Cellulose‐Nanocomposites: Towards High Performance Composite Materials

Abstract

Strong cellulose fibres, e.g. flax and hemp, are increasingly used for composites. Despite substantial advantages, the tensile strength of these fibres is limited due to their complex structure and the unavoidable imperfections of the cell wall, inherent from growth or induced by processing. Essential improvements are possible by using highly crystalline cellulose fibrils (''whiskers'') which can be isolated from the cell wall, thus eliminating the influence of adhesion and defects. Instead of complete fibrillation, which demands special time consuming processing, a partly fibrillation has been achieved by adapted textile finishing procedures which have the potential for mass production. By combining chemical and mechanical/hydro-mechanical treatments it is possible to produce finest fibrils with diameters from below 1 mm down to the nanometer range. The problem of fibril agglomeration during drying has been avoided by forming homogenous fibrous sheets in a wet-laid non-woven process. These sheets can be impregnated with thermosetting resins. Alternatively thermoplastic polymers can be directly integrated to form hybrid materials ready for moulding. The resulting composites show greatly enhanced mechanical properties.

Lignocellulose biorefinery feedstock engineering

“…Kohler (Kohler and Nebel, 2006), through comparisons of SEM pictures, specific surface, and Mercury Injection Apparatus before and after steam explosion, drew the conclusion that compared with straw without steam explosion, the porosity and permeability was improved, the pore area increased, and the total pore volume of the straw decreased through steam explosion. Cellulose is the skeleton of cell walls, and hemicellulose and lignin are the filler, with lignin and hemicellulose apparently degraded after steam explosion.…”

Cellulosic Nanomaterials for Sensing Applications

“…12.2 and 12. 3) It has been shown that the maximum actuator performance of cellulose is at high humidity condition and decreases over time and at dry condition. In order to enhance the performance of the EAPap actuator in ambient humidity, it has been mixed or blended with carbon nanotubes, 38 chitosan, 39 IL, 40 or has been coated with PPy and PANI conductive polymer.…”

All‐Cellulose Composites

“…In order to tackle the issue of interfacial bonding, the most common approach involves modifying the chemistry of the fiber or matrix in order to improve the chemical compatibility between components. Interfacial bonding can also be increased by using nanosized forms of cellulose such as bacterial cellulose [48][49][50], microfibrillated cellulose [51][52][53], and cellulose whiskers [54][55][56][57][58] that provide an increased surface area per volume. Interfacial bonding can also be increased by using nanosized forms of cellulose such as bacterial cellulose [48][49][50], microfibrillated cellulose [51][52][53], and cellulose whiskers [54][55][56][57][58] that provide an increased surface area per volume.…”