SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2024
·
IF 6.3
Meiyang Xu,Gaosheng Wei,Chao Huang,Xiaoze Du
Carbonates have great application potential as heat transfer and thermal energy storage media in the development of future phase change materials. This paper gives thermophysical properties enhancement study on ternary carbonates in liquid state by adding aluminum oxide nanoparticles, multi-walled carbon nanotubes, graphene nanosheets, and experimentally evaluate the performance strengthen ability of multi-dimensional nanoparticles. The thermal diffusivities and specific heats of the prepared samples by the water solution method are determined using the laser flash technique and the differential scanning calorimetry at liquid state, respectively. A thermogravimetric analyzer is deployed for evaluate the high-temperature thermal stability of the composite ternary carbonates. Scanning electron microscopy and Fourier transform infrared spectroscopy techniques are utilized to examine the surface morphologies and chemical structures of the samples. The results indicate that there is a cooperative reinforcement impact on the thermophysical properties of ternary carbonate by utilizing zero-dimensional Al 2 O 3 nanoparticles and two-dimensional graphene nanosheets, with a maximum improvement of 56.7 % for thermal conductivity, and 10.3 % for specific heat, which is apparently larger than adding any single nanoparticle. The composites exhibit superior thermal cycling stability after low-high temperature experiment, and samples can maintain thermal stability until 700 °C in the thermogravimetric analysis.
研究领域:
材料科学
·
热能工程
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2022
·Vol. 14
·期 7
·1333
·
IF 4.967
Jiatian Zhu,Yuqi Bao,Luxiong Lv,Fanyan Zeng,Dasong Du,Chen Liang,Jiayan Ge,Shuangfei Wang,Shuangquan Yao
The preparation of bio-oil through biomass pyrolysis is promoted by different demineralization processes to remove alkali and alkaline earth metal elements (AAEMs). In this study, the hydrothermal pretreatment demineralization was optimized by the response surface method. The pretreatment temperature, time and pH were the response elements, and the total dissolution rates of potassium, calcium and magnesium were the response values. The interactions of response factors for AAEMs removal were analyzed. The interaction between temperature and time was significant. The optimal AAEMs removal process was obtained with a reaction temperature of 172.98 °C, time of 59.77 min, and pH of 3.01. The optimal dissolution rate of AAEMs was 47.59%. The thermal stability of eucalyptus with and without pretreatment was analyzed by TGA. The hydrothermal pretreatment samples exhibit higher thermostability. The composition and distribution of pyrolysis products of different samples were analyzed by Py-GC/MS. The results showed that the content of sugars and high-quality bio-oil (C6, C7, C8 and C9) were 60.74% and 80.99%, respectively, by hydrothermal pretreatment. These results show that the removal of AAEMs through hydrothermal pretreatment not only improves the yield of bio-oil, but also improves the quality of bio-oil and promotes an upgrade in the quality of bio-oil.Keywords:eucalyptus;demineralization;hydrothermal pretreatment;thermostability;pyrolysis products
研究领域:
能源植物学
·
生物质能工程
✓ 已验证
DOI
PubMed
高影响因子
Materials Today Sustainability
·
2021
·
IF 4.524
Q. Zhang,H. Yan,Z. Zhang,J. Luo,N. Yin,Z. Tan,Q. Shi
Fatty alcohols (FAs) have been widely studied as typical phase-change materials for their high latent heat, low undercooling, non-toxicity, and low cost in thermal energy storage applications. The thermal properties, especially the heat capacity, play a vital role in designing-related energy storage techniques. However, there are few studies on the thermal properties of FAs systematically investigated in a wide temperature region, which greatly limit their application in thermal energy storage field. In this study, the thermal properties of even-numbered FAs (C 12 H 25 OH-C 18 H 37 OH), such as thermal stability, thermal conductivity , phase transition temperature, and enthalpy have been systematically investigated using a combination of various thermal analysis and calorimetry methods. The corresponding thermodynamic functions such as the standard molar heat capacity , entropy, and enthalpy at 273.15 K and 0.1 MPa have been calculated based on the heat capacity curve fitting. Most importantly, the heat capacities of 1-tetradecanol and 1-hexadecanol are reported for the first time in the wide temperature range of 1.9–370 K. Furthermore, by fitting the heat capacities of FAs, a function of molar heat capacities ( C p ) related to the number of carbon atoms ( n ) and temperature ( T ) has been established, which can express the heat capacity of FAs between C 12 H 25 OH and C 22 H 45 OH reasonably in the temperature region of 50–240 K. This work provides accurate and systematic thermodynamic data of FA samples for the future study on their thermodynamic property and related processing design of thermal energy storage application.
