THERMOCHIMICA ACTA
·
2014
·
IF 2.105
Yanhong Ma,Shiding Sun,Jianguo Li,Guoyi Tang
Using suspension-like polymerization method, a series of microencapsulated phase change materials (micro-PCMs) with acrylate-based polymer shells and binary core materials were prepared. The phase change properties of the binary mixtures composed of paraffin and butyl stearate were investigated. SEM photographs showed that these micro-PCMs have relatively spherical profiles and compact surfaces with diameter ranging from 10 to 80 μm. DSC results indicated that the microencapsulation ratio of these micro-PCMs ranging from 46 wt% to 68 wt%. Moreover, after being subjected to thermal-cycling test for 500 times, these micro-PCMs kept good thermal reliabilities that the microencapsulation ratio decreased by less than 4 wt%. TGA analysis demonstrated that these micro-PCMs can ensure their thermal stability below 210 °C.
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
POLYMER
·
2018
·
IF 3.483
Hui Gao,Jinrong Li,Fang Xie,Yanju Liu,Jinsong Leng
Recently, shape memory polymers (SMPs) with high optical transmittance have been paid great attentions to endow the flexible optoelectronics with shape memory functions. Herein, a low colored and transparent shape memory copolyimide (SMcoPI) is obtained by suppressing the charge transfer complex interactions. The optical transmittance of the synthesized SMcoPI film could reach at ∼86% at the wavelength of 450 nm, far higher than the nearly zero optical transmittance of yellow and brown Kapton H. The better optical transparency could be attributed to the loose molecular chain arrangements induced by the meta -substituted groups and flexible ether linkages. The glass transition temperature ( T g ) range of the synthesized SMcoPI films is from 179 °C to 220 °C, which is higher than that of reported optically transparent SMPs. The effective decomposition temperature at the weight loss of 5 wt% is 517 °C, showing excellent thermal stability. The SMcoPI also demonstrated good shape memory behaviors with high shape recovery ratio ( R r , >96%) and shape fixity ratio ( R f , >97%). In addition, the SMcoPI could maintain high optical transmittance, good thermostability and excellent shape memory behaviors after the ground-stimulated space thermal cycling test for 250 h. The synthesized SMcoPI has application potentials in high temperature areas or optoelectronic devices.
研究领域:
材料科学
·
航天工程
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2020
·
IF 3.421
Xinchen Zhou,Xuelai Zhang,Qinyue Zheng
This study aims to develop aluminum ammonium sulfate dodecahydrate (NH4Al(SO4)2·12H2O, AASD)-based novel composite phase change materials (CPCMs) for thermal energy storage. Forty types of AASD-based CPCMs were developed by mixing AASD with 1 wt % CF (calcium fluoride) (or 2 wt % CF), 2 wt % xanthan gum (XG), and nanoparticles (α-ION, γ-ION, TDN, CN, or MWCNTs-OH; the mass ratios of the nanoparticles to XG were 1:8, 2:8, 3:8, or 4:8). The effect of multiple additives on the heat storage/release performance of AASD was observed and analyzed by the melting and solidification experiment (MSE). CPCMs with good heat storage/release performance were achieved, which were further characterized by the thermal cycling test. It was shown that the optimal formulation of the CPCM with good thermal reliability was AASD/2 wt % XG/2 wt % CF/4:8 TDN:XG. The structure of AASD was not destroyed by the addition of the above additives. During the process of 30 thermal cycles, the melting temperature, crystallization temperature, and latent heat were 89.4–91.5 °C, 56.6–69.2 °C, and 180.9–220.9 J/g, respectively. The thermogravimetric (TG) test demonstrated that the novel CPCM possessed excellent thermal stability during the operating temperature. The novel CPCM obtained with this simple preparation method and with excellent thermal performance can be used in applications such as solar thermal storage and waste heat recovery.
