Geoscience Frontiers
·
2020
·Vol. 12
·期 2
·957-963
·
IF 4.202
Ruijing Fu,Yaping Chen,Lingrui Wang,Zhiwei Ma,Pengfei Lv,Ying Song,Songrui Yang,Guanjun Xiao,Bo Zou
SiO 2 is the major mineral substance in the upper mantle of the earth. Therefore, studies of the silica-coated materials under high-pressure are essential to explore the physical and chemical properties of the upper mantle. The silica-confined CsPbBr 3 nanocrystals (NCs) have recently attracted much attention because of the improved photoluminescence (PL) quantum yield, owing to the protection of silica shell. However, it remains considerable interest to further explore the relationship between optical properties and the structure of CsPbBr 3 @SiO 2 NCs. We systemically studied the structural and optical properties of the CsPbBr 3 @SiO 2 NCs under high pressure by using diamond anvil cell (DAC). The discontinuous changes of PL and absorption spectra occurred at ∼1.40 GPa. Synchrotron X-ray diffraction (XRD) studies of CsPbBr 3 @SiO 2 NCs under high pressure indicated an isostructural phase transformation at about 1.36 GPa, owing to the pressure-induced tilting of the Pb-Br octahedra. The isothermal bulk moduli for two phases are estimated about 60.0 GPa and 19.2 GPa by fitting the equation of state. Besides, the transition pressure point of CsPbBr 3 @SiO 2 NCs is slightly higher than that of pristine CsPbBr 3 NCs, which attributed to the buffer effect of coating silica shell. The results indicate that silica shell is able to enhance the stabilization without changing the relationship between optical properties and structure of CsPbBr 3 NCs. Our results were fascinated to model the rock metasomatism in the upper mantle and provided a new ‘lithoprobe’ for detecting the upper mantle.
研究领域:
材料科学
·
高压物理
·
纳米材料
·
光学性质
·
地球物理学
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2024
·
IF 8.1
Yixuan Zhang,Guo-Qiang Liu,Danlei Qiao,Jiaguan Chen,Qiang Sun,Lei Wen
This work focuses on the effect of the of Mn 3+ /Mn 4+ ratio in the reactants on the structure and electrochemical properties of NaMn 0.9 Cu 0.1 O 2 cathode materials for sodium-ion batteries. By systematically varying the manganese valence states in the reactants, we observed a phase transition from the β-phase to the P2-phase with increasing Mn 3+ concentrations in the reactants, contrary to the expected favorability of the β-phase at higher Mn 3+ levels. This finding suggests a complex interplay between the valence states of the reactants and phase formation mechanisms, which needs further investigation. Additionally, electrochemical testing indicated that the phase composition significantly impacts the electrochemical performance of the material. Specifically, the M0 sample, possessing the optimal P2/β ratio, exhibited excellent electrochemical performances, achieving a high initial discharge capacity of 155.1 mA h g −1 and remains 88.1 % after 40 cycles. These results emphasize the importance of precursor selection and valence management in the development of high-performance cathode materials for sodium-ion batteries.
研究领域:
材料科学
·
电化学
·
能源存储
·
无机化学
·
固态化学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·Vol. 49
·期 23
·39700-39706
·
IF 5.2
Xinkun Liu,Ying Dai,Xinmei Pei,Wen Chen
Ferroelectric thin films with giant room-temperature electrocaloric effect (ECE) could be very useful in design of solid-state refrigeration devices. Here, lead-free Ba 0.85 Ca 0.15-x Sr x Zr 0.1 Ti 0.9 O 3 (BCZT-xSr, 0.01 ≤ x ≤ 0.10) thin films are successfully prepared on the substrates (Pt/Ti/SiO 2 /Si) via sol-gel route, and the effect of the Sr substitution on the structure, electric properties and ECE of the films were investigated. The dielectric analyses show that the rhombohedral-tetragonal phase transition temperature (T R-T ) move to a higher temperature and the tetragonal-cubic phase transition temperature (T m ) shift to a lower temperature with increasing Sr content, and finally the T R-T peaks merge into the T m peaks at room temperature. The BCZT-0.05Sr film presents a giant ECE with ΔT = 27.1 K and ΔS = 30.6 J K −1 kg −1 at 800 kV cm -1 near room temperature (301 K). The giant ΔT benefits from a multiphase coexisting region with successive R-T and T-C phase transition character near room temperature. These results indicate that the lead-free Sr-doped BCZT thin film is an attractive material for application in ECE refrigeration devices.
