scholarly journals Comprehensive Property Investigation of Mold Inhibitor Treated Raw Cotton and Ramie Fabric

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1105
Author(s):  
Zhixin Zhao ◽  
Wei Cai ◽  
Lei Song ◽  
Xiaowei Mu ◽  
Yuan Hu
Keyword(s):  
Thermal Conductivity ◽  
Thermal Stability ◽  
Optical Properties ◽  
Heat Insulation ◽  
Uv Light ◽  
Dimethyl Fumarate ◽  
Comprehensive Investigation ◽  
Combustion Properties ◽  
Insulation Effect ◽  
Comprehensive Property

At present, research rarely focuses on side effects of the use of mold inhibitors on raw cotton and ramie fabric. Four different mold inhibitors (dimethyl fumarate (DMF), ethyl p-hydroxybenzoate (EHB), propyl p-hydroxybenzoate (PHB), and calcium sorbate (CS)) were used to treat raw cotton and ramie fabric through a dipping method. The optical properties, wettability, thermal conductivity, thermal stability, and combustion properties of treated cotton and ramie samples have been investigated. The reflectance of UV light was improved by the addition of mold inhibitors. In addition, the presence of EHB, PHB, and CS improved the wettability of raw cotton and ramie fabric. It was found that thermal conductivity was slightly increased, influencing the heat insulation effect of the fabrics. Since the additives are flammable, the presence of DMF, EHB, and PHB caused an increase in pHRR and THR for combustion of cotton samples. This addition of CS caused a decrease in pHRR and THR of cotton due to the flame retardancy of CS. This comprehensive investigation of the properties of raw cotton and ramie fabrics treated with these materials should provide a basis for the choice of mold inhibitors.

Thermal Simulation Analysis of Insulation of the New Heat-Insulation Bricks

2014 ◽  
Vol 584-586 ◽  
pp. 1536-1540
Author(s):  
Xiao Ping Feng ◽  
Chun Ting Li ◽  
Jun Jie Wu
Keyword(s):  
Thermal Conductivity ◽  
Thermal Analysis ◽  
Heat Conductivity ◽  
Heat Insulation ◽  
Simulation Analysis ◽  
Thermal Simulation ◽  
Insulating Material ◽  
Filling Materials ◽  
Insulation Effect

Using the ANSYS thermal analysis module to do steady thermal analysis of given heat-insulating bricks. The results show that this kind of bricks can achieve better insulation in both sides; when the thermal conductivity of the heat insulating material in the hole space are less than 0.3 W/(m·K), the bricks can obtain the good insulation effect; the smaller the heat conductivity coefficients of the bricks materials and filling materials are, the better insulation bricks can achieve.

Effect of gamma radiation on the structural, thermal and optical properties of PMMA/Sn0.75Fe0.25S2 nanocomposite

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Ali A. Alhazime ◽  
Nesreen T. El-Shamy ◽  
Kaoutar Benthami ◽  
Mai ME. Barakat ◽  
Samir A. Nouh
Keyword(s):  
Thermal Stability ◽  
Optical Properties ◽  
Gamma Irradiation ◽  
Optical Band Gap ◽  
Color Variation ◽  
Nanocomposite Films ◽  
Color Changes ◽  
Gamma Irradiated ◽  
Intermolecular Crosslinking ◽  
Amorphous Part

AbstractNanocomposite films of polymethylmethacrylate PMMA with Sn0.75Fe0.25S2 nanoparticles (NPs) were fabricated by both thermolysis and casting techniques. Changes in PMMA/Sn0.75Fe0.25S2 nanocomposite (NCP) due to gamma irradiation have been measured. XRD results indicate that the gamma doses of 10–80 kGy cause intermolecular crosslinking that reduces the ordered portion in the NPs. Bonding between the NPs and the host PMMA was confirmed by FTIR. TGA results indicate an enhancement in thermal stability in the NCP films irradiated with doses 20–80 kGy. The optical band gap was reduced from 3.23 to 2.47 eV upon gamma irradiation up to 80 kGy due bonding between the NPs and PMMA which enhanced the amorphous part of the NPs. Finally, the color variation between the blank and irradiated films (ΔE) was determined. Color changes immensely when the PMMA/Sn0.75Fe0.25S2 NCP films are gamma irradiated. Values of ΔE were as much as 31.6 which is an acceptable match in commercial reproduction on printing presses.

scholarly journals Preparation and Thermal Conductivity of Epoxy Resin/Graphene-Fe3O4 Composites

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2013
Author(s):  
Zhong Wu ◽  
Jingyun Chen ◽  
Qifeng Li ◽  
Da-Hai Xia ◽  
Yida Deng ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Thermal Conductivity ◽  
Thermal Stability ◽  
Epoxy Resin ◽  
Thermomechanical Properties ◽  
Packaging Materials ◽  
Mass Ratio ◽  
Degree Of Orientation ◽  
Ep Matrix ◽  
Electrical Insulation Properties

By modifying the bonding of graphene (GR) and Fe3O4, a stable structure of GR-Fe3O4, namely magnetic GR, was obtained. Under the induction of a magnetic field, it can be orientated in an epoxy resin (EP) matrix, thus preparing EP/GR-Fe3O4 composites. The effects of the content of GR and the degree of orientation on the thermal conductivity of the composites were investigated, and the most suitable Fe3O4 load on GR was obtained. When the mass ratio of GR and Fe3O4 was 2:1, the thermal conductivity could be increased by 54.8% compared with that of pure EP. Meanwhile, EP/GR-Fe3O4 composites had a better thermal stability, dynamic thermomechanical properties, and excellent electrical insulation properties, which can meet the requirements of electronic packaging materials.

scholarly journals Formation of Carbon Quantum Dots via Hydrothermal Carbonization: Investigate the Effect of Precursors

