AICHE JOURNAL
·
2022
·Vol. 68
·期 10
·e17786
·
IF 4.167
Xin Huang,Xiaoming Luo,Yunrui Han,Weidong Li,Yuekun Lai,Lin Teng
The deformation and breakup behaviors of droplets containing polymer are investigated by high-speed photography to reveal the mechanism of electric field collapse when treating the emulsion containing polymer. The results show the electric field collapse process caused by droplet breakup consists of three steps. First, the droplet containing polymer ejects liquid filament under strong electric field. Second, the liquid filament is continuously stretched until it touches positive and negative electrodes. Finally, the severe Joule heating effect appears because the strong electric current flows through the liquid filament. The release of a large amount of heat causes the formation, expansion, and collapse of bubble, resulting in the fracture of liquid filament and the collapse of electric field. The increase of polymer concentration strengthens the Joule heating effect and enlarges the influence scope of bubble expansion and collapse. These findings provide significant guidance for the stable operation of electric dehydrator.
研究领域:
化学工程
·
物理学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Baosong Li,Weiwei Zhang,Dandan Li
Ni–Co and Ni–Co/ZrO 2 composite coatings have been synthesized via a single-step direct current (DC) electrodeposition route as a protective coating. The influences of electrodeposition current density, time and ZrO 2 concentration on structural, composition and properties of Ni–Co coating were investigated. All coatings present compact, crack-free and nodular-like morphology in a nanocrystalline structure. Some aggregations still exist in the coating. The preferred orientation of these coatings changed from (200) to (111) texture with a fcc structure . The amount of Co in Ni–Co matrix slightly decreases as current density and time increases. The Co and ZrO 2 content in Ni–Co/ZrO 2 matrix increase with the increasing of ZrO 2 concentration in bath. Less than 60 min is beneficial for low roughness of Ni–Co/ZrO 2 coating. Current density, deposition time and ZrO 2 embedded in metallic matrix affect the hardness of Ni–Co alloy. Ni–Co/ZrO 2 coating has enhanced hardness compared to Ni–Co ones. Although they might not exhibit the best corrosion resistance in the initial immersing stage, Ni–Co/ZrO 2 composite coating obtained at 2 – 4 A dm −2 with 5–10 g L -1 ZrO 2 presents the better corrosion resistance and desirable performance stability during the long-term immersion process in aggressive media. The Ni–Co/ZrO 2 coating exhibits promising advantages as a protective coating.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
CORROSION SCIENCE
·
2020
·
IF 6.479
Ning Peng,Libo Liang,Yuqing Wen
This study investigated the adsorption of hydrogen bubbles and tunnel formation on aluminium foil during direct current (DC) electrochemical etching in an electrolyte with and without silicone oil additive. The results indicated that the etched tunnels obtained in the electrolyte containing silicone oil were more uniformly distributed with a more consistent size and length. This was attributed to the additive ability to facilitate the desorption of large bubbles on the aluminium surface, resulting in uniform corroded regions. Moreover, the generated narrow tunnels can accelerate the hydrogen evolution inside the tunnels, resulting in increasing the length of the etched tunnels.
研究领域:
材料科学
·
电化学
·
金属腐蚀与防护
·
表面工程
✓ 已验证
DOI
高影响因子
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2021
·Vol. 128
·期 1
·1-14
·
IF 2.584
Zhang Dandan,He Yipeng,Wang Rumin,Taub Alan I.
Carbon nanotubes (CNTs) orient in a polymer matrix under electric field due to their highly anisotropic electric polarizability. Under direct current (DC) electric field, CNT also migrates toward electrodes resulting in a non-uniform CNT concentration which can affect the properties gained from CNT alignment. In this study, DC electric field was applied across a CNT/epoxy mixture and the kinetics of CNT migration were studied in real time as a function of electric field strength, CNT concentration and length distribution. The rate constant k of CNT migration was found to be linearly proportional to the electric field strength, while varying the CNT concentration and length distribution exhibited a minimal effect on the migration velocity. Combined with our previous study of the temperature dependence of CNT migration, the relationship between the rate constant k of CNT migration and electric field strength, CNT concentration and length distribution was established. The resulting relationship can be used to manipulate the spatial distribution of CNT to selectively enhance the mechanical, thermal and electrical properties of CNT/polymer composites.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
NANOTECHNOLOGY
·
2020
·Vol. 31
·期 32
·325302
·
IF 3.551
Fangcheng Wan,Haohan He,Shi Zeng,Jianghui Du,Zhao Wang,Haoshuang Gu,Juan Xiong
Flexible transparent electrodes have been fabricated successfully by using a metal nanowire network. Despite its higher conductivity and transparency, raw silver nanowire (AgNW) film suffers from the random arrangement and high surface roughness originating from the overlaps of a few tens of nanometer-thick AgNWs. In this work, a facile and environmentally friendly method is developed to form AgNW flexible transparent electrodes by spray coating at a low DC electric field (less than 6.0 V) and subsequent plasma treatment. The DC voltage, plasma power, and plasma treatment time of the AgNW network are optimized. The obtained electrodes fabricated by this technique exhibited excellent flexible, transparent, and flat junctions of AgNWs with a sheet resistance of 4.64 Ω · sq−1 and a specular transmittance of 87.3% at a wavelength of 550 nm. Furthermore, the AgNW electrodes are very flexible, highly durable, and moiré-free. The resistance remains almost unchanged over 500 cycles of mechanical deformation with a bending distance of 14 mm when its size is 20 × 20 mm. The as-prepared AgNW electrodes exhibited a root mean square roughness below 13.07 nm at a scan size of 5 × 5 μm. We propose that the improved properties can be attributed to the well-arranged AgNW network acheived by applying a DC electric field and a flat connection between the AgNW junctions induced by plasma treatment.
