Numerical Simulation of the Water Vapor Separation of a Moisture-Selective Hollow-Fiber Membrane for the Application in Wood Drying Processes.

In this study, a simplified two-dimensional axisymmetric finite element analysis (FEA) model was developed, using COMSOL Multiphysics software, to simulate the water vapor separation in a moisture-selective hollow-fiber membrane for the application of air dehumidification in wood drying processes. The membrane material was dense polydimethylsiloxane (PDMS). A single hollow fiber membrane was modelled.

Thiol-norbornene reactions to improve natural rubber dispersion in cellulose nanofiber coatings.

Cellulose nanofibrils (CNF) coatings are excellent grease barriers for biodegradable packaging. However, barrier properties are moisture sensitive, so hydrophobic components such as latexes or polymers are needed to impart moisture resistance, but incompatibility leads to poor dispersion. In this work, CNF modified with norbornenes was reacted with natural rubber (NR) latex in water to improve dispersion, coating formation, and coating moisture resistance by creating hybrid particles.

Cellulose and lignocellulose nanofibril suspensions and films: A comparison.

A comparative study on the morphology and physico-mechanical properties of cellulose nanofibrils (CNF) and lignocellulose nanofibrils (LCNF) produced using a pilot-scale ultra-refining facility in the form of slurries and films was conducted. Suspensions and films of CNF and LCNF at different fines contents from 50% to 100% were prepared from bleached kraft pulp and old corrugated container (OCC) feedstock, respectively. We showed that the effect of film density on mechanical properties of CNF and LCNF films can outweigh the effect of fines content (or degree of fibrillation) and consequently an equally strong and stiff film can be produced from lower grades of CNF or LCNF at higher densities.

The influence of versatile thiol-norbornene modifications to cellulose nanofibers on rheology and film properties.

Cellulose nanofibrils (CNF) can form impressive barrier layers but difficult rheological properties, brittleness, and sensitivity to moisture limit their use. To overcome these challenges, esterification reactions were performed in water without volatile organic solvents to create carbic-functionalized CNFs (cCNFs) that enabled versatile, thiol-norbornene secondary modifications. Chemical analysis determined that on average 5% anhydroglucose repeat units were functionalized with norbornene groups.

Reducing Intestinal Digestion and Absorption of Fat Using a Nature-Derived Biopolymer: Interference of Triglyceride Hydrolysis by Nanocellulose.

Engineered nanomaterials are increasingly added to foods to improve quality, safety, or nutrition. Here we report the ability of ingested nanocellulose (NC) materials to reduce digestion and absorption of ingested fat. In the small intestinal phase of an acellular simulated gastrointestinal tract, the hydrolysis of free fatty acids (FFA) from triglycerides (TG) in a high-fat food model was reduced by 48.

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.

Heat and mass transfer models to understand the drying mechanisms of a porous substrate.

While drying of paper and paper coatings is expensive, with significant energy requirements, the rate controlling mechanisms are not currently fully understood. Two two-dimensional models are used as a first approximation to predict the heat transfer during hot air drying and to evaluate the role of various parameters on the drying rates of porous coatings. The models help determine the structural limiting factors during the drying process, while applying for the first time the recently known values of coating thermal diffusivity.

Penetration into three-dimensional complex porous structures.

The short-term uptake of a fluid by porous media is important in a number of processes, such as in coating and printing operations. We present a new model to predict short-term absorption into real pore geometries taking into account fluid properties, surface forces, and the complex pore geometry. Two assumptions are made to reduce the complexity of the situation: (1) the flow resistance between pores can be estimated from pore geometry or air permeability measurements, and (2) the volume of fluid in the constrictions between pores is small.