RSC Advances
·
2016
·Vol. 6
·期 16
·13418-13425
·
IF 3.289
Fubin Luo,Kun Wu,Mangeng Lu
The influence of polybenzoxazine modified ammonium polyphosphate (BMAPP) on the thermal behavior and flame retardancy of a rigid polyurethane foam (PU) are investigated via thermogravimetric analysis (TG), TG coupled with infrared spectroscopy (TG-FTIR), UL-94 vertical burning testing and limit oxygen index (LOI). The TG testing results indicate that BMAPP can enhance the thermal stability of PU, both under air and nitrogen conditions. The initial degradation temperature of the BMAPP/PU composites is 264 °C in air, which is 22 °C and 30 °C higher than that of ammonium polyphosphate (APP)/PU composites and neat PU, respectively. The reason might be attributed to the better dispersion and compatibility of BMAPP particles in PU compared with APP, which can prevent the PU chain from degrading at low temperatures. The LOI value results demonstrate that BMAPP has higher flame retardancy in PU than APP. Residue analysis implies that polybenzoxazine is partially converted into Si–O as char residue during combustion.
研究领域:
高分子材料科学
·
阻燃材料
·
热功能材料
·
复合材料学
·
材料化学
✓ 已验证
DOI
高影响因子
Cell Reports Physical Science
·
2021
·
IF 0
Yijie Liu,Li Yin,Wenwu Zhang,Jian Wang,Shuaihang Hou,Zuoxu Wu,Zongwei Zhang,Chen Chen,Xiaofang Li,Hongjun Ji,Qian Zhang,Zhiguo Liu,Feng Cao
A wearable thermoelectric generator using human body temperature is a promising power supply for wearable electronics. Here we discuss the design and fabrication of one kind of wearable thermoelectric generator constructed by n -type Mg 3.2 Bi 1.498 Sb 0.5 Te 0.002 legs, p -type Bi 0.4 Sb 1.6 Te 3 legs, polyurethane matrices, and flexible Cu/polyimide electrodes. The proposed device has a low thermal bypass and an efficient thermal contact interface, resulting in a peak power density of ∼20.6 μW/cm 2 when placed on a human arm at an ambient temperature of 289 K (air velocity, 1.1 m/s) and a high peak power density of 13.8 mW/cm 2 at a temperature difference of 50 K. In addition, it can withstand 10,000 bending cycles at a bend radius of 13.4 mm, suggesting that the proposed wearable thermoelectric generator has the potential to be a real-time power supply for certain wearable electronics in daily life.
研究领域:
生物医学工程
·
纳米能源材料
·
柔性电子学
·
热电转换技术
·
可穿戴设备
✓ 已验证
DOI
JOURNAL OF PHYSICAL CHEMISTRY A
·
2020
·
IF 2.6
Ming Zhang,Fengqi Zhao,Ting An,Yanjing Yang,Hui Li,Qing Pan,Xiaohong Wang,Zhoufeng Jiang
Thermal decomposition performance of the insensitive energetic compound 1,1-diamino-2,2-dintroethene (FOX-7) is essential for its application in the field of solid propellants. This study seeks to reveal the catalytic effects of reduced graphene oxide–bimetallic oxide nanocomposites (rGO–MFe2O4, M = Ni, Co, and Zn) on the thermal decomposition, kinetic parameters, and pyrolysis mechanism of energetic FOX-7. The results showed that the catalytic activities of the bimetallic iron oxide (NiFe2O4, CoFe2O4, and ZnFe2O4) increased obviously after anchoring on the surface of graphene. Particularly, the rGO–NiFe2O4 nanocomposite possessed the best catalytic activity for FOX-7 thermal decomposition. The high thermal decomposition peak temperature (THDP) and the apparent activation energy (Ea) of FOX-7 were decreased by 57.4 °C and 54.27 kJ mol–1 after mixing with the rGO–NiFe2O4 nanocomposite. The excellent catalytic activity of rGO–NiFe2O4 can be attributed to the synergistic interaction between rGO and NiFe2O4, which is beneficial for the reduction of activation energy and a high thermal decomposition peak temperature of FOX-7. This study is helpful for the rational design of a solid propellant containing FOX-7 and to understand the thermal decomposition kinetics and mechanism of FOX-7.
