PAPERmaking! FROM THE PUBLISHERS OF PAPER TECHNOLOGY Volume 5, Number 2, 2019
Processing nanocellulose to bulk materials: a review, Qianqian Wang et al, Cellulose, 26 (13 – 14), pp.7585 – 7617 . Various types of nanocellulose have been isolated from the cellulosic feedstock. It was expected that nanocellulose could be used to replace fossil-based plastic in certain areas because it is biodegradable, biocompatible, environment-friendly, and has outstanding performance. Unlike conventional plastic processing, nanocellulose is generally isolated and processed in aqueous environments. Therefore, dewatering and drying are essential unit operations for nanocellulose processing. Different drying methods for colloidal nanocellulose suspension mediated different self-assembly behaviors and thus resulted in different nanocellulose morphology and physical properties. The most utilized techniques for nanocellulose processing, such as spinning, vacuum/pressurized filtration, solvent casting and roll to roll casting, coating and roll to roll coating, and additive manufacturing are investigated. Process parameters such as temperature, pH, ion species, concentration, and external electrical field, affect the orientation and assembly behavior of nanocellulose, which in turn influence the properties of the prepared materials. Therefore, the method for assembling nanocellulose into bulk materials in a controlled way is vital for the properties of the fabricated nanocellulose composites. Here, some of the recent advances in the processing of nanocellulose for bulk materials are reviewed. Nanocellulose Applications in Papermaking, Carlos Salas et al, Production of Materials from Sustainable Biomass Resources , pp.61-96. (Part of the Biofuels and Biorefineries book series, BIOBIO, volume 9). Research on the utilization of biomass feedstocks has evolved rapidly in the past decades. Key developments include the production of materials with a more sustainable footprint than those derived from petrochemicals. Among associated materials, nanocelluloses have been produced from different sources and routes, such as high shear fibrillation and hydrolysis (chemical or enzymatic) or their combinations. The unique properties of nanocelluloses have sparked a myriad of uses including those related to the fields of oil and gas, adhesion, film formation, coating, packaging, food and composite processing. High end uses include the development of advanced lightweight materials, biosensors and energy harvesting systems; however, central to this review are uses closer to the source itself, namely fiber processing and, in particular, papermaking. In this chapter, the literature in these latter applications is discussed with emphasis on the use of nanocellulose to achieve favorable strength and barrier properties as well as in coating and paper sheet-forming. NOVEL PRODUCTS Lignin as a Wood Ǧ Inspired Binder Enabled Strong, Water Stable, and Biodegradable Paper for Plastic Replacement, Bo Jiang et al, Advanced Functional Materials , Wiley, online. Plastic waste has been increasingly transferred from land into the ocean and has accumulated within the food chain, causing a great threat to the environment and human health, indicating that fabricating an eco Ǧ friendly and biodegradable replacement is urgent. Paper made of cellulose is attractive in terms of its favorable biodegradability, resource abundance, large manufacturing scale, and low material cost, but is usually hindered by its inferior stability against water and poor mechanical strength for plastic replacement. Here, inspired by the reinforcement principle of cellulose and lignin in natural wood, a strong and hydrostable cellulosic material is developed by integrating lignin into the cellulose. Lignin as a reinforced matrix is incorporated to the cellulose fiber scaffold by successive infiltration and mechanical hot Ǧ pressing treatments. The resulting lignin Ǧ cellulose composite exhibits an outstanding isotropic tensile strength of 200 MPa, which is significantly higher than that of conventional cellulose paper (40 MPa) and some commercial petroleum Ǧ based plastics. Additionally, the composite demonstrates a superior
Technical Abstracts
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