Characterization of CNC Nanoparticles Prepared via Ultrasonic-Assisted Spray Drying and Their Application in Composite Films.

The ultrasonic-assisted spray dryer, also known as a nano spray dryer and predominantly used on a lab scale in the pharmaceutical and food industries, enables the production of nanometer-sized particles. In this study, the nano spray dryer was applied to cellulosic materials, such as cellulose nanofibrils (CNFs) and cellulose nanocrystals (CNCs). CNC suspensions were successfully dried, while the CNF suspensions could not be dried, attributable to their longer fibril lengths.

Spray Drying Enzyme-Treated Cellulose Nanofibrils.

Enzyme-treated cellulose nanofibrils (CNFs) were produced via a lab-scale mass colloider using bleached kraft pulp (BKP) to evaluate their processability and power requirements during refining and spray-drying operations. To evaluate the energy efficiency in the CNF refining process, the net energy consumption, degree of polymerization (DP), and viscosity were determined. Less energy was consumed to attain a given fines level by using the endoglucanase enzymes.

Tunable biocomposite films fabricated using cellulose nanocrystals and additives for food packaging.

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.

Review on Hybrid Reinforced Polymer Matrix Composites with Nanocellulose, Nanomaterials, and Other Fibers.

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.

Step aside, aluminum honeycomb.

A two-step process can turn hardwood into a strong and flexible moldable material.

Optimizing lignocellulosic nanofibril dimensions and morphology by mechanical refining for enhanced adhesion.

Using lignocellulosic nanofibrils as adhesive binders in structural composites is a growing field of interest attributable to their renewability, recyclability, and strength. A fundamental understanding of their adhesion mechanisms is crucial to tailor performance and optimize production costs. These mechanisms were elucidated by studying the morphology dependent adhesion in a model system composed of cellulose nanofibrils (CNFs) at different degrees of refinement and porous paper substrates.

Review on Nonconventional Fibrillation Methods of Producing Cellulose Nanofibrils and Their Applications.

The production of cellulose nanofibrils (CNFs) continues to receive considerable attention because of their desirable material characteristics for a variety of consumer applications. There are, however, challenges that remain in transitioning CNFs from research to widespread adoption in the industrial sectors, including production cost and material performance. This Review covers CNFs produced from nonconventional fibrillation methods as a potential alternative solution.

Properties of Wood-Plastic Composites Manufactured from Two Different Wood Feedstocks: Wood Flour and Wood Pellets.

Driven by the motive of minimizing the transportation costs of raw materials to manufacture wood-plastic composites (WPCs), Part I and the current Part II of this paper series explore the utilization of an alternative wood feedstock, i.e., pellets.

A Critical Evaluation and Modification of the Padé-Laplace Method for Deconvolution of Viscoelastic Spectra.

This paper shows that using the Padé-Laplace (PL) method for deconvolution of multi-exponential functions (stress relaxation of polymers) can produce ill-conditioned systems of equations. Analysis of different sets of generated data points from known multi-exponential functions indicates that by increasing the level of Padé approximants, the condition number of a matrix whose entries are coefficients of a Taylor series in the Laplace space grows rapidly. When higher levels of Padé approximants need to be computed to achieve stable modes for separation of exponentials, the problem of generating matrices with large condition numbers becomes more pronounced.

Comparative Study of the Properties of Wood Flour and Wood Pellets Manufactured from Secondary Processing Mill Residues.

The generation of secondary processing mill residues from wood processing facilities is extensive in the United States. Wood flour can be manufactured utilizing these residues and an important application of wood flour is as a filler in the wood-plastic composites (WPCs). Scientific research on wood flour production from mill residues is limited.

Multi-layer oil-resistant food serving containers made using cellulose nanofiber coated wood flour composites.

Cost-effective, eco-friendly, and oil and grease-resistant food serving containers were made from wood flour with cellulose nanofibrils (CNF) or lignin-containing cellulose nanofibrils (LCNF) coating layers on the surface and in the bulk. The multi-layer wet-on-wet cellulose nanofiber composites were developed using a vacuum filtration process. All composites showed excellent oil/grease resistivity according to the "kit" test passing #12, the highest possible.

Alignment of Cellulose Nanofibers: Harnessing Nanoscale Properties to Macroscale Benefits.

In nature, cellulose nanofibers form hierarchical structures across multiple length scales to achieve high-performance properties and different functionalities. Cellulose nanofibers, which are separated from plants or synthesized biologically, are being extensively investigated and processed into different materials owing to their good properties. The alignment of cellulose nanofibers is reported to significantly influence the performance of cellulose nanofiber-based materials.

Recent Advances in Functional Materials through Cellulose Nanofiber Templating.

Advanced templating techniques have enabled delicate control of both nano- and microscale structures and have helped thrust functional materials into the forefront of society. Cellulose nanomaterials are derived from natural polymers and show promise as a templating source for advanced materials. Use of cellulose nanomaterials in templating combines nanoscale property control with sustainability, an attribute often lacking in other templating techniques.

Aqueous Polymer Modification of Cellulose Nanofibrils by Grafting-Through a Reactive Methacrylate Group.