研究领域:
材料科学
·
凝聚态物理
·
功能材料
·
热电转换
·
固态制冷
✓ 已验证
DOI
高影响因子
Energy Technology
·
2017
·Vol. 5
·期 8
·1322-1327
·
IF 2.789
Shaolei Xie,Jinhe Sun,Shang Liu,Lipeng Han,Guixiang Ma,Yan Jing,Yongzhong Jia
An adipic acid/boric acid (AA–BA) binary eutectic mixture containing 80 wt % adipic acid and 20 wt % boric acid was investigated as a new phase change material (PCM) with high latent heat, high thermal stability, and low cost. The material′s thermophysical properties and thermal stability were studied using differential scanning calorimetry (DSC), X-Ray Diffraction (XRD), and thermogravimetric analysis (TGA). The thermal stability was investigated in situ over 100 cycles using DSC. The phase change temperature of the AA–BA binary eutectic mixture was 135.04 °C and the latent heats of the melting and crystallization process were 283.42 and 272.16 J g −1 , respectively. The latent heat of melting only dropped 4.94 % after in situ 100 cycles using DSC. Following comparison of thermal properties and price of the AA–BA eutectic mixture PCM with those of some composite PCMs, the results indicate that the newly prepared AA–BA eutectic mixture is a potential phase change material for thermal storage tanks.
研究领域:
材料科学
·
热力学
·
能源存储
·
化学工程
·
功能材料
✓ 已验证
DOI
高影响因子
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2024
·Vol. 130
·期 11
·835
·
IF 2.5
Kou Chen,Duan Bin,Shi Lichun,Yang Hongcai,Ni Heng,Wang Haiyuan,Ye Qing,Hu Junshan,Hu Shigang
The Sc 3+ ions doped NaYF 4 : Yb 3+ , Er 3+ upconversion (UC) nanoparticles are synthesized by thermal decomposition method. We successfully obtained the upconversion luminescence (UCL) nanoparticles from green emission to red emission through doping Sc 3+ ions with different concentrations. Based on the XRD, the phase change process of Sc 3+ ions doped NaYF 4 nanocrystalline phase were demonstrated. More importantly, through the analysis of UC spectrum data, the change in the phase of the NaY/ScF 4 : Yb 3+ , Er 3+ nanocrystalline corresponds to the change in its luminous properties. It determines that the change of crystal field will lead to the change of luminescence, and then modulate the luminescence. NaScF 4 : Yb 3+ , Er 3+ UC nanoparticles exhibit strong red light emission. In addition, the temperature-sensitive properties of the optimal doping concentration of Sc 3+ ion were tested. The sensitivity of NaYF 4 : Yb 3+ , Er 3+ nanoparticles doped with Sc 3+ ion reached the maximum value of 0.024 K − 1 at 498 K. The nanocrystalline has great application value in the fields of optical temperature measurement, biomedicine, bioprobes and colorful display.
研究领域:
材料科学
·
光学工程
·
生物医学工程
·
纳米技术
·
分子影像学
✓ 已验证
DOI
高影响因子
MATERIALS LETTERS
·
2018
·
IF 2.687
Xue Chen,Ning Li,Yuan Li,Ping Che
In this work the CH 3 NH 3 PbI x Cl 3−x perovskite is obtained by applying vacuum-rotary evaporation procedure with a precursor solution of PbCl 2 and CH 3 NH 3 I in dimethylformamide. Thermal gravimetric and differential thermal analysis (TG-DTA) and the variable temperature powder X-ray diffraction ( in situ XRD) are employed to research the effect of thermal treatment on the decomposition and the crystal structure of perovskite . It is found that tetragonal to cubic phase transition in the typical perovskite disappears in mixed perovskite crystals because the stabilizing action of Cl. The excess Cl in the precursor leads to the intermediate structure CH 3 NH 3 PbCl 3 , and then transforms into CH 3 NH 3 PbI 3 with temperature increasing.
研究领域:
材料科学
·
无机化学
·
固体物理
·
能源材料
·
晶体学
✓ 已验证
DOI
高影响因子
SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2023
·
IF 6.9
Xuefeng Shao,Yeke Chenxu,Binrui Wang,Nan Zhang,Yanping Yuan
Towards latent heat storage for days, or even extending to months in the context of solar energy utilization, the exploration of phase change materials (PCMs) with stable supercooling and the following crystallization triggering are carried out. The present work confirmed the persistent supercooling property of the xylitol/erythritol eutectic mixture. The coupled technique combining mechanical agitation with seeding was proposed to trigger crystallization, so as to facilitate the heat retrieval whenever heat is in demand. The xylitol/erythritol eutectic keeps supercooling state without crystallization at ambient temperature for at least 10 days, thus it can serve as applicable PCM for controllable heat retrieval. Such severe supercooling is mainly attributed to the particular molecular structure of polyalcohols and dramatic increase of dynamic viscosity . In particular, on the basis of secondary nucleation principle, the coupled technique combining mechanical agitation and seeding can be a preferable technique to efficiently trigger crystallization of the present eutectic PCM , so as to realize controllable heat retrieval. Such combined technique has main advantages of high efficiency and reproducible crystallization process . The agitation duration is shortened to 1.8 min with seeding, in comparison to a longer value of 43.3 min without seeding. Although the single technique of mechanical agitation can also trigger the crystallization, the agitation is found to be time-consuming and the triggered crystallization process is in poor consistency among parallel specimens. Furthermore, the crystallization initiating is greatly advanced with high agitation rate (300 r/min), and the agitation duration to sufficiently activate crystallization can be significantly shortened. The results suggest that appropriately high agitation rate favors the efficient heat retrieval. The obtained results are helpful to gain a better understanding on the supercooled PCMs based controllable heat retrieval.
