Innovating Generation of Nanocellulose from Industrial Hemp by Dual Asymmetric Centrifugation

• Published in: ACS sustainable chemistry & engineering 2020-02, Vol.8 (4), p.1850-1858
• Main Authors: Agate, Sachin, Tyagi, Preeti, Naithani, Ved, Lucia, Lucian, Pal, Lokendra
• Format: Article
• Language: English
• ISSN: 2168-0485; 2168-0485
• DOI: 10.1021/acssuschemeng.9b05992

Among nanobiomaterials, cellulose nanofibrils (CNF) possessing intrinsically appealing fiber dimensions on the nanometer scale and biocompatibility feature arguably the greatest potential for a variety of practical applications such as packaging, hygiene, food, and healthcare products. Herein, a new class of nanofibers are introduced from a very green feedstock using an isolated mechanical processing technique, enabling on-site and on-demand production with a significantly reduced risk of environmental and toxicological concerns during the product life cycle. Serendipitously, we have shown that autohydrolyzed hemp hurds, the short fiber piths of the hemp plant, show a surprising and unparalleled tendency to generate nanocellulose. Hemp hurd fibers were pulverized using a high intensity dual asymmetric centrifugation (DAC) force to defibrillate unbleached hemp cellulosic fibers into lignin-containing cellulose micro and nanofibers (L-CMNF). The impact of biomass composition, chemical processing, and mechanical pretreatment as well as DAC pulverization time and solids content on the fibrillation, crystallinity, charge, and colloidal stability of L-CMNF were studied. The formation of L-CMNF caused reduced crystallinity from 50% → 29% while charge distribution increased from 4.5 → 13 (× 10–5 μ eq Vol./L of p-DADMAC) with higher pulverization time at lower solids in the presence of lignin. Finally, SEM and TEM images substantiated the formation of L-CMNF. Thus, we offer a powerful new approach to CNF generation by pulverizing autohydrolyzed hemp hurds for very short times in an isolated DAC system.