Structure and Performance of Spinning Solution Prepared from Liquefied Wood

A new spinning solution was synthesized from liquefied wood in phenol by adding hexamethylenetetramine (HMTA) as a synthesis agent, and was easily spun into fibers by melt-spinning. Structure evolution of the spinning solution from liquefied wood (LWS) was investigated by FTIR spectroscopy. Results show the functional groups of LWS were changed from that of liquefied wood by adding HMTA during synthesizing the spinning solution. The effects of various synthesis conditions on the properties of the spun fibers are discussed. Spun fibers with a tensile strength of 90-129 MPa and modulus of elasticity of 8-24 GPa were obtained at a phenol/wood ratio of 6, synthesis agent content of 5%, synthesis temperature of 120°C, and temperature-rising time of 40 min. It was also found that thermal stability of LWS is better than that of liquefied wood, and that the spun fibers from LWS could be a precursor for carbon fibers

Variations in Pore Structure of Activated Carbon Fibers from Liquefied Wood with Preoxidation Treatment

Preoxidation treatments in air at 200-280°C were introduced in the preparation of activated carbon fiber from liquefied wood (LWACF) with steam activation at 910°C to enlarge its pore size distribution (PSD). LWACF yield was improved 1.14 times with preoxidation at 200°C. With increasing preoxidation temperature, the specific surface area increased from 2592 to 3068 m2/g. Preoxidations at 200 and 240°C predominantly enhanced the microporosity development without significant pore widening, whereas preoxidation at 280°C significantly enlarged the PSD. Mesopore volume increased by 72%, and methylene blue adsorption capacity improved by 34%

Technical Note: Analysis of Mechanical Relaxation Intensity of Wood at Various Moisture Contents

This study analyzed mechanical relaxation data by the well-known Gaussian function from which the relaxation intensity was determined for various moisture contents over a range of temperatures (-81-0°C). These data were used to suggest a range of bonding mechanisms for sorbed water

Technical Note: Responses of Vertical Sections of Wood Samples to Cyclical Relative Humidity Changes

This study investigated moisture responses of the surface, middle, and central portion in the thickness direction of wood samples to cyclic RH changes. Phase lag and amplitude for these sections were determined quantitatively by Fourier analysis. These data were used to suggest a mechanism for the unexpected phenomenon that moisture changes are slower than dimensional changes found in previous work

Relation Between Moisture Sorption and Hygroexpansion of Sitka Spruce During Adsorption Processes

Moisture adsorption processes carried out in successive steps at three increasing levels of RH (45, 75, 85%) at 20°C for Sitka spruce (Picea sitchensis Carr.) were studied. Moisture content and dimensional changes in radial and tangential directions of the specimens were measured and it was found that moisture changes were slower than dimensional. The modeling on this moisture-dimensional relationship, based on the idea of dividing sorbed water into two components having different effects on dimensional changes, not only shows a good agreement with experimental results, but also presents a new understanding of the mechanism of hygroexpansion of wood

CO2 adsorption and separation properties of M-MOF-74 materials determined by molecular simulation

This study simulated the adsorption and separation of CO2 by the metal-organic frameworks material M-MOF-74, established the skeleton model of M-MOF-74 series adsorbent, and calculated the adsorption of CO2 pure component gas and CO2/N2 mixed gas on MMOF- 74 series adsorbent by the grand canonical Monte Carlo method. Among the CO2 adsorption performances of MOF-74 materials with metal centers of Mg, Co, Ni, and Zn, Mg-MOF-74 had the highest CO2 adsorption capacity, adsorption selection coefficient and adsorption heat. When mixed gas was adsorbed, the law of CO2 adsorption was consistent with that of pure CO2 adsorption. The size law of adsorption heat on MOF-74 was similar to that of adsorption amount. Our findings demonstrated that the interaction between the metal-organic framework material and CO2 is greater than that between the material and N2. The interaction between the gas and the MOF-74 series adsorbent was the main factor affecting the adsorption amount, which reveals the strong influence of metal central atoms on the amount of gas adsorption. Our findings provide new ideas for the design of efficient adsorbent materials.Cited as: Deng, J., Zhao, G., Zhang, L., Ma, H., Rong, Y. CO2 adsorption and separation properties of M-MOF-74 materials determined by molecular simulation. Capillarity, 2023, 6(1): 13-18. https://doi.org/10.46690/capi.2023.01.0

Curcumin exhibits therapeutic effect against spinal cord injury via inhibition of neuronal inflammation and apoptosis

Purpose: To investigate the effect of curcumin on spinal cord injury (SCI) in a rat model. Methods: SCI was induced in the rats using mid thoracic spinal cord compression, after which curcumin was injected intraperitoneally. Western blotting was used for assay of expressions of apoptotic proteins, viz, IL-1β, NF-κB p65, TLR4, TNF-α, LC3, Bax and Bcl-2. Malondialdehyde (MDA) and myeloperoxidase were measured using standard methods. Neuronal loss in spinal cord tissues was determined with TUNEL staining and NeuN labelling. Results: Curcumin treatment significantly (p < 0.05) suppressed SCI-mediated upregulation of myeloperoxidase activity and increase in MDA level in rat spinal cord. The reduction of glutathione (GSH) and superoxide dismutase (SOD) activities in the spinal cord of SCI rats were suppressed by curcumin treatment. Curcumin treatment also led to a significant (p < 0.02) increase in the proportion of NeuN positive cells and marked reduction in TUNEL positive cells, but it decreased caspase-3 in the spinal cord tissues of SCI rats. Moreover, curcumin reversed the effect of SCI on protein expressions of Bax and Bcl 2 in a dose-based manner. There was marked curcumin-induced decline in CD11b and GFAP levels in the spinal cord tissues of the SCI rats. Conclusion: These results demonstrate that curcumin protects rats against SCI via inhibition of oxidative stress-mediated neuronal apoptosis. Therefore, curcumin may be useful for the development of an effective treatment for spinal cord injury

Wood fracture pattern during the water desorption process

Wood is a hygroscopic material and its mechanical properties change with moisture content below the fiber saturation point. Fracture characteristic is one of most important mechanical properties of wood and often is taken as an important safety design factor for wood as an engineered structural material. The aim of this paper is to investigate the effect of moisture content changes on wood fracture properties, focusing on fracture behavior and patterns with different crack orientations of Betula platyphylla Suk. and Pinus bungeana in two different desorption processes. These two desorption processes were, respectively, from fiber saturation point to an equilibrium moisture content corresponding to 82.4%RH at 20ºC and from 82.4%RH to 35.2%RH at the same temperature of 20ºC