研究领域:
材料科学
·
纳米技术
✓ 已验证
DOI
高影响因子
SOFT MATERIALS
·
2017
·
IF 1.101
Ling-xiang Gao,Wen-qing Dai,Jian-li Chen,Zun-yuan Xie,Xuan-feng Yue
The agar/xanthan gum compound hydrogels were synthesized with/without a direct current (DC) electric field, and their behaviors and structure were investigated by dynamic mechanical analyzer (DMA), scanning electron microscope (SEM), infrared spectroscopy (IR), and thermo gravimetry and differential scanning calorimetry (TG-DSC). The results demonstrate that GA (the storage modulus of the agar/xanthan gum compound hydrogel gelled with an electric field) is greater than GB (that gelled without an electric field). The maximum of modulus increment (ΔG = GA-GB) and modulus increment sensitivity (ΔG/GB) appear when the xanthan gum weight fraction is at 0.8 wt%, which is the best electro-response of the compound hydrogels. The agar/xanthan gum compound hydrogel also exhibits a positive electro-response effect by increasing with the increasing field strength. All the response behaviors point to the conclusion that the DC electric field induces a more ordered and denser network structure of agar/xanthan gum compound hydrogel.
研究领域:
材料科学
·
生物工程
✓ 已验证
DOI
高影响因子
Soft Matter
·
2016
·Vol. 13
·期 1
·119-124
·
IF 3.798
Zhou Liu,Xiangyu Fu,Bernard P. Binks,Ho Cheung Shum
In this work, we investigated the coalescence of liquid water marbles driven by a DC electric field. We have found that two contacting liquid marbles can be forced to coalesce when they are charged by a sufficiently high voltage. The threshold voltage leading to the electro-coalescence sensitively depends on the stabilizing particles as well as the surface tension of the aqueous phase. By evaluating the electric stress and surface tension effect, we attribute such coalescence to the formation of a connecting bridge driven by the electric stress. This liquid bridge subsequently grows and leads to the merging of the marbles. Our interpretation is confirmed by the scaling relation between the electric stress and the restoring capillary pressure. In addition, multiple marbles in a chain can be driven to coalesce by a sufficiently high threshold voltage that increases linearly with the number of the marbles. We have further proposed a simple model to predict the relationship between the threshold voltage and the number of liquid marbles, which agrees well with the experimental results. The concept of electro-coalescence of liquid marbles can be potentially useful in their use as containers for chemical and biomedical reactions involving multiple reagents.
研究领域:
胶体与界面化学
·
微流控技术
·
生物医学工程
·
药物递送
·
反应容器
✓ 已验证
DOI
高影响因子
RSC Advances
·
2024
·Vol. 14
·期 1
·147-153
·
IF 3.9
Hongzheng Li,Ying Li,Bo Li,Wenlong Huang,Yushi Ding
ReNiO3 (Re = Pr, Sm, Eu) solid electrolytes were prepared by the sol–gel method, which were sintered in a pure oxygen atmosphere of 20 MPa at 1000 °C for 24 hours. The DC resistivities of the three materials in air and in a hydrogen-containing atmosphere were tested respectively. The resistivities in the hydrogen-containing atmosphere were about 102, 104, and 105 times higher than those in air and XPS analysis showed that after 10%H2–Ar treatment, the proportion of Ni2+ of PrNiO3, SmNiO3 and EuNiO3 increased successively. The proton transport number of PrNiO3 was lower than 0.5 at 50–500 °C, and SmNiO3 and EuNiO3 were almost pure proton conductors below 200 °C. The conductivities of SmNiO3 and EuNiO3 were 1.08 × 10−4 S cm−1 and 1.83 × 10−5 S cm−1 at 200 °C in 5%H2–Ar. The hydrogen sensing properties of SmNiO3 and EuNiO3 show that the measurement results of the two materials were accurate in the range of 0.5–10% H2.