研究领域:
材料化学
·
含能材料科学
·
热力学与动力学
·
纳米复合材料
·
推进剂化学
✓ 已验证
DOI
高影响因子
Materials Today Electronics
·
2024
·
IF 0
Guanzheng Luo,Wang Li,Yingchao Wei,Yao Dai,Wenjie Shu,Linyao Wu,Xin Li,Yubo Luo,Junyou Yang
Cu 3 InSnSe 5 is a newly discovered copper-based diamond-like thermoelectric semiconductor, whose thermoelectric performance can be further enhanced by the MnSe alloying herein. We observed the formation of MnSe 2 precipitates that effectively scattered low-frequency phonons, which significantly reduced the lattice thermal conductivity at mid-to-low temperatures. While a high amount of MnSe alloying led to the formation of MnSe 2 precipitates which enhanced the phonons scattering, a smaller MnSe content improved the power factor in a certain as well. Ultimately, our research achieved a peak ZT of 1.00 and an average ZT of 0.50 over the 300–773 K temperature range by 10 mol.% MnSe alloyed Cu 3 InSnSe 5 pseudo-binary solid solution, demonstrating the potential of MnSe alloying for optimizing the thermoelectric performance of copper-based diamond-like semiconductor materials.
研究领域:
材料科学
·
凝聚态物理
·
半导体物理
·
能源材料
·
热电转换
✓ 已验证
DOI
LANGMUIR
·
2021
·
IF 3.882
Binyao Liu,Xiaoqin Nie,Yi Tang,Shan Yang,Liang Bian,Faqin Dong,Huichao He,Yong Zhou,Kun Liu
The thermal-condensation method is widely used for the synthesis of K-doped g-C3N4 photocatalysts, but the presence of organic byproducts in the resultant products is often overlooked in previous reports. Here, we demonstrated the universal presence of organic byproducts in K-doped g-C3N4 synthesized by typical thermal condensation of KOH/melamine, KOH/dicyandiamide, or KOH/urea. Taking the K-doped g-C3N4 photocatalysis for the degradation of dimethyl phthalate as an example, the negative influence of the organic byproducts on K-doped g-C3N4 photocatalysis was confirmed. Specifically, the organic byproducts can be gradually dissolved into the photocatalytic system of K-doped g-C3N4 as new and stable pollutants. Based on the solubility investigations on the byproducts in several solvents, hot-water washing was demonstrated to be a relatively effective approach to remove the organic byproducts from K-doped g-C3N4. The formation of organic byproducts during the synthesis of K-doped g-C3N4 could be ascribed to the fact that the presence of K salts in melamine, dicyandiamide, or urea molecules results in their insufficient thermal condensation into expected g-C3N4. The present work provides objective information about the K-doped g-C3N4 photocatalysts and reminds researchers about the influence of the organic byproducts on the applications of the other impurity-doped g-C3N4 photocatalysts.
研究领域:
材料化学
·
环境催化
·
光催化
·
纳米材料
·
污染物降解
✓ 已验证
DOI
高影响因子
Energy Materials
·
2022
·Vol. 2
·期 4
·N
·
IF 0
Liqi Dong,Fei Zhai,Hui Wang,Cong Peng,Yiyu Feng,Wei Feng
Azo photoswitches capture ambient heat and light, opening new possibilities for efficient thermal energy conversion, thus enhancing renewable energy utilization.
