Effect of reactant ratio and nanofillers type on the microstructural properties, porosity fluctuations and heavy metal removal ability of chitosan-clay hybrid materials

Abstract

The structure, porosity, and functionality of synthesized chitosan-clay nanocomposites (NCs) are examined throughout this work in relation to the initial stoichiometry and octahedral cavity occupation of the clay fraction. Dioctahedral and trioctahedral smectite are selected as starting materials. X-Ray Diffraction analysis (XRD) confirms the accomplishment of the NCs synthesis process. The stoichiometry fluctuation implies a crystallite exfoliation process provided that the clay fraction contribution must not reach twice the organic ones. From 1:3 stoichiometry ratio, The intercalation process is enhanced by the interlamellar space (IS) closures, and crystallite size increases with crystallinity degree. According to transmission electron microscopy-energy dispersive X-ray (TEM-EDX) investigations, the exfoliation of "clay-particles" wrapping the organic fraction and the intercalation process occurred as the clay fraction abundance increased. Despite the low proportion approved from the synthesis beginning process, Fourier transform infrared spectroscopy (FTIR) reveals the polymer fraction characteristics absorption bands. The Brunauer, Emmett and Teller (BET) analysis of specific surface area and Barrett-Joyner-Halenda (BJH) Analysis of pore size distribution (PSD) supports the findings from TEM/EDX. For slightly saturated soil solution with Pb2+ or Cd2+ cation, Atomic absorption spectroscopy (AAS) evaluate the NCs adsorption capacity. The outcomes are extremely positive for dioctahedral smectite.