研究领域:
材料科学
·
热力学
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Ke Xiang,Hui-Hui Ping,Zhen-Liang Xu,Liwei Zhuang,Yong-Jian Tang
Heat curing is an essential step for industrial-scale fabrication of polyamide nanofiltration membranes, which can improve the membrane stability and promote the membrane element encapsulation feasibility, but thermal stresses cannot be avoided during this process. In this study, oven and microwave were used to cure nanofiltration membranes, and the results showed that compared with oven heat curing, the flux dispersion of nanofiltration membranes cured using microwave heat curing was reduced from 0.318 to 0.093, and its Na2SO4 rejection dispersion was reduced from 0.063 to 0.005, providing a tremendous improvement in the uniformity of nanofiltration membranes. The effect of the thermal stress distribution on the uniformity of nanofiltration membranes during heat curing was elucidated by numerical simulations. The fast microwave heating speed and uniform temperature distribution reduced the defects of the PA layer due to uneven thermal stress distribution. In conclusion, this study demonstrated the effect of thermal stress on membrane uniformity in different thermal curing modes, which provides good prospects for the application of microwaves in the field of nanofiltration membranes.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2024
·
IF 2.2
Zhuoxue Xie,Huimin Yan,Henan Dai,Yan Kou,Xuemei Yan,Ying Tian,Quan Shi
Fatty acids are commonly used as phase change materials (PCMs) for thermal energy storage due to their high latent heat, non-toxicity, and biocompatibility. However, the thermodynamic properties of fatty acids have not been systematically studied, especially for their heat capacity data over a wide temperature range. This limitation greatly restricts their practical applications in designing and constructing fatty acids based PCMs and corresponding thermal management techniques. Herein, the heat capacities of a series of fatty acids (octanoic acid, decanoic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, and octadecanoic acid) have been measured using a combined relaxation, adiabatic, and differential scanning calorimetry techniques over a temperature range from 1.9 K to 380 K. The corresponding thermodynamic functions and phase transition thermodynamic parameters have been calculated based on heat capacity data fitting. Additionally, the thermal stability and thermal conductivity of these fatty acids have also been determined using a thermogravimetric analysis instrument and a thermal constant analyzer, respectively. These obtained thermodynamic properties can provide crucial fundamental information for the study and application of fatty acid PCMs and related thermal energy storage techniques.
研究领域:
材料科学
·
热力学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Zhen Wan,Cheng Li,Ronghui Liu,Wei Zhou,Wenjing Fan,Chuanxue Huang,Yang Liu
Two-dimensional (2D) Ti3C2Tx MXene materials show great potential in electrochemical and flexible sensors due to their high electrical conductivity, good chemical stability, and special delaminated structure. However, their thermal properties were rarely studied, which remarkably affect the stability and safety of various devices. Here, we fabricated a suspended MXene drum resonator photothermally driven by a sinusoidally modulated laser, measured the thermal time constant by demodulating the thermomechanical motion, and then calculated the thermal conductivity and thermal diffusivity of the MXene film. Experiments show the thermal conductivity of the film increases from 3.10 to 3.58 W/m·K while the thermal diffusivity from 1.06 × 10–6 to 1.22 × 10–6 m2/s when temperature increases from 300 to 360 K. We also confirm the film thermal conductivity is mainly contributed by phonon transport rather than electron transport. Furthermore, the relationship between the mechanical and thermal properties of the MXene films was disclosed. The thermal conductivity decreases when film strain increases, caused by enhanced phonon scattering and softening of high-frequency phonons. The measurements provide a noninvasive method to analyze the thermal characteristics of suspended MXene films, which can be further extended to the thermal properties of other 2D materials.
