Preparation of cellulose nanofibers from Miscanthus x. Giganteus by ammonium persulfate oxidation

Han Yang; Yefei Zhang; Ryo Kato; Stuart J Rowan

doi:10.1016/j.carbpol.2019.02.008

Preparation of cellulose nanofibers from Miscanthus x. Giganteus by ammonium persulfate oxidation

Carbohydr Polym. 2019 May 15:212:30-39. doi: 10.1016/j.carbpol.2019.02.008. Epub 2019 Feb 10.

Authors

Han Yang¹, Yefei Zhang¹, Ryo Kato¹, Stuart J Rowan²

Affiliations

¹ Institute of Molecular Engineering, University of Chicago, 5640 S Ellis Ave., Chicago, IL 60637, United States.
² Institute of Molecular Engineering, University of Chicago, 5640 S Ellis Ave., Chicago, IL 60637, United States; Department of Chemistry, University of Chicago, 5735 S Ellis Ave., Chicago, IL 60637, United States; Chemical and Engineering Sciences, Argonne National Laboratory, 9700 Cass Ave, Lemont, IL 60439, United States. Electronic address: stuartrowan@uchicago.edu.

PMID: 30832861
DOI: 10.1016/j.carbpol.2019.02.008

Abstract

Carboxylic acid functionalized cellulose nanofibers (MxG-CNF^A-CO₂H) were successfully isolated from a sustainable grass hybrid Miscanthus x. Giganteus by a new two-step chemical oxidation, that involves bleach treatment and ammonium persulfate oxidation, followed by ultrasonication. The resulting MxG-CNF^A-CO₂Hs have ca. 1200 mmol/kg carboxylic acid surface groups, an aspect ratio of 230 (height of ca. 3.8 ± 0.8 nm and length of ca. 880 ± 300 nm) and 70% crystallinity. Interestingly, these MxG-CNF^A-CO₂Hs exhibit better thermal stability (as measured by thermal gravimetric analysis) and better dispersibility in DMF than corresponding cellulose nanocrystals (CNC) obtained from same biosource (MxG-CNC-CO₂Hs) via acid hydrolysis. Poly(vinyl acetate):MxG-CNF^A-CO₂H composites show an increase in storage modulus (above T_g) with increasing filler content. Importantly, the mechanical properties of the poly(vinyl acetate):nanocellulose composites showed that the MxG-CNF^A-CO₂Hs exhibit significantly better reinforcement than the MxG-CNC-CO₂H at the same weight percent filler content.

Keywords: Cellulose nanocrystals; Cellulose nanofibers; Miscanthus x. Giganteus; Nanocellulose; Nanocomposites.