研究领域:
材料科学
·
能源工程
✓ 已验证
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2022
·
IF 6.364
Liang Cai,Guangfan Tan,Xin Hu,Zhen Shen,Li Wan,Yingchun Zhang
Li 2 TiO 3 is regarded as a vital tritium breeder candidate due to its favorable properties in Helium-Cooled Pebble Bed. However, the point contact stress breakage for traditional pebble structure can cause the blocking of tritium recovery system, and seriously reduce the safety and tritium self-sufficiency ability of fusion reactor. For addressing above problems, in this paper, complex-shaped Li 2 TiO 3 cubic units were manufactured firstly via lithography-based 3D printing . According to the principle of tritium transport, the cubic unit structures with ordered channels were built and evaluated by finite element analysis . The photocuring parameters were optimized to improve printing accuracy by establishing an overgrowth model. After optimizing the sintering schedule, the Li 2 TiO 3 cubic units with excellent relative density (92.3%TD) and packing factor (80.99%) were yielded, and it also had an outstanding compressive strength (84.4 MPa). The results of thermal cycling test shown that the Li 2 TiO 3 cubic units possessed a prominent thermal cyclic durability.
研究领域:
核工程
·
材料科学
·
增材制造
✓ 已验证
DOI
高影响因子
APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
·
2014
·Vol. 172
·期 6
·3128-3140
·
IF 1.687
Zhang Wei-Wei,Wang Na,Zhang Ling,Wu Wan-Xia,Hu Cheng-Li,Yu Xiao-Qi
An inexpensive, facile, and environmentally benign method was developed to improve the activity and stability of Candida rugosa lipase (triacylglycerol acylhydrolase) immobilized on microemulsion-based organogels (CRL MBGs) via the addition of additives during immobilization. The additives used were polyethylene glycol (PEG) or polysaccharides. This study is the first report on the effect of additives in CRL MBGs. Among the tested additives, PEG produced the most improvement in the immobilized CRL, enhancing its stability in organic solvents (specifically polar solvents). The results of circular dichroism and fluorescence spectra experiments indicated that exposure of the acidic CRL to electronegative additives in the buffer, such as polyethylenimine and the electropositive surfactant cetyltrimethylammonium bromide, may change the lipase secondary structure, ultimately causing enzyme inactivation. However, sodium bis(2-ethylhexyl)sulfosuccinate and PEG 2000 had minimal effects on the secondary structure of CRL. The CRL MBGs containing PEG 2000 demonstrated remarkable retention of their catalytic activity during the recycling test. No significant changes in enzymatic activity were observed, even after nine runs, and 90 % of the original yield was maintained after 15 cycles.
研究领域:
生物技术
·
酶学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Frontiers of Chemical Science and Engineering
·
2022
·Vol. 16
·期 11
·1606-1615
·
IF 4.803
Liu Zihan,Luo Yang,Ning Lianchao,Liu Yong,Zhang Ming
The increasing applications of seawater desalination technology have led to the wide usage of polyamide reverse osmosis membranes, resulting in a large number of wasted reverse osmosis membranes. In this work, the base nonwoven layer of the wasted reverse osmosis membrane was successfully modified into the hydrophobic membrane via surface deposition strategy including TiO 2 and 1H,1H,2H,2H-perfluorooctyltrichlorosilane (PFOTS), respectively. Various techniques were applied to characterize the obtained membranes, which were then used to separate the oil—water system. The optimally modified membrane displayed good hydrophobicity with a contact angle of 135.2° ± 0.3°, and its oil—water separation performance was as high as 97.8%. After 20 recycle tests, the oil—water separation performance remained more than 96%, which was attributed to the film adhesion of the anchored TiO 2 and PFOTS layer on the surface. This work might provide a new avenue for recycling the wasted reverse osmosis membrane used in oily wastewater purification.
研究领域:
环境工程
·
材料科学
·
水处理
✓ 已验证
DOI
高影响因子
ChemPlusChem
·
2024
·
IF 3
Zhijun Zhu,Zhihong Yu,Guihuan Chen,Boyan Li,Aiju Li
Graphical The shuttle effect in lithium-sulfur batteries has been a thorny issue, for which researchers have conducted a lot of studies. Of the various directions attempted, separator modification is more convenient and easy to operate. In this paper, CeVO 4 /KB material is proposed to improve the separator and suppress the shuttle effect through its catalysis and adsorption. Catalytic adsorption of the rare earth metal Ce and transition metal V, efficient binding of oxides to polysulfides, and physical adsorption of porous KB prevent the transport of polysulfides to the anode and facilitate the reaction kinetics. Of course, the CeVO 4 /KB/PP batteries show brilliant performances. The CeVO 4 /KB/PP cell achieves 1059.9 mAh g −1 and 92.3 % capacity recovery rate when 3 C is reverted to 0.2 C, demonstrating the outstanding reversibility provided by the CeVO 4 /KB/PP separator. In the long cycle test, the initial specific capacity reaches 1200.9 mAh g −1 with a capacity retention rate of 86.5 % after 100 cycles at 0.2 C. Even at 3 C, CeVO 4 /KB/PP batteries reach 882.7 mAh g −1 in the first cycle with a capacity decay rate of 0.063 % per cycle on 1000 stable cycles. This work provides guidance on the selection of future separator modification materials and expects other work to be a breakthrough. Lithium-sulfur (Li−S) batteries display promise as redox-based batteries, where separators are an essential part of preventing short-circuiting of the positive and negative electrodes, while the shuttle effect is a critical issue of separators. Currently, commercial PP separators are weak in inhibiting the polysulfides shuttling, so modified separators are needed to inhibit it to improve the battery performance. This paper reports that CeVO 4 /KB composites act as separator materials. CeVO 4 /KB modified PP separators enhanced the adsorption of LiPSs, accelerated the rate of Li + migration, and catalyzed the conversion of LiPSs. These bring about the effect that CeVO 4 /KB/PP batteries reach 1200.9 mAh g −1 in the first cycle with a capacity retention rate of 86.5 % after 100 cycles at 0.2 C and reach 882.7 mAh g −1 of the initial cycle with a capacity decay rate of 0.063 % after 1000 cycles at 3 C. This work introduces rare earth metal vanadates to modify the separator, adding new ideas for designing separators for good-performance batteries.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
·
2018
·Vol. 32
·期 4
·e4285
·
IF 3.581
Zhiquan Yang,Jie Ding,Jinna Feng,Chong He,Ying Li,Xiaowen Tong,Xiaojun Niu,Hongguo Zhang
Because of their desired features, including very specific surface areas and designable framework architecture together with their possibility to be functionalized, Metal Framework (MOF) is a promising platform for supporting varied materials in respect of catalytic applications in water treatment. In this work, a novel visible-light-responsive photocatalyst that comprised BiVO 4 together with MIL-125(Ti), was synthesized by a two-step hydrothermal approach. The characterization of as-obtained samples as performed by X-ray diffraction, scanning electron microscopy, high resolution transmission electron microscopy, Fourier transform infrared spectroscope, X-ray photoelectron spectroscopy and ultraviolet-visible diffuse reflection spectra. Rhodamine B was selected being a target for the evaluation of the photocatalytic function of as-developed photocatalyst. The photocatalytic reaction parameters, for example, the content of BiVO 4 as well as initial concentration of Rhodamine B was researched. The composite photocatalyst possessing Bi:Ti molar ratio of 3:2 brought to light the fact that the greatest photocatalytic activity had the ability to degrade 92% of Rhodamine B in 180 min. In addition to that, the BiVO 4 /MIL-125(Ti) composite could keep its photocatalytic activity during the recycling test. The phenomenon of disintegration of the photo-generated charges in the BiVO 4 /MIL-125(Ti) composite was brought to discussion as well.
研究领域:
材料科学
·
环境科学
·
催化
·
水处理
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS LETTERS
·
2020
·
IF 3.204
Bichuan Chi,Yan Yao,Suping Cui,Xiaodong Jin
In this work, the form-stable phase change material (PCM) was prepared by absorbing tetradecanol (TD) into expanded graphite (EG). Then, the obtained TD/EG was coated with graphene oxide (GO) through electrostatic self-assembly to prepare a novel composite PCM (TD/EG-GO). The morphology, phase change and thermal properties of TD/EG-GO were fully discussed. The DSC analysis shows that the TD/EG-GO composite melts at 35.2 °C with latent heat value of 189.5 J/g and freezes at 34.9 °C with latent heat value of 187.9 J/g. The thermal cycling test results reveal that the latent heat of TD/EG-GO composite decrease by less than 1% after 500 thermal cycles, indicating that the structure of GO-coated EG efficiently prevents the leakage of TD. The thermal stability and thermal conductivity of TD/EG-GO composite are also improved compared with that of uncoated TD/EG, demonstrating the multiple benefits of surface coating of GO.