研究领域:
材料科学
·
热物理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Microsystems & Nanoengineering
·
2024
·Vol. 10
·期 1
·1-9
·
IF 7.3
Li Fuwang,Wei Jian,Qin Xiaomei,Chen Xue,Chen Dawei,Zhang Wentao,Han Jiaguang,Yuan Libo,Deng Hongchang
Field-controlled micromanipulation represents a pivotal technique for handling microparticles, yet conventional methods often risk physical damage to targets. Here, we discovered a completely new mechanism for true noncontact manipulation through photothermal effects, called thermal-optical tweezers. We employ a laser self-assembly photothermal waveguide (PTW) for dynamic microparticle manipulation. This waveguide demonstrates superior photothermal conversion and precision control, generating a nonisothermal temperature field. The interaction of thermal convection and thermophoresis within this field creates a microfluidic potential well, enabling noncontact and nondestructive particle manipulation. By varying the path of PTWs in lithography and manipulating laser loading modes, diverse manipulation strategies, such as Z-shaped migration, periodic oscillation, and directional transport, are achievable. Our innovative noninvasive micromanipulation technology minimizes not only physical damage to target objects but also enables precise and diverse manipulation of micro entities, opening up new avenues for the photothermal control of cells and biomolecules.
研究领域:
生物物理学
·
光学工程
·
细胞生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2024
·
IF 7.1
Qian Yan,Renjie Ding,Pengyang Li,Haowen Zheng,Zhong Chen,Jinhua Xiong,Zonglin Liu,Xu Zhao,Fuhua Xue,Liangliang Xu,Huanxin Lian,Shanyi Du,Zhigong Tang,Qingyu Peng,Xiaodong He
Solar-energy thermal management, characterized by its environmental friendliness, cost-effectiveness, and efficiency, holds a promising future, which has brought about widespread interest in the evolution of solar-to-thermal materials with the desired properties. Nevertheless, in both hot and cold environments, challenges in developing functionally integrated hydrogels for sustainable thermal regulation still remain. In this study, a rationally, simply, and effectively designed structured Janus membrane, consisting of a Ti3C2Tx MXene/GO/alginate fibers nonwoven (GMF) layer and a P (NIPAM co-DMAA) (PAD) hydrogel layer. The GMF with excellent hydrophilicity forms an interpenetrating structure with the PAD hydrogel through strong hydrogen bonds and can be easily adapted to multishape and multifield applications. By adjusting the content of thermochromic PAD hydrogel monomers, an improvement in the critical transition temperature (37.7 °C) and a reduction in volume shrinkage has been achieved, and the full-spectrum intrinsic transmittance is 67.59%, which is of excellent practicability and cyclic stability. Under constant sunlight, the hydrogel’s phase transition decelerates the temperature increment in the photothermal layer, thereby establishing a stable equilibrium temperature in the environment. The equilibrium temperature of the photothermal layer can be adjusted between 32 and 36 °C to match a variety of climates by regulating the relative content of the Ti3C2Tx MXene and GO in the photothermal layer. Additionally, the existence of the thermochromic hydrogel in the Janus membrane prevents the indoor temperature from overheating. Furthermore, the membrane’s asymmetric structure enhances its ability to reduce heat dissipation, crucial for high-performance thermal management. Moreover, this novel structure can be used as a self-supporting agricultural film to maintain a stable temperature in the environment for efficient plant growth, demonstrating significant potential in new modern agriculture.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
THERMOCHIMICA ACTA
·
2020
·
IF 2.762
Yuxin Zheng,Chen Zhang,Haihua Liu
A new flow calorimeter is developed to analyze the isobaric heat capacity of liquid. The characteristics of calorimeter have been studied at temperatures from 293 K to 353 K and pressures from 0.1 MPa to 15 MPa. The design of the calorimeter includes the innermost part of the calorimeter with two thick-walls, aluminum shields and microheater. The function of thick-walls with aluminum shields is to replace the conventional constant temperature bath for minimizing heat loss and precisely controlling the temperature of calorimeter. In order to verify the feasibility and reliability of the apparatus, the heat loss is checked by pure water under given pressure and various temperatures. The heat capacity of toluene, heptane and cyclohexane are measured at various temperatures and pressures. The experimentally measured data as a whole is in good agreement with the literature values available. Compared with the literature data, the experimental results by using the new calorimeter show that the deviations are less than 2%.
