Flocculation performance of anionic starch in oil sand tailings

Abstract A series of carboxymethyl starches (CMSs), with various degrees of substitution from 0.1 to 0.79, were synthesized and selected as a model to study the feasibility of using natural polymers as flocculants for oil sand tailings treatment. The flocculation performance of modified CMS in kaolin clay suspensions and oil sand tailings was evaluated in terms of settling rate, solids content, capillary suction time, and specific resistance to filtration of the sediment phase. It was found that the synthesized CMS effectively accelerates settling of kaolin suspensions and oil sand fine tailings, thus demonstrating the feasibility of this application

Six cation-templated halometal complexes and C–H activation of alkylene-bridged azoles

<div><p>Six dication-templated complexes were discovered in efforts to investigate the effect of linear imidazolium-based template, 1,<i>ω</i>-bis(3,3′-methylimidazolium)alkyl dibromide, on pure inorganic halometal clusters. Complexes {[C₄(Mim)₂](Pb₂I₆)}_<i>n</i> (<b>1</b>) (<i>ω</i> = 4), {[C₁(Mim)₂] (Ag₂I₄)}_<i>n</i> (<b>2</b>) (<i>ω</i> = 1), {[C₃(Mim)₂](Ag₂I₄)}_<i>n</i> (<b>3</b>) (<i>ω</i> = 3), and {[C₄(Mim)₂](Ag₂I₄)}_<i>n</i> (<b>4</b>) (<i>ω</i> = 4) possess 1-D chain architecture with different organic cations trapped in it. Compound {[C₃′(Mim)₂](CuBr₃)} (<b>5</b>) (<i>ω</i> = 3) contains the mononuclear anion (CuBr₃)²⁻ and intra-molecular coupled organic cation with the formed seven-membered ring. {[C₂(Mim)₂S₂]₂(Cu₂I₂)}_<i>n</i> (<b>6</b>) (<i>ω</i> = 2) presents an infinite 2-D coordination polymer as the first representative polyrotaxane example featuring the biimidazolium thiolate cation ligand. All compounds were further characterized with IR spectra and thermal analysis properties.</p></div