研究领域:
材料科学
·
热能存储
·
物理化学
·
能源材料
·
传热学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Qijing Guo,Hao Yi,Feifei Jia,Shaoxian Song
Phase change materials (PCMs) offer significant advantages in energy conversion and storage by facilitating the storage and release of thermal energy during phase transition processes. However, challenges such as leakage during PCM phase transitions and poor light absorption properties have constrained their application in the field of photothermal energy storage. In this study, Montmorillonite (Mt) and molybdenum disulfide (MoS 2 ) has been used to design and synthesize hybrid aerogels (MoS 2 /Mt) boasting high mechanical strength and excellent photothermal conversion performance. These aerogels are then used to encapsulate polyethylene glycol (PEG) to prepare composite PCMs with outstanding solar-thermal conversion and storage performances. The results show that the synthesized MoS 2 /Mt-PEG composite PCMs exhibit high enthalpies of melting and solidification of 169.16 J/g and 170.78 J/g, respectively, while the aerogel supporting material has a high compressive modulus of 1.96 MPa. Moreover, the composite material displayed excellent thermal stability and leakage resistance after undergoing 30 melting-cooling cycles. Furthermore, the incorporation of MoS 2 imparted outstanding light absorption properties to the MoS 2 /Mt-PEG composite, resulting in a high light absorption and photothermal conversion-storage efficiency of 93.4 % and 96.47 %, respectively. Synthesized composite PCMs also demonstrate outstanding performance in solar-thermal-electricity conversion, achieving a voltage output of 458 mV under illumination conditions and maintaining a sustainable voltage output even after removing the light source. Thus, the composite PCMs prepared in this work can meet the requirements of high enthalpy, effective leakage prevention, efficient solar-thermal conversion and solar-thermal-electricity conversion performance, thereby presenting potential applications in practical solar energy collection, conversion, and storage.
研究领域:
材料科学
·
能源化学
·
纳米复合材料
·
热能存储
·
光热转换
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2016
·
IF 2.76
Caili Dai,Zhe Yang,Huili Yang,Yifei Liu,Jichao Fang,Wenxia Chen,Weitao Li,MingWei Zhao
Micelle-to-vesicle aggregate transition is investigated in this work through the addition of β-cyclodextrin 1 (β-CD) in mixed catanionic surfactant aqueous solutions. The catanionic system is composed of 1-hexadecyl-3-methylimidazolium chloride (C 16 mimCl) and sodium oleate (NaOle) which are cationic surfactant and anionic surfactant, respectively. The mixed surfactant solutions can self −assemble into micelles, which are studied by dynamic light scattering measurements and the calculation of molecular interaction parameter. The inclusion complexation of β-CD to C 16 mimCl-NaOle surfactants is studied by surface tension measurements and the calculation of association constants. The dynamic light scattering (DLS), rheological measurements, freeze-fracture transmission electron microscopy(FF-TEM)were conducted to indicate that micelles can transform into vesicles with the addition of β-CD. Finally, the transformation mechanism is proposed. The main reason for micelle-to-vesicle aggregate transition is the inclusion complexation of β-CD to surfactants and it will alter the composition of mixed C 16 mimCl-NaOle surfactant systems which should be responsible for the phase behavior.
