Abstract: his work demonstrated a successful strategy that simple ionic liquids (ILs) mediated pretreatment could effectively reduce crystallinity of cellulose from 71% to 46% (by C2MIM.Cl) and 53% (by C4MIM.Cl). The IL-mediated regeneration of cellulose greatly promoted its reactivity for TEMPO-catalysed oxidation, which the resulting COO- density (mmol/g) increased from 2.00 for non-IL-treated cellulose to 3.23 (by C2MIM.Cl) and 3.42 (C4MIM.Cl); and degree of oxidation enhanced from 35% to 59% and 62%, respectively. More significantly, the yield of oxidized cellulose increased from 4% to 45-46%, by 11-fold. IL-regenerated cellulose can also be directly subjected to alkylsuccinylation without TEMPO-mediated oxidation, producing nanoparticles with properties similar to oxidized celluloses (55-74nm in size, -70--79mV zeta-potential and 0.23-0.26 PDI); but in a much higher overall yield (87-95%) than IL-regeneration-coupling-TEMPO-oxidation (34-45%). Alkylsuccinylated TEMPO-oxidized cellulose showed 2-2.5 times higher ABTS* scavenging ability than non-oxidized counterpart; while alkylsuccinylation results in a significant decline in Fe2+ chelating property.
