Morphology and phase transition of waxy cornstarch in solvents of 1-allyl-3-methylimidazolium chloride/water.

The morphologies and phase transitions of waxy cornstarch in solvent mixtures of ionic liquid 1-allyl-3-methylimidazolium chloride (AMIMCl) and water were systematically studied, combining microscopic observation with SEM and DSC measurements. In pure AMIMCl at room temperature (25 °C), starch granules were gradually dissolved over time; the dissolution process was completed in 52 h. With the presence of water in the solvent mixture, dissolution of starch was obviously delayed and even inhibited. During the heat-dispersed process of starch in solvent mixtures of AMIMCl/water at various ratios, starch dissolution and gelatinization occurred simultaneously, depending on the ratio. After 7 days of storage, no apparent retrogradation was observed, as evidenced in the DSC measurements, and the correlations within the double helices of the gelatinized starch were considered to be permanently eliminated in the presence of a large amount of AMIMCl.