Enzymatic degradation of model cellulose films

Eriksson, Jan Christer; Malmsten, Martin; Tiberg, Fredrik; Callisen, Thomas H.; Damhus, Ture; Johansen, Katja Salomon

doi:10.1016/j.jcis.2004.10.041

Cited by 71 publications

(91 citation statements)

References 45 publications

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“…Hence, the reduction of all the bands might be explained by a thinning of the fibre, where all components were partly ''excised'' as reported by White and Brown [28] for the thinning of bacterial cellulose due to cellulase treatment. Recently, similar thinning of cellulose films due to cellulase activity was reported [29]. Though enzymes are substrate specific, our FT-IR results show some degree of removal of glucomannan and lignin after enzyme treatment.…”

Section: Discussionsupporting

confidence: 84%

Inducing large deformation in wood cell walls by enzymatic modification

et al. 2007

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It has been shown recently that wood with a high cellulose microfibril angle in the S2-layer, e.g. compression wood, shows permanent plastic deformation without significant mechanical damage to the matrix. This molecular stick-slip mechanism was explained by a gliding of the cellulose fibrils, after a certain shear stress in the matrix was exceeded [1]. Such a material behaviour would be desirable for various applications, for instance, to cover complex geometries with highly deformable veneers as needed in the automotive industry. However, veneers that are typically used for these purposes have a rather brittle failure behaviour, which leads to breakage, and drastic quality and productivity losses. A better deformability of such veneers might be achieved when the underlying deformation principles are conferred by modifying the wood cell wall components, in particular the cellulose fibrils and their matrix coupling. Enzyme treatments were performed on mechanically isolated wood fibres to plastify the entire lignified secondary cell wall. Cellulase Onozuka R-10 from Trichoderma viride (E.C.3.2.1.4) with activity on cellulose and xylan was utilized. Micromechanical tests and FT-IR microscopy studies revealed the change of mechanical properties and nanostructural features of the cell wall. An extended deformability was achieved for two of ten of the modified fibres.

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Section: Discussionsupporting

confidence: 84%

Inducing large deformation in wood cell walls by enzymatic modification

et al. 2007

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“…Pure cellulose -water contact angles have been reported in the range of 33°-24° (Eriksson et al 2005). This large difference in water contact angle clearly shows the higher hydrophilicity of cellulose.…”

Section: Nanocomposite Propertiesmentioning

confidence: 99%

Sisal cellulose whiskers reinforced polyvinyl acetate nanocomposites

2006

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Sisal nanowhiskers were used as novel reinforcement to obtain nanocomposites with polyvinyl acetate (PVAc) as matrix phase. They are seen as attractive materials due to the widespread availability and low cost of the sisal source material. Statistical analysis of the sisal whisker length and diameter resulted in average values of 250 nm and 4 nm, respectively, resulting in an average aspect ratio in the upper range of reported cellulose nanowhisker values. The high aspect ratio ensures percolation, with resulting mechanical improvements and thermal stability, at lower fiber loads. Water uptake and thermal behaviour of the sisal whisker -PAVc composites were studied. Whisker addition was found to stabilize the nanocomposites with no benefit seen when increasing the whisker content beyond the percolation threshold: For all whisker contents studied above percolation, the water uptake stays constant, and the Tg does not vary with whisker content at a given relative humidity. The water diffusion rate however increases due to water accumulation at the whisker -PVAc interface. Below whisker percolation, stabilization is only noticed at low relative humidity, whereas high humidity results in disruption of whisker -PVAc interactions. This work shows the potential of cellulose nanowhiskers to stabilize polar polymers even at high humidity conditions with minimal reinforcement addition.

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“…1138) [15]. The surface morphology involved in the chemical composition, roughness, electrical charges and other physicochemical properties is of great important factors affecting wettability, swellability, chemical sensitivity and bioaffinity [10,11,[15][16][17][18][19]. Hence, the morphological control of the cellulose model surfaces would contribute greatly to the cellulose material design aimed at understanding cellulosic interfaces.…”

Section: Introductionmentioning

confidence: 99%