Nanocellulose morphology

Mora n JI, Alvarez VA, Cyras VP, Va zquez A et al (2008) Extraction of cellulose and preparation of nanocellulose from sisal fibres. Cellulose 15 149-159 89. Wang B, Sain M, Oksman K et al (2007) Study of structural morphology of hemp fibre fi-om the micro to the nanoscale. Appl Compos Mater 14 89-103... 

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. 

Nanocelluloses have attracted a great deal of interest in the nanocomposites field due to their appealing intrinsic properties such as nanoscale dimensions, high surface area, unique morphology, low density [which is estimated to be 1.61 g/cm ... 

The aim of this study was extraction of cellulose from kenaf fiber which is available in Malaysia and preparation of nanocellulose whiskers from extracted cellulose in controlled hydrolysis condition. Chemical composition, size of particles, morphology, crystallinity, and thermal analysis of cellulose whiskers were investigated. 

Figure 12.8 shows the morphological features of cellulose, NC, NC/PVA, and AMO-P(AA-co-AMPS)-g-NC/PVA. Cellulose seems to be fibrous in nature, while, NC looks fluffy and behaves like a gel, which may be due to the increased hydrophi-licity. This gel structure is suitable for the drug delivery vehicles. NC/PVA combines both the nature of NC and PVA. Nanocellulose fibers appear to be dispersed in the PVA matrix. AMO-P(AA-c<9-AMPS)-g-NC/PVA clearly indicates the drug loading and the polymers adhered on the surface of the NC/PVA composite. 

BC/ PPy-APS composite. They explained this behavior by three main reasons (i) the highest electrical conductivity of PPy-FeCl coating layer (ii) BC/PPy FeClj composite showed higher PPy content than those found for BC/PPy-APS system at the same monomer concentration and finally, (iii) morphological differences between BC/PPy FeClj and BC/PPy APS composites, as seen in SEM micrographs. This work thus showed that the oxidative polymerization of pyrrole in a bacterial cellulose (BC) hydrogel can be an effective way to develop novel nanocellulose-based electrically active materials which can be explored for new technological applications. 

Keywords Nanocellulose, polymer, nanocomposite, morphology, properties, compatibility,... 

In the case of potential applications, these particular dimensions affect the final structure and properties of the fabricated products. According to different terms of nanocelluloses, these can be divided into two basic categories (a) cellulose nanofibers (CNFs) and (b) cellulose nanocrystals (CNCs). Morphology (TEM images) of CNFs and CNCs is shown in Figure 15.3. 

Both types of nanocelluloses may show different properties as a nanoreinforcement. In this case, Xu et at performed a comparative study between CNCs and CNFs regarding their morphology, crystalline structure, dispersion properties, and reinforcing effect in polyethylene oxide (PEO) polymer matrix. These are nanoscale cellulose fibers having different shape, size, and compositions. 

Figure 1.3 Morphologies of nanocellulose/PANI composite (a) SEM micrographs of nanocellulose/PANI composite Him at low and high magnifications and (b) TEM micrograph of PANI-coated nanocellulose.

Figure 1.4 Morphologies of cross-sectional surface of fractured (a) pure nanocellulose film, (b) nanocellulose/PANI composite film and (c) digital picture of bent nanoceUulose/PANI composite film.

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