Isolation of Thermally Stable Cellulose Nanocrystals by Phosphoric Acid Hydrolysis

On account of their intriguing mechanical properties, low cost, and renewable nature, high-aspect-ratio cellulose nanocrystals (CNCs) are an attractive component for many nanomaterials. Due to hydrogen bonding between their surface hydroxyl groups, unmodified CNCs (H-CNCs) aggregate easily and are often difficult to disperse. It is shown here that on account of ionic repulsion between charged surface groups, slightly phosphorylated CNCs (P-CNCs, average dimensions 31 ± 14 × 316 ± 127 nm, surface charge density = 10.8 ± 2.7 mmol/kg cellulose), prepared by controlled hydrolysis of cotton with phosphoric acid, are readily dispersible and form stable dispersions in polar solvents such as water, dimethyl sulfoxide,…

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  Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung