KOREAN JOURNAL OF CHEMICAL ENGINEERING
·
2025
·
IF 3.2
Liu Yang,Liang Kaili,Zhang Keqin,Du Bowen,Hu Lishuang,Yuan Zhilei,Zhang Jianren,Lu Yuewen,Yu Qi,Lv Zhixing
The output energy properties of the AP/Ti, Cl-20/Ti, HMX/Ti, and DAP-4/Ti mixtures were compared using an oxygen bomb calorimeter. The thermal decomposition processes of the above four kinds of mixed energetic materials were studied with a differential scanning calorimeter (DSC), and the apparent activation energies of the mixed materials were calculated using the Kissinger equation. The combustion flames of the four energetic materials were captured through high-speed photography, and the combustion properties of the mixed energetic materials with titanium powders were analyzed. The results indicate that the combustion heat value of DAP-4/Ti mixed energetic materials is up to 10,133 J·g −1 , significantly higher than the 8613 J·g −1 of the Cl-20/Ti mixture and the 9720 J·g −1 of the HMX/Ti mixture. The combustion process of the DAP-4/Ti mixture only takes 145 ms. The heat release, burning rate, and flame strength of the DAP-4/Ti mixture are better than those of other mixed energetic materials. The calculated apparent activation energy of DAP-4/Ti mixture is 150.4 kJ·mol −1 , which is 55 kJ·mol −1 lower than that of DAP-4. The apparent activation energies of Cl-20/Ti and HMX/Ti are 173.6 kJ·mol −1 and 317.2 kJ·mol −1 , respectively. These findings demonstrate that DAP-4/Ti mixed energetic materials exhibit good energy characteristics and combustion performance.
研究领域:
材料科学
·
化学工程
·
燃烧学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2021
·
IF 3.196
Simin Liu,Defei Yin,Wei Li,Dongzhi Liu,Xueqin Zhou
In this paper, three new compounds were synthesized by introduction of benzyloxy group to phenylethyl phenylacetate ( PPA ) and shorting the flexible ester linker. NMR spectra and mass spectra are achieved to confirm the structure of the compounds. The solid-liquid and liquid-solid phase change behaviors of PPA and these three compounds were explored by direct observation and differential scanning calorimetry (DSC) measurements. It was found that all four compounds would form supercooled liquids during a heating-cooling cycle. The supercooling degree is as large as 44 °C or above. The effects of benzyloxy group and the flexible linker on the phase transition processes as well as the supercooling degrees were discussed in detail with the computational optimized geometry of isolated molecules. It was revealed that the dihedral angles between adjacent phenyl rings play a significant role in tuning their phase transition temperatures. This work also discovers the high enthalpies of PPA derivatives and analogues in both solid-liquid and liquid-solid phase transition processes, making them great potentials for the thermal energy control of appropriate working temperature regions.
研究领域:
材料科学
·
物理化学
✓ 已验证
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2024
·
IF 7.4
Yingjie Hou,Feng Ma,Zhen Fu,Jiasheng Dai,Yujie Tang,An Qiang,Xinye Jiang,Zheng Wang
Cost and thermal stability are critical for the application of low-temperature phase change materials (PCMs) in asphalt pavements. Aliphatic eutectic phase change materials (AEPCMs) are expected to be potential candidates for new low-temperature PCMs. The objective of this study was to develop a set of low-temperature AEPCMs with a phase transition temperature of − 3.58 to 16.21 °C and a latent heat of 144.01 to 195.96 J/g in an attempt to replace tetradecane (TD). To fully evaluate the properties of low-temperature AEPCMs and TD, and the impacts of their direct incorporation into asphalt, the chemical structures , enthalpies, mass retention, economic costs, and changes in the physical and rheological properties of the modified asphalt were investigated. The results showed that AEPCMs with a phase transition temperature similar to that of TD could be obtained by eutectic crystallization and retained the chemical properties of their components. However, the latent heat decreased progressively with the increase in the number of components. The AEPCMs exhibited higher thermal stability than TD, with a maximal increase in mass retention from 37.24% to 86.66% at 180 °C. In addition, AEPCMs exhibited significant cost advantages. The most inexpensive AEPCMs synthesized in the laboratory is only 112.01 ¥/kg and an enthalpy cost of 0.57 ¥/kJ, accounting for 30.1% and 35.8% of TD cost, respectively. Incorporation of AEPCMs and TD increased the lightweight component of asphalt binders and caused damage to the conventional physical and rheological properties of asphalt binders, but polar AEPCMs had fewer deleterious effects on asphalt compared to nonpolar TD.
研究领域:
材料科学
·
土木工程
✓ 已验证
产品关联
DOI
高影响因子
Nano-Micro Letters
·
2023
·Vol. 15
·期 1
·1-12
·
IF 26.6
Liu Hanqing,Zhou Feng,Shi Xiaoyu,Sun Keyan,Kou Yan,Das Pratteek,Li Yangeng,Zhang Xinyu,Mateti Srikanth,Chen Ying,Wu Zhong-Shuai,Shi Quan
Phase change materials have a key role for wearable thermal management, but suffer from poor water vapor permeability, low enthalpy value and weak shape stability caused by liquid phase leakage and intrinsic rigidity of solid–liquid phase change materials. Herein, we report for the first time a versatile strategy for designed assembly of high-enthalpy flexible phase change nonwovens (GB-PCN) by wet-spinning hybrid graphene-boron nitride (GB) fiber and subsequent impregnating paraffins (e.g., eicosane, octadecane). As a result, our GB-PCN exhibited an unprecedented enthalpy value of 206.0 J g −1 , excellent thermal reliability and anti-leakage capacity, superb thermal cycling ability of 97.6% after 1000 cycles, and ultrahigh water vapor permeability (close to the cotton), outperforming the reported PCM films and fibers to date. Notably, the wearable thermal management systems based on GB-PCN for both clothing and face mask were demonstrated, which can maintain the human body at a comfortable temperature range for a significantly long time. Therefore, our results demonstrate huge potential of GB-PCN for human-wearable passive thermal management in real scenarios.
研究领域:
材料科学
·
纺织工程
·
热能工程
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Yu Fan,Xiaomu Wang,Junying Zhang,Jue Cheng,Qingsong Lian
High encapsulation rate resulting from the good compatibility between cross-linking network and encapsulated solid–liquid phase change materials (SLPCMs) cannot necessarily result in high enthalpy value for the polymeric PCMs. However, the inner mechanism considering the above fact is not clear due to the lack of suitable model compound systems. In this work, a type of epoxy resin with crystalline alkyl side chains (named D18) and four types of amine curing agents (with similar structure but different polarity and molecular size) were primarily used as the model compound to achieve the encapsulation of beeswax (Bw, a kind of bio-based wax), and then the influence of the cross-linking network structure (using different curing agents) on the phase change performances of the D18/Bw polymeric form-stable PCMs (FSPCMs) was systematically studied. The results suggest that polarity effect and steric hindrance effect are the two factors that affect the phase change performances of the polymeric FSPCMs. Though the encapsulation rate of Bw is the highest (near 70 wt%) in the EP H-Y systems (using 1,3-Cyclohexanebismethylamine as the curing agent), it is the EP M-60 sample (using M−Xylylenediamine as the curing agent and containing 60 wt% Bw) that exhibited the highest enthalpy value of 146.2 J/g. Subsequently, different amount of multi-walled carbon nanotubes (CNT) was introduced to improve the thermal conductivity (TC) and achieve multifunctionalization of the EP M-60 sample. The TC, electromagnetic interference (EMI) shielding performance, and contact angle of the 30 wt% CNT modified EP M-60 sample can reach 1.37 W/mK, 37.4 dB, and 137°, while the enthalpy value can remain 101.1 J/g. This work is very helpful in clarifying the relationship between cross-linking network structure and phase change performances of polymeric FSPCMs, so as to providing theoretical guidance for the cross-linking network structure optimization in preparing other reliable polymeric FSPCMs with high enthalpy value, high reliability, and multifunctionalization.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energy Storage
·
2023
·
IF 9.4
Xiaoyin Cao,Lijuan Yang,Jia Zhang,Zhaoqi Zhu,Jiyan Li,Hanxue Sun,Weidong Liang,An Li
The fabrication of composite phase change materials (CPCMs) is significant for harvesting and converting solar energy. Hence, we first report novel CPCMs based on inorganic multi-shelled hollow spheres (MHS) via a facile hydrothermal method and calcination treatment. 1-Hexadecylamine (HDA) and Octadecylamine (ODA) were incorporated into MHS by a simple impregnation treatment to prepare CPCMs. Owing to its multi-shelled structure, the CPCMs have an outstanding ability of leakage resistance . In addition, the CPCMs themselves exhibit excellent solar absorption of up to 80 % without further surface modification. The thermal conductivity of the CPCMs containing HDA and ODA was increased by 1.03 times and 1.67 times by comparison with that of pure PCMs. The enthalpy of the as-resulted CPCMs is 207.6 J/g and 151.5 J/g, which is higher than most existing CPCMs, and the enthalpy of the CPCMs containing HDA and ODA after 100 times cycles can still attain 110.9 J/g and 104.7 J/g. Under 1sun irradiation, the light-to-thermal conversion efficiency of the CPCMs containing HDA and ODA was measured to be 90.0 % and 92.1 %, respectively. Taking advantage of its inherently physicochemical stability, superior light absorption and thermal conductivity and leakage resistance , scalable and cost-efficient fabrication process, such MHS-based CPCMs may have great potential for a wide variety of applications such as photothermal conversion, solar energy harvesting and storage, and so on.
