Direct growth of layered double hydroxides in an aqueous suspension of carbon nanotubes and their application as fillers in polypropylene

Interesting composites with three-dimensional (3D) structure that combine one-dimensional (1D) carbon nanotubes (CNTs) with two-dimensional (2D) lamellar flakes show excellent potential properties for application in polymer matrices. Herein, we describe the construction of a composite of CNTs and 2D flakes by in situ growth of layered double hydroxides (LDH) in CNTs aqueous suspensions. It has been found that the morphology of the LDH/CNTs composites can be easily tuned by changing the CNTs concentration (CCNTs) and the LDH growth time. The introduction of CNTs did not severely perturb the main crystalline structure of LDH. A plausible model for the in situ growth mechanism is proposed to describe the temporal evolution of the LDH morphology as well as the influence of CCNTs on the morphology of the LDH/CNTs composites. The as-obtained LDH/CNTs 3D composites with interlayer dodecyl-benzenesulfonate anions have proved to be efficient fillers, significantly improving the mechanical properties and thermal stability of polypropylene (PP).