研究领域:
材料科学
·
固态离子学
·
能源材料
·
无机化学
·
传感器技术
✓ 已验证
DOI
高影响因子
Materials
·
2022
·Vol. 15
·期 18
·6298
·
IF 3.748
Yiyi Zhang,Keshuo Shi,Chunyan Zang,Wenchang Wei,Chuanhui Xu,Junwei Zha
Owing to its lack of crosslinking, polypropylene (PP) is considered an environmentally friendly alternative to crosslinked polyethylene as high-voltage direct current (HVDC) cable insulation. However, pure PP can accumulate space charges under a HVDC, and thus must be modified for use as an insulating material for HVDC cables. In this study, 4-methylstyrene is grafted onto PP using an aqueous suspension grafting method to improve its properties. The effects of the swelling time, reaction time, and 4-methylphenylene concentration on the reaction were investigated. The optimum process conditions were determined, including an optimum grafting ratio of 0.97%. The volume resistivity, ability to suppress space-charge accumulation, and DC breakdown strength of modified PP were also studied. Modified PP with a grafting ratio of 0.88% showed optimal space-charge suppression and the highest volume resistivity and breakdown strength. The work will facilitate the design and development of more efficient insulation materials for HVDC cables.Keywords:aqueous suspension grafting;polypropylene;HVDC cable insulation;DC breakdown strength;space-charge suppression;4-methylphenylene
研究领域:
材料科学
·
电气工程
✓ 已验证
DOI
PubMed
高影响因子
Magnetochemistry
·
2022
·Vol. 8
·期 8
·75
·
IF 3.336
Yujie Yang,Congliang Chen,Dongyang Chen,Yingming Zhang,Yuting Meng,Cong Zhang,Shuangjiu Feng
The solid-state reaction method is used to synthesize W-type Sr hexagonal ferrites Sr0.8Pr0.2(Zn1.0−xCox)2Fe16O27(x = 0.00, 0.15, 0.30, 0.45, 0.60, 0.75). The results of XRD for the W-type hexagonal ferrites, when Co content (x) is 0.00 ≤ x ≤ 0.75, exhibit that they are in the single W-type hexaferrite phase. As shown by morphological analysis, the particles are hexagonal-shaped platelets. The saturation magnetization (Ms) and magneton number (nB) increases with Co content (x) from 0.00 to 0.60.MsandnBbegins to decrease at Co content (x) ≥ 0.60. With increasing Co content (x) from 0.00 to 0.75, the magnetic anisotropy field (Ha), first anisotropy constant (K1), and coercivity (Hc) decrease gradually. The values of DC electrical resistivity for W-type hexagonal ferrites Sr0.8Pr0.2(Zn1.0−xCox)2Fe16O27(0.00 ≤ x ≤ 0.75) are in the range of 20.854 × 107Ω-cm and 22.755 × 107Ω-cm.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
Nanomaterials
·
2021
·Vol. 11
·期 8
·1962
·
IF 5.076
Lingjun Li,Guangli Li,Yuliang Cao,Yvonne Yanwen Duan
High-definition transcranial direct current stimulation (HD-tDCS) is a promising non-invasive neuromodulation technique, which has been widely used in the clinical intervention and treatment of neurological or psychiatric disorders. Sintered Ag/AgCl electrode has become a preferred candidate for HD-tDCS, but its service life is very short, especially for long-term anodal stimulation. To address this issue, a novel highly durable conductive carbon/silver/silver chloride composite (C/Ag/AgCl) electrode was fabricated by a facile cold rolling method. The important parameters were systematically optimized, including the conductive enhancer, the particle size of Ag powder, the C:Ag:PTFE ratio, the saline concentration, and the active substance loading. The CNT/Ag/AgCl-721 electrode demonstrated excellent specific capacity and cycling performance. Both constant current anodal polarization and simulated tDCS measurement demonstrated that the service life of the CNT/Ag/AgCl-721 electrodes was 15-16 times of that of sintered Ag/AgCl electrodes. The much longer service life can be attributed to the formation of the three-dimensional interpenetrating conductive network with CNT doping, which can maintain a good conductivity and cycling performance even if excessive non-conductive AgCl is accumulated on the surface during long-term anodal stimulation. Considering their low cost, long service life, and good skin tolerance, the proposed CNT/Ag/AgCl electrodes have shown promising application prospects in HD-tDCS, especially for daily life scenarios.
研究领域:
神经科学
·
生物医学工程
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2015
·Vol. 133
·期 1
·
IF 1.768
Yao Zhou,Jinliang He,Jun Hu,Bin Dang
Polypropylene (PP)/polyolefin elastomer (POE) blends and MgO/PP/POE nanocomposites were fabricated by melt blending. The morphology, mechanical, and electrical properties of the nanocomposites were investigated. Scanning electron microscopy showed that the surface-modified MgO nanoparticles were well dispersed in the polymer matrix at low loadings of less than 3 phr. X-ray diffraction demonstrated that the crystalline phases of PP in the composites were changed and that the β phase significantly increased. An examination of the electrical properties revealed that the direct-current (dc) electric breakdown strength and space-charge suppression effect were remarkably improved by the introduction of the surface-modified MgO nanoparticles. In addition, obvious enhancements in the tensile modulus and strength were obtained as a result of the synergistic toughening of the POE and MgO nanoparticles. Thus, MgO/PP/POE nanocomposites with enhanced mechanical and electrical properties have great potential to be used as recyclable insulation materials for high-voltage dc cables with large transmission capacities and high operating temperatures. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 132 , 42863.
研究领域:
高分子材料科学
·
电气工程材料
·
纳米复合材料
·
介电物理
·
绝缘材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）