#Magicplot pro combining figures series

For example, antimicrobial activity against E. Another possibility is to use CNCs as antimicrobial agents, which is of great interest to the food packaging industry. Hydrophobisation of cellulose nanocrystals allows them to be used as coating agents for marine vehicles, biomedical devices, windows, textiles or paints. īesides using CNCs as a reinforcement in polymer nanocomposites, other applications of modified cellulose nanocrystals are demonstrated in the literature. Functionalisation of the filler allowed a further reaction with a bio-based epoxy resin, derived from diphenolic acid, to manufacture bio-based epoxy hybrid nanocomposites. Amine functionalised CNCs were obtained by Yue et al. įurthermore, the decorating of nanocellulose with functional organic moieties provides nanoparticles with the desired reactivity in further processing steps. as a result of triazine derivative grafting on the cellulose surface to replace hydroxyl groups. However, the improved thermal stability of nanocellulose was reported, for example, by Yin et al. Chemical derivatisation of cellulose nanomaterial is likely to diminish its thermal stability, which is another critical factor for the processing of polymeric nanocomposites. The most common chemical methods of CNC surface functionalisation with organic substituents are esterification, etherification and grafting.

who used nitric acid or nitric acid-sodium nitrite mixtures for this purpose, and this method was shown to be less energy and water intensive compared to the TEMPO oxidation of cellulose. Another approach for preparing carboxycellulose was described by Sharma et al. Surface carboxylated cellulose nanocrystals, with repelling forces between individual nanocrystals, were also prepared via 2,2,6,6-tetramethylpiperidine-1-oxyl(TEMPO)-mediated oxidation of cotton linters by Montanari et al. obtained carboxylated cellulose nanocrystals with negatively charged carboxylic groups from borer powder of bamboo by direct oxidative degradation with ammonium persulfate. The introduction of charged groups and the reduction of CNC hydrophilicity, by decorating their surface with less-polar organic moieties, has been widely reported.

#Magicplot pro combining figures series

Alongside methods such as silylation or acylation, the carboxylation of cellulose nanocrystals leads to their better compatibility with hydrophobic thermoplastic matrices, and moreover it was shown that the yield of nanoparticles increases with the carboxyl group content for a series of TEMPO-oxidized samples. CNCs often require previous surface modification in order to achieve good compatibility with a polymer matrix and a better individualisation of nanoparticles. One of the main applications predicted for CNCs is the manufacturing of polymeric nanocomposites. Other approaches employed in cellulose hydrolysis included, for example, application of hydrochloric acid, a mixture of acetic and nitric acid, and formic or hydrobromic acid. Amongst mineral acids, the application of phosphoric acid allowed for the production of nanocrystalline cellulose with higher thermal stability in comparison to sulphuric acid hydrolysis. Since cellulose nanocrystals obtained from sulphuric acid are characterised by a relatively low thermal stability, other mineral and organic acids have been used to produce CNCs. investigated the influence of reaction time and sulphuric acid-to-pulp ratio on nanocrystal properties, and showed that longer hydrolysis times produced shorter, less polydisperse cellulose nanocrystals, and furthermore, increasing the acid-to-pulp ratio caused a reduction of CNC dimensions.

According to the literature, sulphuric acid has the widest application in cellulose hydrolysis. The most commonly used method of CNC preparation is the hydrolysis of cellulose materials in mineral acids. Thus, extensive work has already been carried out to obtain thermally stable cellulose nanocrystals. However, the limited thermal stability of cellulose nanoparticles is a significant problem in nanocomposite manufacturing. Due to their high mechanical strength, low density, functionalisability, environmental sustainability and low cost, they have been extensively explored as a reinforcement in polymer nanocomposites. Cellulose nanocrystals, or CNCs, have recently emerged as a new class of versatile building blocks delivered from renewable feedstock.