研究领域:
物理化学
·
热力学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Zhi-Guo Wang,Jia-Cheng Lv,Zi-Li Zheng,Ji-Guang Du,Kun Dai,Jun Lei,Ling Xu,Jia-Zhuang Xu,Zhong-Ming Li
Innovations of transistors toward miniaturization and integration aggravate heat accumulation of central processing units (CPUs). Thermal interface materials (TIMs) are critical to remove the generated heat and to guarantee the device reliability. Herein, maltose-assisted mechanochemical exfoliation was proposed to prepare maltose-g-graphene as a structural motif of TIMs. Then, maltose-g-graphene/gelatin composite films with a bilayer structure were prepared by two-step vacuum filtration to construct effective thermally conductive pathways consisting of the directionally arranged and tightly packed maltose-g-graphene. The bilayer composite film exhibited a remarkable in-plane thermal conductivity (30.8 W m–1 K–1) and strong anisotropic ratio (∼8325%) at 40 wt % maltose-g-graphene addition. More intriguingly, the cooling effect on CPUs was significantly better for the bilayer composite films than commercial thermal pads as TIMs. The outstanding thermally conductive stability in resistance to instantaneous and prolonged thermal shocks as well as fatigue stability was gathered. Our work offers a valuable reference to design and fabricate high-performance TIMs for CPU cooling to surmount harsh application scenarios.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED THERMAL ENGINEERING
·
2022
·
IF 6.465
Yu Zhao,Zhengguo Zhang,Ziye Ling,Xuenong Gao,Xiaoming Fang
Thermal interface materials that possess high thermal conductivity and can reach low thermal impedance during service, are highly desirable for chip heat dissipation systems, especially when cooling high-power chips. Herein, a novel thermal pad was developed by combining low melting point alloy having metal-level thermal conductivity and liquid-like rheological property with expanded graphite possessing large pore volume and high thermal conductivity. Specifically, the alloy 62.5Ga21.5In16Sn was modified by the trace-oxidation method to obtain oxidized alloy, followed by adsorbing into expanded graphite and then molding and pressing to fabricate the thermal pad. It is found that the oxidation treatment resulted in the generation of refractory metal oxides Ga 2 O 3 and SnO 2 within the alloy, thereby preventing the leakage of the alloy from the composite thermal pad. Impressively, the optimal low melting point alloy/expanded graphite composite thermal pad, prepared at the oxidation duration of 24 min, expanded graphite mass fraction of 4 % and compact density of 3.125 g/cm 3 , reached a thermal conductivity of as high as 26.94 W/m·K and a thermal impedance of as low as 0.42 K·cm 2 /W, along with exhibiting a good shape-stability. More significantly, when employed into a simulative desktop CPU cooling system, this thermal pad exhibited 36.78 % higher cooling efficiency under the forced air convection, extended ten times in the time for the chip to reach the upper limit temperature (100 ℃) under the natural air cooling, and benefited to the chip to fight with the pulse-type instantaneous thermal shock, as compared to the commercial thermal pad. These excellent characteristics and good heat dissipation performance make the low melting point alloy/expanded graphite composite thermal pad show great potential for use in chip thermal management systems.
研究领域:
材料科学
·
热管理技术
✓ 已验证
产品关联
DOI
高影响因子
Energy Technology
·
2020
·Vol. 8
·期 12
·2000550
·
IF 3.404
Jun Li,Longjian Li,Huichang Wang,Xiaoyun Zhu,Ying Chen,Lisi Jia
Herein, a water-limited sol–gel method is applied to fabricate microencapsulated phase change materials (MEPCMs) which have a sodium nitrate (NaNO 3 ) core and a titanium dioxide (TiO 2 ) shell. The MEPCM has a high melting temperature of 306.5 °C and a solidification temperature of 296.7 °C, which shows a potential usage as a high-temperature compatible thermal storage medium for industrial waste heat recovery and concentrated solar power (CSP). The MEPCM is demonstrated to be thermally stable for 200 thermal cycles with a high latent heat of 135.3 J g −1 . The high-temperature latent functional thermal fluid (HT-LFTF) is prepared by dispersing the NaNO 3 @TiO 2 MEPCMs into thermal oil. The test results show that MEPCMs provide an 18.4% effective thermal conductivity enhancement and 131.7% effective specific heat enhancement compared with base thermal oil. The rheological test indicates that the MEPCMs added in the thermal oil enhance the viscosity of the suspension and it increases with the MEPCM concentration. This work provides a new type of thermal oil–based functional thermal fluid containing high-temperature MEPCM and paves the way for the application of LFTF in high-temperature heat storage and transfer.
研究领域:
材料科学
·
热能工程
·
可再生能源
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）