研究领域:
材料科学
·
热能工程
·
能量存储
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2022
·
IF 9.965
Huan Wang,Guo Du,Shaohua Chen,Zhipeng Su,Pingchuan Sun,Tiehong Chen
As an important heterogeneous catalyst , Titanium Silicalite-1 (TS-1) zeolite has been widely applied in various catalytic processes. Here, hierarchical TS-1 single-crystals were successfully synthesized by a steam-assisted crystallization strategy using hierarchically porous titanium-containing silica (Ti-NKM-5) as a precursor. Due to the presence of large mesopores (10–40 nm)， the microporous structure-directing agents penetrated the interstitial structure of silica particles, inducing the dissolution and crystallization process . During crystallization, the generated nanocrystals grew together to form a hierarchical structure. Titanium was fully incorporated into the zeolite framework, and no extra-framework anatase was formed. Compared with the traditional microporous TS-1 zeolite, the synthesized hierarchical TS-1 single-crystal exhibited superior catalytic performance in oxidative desulfurization (ODS) of dibenzothiophene (DBT) and 4, 6-dimethyl dibenzothiophene (4, 6-DMDBT) owing to the hierarchically porous and anatase-free structure. The recycling test revealed the durability of the obtained hierarchical TS-1 catalyst under moderate reaction conditions.
研究领域:
化学
·
材料科学
·
催化
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nano Research
·
2023
·Vol. 16
·期 8
·11018-11029
·
IF 9.9
Chen Dingyang,Wu Wanning,Zhao Xinyue,Feng Danyang,Zhao Rui,Zhu Guangshan
Co 3 O 4 particles are promising heterogeneous catalysts for peroxymonosulfate (PMS) activation; whereas they still surfer from the extensive agglomeration, serious Co leaching, poor electronic conductivity, and difficult recovery. Herein, a novel hybrid nanoarchitectonic constructed by encapsulating Co 3 O 4 nanoparticles into continuous polypyrrole (PPy) nanotubes (Co 3 O 4 @PPy hybrids) was developed using electrospun fibers as the templates, which boosted the catalytic degradation toward tetracycline (TC). The continuous polypyrrole nanotubes could provide the confined spaces, offer effective electron transfer pathway, suppress cobalt ion loss, facilitate the oxygen vacancy (O vac ) formation, and accelerate the Co 2+ /Co 3+ cycles. Co 3 O 4 @PPy hybrids thereby exhibited a remarkably enhanced catalytic activity with the TC degradation efficiency of 97.2% ( k obs = 0.244 min −1 ) within 20 min and total organic carbon (TOC) removal rate of 66.8%. Furthermore, the recycle test, real natural water treatment, and fluidized-column catalytic experiments indicated the potential of Co 3 O 4 @PPy hybrids in the practical large-scale applications.
研究领域:
环境科学
·
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
·
2020
·
IF 3.762
Jingchen Xing,Yucheng Zhou,Keyan Yang,Jianmin Chang,Yuxiang Yu,Liping Cai,Sheldon Q Shi,Zhenhua Huang
MEPCMs have drawn tremendous attention in TES fields. In this study, eutectic of CA and PA was encapsulated by PVC, and the novel MEPCM for TES applications was developed. Microcapsules were prepared by solvent evaporation method and examined using DSC, SEM, LPSA, FTIR, thermal cycling test and TGA. DSC results demonstrated that the phase change temperature of CA-PA eutectic decreased after microencapsulation. The most satisfied sample was the MEPCM with a shell-core ratio of 1:2, which melted at 17.1 °C with the latent heat of 92.1 J/g, the encapsulation ratio was 57.7%. SEM images and LPSA results showed that the prepared MEPCMs were consisted with micro-sized spheres. FTIR results confirmed that the PCM core was successfully encapsulated by the PVC shell, and no chemical reaction was found among the components. The prepared MEPCM showed an excellent thermal reliability after 500 times of thermal cycling. Microencapsulation enhanced the starting temperature of CA-PA eutectic thermal decomposition, and the novel MEPCM exhibited an excellent thermal stability at working temperature from TGA results. Consequently, MEPCM (1:2) was the optimal composition and had great potential for TES applications.
研究领域:
材料科学
·
热能存储
·
相变材料
✓ 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）