Journal of Materials Chemistry A
·
2021
·Vol. 10
·期 2
·593-601
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IF 12.732
Maohua Li,Linhong Li,Yue Qin,Xianzhe Wei,Xiangdong Kong,Zhenbang Zhang,Shaoyang Xiong,Hainam Do,James C. Greer,Zhongbin Pan,Tao Cai,Wen Dai,Cheng-Te Lin,Nan Jiang,Jinhong Yu
Considering the significant threat of heat to electronic equipment and heat dissipation problems existing in powerful systems, thermal management materials are in high demand. In conjunction with the increasing need to dissipate heat and stabilize temperature, high thermal conductivity and phase change latent heat are attracting more attention when designing thermal management materials. This work proposes a strategy to combine a phase change matrix and thermally conductive filler using freeze casting. The highest thermal conductivity reaches 23.1 W m−1 K−1 accompanied by 62 J g−1 phase change latent heat. Meanwhile, replacing ice with an organic phase change material in freeze casting can result in an aligned structure. This discovery will pave a novel way for introducing thermal latent heat without abandoning the aligned structure.
研究领域:
材料科学
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热管理技术
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DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
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2018
·Vol. 135
·期 46
·46824
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IF 1.901
Yuyu Liu,Lingli Deng,Cen Zhang,Kailun Chen,Fengqin Feng,Hui Zhang
In this study, we fabricated ethyl cellulose (EC)–gelatin (G) composite films by solvent casting and electrospinning. The characterization of the cast and electrospun films was performed by scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectrometry, and water contact angle measurements. The results showed that the blending of EC with G improved the spinnability of the composite films with higher thermal stability. Compared with solvent casting, electrospinning induced a helix-to-coil transition of G and provided more hydrogen-forming sites for EC to form a compatible network. Interestingly, the electrospun composite film had a hydrophobic surface with a water contact angle of 113.8°, whereas the cast composite film showed a hydrophilic surface at 67.5°. The confocal laser scanning microscopy observations suggested that after water immersion, the cast composite film collapsed into aggregates, whereas the electrospun composite film maintained the nanofibrous structures well; this indicated an improved water resistance. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135 , 46824.
研究领域:
材料科学
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生物医学工程
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
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2021
·Vol. 56
·期 25
·13989-14000
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IF 4.22
Wang Yang,Liu Qiang,Zhang Biao,Zhang Haoqian,Jin Yicheng,Zhong Zhaoxin,Ye Feng,Wang Wen
Freeze casting technique has become a promising way to assemble various components into multifunctional nacre-like materials. Surprisingly, although many ceramics materials have been processed by this approach, there are few studies reporting the structure–property-processing relationships of freeze-cast porous B 4 C ceramics. Here we generate bimodally lamellar porous B 4 C scaffolds by freeze casting and describe how processing parameters such as solid concentration and freezing front velocity control the architecture. The porosity, pore morphology and lamella thickness of B 4 C scaffolds can be tailored via altering such two parameters, which makes the scaffolds with excellent mechanical properties suitable as a support for the melt infiltration process. The pore morphology, structural characteristics, compressive mechanical response and fracture mechanism of the scaffolds are explored. Additionally, we have utilized a morphology map to identify the different structures such as lamellar and dendritic, which are formed by varying processing parameters. This study offers the freeze-cast scaffolds with custom-designed structure and mechanical properties for developing bioinspired multifunctional materials represented by B 4 C/Al composites.
研究领域:
材料科学
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生物医学工程
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DOI
高影响因子
MATERIALS LETTERS
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2018
·
IF 2.687
Peng Qu,Xiaolin Liu,Sijing Wang,Chen Xiao,Shanshan Liu
Moderate dehydrofluorinated PVDF (MD PVDF) composed of polyene and untreated PVDF was produced by elimination reaction in polyvinyl pyrrolidone (PVP) and KOH aqueous solution. Dielectric films of MD PVDF were fabricated by solution casting method to study the energy density performance of the polymer. The energy density of MD PVDF was enhanced and the maximum energy density was 10.5 J/cm 3 at 450 kV/mm with an efficiency of 46%. The enhanced energy density was attributed to combined effects of high conductivity of polyene and charges blockage of untreated PVDF. This work may provide a new way to enhance the energy density performance of polymer dielectrics by moderate dehydrofluorination.
