scholarly journals A cyan-emitting phosphor Ca3SiO4(Cl,Br)2:Eu2+ with high efficiency and good thermal stability for full-visible-spectrum LED lighting

2021 ◽  
Vol 232 ◽  
pp. 117854
Author(s):  
Yuan Zhu ◽  
Lei Fu ◽  
Di Wu ◽  
Jiaqing Peng ◽  
Fu Du ◽  
...  
2021 ◽  
Author(s):  
Zhijun Hu ◽  
Xinyu Cao ◽  
Guanhong Huang ◽  
Daliang Guo

Abstract Here, a new pretreatment method has been developed to produce CNFs from micro-fibrillated cellulose (MFC) by supercritical CO 2 pretreatment followed with ball-milling (SCB). MFC was obtained from cotton stalk by chemical purification.Experimental factors were controlled to enhance the properties of SCB-CNF, meanwhile a comparative study was conducted with the method of TEMPO oxidation and microfluid homogenization (TMH). Compared to TMH-CNF, the SCB-CNF has such advantages as Energy saving, high efficiency and environmental protection, indicating a wide application in heat-resistant materials, load materials and other fields. The solid yields of P-MFC after supercritical CO 2 pretreatment gradually decreased together with the temperature and the reaction time. Scanning electron microscope (SEM) images of the SCB-CNF and TMH-CNF show that the morphology of the SCB-CNF was basically acicular but that of the TMH-CNF was mainly soft fibrous. The SCB-CNF is smaller in width and shorter in length, and its size is between CNC and CNF. Thermal gravimetric results suggest that the thermal stability of the SCB-CNF was substantially higher than those of the TMH-CNF. XRD results indicate that the crystallinity showed an initial increasing trend and then declined with increasing temperature and reaction time, and the crystallinity value of SCB-CNF was larger than that of CNFs. The smaller SCB-CNF became rougher and had a larger surface area. High crystallinity make good thermal stability, short and coarse fiber, easier to disperse than CNF, less energy consumption for dispersion, better than 3D mesh. It can be widely used in polymer composites, reinforcing agents, membrane materials and other fields.


RSC Advances ◽  
2019 ◽  
Vol 9 (36) ◽  
pp. 20733-20741 ◽  
Author(s):  
HyunKyung Lee ◽  
Sora Oh ◽  
Chang Eun Song ◽  
Hang Ken Lee ◽  
Sang Kyu Lee ◽  
...  

A 3D-shaped SF-HR was designed and synthesized for use in non-fullerene organic solar cells. Owing to the aligned energy levels, the P3HT:SF-HR system exhibited a high efficiency of 4.01% with good thermal stability and photostability.


RSC Advances ◽  
2016 ◽  
Vol 6 (80) ◽  
pp. 77059-77065 ◽  
Author(s):  
Fu Du ◽  
Weidong Zhuang ◽  
Ronghui Liu ◽  
Yuanhong Liu ◽  
Jiyou Zhong ◽  
...  

A series of phase pure nitride yellow phosphors La3−xYxSi6N11:Ce3+ with good thermal stability and tunable luminescence properties have been synthesized and the crystal structure was investigated in detail.


2012 ◽  
Vol 22 (30) ◽  
pp. 15136 ◽  
Author(s):  
Xing Xing ◽  
Lixin Xiao ◽  
Lingling Zheng ◽  
Shuangyuan Hu ◽  
Zhijian Chen ◽  
...  

2012 ◽  
Vol 531-532 ◽  
pp. 8-12
Author(s):  
M.A. Sai Balaji ◽  
K. Kalaichelvan

Organic fibres (Kevlar/ Arbocel / Acrylic) have good thermal stability, higher surface area and bulk density. The optimization of organic fibres percentage for thermal behaviour is considered using TGA. The temperature raise during brake application will be between 150-4000 C and this temperature zone is very critical to determine the fade characteristics during friction testing. Hence, three different friction composites are developed with the same formulation varying only the Kevlar, Arbocel and Acrylic fibres which are compensated by the inert filler namely the barites and are designated as NA01, NA02 and NA03 respectively. After the fabrication, the TGA test reveals that the composite NA03 has minimum weight loss. The friction coefficient test rig is then used to test the friction material as per SAE J661a standards. The results prove that the brake pad with minimum weight loss during TGA has higher friction stability. Thus, we can correlate the thermal stability with the stability of friction.


Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3827
Author(s):  
David Baeza Moyano ◽  
Roberto Alonso González-Lezcano

The existence of a growing myopia pandemic is an unquestionable fact for health authorities around the world. Different possible causes have been put forward over the years, such as a possible genetic origin, the current excess of children’s close-up work compared to previous stages in history, insufficient natural light, or a multifactorial cause. Scientists are looking for different possible solutions to alleviate it, such as a reduction of time or a greater distance for children’s work, the use of drugs, optometric correction methods, surgical procedures, and spending more time outdoors. There is a growing number of articles suggesting insufficient natural light as a possible cause of the increasing levels of childhood myopia around the globe. Technological progress in the world of lighting is making it possible to have more monochromatic LED emission peaks, and because of this, it is possible to create spectral distributions of visible light that increasingly resemble natural light in the visible range. The possibility of creating indoor luminaires that emit throughout the visible spectrum from purple to infrared can now be a reality that could offer a new avenue of research to fight this pandemic.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Juanyong Wan ◽  
Yonggao Xia ◽  
Junfeng Fang ◽  
Zhiguo Zhang ◽  
Bingang Xu ◽  
...  

AbstractNonfullerene organic solar cells (OSCs) have achieved breakthrough with pushing the efficiency exceeding 17%. While this shed light on OSC commercialization, high-performance flexible OSCs should be pursued through solution manufacturing. Herein, we report a solution-processed flexible OSC based on a transparent conducting PEDOT:PSS anode doped with trifluoromethanesulfonic acid (CF3SO3H). Through a low-concentration and low-temperature CF3SO3H doping, the conducting polymer anodes exhibited a main sheet resistance of 35 Ω sq−1 (minimum value: 32 Ω sq−1), a raised work function (≈ 5.0 eV), a superior wettability, and a high electrical stability. The high work function minimized the energy level mismatch among the anodes, hole-transporting layers and electron-donors of the active layers, thereby leading to an enhanced carrier extraction. The solution-processed flexible OSCs yielded a record-high efficiency of 16.41% (maximum value: 16.61%). Besides, the flexible OSCs afforded the 1000 cyclic bending tests at the radius of 1.5 mm and the long-time thermal treatments at 85 °C, demonstrating a high flexibility and a good thermal stability.


2013 ◽  
Vol 734-737 ◽  
pp. 2191-2194
Author(s):  
Li Li Wu ◽  
Yuan Lian ◽  
Dan Liu ◽  
Hua Zheng ◽  
Dian Wu Huang

In this study, flame retardant microcapsules were synthesized using magnesium hydroxide as core materials, melamine resin as the shell material. The structure, diameters and thermal properties of prepared microcapsules were investigated by using FTIR, ELS, DSC and TGA. The effects of core/shell ratio on the properties of microcapsules were studied.Flame retardant materials of low-density polyethylene/magnesium hydroxide microcapsules were prepared.The tensile strength and elongation at break tests were performed to determine its mechanical property.Inflammability of the materials was also studied.The results showed the prepared magnesium hydroxide microcapsule shows good thermal stability and it has free compatibility with the polymer.The composites of HDPE/MH microcapsules have good performance.


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