研究领域:
物理化学
·
材料科学
·
能源化学
·
光功能材料
·
热能存储
✓ 已验证
DOI
RSC Advances
·
2015
·Vol. 5
·期 85
·69878-69885
·
IF 3.84
Guang-Kun Ren,Jin-le Lan,Sajid Butt,Kyle J. Ventura,Yuan-Hua Lin,Ce-Wen Nan
BiCuSeO oxyselenides have been successfully fabricated by self-propagating high-temperature synthesis (SHS). Compared with the SHS process of binary or ternary alloys, thermal analysis indicates the ignition temperature of quaternary layered BiCuSeO oxyselenides approaches the second lower melting point of the compound. The ZT value of SHS-synthesized BiCuSeO is almost 1.5 times larger than that of the solid state reaction (SSR) product at 873 K. This is attributed to the existing amorphous region, nano-pores, and optimized grain size. Furthermore, with the partial substitution of Pb2+ for Bi3+, ZT was enhanced through the optimization of charge carrier concentration and band gap narrowing. This achieved a ZT of 0.91 at 873 K for Bi1−xPbxCuSeO (x = 0.04). Combining with the Debye–Callaway model analysis, the ultralow lattice thermal conductivity of BiCuSeO can potentially be derived from the synergistic effect of intrinsic point defects, efficient grain boundaries and some other mechanisms.
研究领域:
材料科学
·
凝聚态物理
·
无机非金属材料
·
能源材料
·
热电转换
✓ 已验证
DOI
高影响因子
RARE METALS
·
2023
·Vol. 42
·期 12
·3977-3984
·
IF 8.8
Cheng Peng-Tao,Zhang Zhao,Kan Xu-Cai,Zhang Cheng-Liang,Zhang Zheng-Ming,Li Bing,Wang Dun-Hui
压热制冷由于其环保以及高效等优点被认为是很有可能替代传统气体压缩制冷的制冷方式。然而，目前所发现的大部分压热制冷材料的驱动压力都很大，不利于实际应用。在这篇文章中，我们报道了一级磁结构相变合金MnAs 0.94 Sb 0.06 在低压力下诱导的压热效应。MnAs 0.94 Sb 0.06 合金的相变温度对压力非常敏感，其压力系数dT c /dP在降温时为134 K·GPa -1 ，在升温时为126 K·GPa -1 。在40 MPa的微小压力下，MnAs 0.94 Sb 0.06 合金的压热熵变可以达到26.3 J·kg -1 ·K -1 ，绝热温变可以达到14.4 K，表现出了非常优异的压热性能。我们对于MnAs 0.94 Sb 0.06 合金压热效应的研究表明该系列合金是压热制冷非常有潜力的候选材料。 Graphical abstract
研究领域:
材料科学
·
凝聚态物理
·
功能材料
·
制冷技术
·
磁学
✓ 已验证
DOI
高影响因子
ZEITSCHRIFT FUR ANORGANISCHE UND ALLGEMEINE CHEMIE
·
2021
·Vol. 647
·期 6
·681-685
·
IF 1.492
Xieyang Wang,Zhen Dong,Rui Yang,Shengren Zhou,Zhiwen Ye
Two energetic salts of cyclo-N 5 − , O-methylisoure pentazolate ( 1 ) and guanidinoacetic acid pentazolate ( 2 ), were synthesized by metathesis reaction. All the energetic cyclo-N 5 − salts were characterized by single-crystal XRD, IR spectroscopy, 1 H and 13 C multinuclear NMR spectroscopy, thermal analysis (DSC) and elemental analysis. They exhibit good thermal stability with decomposition temperatures of more than 100 °C and they are in excellent agreement with those reported non-metallic salts. Salt 1 also exhibits strong π-π interactions. The standard enthalpies of formation and detonation performances of these salts were calculated using Gaussian 09 and EXPLO5 v6.01 programs. The detonation velocities of compound 1 and 2 are both about 7400 m s −1 and these two salts exhibit low mechanical sensitivity (IS>23 J, FS>220 N). Therefore, in this work, the synthesis of the new pentazolate salts enriches the cyclo-pentazolate salts system, which is conducive to the exploration of more heat-resistant and higher detonation velocities pentazolate salts.
