Nanocellulosic fibrils

Most methods have typically been applied to the investigation of dried nanocellulose dimensions, although a study was conducted by Paakko et al. [47] where the size and size-distribution of enzymatically pretreated nanocellulose fibrils in a suspension were studied using cryotransmission electron microscopy, atomic force microscopy, and cross-polarization/magic-angle... 

Application of Nanocellulosic Fibrils-Mineral Pigment Composites in Paper. 134... 

This chapter aims to introduce the concept of nanocellulosic-fibril and precipitated calcium carbonate (PCC) composites. The effect of cogrinding of lime and pulp fibres and different precipitation conditions on the production of PCC and modification of its morphologies are analysed in this chapter. 

Finally, the impact of these new PCC-nanocellulosic fibril composites on paper properties is elucidated. In addition, we describe a novel and rather simple method to produce a new composite paper in laboratory scale. This paper based on cellulosic fibrils, which can be defined as the structural elements of the biopolymers, has radically higher filler proportion than conventional printing paper and exhibits superior quality. 

Recently, various methods have been proposed to obtain nanocellulosic fibrils from cellulosic fibres. Chemical and enzymatic treatments followed by mechanical disintegration, homogenisation, or ultrasound sonication are being used extensively... 

Nanocellulosic fibrils can be used as a substrate for the production of precipitated calcium carbonate-nanocellulose composites. These, PCC-nanocellulose composites can contribute toward increasing the strength and optical properties of paper. We investigated formation and properties of a new composite paper composed of fibrillar fines and calcium carbonate as the base furnish in combination with cellulosic fibres as reinforcing elements. 

Abraham, E., Deepa, B., Pothan, L. A., Jacob, M., Thomas, S., Cvelbar, U., Anandjiwala, R. (2011). Extraction of nanocellulose fibrils from lignocellulosic fibres A novel approach. (4), 1468-1475. 

A novel concept to prepare nanocellulose fibrils has been reported, where enzymatic hydrolysis was used in combination with mechanical shearing and high-pressure homogenization to produce defibrillation of the fiber wall and obtain fibrils with a diameter of around 5-6 nm and aggregates of around 10-20 nm (Paakko et al. 2007). 

Abraham E, Deepa B, Pothan LA, Jacob M, Thomas S, Cvelbar U, Anandjiwala R (2011) Extraction of nanocellulose fibrils from lignocellulosic fibres a novel approach. Caibohyd Polym 86 1468-1475... 

Figure 5.5 Schematic showing the preparation of NFC/PANi composite paper through in-situ polymeri2ation of aniline monomers on nanocellulose fibrils and b) NFC, PANi and NFC/PANi composite suspensions. Reproduced from [61] with permission of Elsevier.

Iwamoto S, Nakagaito AN, Yano H (2007) Nano-fibrillation of pulp fibres for the processing of transparent nanocomposites. Appl Phys A-Mater Sci Process 89 461-466 Klemm D, Schumann D, Kramer F, Hessler N, Homung M, Schmauder HP, Marsch S et al (2006) Nanocelluloses as innovative polymers in research and application. Polysaccharides 205 49-96... 

At nanoscale thickness, fibrils are named as nanofibrillar cellulose (NFC) or nanocellulose [26-28]. Highly crystalline cellulose nanowhiskers, also called cellulose micelles, cellulose nanorods, cellulose nanocrystals, or nanocrystalline cellulose are produced under strong acid hydrolysis (e.g., mineral acids such as hydrochloric acid or sulphuric acid) combined with mechanical shearing [22, 29]. 

On the other hand, native cellulose is an abundant and inexpensive macromolecular compound that reinforces most plant cell walls. During recent years, attention has been devoted to the use of cellulose (nanocellulose or nanofibrillated cellulose), and important studies have been published [13-22]. The outstanding mechanical properties of nanocellulose or nanofibrillated cellulose, linked to its wide availability, biodegradability, and extensive number of alternatives for chemical modification, have been the driving force for its utilization as reinforcement in polymers. These cellulosic materials are composed of nanosized cellulose fibrils with a high aspect ratio (length-to-width... 

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