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Cellulose nanocrystals (CNCs) are considered a prospective packaging material to partially replace petroleum-based plastics attributed to their renewability, sustainability, biodegradability, and desirable attributes including transparency, oxygen, and oil barrier properties. However, neat CNC films are rigid and too brittle to handle or utilize for packaging applications. Hence different additives, including sorbitol, polyvinyl alcohol (PVA), chitin, and κ-carrageenan (CG) were selected to mix with CNCs for packaging film preparation. The influence of additive categories (plasticizer,...

Multilayer films consisting of nanocellulose and nanochitin as oxygen barrier coatings and a conventional petroleum-based moisture barrier plastic as the substrate have been widely studied for food packaging applications. A challenge with enabling recycling of such hybrid multilayer materials is separating the coating from the substrate. In this work, we studied multilayer films consisting of poly(ethylene terephthalate) (PET) as a model substrate with chitin nanowhiskers (ChNWs) and cellulose nanocrystals (CNCs) as bilayer barrier coatings. Dissolution in aqueous media at different pH...

In this study, we perform a comprehensive examination of the ultrasonic dewatering of cellulose nanofibril (CNF) suspensions, with particular emphasis on the role of fines content. The production of CNFs involves mechanical fibrillation which leads to the presence of different percentages of fines (fibrils under 200 μm) in the final product. Although fines have demonstrated mechanical advantages in composite materials, they also increase water retention by the fibrils, leading to increased dewatering time and energy. We selected two distinct CNF samples with 60% and 90% fines, respectively,...

Diaphragms are used to transmit lateral loads to the vertical elements (e.g., shear walls) of the lateral force resisting system of a structure. The extent of deflection in diaphragms can determine what mechanism needs to be considered during design for transfer of forces to the vertical elements. Current design specifications do not provide equations that engineers can use to determine the deflections in cantilever Cross-Laminated Timber (CLT) diaphragms. In this paper, the CLT shear wall equation prescribed by 2021 Special Design Provisions for Wind and Seismic (SDPWS) was adapted to get...

The wood of African mahogany (Khaya spp.) is known for its high quality and similarity to the more expensive Brazilian mahogany (Swietenia macrophylla King). Interest in African mahogany has been increasing because of the reduced availability of native Brazilian mahogany, which has become illegal to harvest. Most African mahogany comes from managed plantations, so the increased consumption of this wood helps to alleviate issues related to illegal harvesting by reducing the trade of Brazilian mahogany. African mahogany has also been gaining popularity in the United States, particularly for...

The use of composite materials has seen many new innovations for a large variety of applications. The area of reinforcement in composites is also rapidly evolving with many new discoveries, including the use of hybrid fibers, sustainable materials, and nanocellulose. In this review, studies on hybrid fiber reinforcement, the use of nanocellulose, the use of nanocellulose in hybrid forms, the use of nanocellulose with other nanomaterials, the applications of these materials, and finally, the challenges and opportunities (including safety issues) of their use are thoroughly discussed. This...

Cotton is a natural fiber containing more than 95% of cellulose. With worldwide cotton consumption continuously increasing, the amount of cotton waste generated is enormous. Most of the cotton waste ends up in landfill or incinerators, resulting in a huge waste of this excellent natural resource. In this project, cotton waste was recycled to produce polypropylene nanocomposites. Instead of using the traditional two-step nanofiber extraction and compounding technique, an integrated process was adopted to combine nanofibrillation and compounding into one step. Results showed that cotton...

Regardless of their applications, polymers are still considered me­chanically weak and functionally insufficient for certain demanding coating and adhesive uses. To address those issues, nanomaterials have been extensively studied as reinforcing fillers, which have been proven to effectively promote the performance of polymer coatings/adhesives. However, conventional nanofillers are expen­sive and non-biodegradable. Meanwhile, cellulose nanomaterials (CNMs), a class of nanomaterials produced from biomass feedstocks, can circumvent the drawbacks of conventional nanofillers. This re­view...

Self-standing cellulose nanofibril (CNF) films are regarded as one of the promising alternatives to current petroleum-based packaging materials mostly due to their ability to form dense self-assembled structures exhibiting high gas barrier properties. Nonetheless, one of the major obstacles to the commercialization of these materials in packaging applications is the high cost of raw materials and production energy. In his study, we created self-standing films of lignin-containing cellulose nanofibrils (LCNFs) derived from a recycled old corrugated cardboard (OCC) pulp that costs less than...

Inherent hydrophilicity and poor water resistance prevent using lignocellulosic materials as green plastic alternatives to fossil fuel-based plastics. Here, we report a facile metal-ion-modification (MIM) route, swelling with aqueous metal ion solutions, and drying to convert conventional hydrophilic paper and wood pulp into biodegradable hydrophobic paper and tableware without the addition of hydrophobic sizing chemicals/materials. Metal ions such as Fe3+ and Zr4+ can coordinate with pulp fibers’ polar groups (i.e., OH, C=O, and COOH) that induce self-assembly of their surface fibrillated...