Morphology control synthesis of iron-rich Sinai clay by novel O, N, S-heterocyclic moieties: Magnetic organoclays for various strategic uses in lubricating oilfield industry

Abstract

Herein, iron-rich Sinai clay (ATT)was chemically-modified by inventive azacoumarin (Az), spiropyrrolidine (Sp)and imidazothiadiazole (Im)compounds forming clay-containing hematite particles. Interplay between the chemistry of organo-compounds and the clay-sheet structure was interpreted by running DFT-calculations and physicochemical studies (XRD, FTIR, DLS, HR-TEM, N2-physisorption and magnetic analyses). The planar/nucleophilic Az-molecules preferentially occupied clay interlayer-spacings and weaken the combination between silicate-layers, forming large-sizes of completely intercalated clay layers of mesoporous structure with poor physicochemical properties. Besides, angstrom-size hematite particles (<20 Å)appeared in these spacings. The non-planar/electrophilic Sp-molecules promptly attack silicate-layers to form low-sized fully exfoliated clay particles with micro/meso- porous structure of developed magnetic and physicochemical properties. The planar Im-molecules of nucleophilic/electrophilic character enthused construction of intercalated/exfoliated clay system over which magnetic hematite-nanospheres (~10 nm)were splattered. A road ahead to setting-up these organoclays in lubricant-oil industry was planned. Magnetic Sp/ATT organoclay was promisingly behaving as base-oil lubricant additive of increased-efficiency (164%)to oil electrical property. Magnetic Im/ATT organoclay was candidate for being an easily-separable waste-oil regeneration agent, while Az/ATT was highlighted as efficient catalyst for acetic-acid production from waste-lubricant-oil (45% yield). Future studies to applicability of iron-rich organoclays in lubricant-oil industry are optimistic and withstand overwhelmingly positive thus far.