研究领域:
材料科学
·
能源材料
·
太阳能转换
·
热管理
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2021
·
IF 6.953
Huishan Shen,Yu Guo,Jiangyan Zhao,Jian Zhao,Xiangzhen Ge,Qian Zhang,Wenjie Yan
Plasma is a simple, effective and promising food processing technology with great potential for starch modification. Mung bean starch was subjected to ultrasound (300 W, 10, 30 and 50 min), plasma (40 V, 1, 3 and 9 min) and the synergistic treatment, as well as investigating its effects on the morphology, chain length distribution, molecular weight, crystalline structure and physicochemical properties of starch. Ultrasound and plasma treatment did not change the granule shape, but caused some corrosions on the surface, and dual treatment increased the damage degree of starch granules surface. All treatments decreased the molecular weight (Mw), amylopectin long chains and crystallinity but increased the gelatinization temperatures and enthalpy. Different from ultrasound irradiation, single plasma treatment significantly reduced the swelling power and pasting viscosities. Furthermore, dual treatment increased the thermal stability of starch paste, owing to the reinforcement effect between ultrasound and plasma. Thus, dual modification displayed an excellent ability to modify starch with specific characteristics and expand the potential application of mung bean starch in the food industry.
研究领域:
食品科学
·
淀粉改性
·
物理化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2022
·Vol. 32
·期 26
·2200570
·
IF 19.924
Shang Gong,Xinxin Sheng,Xiaolong Li,Mengjie Sheng,Hao Wu,Xiang Lu,Jinping Qu
The rapid development of portable flexible electronic devices means a multifunctional composite film with excellent thermal management capability, high electromagnetic interference (EMI) shielding, and a strong fire safety performance is urgently required. In this paper, inspired by a “brick–mortar” sandwich structure, phase change capsules (PCCs) and MXene nanosheets are prepared. Subsequently, a one-step vacuum-assisted filtration method is used to fabricate a multifunctional flexible PCC/MXene/polyvinyl alcohol (PMP) phase change composite film with high light-to-thermal conversion efficiency, Joule heating generation, fire safety, and EMI shielding effects. The superior preparation technology endows the film with multi-source driven thermal management capabilities and excellent EMI shielding effectiveness values (43.13 dB). In addition, the PMP film exhibits good flexibility and high enthalpy (136.8 J g −1 ). Surprisingly, the PMP film's excellent fire safety properties improve its reliability and safety. In summary, the simple preparation technique and outstanding overall performance of the PMP films provide broad application prospects in advanced thermal management and EMI shielding in wearable products.
研究领域:
材料科学
·
纳米技术
·
电子学
·
热工程
·
防火工程
·
复合材料
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energy Storage
·
2024
·
IF 8.9
Xuefeng Li,Chunhua Ge,Keke Chen,Hongyu Guan,Xiangdong Zhang
Phase change materials (PCMs) are widely used in a range of energy storage applications due to high latent heat absorption and release capacities during phase change processes. There is still a lot to be done to resolve the inherent leakage, stiffness problems, and poor solar-thermal and electrical-thermal conversion capacities of PCMs to functionalize them. Here, a novel solid-solid phase change material (IGPCM) is created using block copolymerization. The IGPCM has a tunable enthalpy (from 58.16 to 99.60 J g −1 ) by adjusting the molecular weight of the PEG. The obtained IGPCM10K has high toughness (479.1 MJ/m 3 ), excellent bending and malleability. Since IGPCM10K suffers from poor thermal conductivity, photo responsiveness, and electro-thermal conversion, carbon nanotubes (CNT) can be added to our IGPCM10K in a simple way to improve these issues. The thermal conductivity of IGPCM10K-CNT-3 is improved by 55.6 % compared to IGPCM10K. The photothermal conversion efficiency is 84.9 % at 300 mW/cm 2 . The electrothermal conversion efficiency is 82.3 % at 12 A. The prepared flexible PCM composites have super toughness, high enthalpy, excellent thermal conductivity, and photo-thermal and electro-thermal conversion capabilities, which will show great potential in future applications.
研究领域:
材料科学
·
能量存储
·
纳米技术
·
复合材料
✓ 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）