Behavior of Interlayered Water in Open Hydroxide Layered Lattices. Final Report,February 1987-September 1990

摘要

Double metal layered hydroxides (DMLH) compounds consist of mixed-metal hydroxidelayers separated by intercalated anions. The interlayer region is thus accessible to small polar molecules such as water. DMLH compounds of the hydrotalcite (HT)-like form have been synthesized consisting of Mg-Al, Ca-Al, and Zn-Cr cation pairs and containing nitrate, sulfate, carbonate, chloride, and ferricyanide as the interlayer anions. Gibbsite-like DMLH compounds were also synthesized having Al-Li mixed metals in the layers and nitrate, carbonate, or sulfate in the interlayer. These compounds were evaluated as water sorbents and the dynamics of water in the interlayer was studied by solid-state NMR techniques. Most compounds exhibited at Langmuir Type I sorption isotherm and water uptake ranged between 3 and 10 wt%. NMR studies revealed that the sorbed water is strongly held, possibly by hydrogen bonds.