Getting Environmentally Friendly and High Added-Value Products from Lignocellulosic Waste

In recent years, alternatives have been sought for the reuse of lignocellulosic waste generated by agricultural and other industries because it is biodegradable and renewable. Lignocellulosic waste can be used for a wide variety of applications, depending on their composition and physical properties. In this chapter, we focus on the different treatments that are used for the extraction of natural cellulose fibers (chemical, physical, biological methods) for more sophisticated applications such as reinforcement in biocomposites. Due to the different morphologies that the cellulose can present, depending from sources, it is possible to obtain cellulose nanocrystals (CNCs), micro- nanofibrillated cellulose (MFC/NFC), and bacterial nanocellulose (BNC) with different applications in the industry. Among the different cellulose nanomaterials highlighted characteristics, we can find improved barrier properties for sound and moisture, the fact that they are environmentally friendly, increased tensile strength and decreased weight. These materials have the ability to replace metallic components, petroleum products, and nonrenewable materials. Potential applications of cellulose nanomaterials are present in the automotive, construction, aerospace industries, etc. Also, this chapter exhibits global market predictions of these new materials or products. In summary, lignocellulosic residues are a rich source of cellulose that can be extracted to obtain products with high value-added and eco-friendly characteristics.

An Innovative Computational Strategy to Optimize Different Furnish Compositions of Tissue Materials Using Micro/Nanofibrillated Cellulose and Biopolymer as Additives

The furnish management of tissue materials is fundamental to obtain maximum quality products with a minimum cost. The key fiber properties and fiber modification process steps have a significant influence on the structural and functional properties of tissue paper. In this work, two types of additives, a commercial biopolymer additive (CBA) that replaces the traditional cationic starch and micro/nanofibrillated cellulose (CMF), were investigated. Different formulations were prepared containing eucalyptus fibers and softwood fibers treated mechanically and enzymatically and both pulps with these two additives incorporated independently and simultaneously with drainage in the tissue process range. The use of these additives to reduce the percentage of softwood fibers on tissue furnish formulations was investigated. The results indicated that a maximum of tensile strength was obtained with a combination of both additives at the expense of softness and water absorbency. With a reduction of softwood fibers, the incorporation of additives increased the tensile strength and water absorbency with a slight decrease in HF softness compared with a typical industrial furnish. Additionally, a tissue computational simulator was also used to predict the influence of these additives on the final end-use properties. Both additives proved to be a suitable alternative to reduce softwood fibers in the production of tissue products, enhancing softness, strength and absorption properties.

Iso- and Anisotropic Etching of Micro Nanofibrillated Cellulose Films by Sequential Oxygen and Nitrogen Gas Plasma Exposure for Tunable Wettability on Crystalline and Amorphous Regions

The surface of cellulose films, obtained from micro nanofibrillated cellulose produced with different enzymatic pretreatment digestion times of refined pulp, was exposed to gas plasma, resulting in a range of surface chemical and morphological changes affecting the mechanical and surface interactional properties. The action of separate and dual exposure to oxygen and nitrogen cold dielectric barrier discharge plasma was studied with respect to the generation of roughness (confocal laser and atomic force microscopy), nanostructural and chemical changes on the cellulose film surface, and their combined effect on wettability. Elemental analysis showed that with longer enzymatic pretreatment time the wetting response was sensitive to the chemical and morphological changes induced by both plasma gases, but distinctly oxygen plasma was seen to induce much greater morphological change while nitrogen plasma contributed more to chemical modification of the film surface. In this novel study, it is shown that exposure to oxygen plasma, subsequently followed by exposure to nitrogen plasma, leads first to an increase in wetting, and second to more hydrophobic behaviour, thus improving, for example, suitability for printing using polar functional inks or providing film barrier properties, respectively.