研究领域:
材料科学
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能源存储
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DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
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2021
·Vol. 138
·期 31
·50750
·
IF 3.125
Feng Lang,Ling Song,Yi Lin,Yilan You,Duxin Li,Qibin Jiang
A poly(phenylsulfone)-urea (PPSUU) macro-activator is synthesized by in situ anionic polymerization of 4,4′-diaminodiphenylsulfone and hexamethylene diisocyanate. The PPSUU segment is embedded into the nylon molecular chain through copolymerization to improve the wear resistance and flame retardancy of monomer cast nylon 6 (MC PA6) materials. The mechanical properties, thermal stability, friction and wear properties and combustion heat release rate of copolymers with different macro-activator contents are tested. Results indicate that a small amount of PPSUU can improve the wear resistance and impact properties of nylon materials. The wear loss of MC nylon is 54.8% less than pure MC nylon from 1.049 × 10 −8 to 0.474 × 10 −8 g/Nm with 6 wt% PPSUU. Moreover, better flame retardancy is verified. The peak of HRR reduced 36.8% from 654 to 413 kw/m 2 with 4 wt% PPSUU, accompanied by advanced ignition time and flame extinction time, thus reducing the risk of fire.
研究领域:
材料科学
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高分子化学
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DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2016
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IF 2.933
Xiaoxia Hu,Lina Yang,Lingyu Li,Dieni Xie,Haiyan Du
Freeze casting was employed to fabricate alumina fiber-based porous ceramics . The binder particles were rejected by ice crystals from the gaps of the network to fibers and bonded them to obtain strong and light network. The effects of fiber character, cooling temperature and slurry viscosity on the structure formation were investigated. The structure and properties of the fibrous porous ceramics were determined by two factors: the fiber network and the dispersion of binders. The cooling temperature and slurry viscosity affected the dispersion of the particles rejected by the solidification front while the fiber length affected the fiber network. The material with optimal properties was obtained with 5 wt% PVA, 5 wt% silica sol and 1 vol% alumina fibers when freezing at −20 °C. The bulk density was 0.199 g/cm 3 and the specific strength was 3.860 N m/kg.
研究领域:
材料科学
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陶瓷工程
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DOI
高影响因子
Polymers
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2020
·Vol. 12
·期 4
·892
·
IF 3.426
Rossella Arrigo,Mattia Bartoli,Giulio Malucelli
Biocomposites based on poly(lactic acid) (PLA) and biochar (BC) particles derived from spent ground coffee were prepared using two different processing routes, namely melt mixing and solvent casting. The formulated biocomposites were characterized through rheological, thermal, and mechanical analyses, aiming at evaluating the effects of the filler content and of the processing method on their final properties. The rheological characterization demonstrated the effectiveness of both exploited strategies in achieving a good level of filler dispersion within the matrix, notwithstanding the occurrence of a remarkable decrease of the PLA molar mass during the processing at high temperature. Nevertheless, significant alterations of the PLA rheological behavior were observed in the composites obtained by melt mixing. Differential scanning calorimetry (DSC) measurements indicated a remarkable influence of the processing method on the thermal behavior of biocomposites. More specifically, melt mixing caused the appearance of two melting peaks, though the structure of the materials remained almost amorphous; conversely, a significant increase of the crystalline phase content was observed for solvent cast biocomposites containing low amounts of filler that acted as nucleating agents. Finally, thermogravimetric analyses suggested a catalytic effect of BC particles on the degradation of PLA; its biocomposites showed decreased thermal stability as compared with the neat PLA matrix.Keywords:poly(lactic acid);biochar;melt mixing;solvent casting;rheological behavior;thermal properties
研究领域:
材料科学
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环境科学
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DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2024
·
IF 5.8
Zhilei Wei,Wenqi Xie,Jiabin Hu,Zhejian Zhang,Biao Zhang,Lei Zhao,Yanjun Li,Bo Wang,Zhongqi Shi
Unidirectional porous (UP) Si 3 N 4 ceramics are promisingly applied in high-temperature filtration devices. However, traditional techniques exhibit the drawbacks of high energy consumption and difficult to control the pore structures. Herein, a novel technique of freeze casting combined with combustion synthesis was proposed to prepare the UP Si 3 N 4 ceramics using Si powder and Si 3 N 4 diluent as raw materials. The effects of Si 3 N 4 diluent content and solid loading on the phase composition, microstructure and permeable/mechanical/filtration properties were investigated systematically. The results showed that the porosity and structure wavelength of UP Si 3 N 4 ceramics with uniform microstructures can be tailored in a wide range of 50.8–86.0 % and 21.7–45.6 μm, respectively. The products exhibited anisotropic compressive strength, good permeable and filtration properties. This novel route with the advantages of energy-saving and high efficiency offers new insights for fabricating UP ceramics.