研究领域:
胶体化学
·
纳米材料
·
药物递送
·
自组装体系
·
物理化学
✓ 已验证
DOI
高影响因子
Case Studies in Construction Materials
·
2024
·
IF 6.5
Ya Yin,Lan Qiao,Qingwen Li,Lu Chen,Miao Miao,Jinshui Dong,Linbo Song,An Luo,Haiqi Zheng
The functional backfilling in mining achieves synergistic co-mining of deep-earth deposits-geothermal, and the development of functional filling materials with suitable phase change parameters and excellent physicochemical properties is imminent. This study aims to investigate the optimal composition of phase change energy storage backfill material based on MicroPCM. To address the issues of reduced compressive strength and specific heat capacity of MicroPCM-backfill, silicon carbide (SiC) is introduced to prepare MPSC-backfill. Box-Behnken Design (BBD) is proposed to design and analyze according to four factors (ash-sand ratio, slurry concentration, MicroPCM, SiC), three levels (compressive strength, thermal conductivity, specific heat capacity) and three center points. Based on the Response Surface Methodology, the multivariate quadratic polynomial model was used to perform multiple linear regression and binomial fitting analysis to explore the optimal ratio. Combined with SEM-EDS (Scanning Electron Microscope with Energy-Dispersive X-ray Spectroscopy) analysis, the following conclusions were drawn. SiC exhibits an overall enhancement of the compressive strength of the backfill, and the thermal conductivity tends to increase almost linearly. The specific heat capacity grows in a small amount of silicon carbide doping, but excessive amounts lead to a decrease, with an overall limited impact. The addition of SiC does not affect the phase change ability of MicroPCM. And within a certain range of added quantities, it optimizes specific heat capacity, thermal conductivity, and compressive strength. Experimental validation based on the obtained optimal composition shows errors within a 5% margin, indicating the response model's good accuracy and predictability. High and low-temperature cyclic tests confirm the long-term thermal energy storage stability of MPSC-backfill during phase change cycles.
研究领域:
材料科学
·
矿业工程
·
热能存储
·
功能材料
·
物理化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Mengdi Yuan,Chao Xu,Tieying Wang,Tianying Zhang,Xinyu Pan,Feng Ye
The serious supercooling of erythritol (ET) limits its application in the field of mid-temperature thermal energy storage (TES), especially in the recently developed form-stable phase change materials (PCMs). The primary purpose of this paper is to find out the factors to mitigate the supercooling of ET/expanded graphite (EG) form-stable composite PCM and obtain the correlation among the morphology, kinetic parameters, and a supercooling degree in the non-isothermal crystallization process. Firstly, five types of supercooling relaxation agents (nano-Al 2 O 3 , nano-SiO 2 , CMC, urea, and citric acid) were added to prepare the ET/EG form-stable CPCMs. Among them, the ET/EG/nano-Al 2 O 3 exhibited excellent form-stable ability, a high heat release ratio of 78.9%, and the lowest supercooling degree (Δ T ) of 45.7 °C. Based on the chosen ET/EG/nano-Al 2 O 3 CPCM, the tablet pressures from 1 to 13 MPa were applied, obtaining lowest Δ T decreased by 59.0% in 1 MPa. Moreover, the non-isothermal crystallization processes were discussed on the ET/EG/nano-Al 2 O 3 with the Avrami equation modified by Jeziorny. ET tended to grow spherulites under the high cooling rate of 18 °C/min with triggering as the Johnson-Mehl-Avrami exponent n increased to 4.22. Meanwhile, the supercooling degree increased from 48.8 to 56 °C with the cooling rate growing from 2 to 18 °C/min. And the activity energy Δ E of the ET/EG/nano-Al 2 O 3 CPCM (7092.35 kJ/mol) was smaller than that of the ET/EG CPCM (8211.19 kJ/mol) because of the interaction between the heterogeneous nucleation effect and blocker effect of nano-Al 2 O 3 .
研究领域:
材料科学
·
热能存储
·
物理化学
·
复合材料
·
能源材料
✓ 已验证
DOI
高影响因子
APPLIED THERMAL ENGINEERING
·
2016
·
IF 3.043
Min-Jie Liu,Li-Wu Fan,Zi-Qin Zhu,Biao Feng,Han-Cong Zhang,Yi Zeng
In order to study quantitatively the inward solidification heat transfer of a phase change material (PCM) enclosed in spherical capsules, an experimental method was proposed in this Technical Note, which is based upon measurement on the instantaneous volume shrinkage of the PCM during solidification. The shrunk volume was compensated continuously by an extra amount of liquid PCM preserved in a tube, and the descending height in the tube was recorded to calculate the volume shrinkage. Other quantities of interest, solidification fraction and surface-averaged heat flux for example, were readily reduced as single-valued functions of the volume shrinkage. Using 1-tetradecanol as the PCM, the proposed method was realized in laboratory with a stainless steel spherical capsule having an inner diameter of approximately 60 mm. Parallel tests were carried out for a set of three boundary cooling temperatures. It was shown that the measured descending heights are reproducible and are in agreement with the theoretical maximum values approaching the end of solidification. The experimental results were then discussed with an emphasis on the transient variations of solidification and heat transfer. Correlations were obtained for both solidification fraction and surface-averaged Nusselt number with respect to the product of Fourier and Stefan numbers.
研究领域:
热科学与工程
·
储能技术
·
传热传质学
·
材料科学
·
能源工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）