Microwave-assisted step reduced extraction of seaweed (Gelidiella aceroso) cellulose nanocrystals

•Cellulose nanocrystal were isolated from seaweed via a microwave assisted step reduce process.•Rod-shaped CNCs with an average diameter of 14-50 nm successfully synthesized.•Isolated CNCs from seaweed (Gelidiella aceroso)fiber are a new source of green material.

In the present work, cellulose nanocrystals were isolated from seaweed by microwave-assisted alkali treatment, bleaching, and an acid hydrolysis process. Microwave-assisted alkali treatment reduces the heating time and eliminates the traditional dewaxing process. This is different from the commonly adopted procedure for cellulose nanocrystal (CNC) synthesis, in which CNC synthesis generally follows the dewaxing process. Further, samples obtained after each stage of treatment were characterized and final samples were freeze-dried for further characterization. TEM results revealed that isolated CNCs had a 32 nm average diameter and an average length of 408 nm. FTIR and XRD data showed that after each stage of chemical treatment, no cellulosic components were removed. The adopted method is faster than the previous traditional method used for isolation of CNCs from seaweed fibers.

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