Colloidal systems of surface active ionic liquids and sodium carboxymethyl cellulose: physicochemical investigations and preparation of magnetic nano-composites

Abstract

The complexation of three surface active ionic liquids (SAILs): 1-methyl-3-dodecylimidazolium chloride, [C₁₂mim][Cl], and its amide, 3-(2-(dodecylamino)-2-oxoethyl)-1-methyl-1H-imidazol-3-ium chloride, [C₁₂Amim][Cl], and ester, 3-methyl-1-dodecyloxycarbonylmethylimidazolium chloride, [C₁₂Emim][Cl], functionalized counterparts with sodium carboxymethylcellulose (NaCMC), has been investigated. The behaviour of colloidal systems comprising SAILs and NaCMC at the air–solution interface has been investigated using tensiometry. The formed colloids in the bulk have been characterized for their mobility, surface charge, shape, size and morphology along with their relative hydrophobicity/hydrophilicity and other thermodynamic parameters of interest in different concentration regimes of the SAILs. For this, various techniques such as conductivity, turbidity, dynamic light scattering, ζ-potential, scanning electron microscopy (SEM) and fluorescence measurements have been employed. H-bonding prone SAILs, i.e. [C₁₂Amim][Cl] and [C₁₂Emim][Cl], are found to interact with NaCMC in a contrasting manner as compared to their non-functionalized counterpart. The formed complexes of SAILs and NaCMC have been explored for the one pot preparation of magnetic nano-composites by doping colloids of SAILs and NaCMC with zinc ferrite (ZnFe₃O₄) nano-particles. The prepared magnetic nano-composites are characterised using X-ray diffraction (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometry (VSM). It is expected that the present work would offer a new colloidal route for the preparation of SAILs and biopolymer assisted nano-composites along with providing physical insights into the complexation phenomenon.