研究领域:
材料科学
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陶瓷工程
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DOI
高影响因子
FOOD HYDROCOLLOIDS
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2017
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IF 4.747
Lingli Deng,Xuefan Kang,Yuyu Liu,Fengqin Feng,Hui Zhang
In this study, the gelatin, zein , and gelatin/zein films were fabricated by electrospinning and solvent casting, respectively. Scanning electron microscopy , differential scanning calorimetry , Fourier transform infrared spectroscopy and water contact angle measurements were performed to characterize the morphology, molecular interactions, thermal behavior, and surface hydrophilicity of the electrospun and casted films. Results showed that the zein particles prevented the gelatin chains from aggregating intra-molecularly in the casted films due to heterogeneous mixing, while strong hydrogen bonding was formed in the nanofibrous film as a result of homogeneous mixing. Interestingly, the gelatin/zein nanofibrous film had a hydrophobic surface (water contact angle of 118.0°), while the casted gelatin/zein film had a hydrophilic surface (water contact angle of 53.5°). The confocal laser scanning microscopy observations suggested that the zein particles were well dispersed in the gelatin network to maintain the nanofibrous structures after immersion in water or ethanol, leading to the improved solvent resistance.
研究领域:
材料科学
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生物医学工程
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DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2020
·
IF 4.495
Zhilei Wei,Wenqi Xie,Xiaoyu Zhang,Zhejian Zhang,Yanjun Li,Hongyan Xia,Bo Wang,Zhongqi Shi
Highly permeable AlN micro-honeycomb (AlN-H) ceramics with unidirectional macropore channels and porous struts were fabricated via tertiary butyl alcohol (TBA)-based freeze-casting. The effect of the AlN solid loading of the freezing slurries on the microstructure, open porosity, N 2 gas permeability, and compressive strength of the as-prepared AlN-Hs were systematically investigated. The results showed that the honeycomb structure and open porosity of the AlN-Hs can be adjusted by altering solid loading. With the increase in solid loading from 10 vol% to 30 vol%, the approximate pore channel size of the AlN-Hs decreased from 50.1 μm to 15.6 μm, strut thickness increased from 8.2 μm to 16.6 μm approximately, and the corresponding open porosity decreased from 87.6–56.6%. The as-fabricated AlN-H with an open porosity of 64.9% possessed high N 2 gas permeability and essential compressive strength and can be used as a catalyst support or filter in industries.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 137
·期 22
·48753
·
IF 2.188
Ling Song,Haiyang Yang,Duxin Li,Qibin Jiang,Dan Zeng
In order to improve the toughness, wear resistance, and combustion properties of the monomer casting nylon (MC nylon) materials, the polydimethylsiloxane (PDMS) segment is bonded to the nylon molecular chain by copolymerization. PDMS/MC nylon copolymers are prepared via in situ anionic polymerization with macro-activator based on PDMS terminated with hexamethylene diisocyanate. The effects of different macro-activator content on the mechanical properties, water absorption, thermal stability, friction and wear properties, and combustion properties of the copolymers are characterized. The results show that the impact strength of the copolymer improves significantly (optimally increases by 2.6 times) and the water absorption rate decreases with the increase of PDMS content. The introduction of the silicon–oxygen structure reduces the peak heat release rate of copolymer materials (optimally decreases about 28.7%), while it promotes the decomposition of the system, resulting in a slight decrease in the thermal stability of the materials. Adding 5 wt % PDMS can decrease the wear loss of MC nylon from 6.2 mg of pure nylon to 1.6 mg. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 48753.
研究领域:
高分子化学
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材料科学
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产品关联
DOI
高影响因子
JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
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2020
·
IF 1.701
Jie Han,Xueqin An
A novel method was presented to synthesize self-assembly lipid vesicles as carrier of hydrophilic bioactive substances. Based on the interaction of nonpolar groups of surfactants in the transmembrane process, the surface of particles was reassembled in the particles transfer process. In this method, water droplets loaded with hydrophilic bioactive substances in inverted microemulsion were transformed into surfactant solution through an oil/water interface contained with rich surfactants by using centrifugal casting process, and then unilamellar nanoscale lipid vesicles loaded with hydrophilic bioactive substances were formed. The water droplets in the inverted microemulsion were used as soft template to load hydrophilic substances. The dimensions of the lipid vesicles can be controlled by adjusting size of droplets in the microemulsion. Some important parameters for the preparation of lipid vesicles were optimized. The encapsulation efficiency of hydrophilic bioactive substances in the lipid vesicles could be as high as 50%, and it is much higher than that prepared by other method. This method could be used to synthesize size-control lipid vesicles, and the lipid vesicles possess high encapsulation efficiency of bioactive substances and high stability.
研究领域:
药剂学
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生物材料科学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）