Modifying the surface of cellulose nanofibrils (CNFs) produced by mechanical refinement with a variety of polymer functional groups in an entirely water-based system is challenging because only surface hydroxyl groups are accessible. To address this limitation, an entirely water-based, polymer modification scheme is developed. CNFs are functionalized with a reactive methacrylate functional group followed by subsequent grafting-through polymerization.

Biopolymer blends of polyhydroxybutyrate and polylactic acid reinforced with cellulose nanofibrils.

Poly(lactic acid) (PLA) was used in an effort to enhance the mechanical properties of poly(hydroxybutyrate) (PHB) and the blends were reinforced with cellulose nanofibrils (CNF). The conventional and dynamic mechanical, morphological, thermal and rheological properties of the obtained composite blends were determined. The results showed that the mechanical properties of neat PHB noticeably increased attributable to the good interaction between the biopolymers and CNF from the scanning electron microscopy (SEM) characterization.

Material Extrusion Additive Manufacturing of Wood and Lignocellulosic Filled Composites.

Wood and lignocellulosic-based material components are explored in this review as functional additives and reinforcements in composites for extrusion-based additive manufacturing (AM) or 3D printing. The motivation for using these sustainable alternatives in 3D printing includes enhancing material properties of the resulting printed parts, while providing a green alternative to carbon or glass filled polymer matrices, all at reduced material costs. Previous review articles on this topic have focused only on introducing the use of natural fillers with material extrusion AM and discussion of their subsequent material properties.

Flexural Creep Behavior of High-Density Polyethylene Lumber and Wood Plastic Composite Lumber Made from Thermally Modified Wood.

The use of wood plastic composite lumber as a structural member material in marine applications is challenging due to the tendency of wood plastic composites (WPCs) to creep and absorb water. A novel patent-pending WPC formulation that combines a thermally modified wood flour (as a cellulosic material) and a high strength styrenic copolymer (high impact polystyrene and styrene maleic anhydride) have been developed with advantageous viscoelastic properties (low initial creep compliance and creep rate) compared with the conventional WPCs. In this study, the creep behavior of the WPC and high-density polyethylene (HDPE) lumber in flexure was characterized and compared.

Structural Performance of HDPE and WPC Lumber Components Used in Aquacultural Geodesic Spherical Cages.

Based on previous research, a novel wood-plastic composite (WPC) lumber has shown potential to replace high-density polyethylene (HDPE) lumber in the construction of aquacultural geodesic spherical cage structures. Six HDPE and six WPC assemblies, which are representative of typical full-size cage dimensions, were fabricated by bolting pairs of triangular panel components made with connected struts. Half of the panel assemblies had a plastic-coated steel wire mesh to simulate the actual restraint in field applications of the cages.

Poplar as Biofiber Reinforcement in Composites for Large-Scale 3D Printing.

The economic viability of the biofuel industry could be improved by adding a high-value revenue stream for biomass supply chains: bioderived composites for the rapidly expanding large-scale additive manufacturing industry (i.e., 3D printing).

Dewatering Behavior of a Wood-Cellulose Nanofibril Particulate System.

The novel use of aqueous suspensions of cellulose nanofibrils (CNF) as an adhesive/binder in lignocellulosic-based composite manufacture requires the removal of a considerable amount of water from the furnish during processing, necessitating thorough understanding of the dewatering behavior referred to as "contact dewatering". The dewatering behavior of a wood-CNF particulate system (wet furnish) was studied through pressure filtration tests, centrifugation, and characterization of hard-to-remove (HR) water, i.e.

Electrospinning of Cellulose Nanocrystal-Filled Poly (Vinyl Alcohol) Solutions: Material Property Assessment.

Poly (vinyl alcohol) (PVA) and cellulose nanocrystals (CNC) random composite mats were prepared using the electrospinning method. PVA/CNC mats were reinforced with weight concentrations of 0, 20 and 50% CNC (/) relative to PVA. Scanning electron microscopy was used to measure the fiber diameter, which ranged from 377 to 416 nm.

Fully Bio-Based Hybrid Composites Made of Wood, Fungal Mycelium and Cellulose Nanofibrils.

Novel hybrid panel composites based on wood, fungal mycelium, and cellulose nanofibrils (CNF) were developed and investigated in the present study. In one set of experiments, mycelium was grown on softwood particles to produce mycelium-modified wood which was then hybridized with various levels of CNF as binder. The other set of experiments were conducted on unmodified wood particles mixed with CNF and pure mycelium tissue.

Dry-Spun Neat Cellulose Nanofibril Filaments: Influence of Drying Temperature and Nanofibril Structure on Filament Properties.

Cellulose nanofibrils (CNF) were spun into filaments directly from suspension without the aid of solvents. The influence of starting material properties and drying temperature on the properties of filaments produced from three different CNF suspensions was studied. Refiner-produced CNF was ground using a microgrinder at grinding times of 50 and 100 minutes.

Production and Characterization of Laminates of Paper and Cellulose Nanofibrils.

A novel laminate system comprising of sheets of paper bound together using cellulose nanofibrils (CNF) is manufactured and characterized. Bonding properties of CNF were first confirmed through a series of peeling tests. Composite laminates were manufactured from sheets of paper bonded together using CNF at two different consistencies, press times, and press temperatures.