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 986
Author(s):  
Md Rifat Hasan ◽  
Nepu Saha ◽  
Thomas Quaid ◽  
M. Toufiq Reza
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Microcrystalline Cellulose ◽  
Uv Light ◽  
Synthesis Method ◽  
Hydrothermal Carbonization ◽  
Carbon Quantum Dots ◽  
Medical Diagnostics ◽  
Particle Size Range ◽  
Wide Range

Carbon quantum dots (CQDs) are nanomaterials with a particle size range of 2 to 10 nm. CQDs have a wide range of applications such as medical diagnostics, bio-imaging, biosensors, coatings, solar cells, and photocatalysis. Although the effect of various experimental parameters, such as the synthesis method, reaction time, etc., have been investigated, the effect of different feedstocks on CQDs has not been studied yet. In this study, CQDs were synthesized from hydroxymethylfurfural, furfural, and microcrystalline cellulose via hydrothermal carbonization at 220 °C for 30 min of residence time. The produced CQDs showed green luminescence behavior under the short-wavelength UV light. Furthermore, the optical properties of CQDs were investigated using ultraviolet-visible spectroscopy and emission spectrophotometer, while the morphology and chemical bonds of CQDs were investigated using transmission electron microscopy and Fourier-transform infrared spectroscopy, respectively. Results showed that all CQDs produced from various precursors have absorption and emission properties but these optical properties are highly dependent on the type of precursor. For instance, the mean particle sizes were 6.36 ± 0.54, 5.35 ± 0.56, and 3.94 ± 0.60 nm for the synthesized CQDs from microcrystalline cellulose, hydroxymethylfurfural, and furfural, respectively, which appeared to have similar trends in emission intensities. In addition, the synthesized CQDs experienced different functionality (e.g., C=O, O-H, C-O) resulting in different absorption behavior.

A multilayer solar absorber coating based on NbMoTaW refractory high entropy alloy: Optical properties, thermal stability and failure mechanism

2021 ◽  
pp. 100789
Author(s):  
Dong-Mei Yu ◽  
Cheng-Yu He ◽  
Xiao-Li Qiu ◽  
Shuai-Sheng Zhao ◽  
Hui-Xia Guo ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Optical Properties ◽  
Failure Mechanism ◽  
High Entropy Alloy ◽  
High Entropy ◽  
Solar Absorber

scholarly journals Research on Thermal Stability and Properties of Ca3ZrSi2O9 as Potential T/EBC Materials

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 583
Author(s):  
Yangyang Pan ◽  
Bo Liang ◽  
Yaran Niu ◽  
Dijuan Han ◽  
Dongdong Liu ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Stability ◽  
Fracture Toughness ◽  
Room Temperature ◽  
Coefficient Of Thermal Expansion ◽  
Atmospheric Plasma ◽  
Thermal Barrier ◽  
Mechanical And Thermal Properties ◽  
Self Healing ◽  
Barrier Coating

In this study, a new coating material for thermal barrier coating (TBC) or environment barrier coating (EBC) application, Ca3ZrSi2O9 (CZSO), was synthesized and prepared by atmospheric plasma spray (APS) technology. The evolution of the phases and microstructures of the coatings with different thermal-aged were characterized by XRD, XRF, EDS and SEM, respectively. The thermal stability was measured by TG-DTA and DSC. The mechanical and thermal properties, including Vickers hardness (HV), fracture toughness (KIC), thermal conductivity () and coefficient of thermal expansion (CTE) were focused on. It was found that the as-sprayed CZSO coating contained amorphous phase. Crystalline transformation happened at 900–960 ∘C and no mass changes took place from room temperature (RT) to 1300 ∘C. The phenomena of microcrack self-healing and composition uniformity were observed during thermal aging. The of coating was very low at about 0.57–0.80 Wm−1K−1 in 200–1200 ∘C. The combined properties indicated that the CZSO coating might be a potential T/EBC material.

Onset of Natural Convection from a Suddenly Heated Horizontal Cylinder

1980 ◽  
Vol 102 (4) ◽  
pp. 636-639 ◽  
Author(s):  
J. R. Parsons ◽  
J. C. Mulligan
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Thermal Stability ◽  
Heat Capacity ◽  
Natural Convection ◽  
Stability Analysis ◽  
Horizontal Cylinder ◽  
Finite Cylinder ◽  
Global Motion ◽  
Experimental Apparatus

A study of the onset of transient natural convection from a suddenly heated, horizontal cylinder of finite diameter is presented. The termination of the initial conductive and “locally” conuectiue heat transfer regime which precedes the onset of global natural convection is treated as a thermal stability phenomenon. An analysis is presented wherein the effects of finite cylinder diameter, cylinder heat capacity, and cylinder thermal conductivity are included in calculations of the convective delay time. A simple experimental apparatus is described and data presented. The thermal stability analysis is confirmed experimentally and data is presented which indicates localized natural convection prior to global motion.

Amino acid-templated zinc phosphites: low-dimensional structures, fluorescence, and nonlinear optical properties

2021 ◽  
Author(s):  
Yumei Mao ◽  
Xuehua Dong ◽  
Yuandan Deng ◽  
Jing Li ◽  
Ling Huang ◽  
...  
Keyword(s):  
Optical Properties ◽  
Amino Acid ◽  
Nonlinear Optical ◽  
Uv Light ◽  
Nonlinear Optical Properties ◽  
Light Irradiation ◽  
Blue Fluorescence ◽  
Structure Directing Agent ◽  
Uv Light Irradiation ◽  
Low Dimensional

Two new zinc phosphites were prepared using the amino acid alanine as structure-directing agent. They have tubular and ladder-like structures exhibiting blue fluorescence upon UV light irradiation. Notably, the tubular...

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