研究领域:
无机化学
·
含能材料
·
热分析
·
结构化学
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2021
·
IF 9.127
Hongbing Li,Yudong Zong,Qijun Ding,Wenjia Han,Xia Li
Cellulose is the most abundant polymer material in nature. After being produced on the nanometer scale, it is widely used in research on flexible energy storage equipment and power supply equipment. Therefore, this study has prepared a nanocomposite thermoelectric material based on multi-walled carbon nanotube (MWCNT) and carboxylated nanocellulose fiber (C-CNF) and obtained a free-standing paper-based thermoelectric generator (TEG) through a simple printing method. The equipment exhibits excellent mechanical flexibility. At the same time, the thermal conductivity is significantly reduced under the dual effects of paper and C-CNF (is reduced to 0.02–0.09 W/mK). The TEG prototype has four P-shaped feet. Under a temperature gradient of 70 K, the open circuit voltage is 3.3 mV, and the output power is up to 3.7 nW. This work not only confirms the improvement of MWCNT thermoelectric performance by C-CNF but also provides a new strategy for the preparation of low-cost and environmentally friendly thermoelectric generators.
研究领域:
材料科学
·
能源技术
·
纳米技术
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2019
·
IF 4.561
Qi Liu,Xiaoxiao Chen,Yan Guo,Chuanhong Han,Jing Li,Lihan Jia,Jie Liu,Xilian Wei
A ternary phase diagram of the system of 1-butyl-3-methylimidazolium tetrafluoroborate ([ Bmim ]BF4), sodium dodecylbenzenesulfonate (SDBS) and water using ocular estimate and turbidity method was drawn based on experimental data at 298.2 K. We got a narrow aqueous two-phase region near the side of water-ionic liquid (IL). A series of samples with different compositions around the phase diagram were chosen. The enthalpy change of these systems after injecting triply distilled water into these samples has been studied by using isothermal titration microcalorimetry (ITC). It is found that with increasing the water content there are weak endothermic and exothermic processes appearing, separately, which matches perfectly with the location of the formation and disappearance of the aqueous two-phase in the ternary phase diagram. This suggests the ITC is a feasible and effective method for the thermodynamic study of aqueous two-phase systems (ATPS) and was first reported. The experimental results show that the formation of the ATPS is endothermic (Δ H > 0), but the process of disappearing is exothermic (Δ H < 0). Due to the formation of aqueous two-phase is a thermodynamic spontaneous process under the isothermal constant pressure, we can judge that the formation of this ATPS is an entropy driven course and the vanishing is a synergy driven process by entropy and enthalpy.
研究领域:
物理化学
·
热力学
·
胶体与界面化学
·
分离科学
·
分析化学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·Vol. 49
·期 14
·23538-23545
·
IF 5.2
Jianbo Zhu,Jing Lin,Chao Yu,Yi Fang,Zhenya Liu,Zhonglu Guo,Chengchun Tang,Yang Huang
Boron nitride (BN) aerogels is a class of three-dimensional (3D) hierarchical network structure assembled from BN micro/nanostructures. The construction of BN/BN composite aerogel by introducing of BN micro/nano-structural units into the 3D BN aerogel scaffold provides an effective strategy for obtaining BN aerogel with improved all-round properties. Here, a novel kind of BN/BN composite aerogels has been developed by vacuum impregnation of ammonia borane (AB) into fiber-based BN aerogels, followed by high-temperature pyrolysis . The introducing of AB into BN aerogels makes the formation of unique AB/BN composite aerogels, and the high-temperature decomposition of AB results in the obtaining of a series of multifunctional composites, i.e. BN/BN composite aerogels. As compared with the porous BN microfibers in original BN aerogel, the self-assembled fibers in BN/BN composite aerogel are densely covered with high crystalline BN nanoflakes, which are generated by the AB decomposition. The obtained BN/BN composite aerogels have shown excellent thermal stability, significantly improved hydrophobic effect and heat transfer capability. This work provides a new idea for the future research and development of BN composite aerogels.
研究领域:
材料科学
·
纳米材料
·
热功能材料
·
多孔材料
·
复合材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）