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Mechanical milling demonstrates potential in the pretreatment arena to valorize lignocellulosic biomass because it eliminates chemicals and simplifies processing. The development of physical properties and energy consumption for generating micronized particles are key factors affecting potential use. This study investigated the effect of input moisture content, and feedstock particle size on developing physical characteristics of micronized particles and the resultant specific energy consumption in the milling process. Wood particles with different sizes were effectively comminuted to...

The hierarchical structure of wood cell walls resulting from complex arrangement and distribution of the heterogeneous components is considered to impact significant impediment to enzymatic hydrolysis of cellulose for biofuels. In this work, micronized wood with significant cell wall ultrastructural deconstruction were effectively produced from ring and puck milling within 12 min. In a subsequent enzymatic hydrolysis, micronized wood resulted in increase of cellulose hydrolysability by 4–14 folds over that of starting material. The underlying mechanism towards facilitating enzymatic...

This study was aimed to identify the best approach of incorporating cellulose nanocrystals (CNCs) into a poly (lactic acid) (PLA) matrix by examining two different CNC addition approaches. The first approach consisted of melt-blending (MB) PLA and CNCs in a three-piece internal mixer whereas the second method involved direct drymixing of PLA and CNCs in a high intensity mixer. The compounded materials were then blown into films and compared in terms of particle dispersion, optical, thermal, molecular weight and barrier properties. Good distribution was achieved by both the direct dry- and...

Endoxylanases are important enzymes in bioenergy research because they specifically hydrolyze xylan, the predominant polysaccharide in the hemicellulose fraction of lignocellulosic biomass. For effective biomass utilization, it is important to understand the mechanism of substrate recognition by these enzymes. Recent studies have shown that the substrate specificities of bacterial and fungal endoxylanases classified into glycoside hydrolase family 30 (GH30) were quite different. While the functional differences have been described, the mechanism of substrate recognition is still unknown....

The effect of fiber drying on the properties of lignin containing cellulose nanocrystals (LCNC) and nanofibrils (LCNF) produced using concentrated maleic acid hydrolysis of a never dried unbleached mixed hardwood kraft pulp was evaluated. Two drying conditions, i.e., air drying and heat drying at 105°C were employed. It was found that drying (both air and heat) enhanced acid hydrolysis to result in slightly improved LCNC yields and less entangled LCNF. This is perhaps due to the fact that drying modified the cellulose supermolecular structure to become more susceptible to acid hydrolysis...

This paper introduces a concentrated di-carboxylic acid (DCA) hydrolysis process for the integrated production of thermally stable and carboxylated cellulose nanocrystals (CNCs) and cellulose nanofibrils (CNFs). The DCA hydrolysis process addressed several issues associated with mineral acid hydrolysis for CNC production, such as cellulose loss and acid recovery. The surface and morphological properties of the cellulose nanomaterials resulting from the DCA hydrolysis process can be tailored simply by controlling the severity of DCA hydrolysis. To further reduce cost, a low temperature...

In this chapter, we present recent advances in the multi-scale data-driven inverse constitutive characterization of composites via multi-axial robotic testing, high-performance full-field strain measurement methods and surrogate models. Emphasis is given first on the motivating aspects for multi-scale model inversion for the case of laminated composites, followed by a description of a data-driven inverse constitutive characterization of the bulk lamina of composites via multi-axial loading of laminate-level coupons. A description of a surrogate modeling approach is presented in order to...

The formation of carbon-based nanomaterials was investigated through heating iron nitrate promoted kraft lignin at different temperatures up to 600°C under argon gas at atmospheric pressure. High-resolution transmission electron microscopy and electron diffraction images showed that multi-layer turbostratic-structured graphene presented in samples heated at 600°C. X-ray diffraction results indicated that iron oxides nanoparticles started their formation as an amorphous carbon matrix at 300°C, and turned into α-Fe nanoparticles at 600°C. It is believed that the formation of observed...

A free-standing, lightweight, highly porous, and highly flexible cellulose nanofibril (CNF)–reduced graphene oxide (RGO)–molybdenum oxynitride (MoOxNy) aerogel film electrode was synthesized by freeze-drying a CNF/GO/MoO3 aqueous dispersion followed by subsequent in situ hydrazine reduction. Due to the partial reduction and nitrogen doping of the MoO3 nanobelts and the highly open and continuous porous structure, the free-standing CNF/RGO/MoOxNy aerogel film electrode delivered an outstanding specific capacitance of 680 F g
1 in an aqueous electrolyte and 518 F g
1 in an ionic liquid...

Graphene-encapsulated copper nanoparticles (GECNs) can be applied in the wood protection industry. In this study, a simple thermal treatment was applied to a mixture of kraft lignin and copper sulfate for the synthesis of GECNs. The effect of temperature, duration time, temperature rising ramp, and argon gas flow rate were investigated on the quality of the GECNs. Temperature was found to be the most important factor in the growth of graphene; high temperature was preferred to obtain less defective graphene shells. Gas flow rate, duration time, and temperature rising ramp had less effect....