Analysis of the Thermal Aging Kinetics of Tallow, Chicken Oil, Lard, and Sheep Oil.

Understanding the thermal aging kinetics of animal oils is of vital importance in the storage and applications of animal oils. In this work, we use four different techniques, including UV-Vis spectrometry, viscometry, impedance spectroscopy, and acid-base titration, to study the thermal aging kinetics of tallow, chicken oil, lard, and sheep oil in the temperature range from 120 °C to 180 °C. The evolutions of the UV-Vis absorbance, dynamic viscosity, electric impedance, and acid titration are discussed with the defect kinetics.

Thermal Degradation of Vegetable Oils.

Vegetable oils provide lipids and nutrition and provide foods with a desirable flavor, color, and crispy texture when used to prepare fried foods. However, the oil quality is degraded at elevated temperatures, and thus must be examined frequently because of the damage to human health. In this study, sunflower, soybean, olive, and canola oils were examined, and their properties were measured periodically at different elevated temperatures.

Thermo-Mechanical and Creep Behaviour of Polylactic Acid/Thermoplastic Polyurethane Blends.

There is a great need to develop biodegradable thermoplastics for a variety of applications in a wide range of temperatures. In this work, we prepare polymer blends from polylactic acid (PLA) and thermoplastic polyurethane (TPU) via a melting blend method at 200 °C and study the creep deformation of the PLA/TPU blends in a temperature range of 10 to 40 °C with the focus on transient and steady-state creep. The stress exponent for the power law description of the steady state creep of PLA/TPU blends decreases linearly with the increase of the mass fraction of TPU from 1.

Stress Relaxation Behavior of Poly(Methyl Methacrylate)/Graphene Composites: Ultraviolet Irradiation.

The graphene/poly (methyl methacrylate) (PMMA) composites are a promising candidate for electronic, optoelectrical, and environmental applications. Understanding the mechanical degradation of PMMA-based materials is of practical importance in improving the reliability and lifespan of the associated structures and systems. In this study, we investigate the effects of functionalized graphene (FG) and UV irradiation on the stress-relaxation of PMMA.

Kinetics for the Slip Motion of Ripple Dislocations on Gold-Coated Poly(dimethylsiloxane).

Understanding the evolution of the defects in surface patterns is of practical importance to improve the performance and structural durability of the pattern-based micro- and nanodevices. In this work, we investigate the effects of temperature, compressive strain, and relative direction of the compression to the prestretch on the slip motion of ripple dislocations formed on the surface of gold-coated poly(dimethylsiloxane) films. Applying compression in the direction parallel to the direction of prestretch cannot cause the slip motion of the ripple dislocations.

Spreading of Water Droplets on Cellulose-Based Papers: the Effect of Back-Surface Coating.

Regulation of wetting and spreading of liquid on porous material plays an important role in a variety of applications, such as waterproofing, anti-icing, antioxidation, self-cleaning, etc. In this work, we reveal the role of back-surface coating with superhydrophobic nanoparticles in controlling the spreading of water droplets on cellulose-based papers. A layer of superhydrophobic polydivinylbenzene (PDVB) nanoparticles is spin-coated on the back surface of different types of papers.

Mechanical creep of tea leaves.

Background: Tea processing involves fermentation, withering, steaming or pan-firing, rolling, baking, and drying. Some of these steps are performed at a high temperatures. At such temperatures the creep of the tea leaves plays an important role in the quality of tea.

Growth of Polystyrene Pillars in Electric Field.

Surface patterning on polymer films, which is a self-assembly process under the action of external and/or internal impetus, has a variety of applications, including drug delivery and flexible electronics. In this work, we study the growth of polystyrene pillars in the electric field for different combinations of annealing temperature, film thickness, and electrode separation (electric field intensity). There are five stages for the growth of the polystyrene pillars for all the configurations used in this work, including a nucleation stage, a linear growth stage, an acceleration stage in the pillar length prior to the contact between the top surface of a pillar and the upper electrode, a radial growth stage after the contact, and a stationary stage without further growth of the pillar.

Time-dependent deformation of artificial muscles based on Nylon 6.

Considering the potential applications of the Nylon 6 with thermal-induced deformation, we studied the creep deformation of non-twisted Nylon 6 wires and Nylon 6 artificial muscles as functions of annealing temperature. For comparison, we also studied the creep deformation of chicken muscle fibers in a temperature range of 20 to 35 °C. The experimental results showed that we could use the standard linear viscoelastic model to describe the creep deformation of the chicken muscle fibers, the non-twisted Nylon 6 wires, and the Nylon 6 artificial muscles.

Brownian motion and Einstein relation for migration of coffee particles in coffee suspensions.

Background: The migration of particles in a liquid plays an important role in determining the stability of the corresponding suspension. The preparation of a cup of coffee involves the migration/dispersion of coffee particles in aqueous solutions. We investigate the Brownian motion of coffee particles in coffee suspensions at different temperatures for three different coffee beans via the migration of the coffee particles of the coffee suspensions in water.

Effect of graphene on the absorption of methanol and crack healing in poly(methyl methacrylate)-based composites.

This work is focused on the mass transport of methanol and the methanol-assisted crack healing in poly(methyl methacrylate) (PMMA)-graphene composites at different temperatures. The effect of the fraction of graphene on the mass transport of methanol and the methanol-assisted crack healing is also studied. The experimental results reveal that adding graphene to the PMMA matrix increases the resistance to the migration/diffusion of methanol and polymer chains in the PMMA matrix, and the absorption of methanol follows anomalous diffusion.

Caffeine Extraction from Raw and Roasted Coffee Beans.

Unlabelled: Coffee is a stimulant, psychoactive, popular daily beverage, and its caffeine affects human physiological health and behavior. These important issues prompted us to study caffeine extraction from both the raw and roasted coffee beans of 3 types at different temperatures. A hemispheric model is developed to simulate the extraction process of the caffeine from the coffee beans of hemisphere is proposed.

Absorption behavior of poly(methyl methacrylate)-multiwalled carbon nanotube composites: effects of UV irradiation.

Understanding the effects of carbon nanotubes (CNTs) and ultraviolet (UV) irradiation on solvent transport in polymers is of practical importance for the applications of polymer-CNT composites in electronics and photonics. The transport behavior of methanol in poly(methyl methacrylate)-multiwalled carbon nanotube (PMMA-MWCNT) composites with and without UV light irradiation has been studied. The anomalous transport has been investigated as a function of the weight percentage of MWCNTs and UV dose in the temperature range of 30-50 °C.

Kinetics of Field-Induced Surface Patterns on PMMA.

A simple model was developed to analyze the growth of a liquid pillar under the action of an electric field between two parallel electrodes. A quadratic relationship between time and the diameter of the pillar was obtained. The diameter of the pillar increases with time.

Surface wrinkling of an elastic film: effect of residual surface stress.

The effect of residual surface compression on the surface evolution of solid thin films was analyzed. Analytical relation was derived among the apparent surface stress, the spatial frequency of the surface modulation, and the film thickness. Using this relationship, we calculated the dependence of the apparent surface stress on the film thickness from the experimental results of the polymer resist coated on glass slide.