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The use of chemical and energy intensive delignification processes in industrial pulping generates cellulosic fibres that are hydrophilic, hygroscopic and functionally restricted to paper and cardboard applications. Here, we propose a bio-based alternative to chemical pulping utilising herbivores to harvest and grind lignocellulosic materials followed by natural fungal growth to delignify and hybridise them to generate hierarchical composite papers with altered, water-repelling surface properties. These papers comprise cellulose and fungal biopolymers produced by cultivation of T. versicolor and P. ostreatus on elephant manure. Papers with considerably more hydrophobic surfaces were obtained at glucosamine contents as low as 0.1 wt%. Paper tensile strengths and elastic moduli were improved with longer fungal growth periods, spanning several weeks, resulting in comprehensive interfacing of cellulose microfibrils through tough nanoscale fungal chitin-β-glucan networks within the papers. Papers produced from lignocellulosic material colonised with P. ostreatus for 16 weeks exhibited the highest tensile strengths and more hydrophobic surfaces than T. versicolor. Hybridisation of lignocellulose with fungal biopolymers resulting in improved surface and mechanical properties highlights the extended opportunities of fungal delignification bioprocessing and demonstrates the considerable potential of the fungal biorefinery as an economical, and as of yet underexploited technology.

Mechanical frothing is one of the most commonly used methods to create gas-liquid foams. Until recently, the polymerisation of mechanically frothed gas-liquid foams was limited to the synthesis of quasi two-dimensional polymer structures, such as films. In this study we show that three-dimensional bio-based polymer foams can be created by microwave curing of gas-soybean oil foams created by mechanical frothing using lauryl peroxide as the radical initiator. It was found that the introduction of air during the mechanical frothing was necessary to create the three-dimensional polymer foams. Using bacterial cellulose nanofibrils (BC) simultaneously as a foam stabiliser has potential because it obstructs the flow of liquid from the lamella region in these gas-soybean oil foams while simultaneously acting as nano-filler in the polymer foam. It was found that the stability of the gas-soybean oil foam templates and the mechanical properties of the polymer nanocomposite foams are enhanced upon the addition of BC in to the foams.

Fully renewable macroporous thermosetting and UV-cured cellulose nanocomposites have been synthesized from medium and high internal phase water-in-acrylated soybean oil emulsions stabilized solely by hydrophobized bacterial cellulose nano-fibrils.

New applications of lignocellulosic fibres have been driven by numerous factors, including pressure from environmental groups, stringent environmental laws, waste minimisation efforts, recycling and cost reduction initiatives and responsible social awareness. However, the exploitation of such fibres in, for instance, fibre-reinforced composites or in the textile industry is hindered by the presence of waxy layers on the surfaces of lignocellulosic fibres. Many surface treatments are traditionally used to optimise the surface properties of natural fibres. A potential and environmentally sound surface treatment regards the use of atmospheric air pressure plasma (AAPP). The surfaces of various lignocellulosic fibres were modified using AAPP. We investigated the effect of AAPP treatment duration (i.e. 1 min and 3 min) on the surface properties of the lignocellulosic fibres using wetting and electrokinetic measurements. The critical surface tension of the untreated and AAPP-treated fibres was determined from wetting measurements using the capillary rise technique, whereas the changes in the surface chemistry were characterised by means of zeta (ζ)-potential measurements. A slight increase in the critical surface tension of the lignocellulosic fibres was found with prolonged treatment time, with the exception of abaca fibres. The post-treated fibres show a larger degree of hydrophilicity measured from the difference, Δζ, in the decay of the ζ-potential measured as function of time, with the exception of hemp fibres. Finally, ζ-potential measurements as function of pH validated the performance of both AAPP treatments.