Preparation and Surface Functionalization of Carboxylated Cellulose Nanocrystals

Abstract

In recent years, cellulose nanocrystals (CNCs) have emerged as a leading biomass-based nanomaterial owing to their unique functional properties and sustainable resourcing. Sulfated cellulose nanocrystals (sCNCs), produced by sulfuric acid-assisted hydrolysis of cellulose, is currently the predominant form of this class of nanomaterial; its utilization leads the way in terms of CNC commercialization activities and industrial applications. The functional properties, including high crystallinity, colloidal stability, and uniform nanoscale dimensions, can also be attained through carboxylated cellulose nanocrystals (cCNCs). Herein, we review recent progress in methods and feedstock materials for producing cCNCs, describe their functional properties, and discuss the initial successes in their applications. Comparisons are made to sCNCs to highlight some of the inherent advantages that cCNCs may possess in similar applications.

Neuro-nanotechnology: diagnostic and therapeutic nano-based strategies in applied neuroscience

“…This issue is made even more difficult by the intricate functional and anatomical "wiring," the diverse molecular and cellular milieu, and the sophisticated processing of information [ 44 ]. As a reaction to these challenges, an expanding variety of groups are doing research into the characteristics of a wide range of nanoparticles to make use of the benefits that are inherently associated with their nanometer dimensions [ 45 – 47 ].…”

Citrated cellulose nanocrystals from post-consumer cotton textiles

“…These two peaks suggested that the esterification of cellulose was successful and that the carboxyl groups are covalently bonded to cotton. Hence, no pretreatments on cotton fabrics were needed for a successful functionalization, which is a significant advantage since most of the feedstocks used for the extraction of carboxylated CNCs require bleach processing prior to hydrolysis 65 . Although our reaction is not regioselective, there is a larger preference for the esterification of cellulose with citric acid at the C6 position 31 .…”

“…The carboxylic groups of CitCNCs can undergo chemical modifications not possible for the sulfate-half ester groups in SCNCs. For example, amidation or esterification with alcohols can be performed on carboxylated CNCs 65 . Additionally, citrate groups serve as reducing agents, capping agents, and chelating agents, and their interactions can be tailored through pH variations.…”

Carboxylated Cellulose Nanocrystals Decorated with Varying Molecular Weights of Poly(diallyldimethylammonium chloride) as Sustainable Antibacterial Agents

“…There are still limited studies on the design of cationic CNC-based antibacterial agents and hence, in this work, we explored the design, synthesis, characterization, and antibacterial properties of wood-based carboxylated CNCs (cCNCs) coated with the cationic polymer, poly(diallyldimethylammonium chloride) (PDDA). cCNCs were prepared via an oxidation method using ammonium persulfate (APS) as a mild, low-cost, and low-toxicity oxidant [ 34 ]. An advantage to the APS process is its versatility in converting different lignocellulosic biomass into cCNCs without the need for pre-treatments of the starting biomass.…”