHs. Zn-Al LDHs containing lactate or combinations of lactate and simple inorganic anions were synthesized by a coprecipitation method, and water-washed and undried LDHs were dispersed in water. Among them, suspensions of Zn-Al LDHs containing both lactate and bicarbonate were unique in that they rapidly became translucent colloidal dispersions when the molar ratio of added bicarbonate to added Al was ≤ 0.5. The resulting LDH nanoplates in the dispersions were delaminated single layers or nanoplates with a thickness of several layers, depending on the amount of bicarbonate.