Coassembly of Inorganic Macromolecule of Exfoliated LDH Nanosheets with Cellulose

Abstract

Nanosheets exfoliated from layered inorganic crystals can be regarded as inorganic macromolecules. Herein, coassembly of layered double hydroxide (LDH) nanosheets with carboxymethyl cellulose (CMC) was presented. CHN analysis, XRD, FTIR, TG-DSC and SEM were employed to characterize the coassembly process. The results showed that the colloidal suspension of the exfoliated MgAl−LDH nanosheets in formamide were restacked when in contact with water. Nevertheless, CMC can prevent the colloidal state from flocculation even after all included formamide molecules were removed by water, that is the interaction of CMC molecules and the nanosheets stabilized the dispersion in aqueous media. Drying at 40 °C led the nanosheets and CMC to restack to a layered nanocomposite with a basal spacing of 1.75 nm, indicating a bilayer arrangement of CMC in the interlayer. The thermal degradation temperature of CMC in the composite was raised by about 160 °C.