JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
·
2013
·Vol. 13
·期 10
·6953-6960
·
IF 1.149
Shi Haowei,Huang Yan,Cheng Chao,Ji Guoyuan,Yang Yuxiang,Yuan Hongming
The size- and shape-controlled Fe3O4@SiO2 nanocomposites were successfully synthesized via the sol–gel method. The results showed that the size, shape, and property of the products were directly influenced by the amount of TEOS, and the concentration
of water-based magnetic fluid in the coating process. The morphology and properties of the products were characterized by TEM, SEM, X-ray powder diffraction, IR and EDS. The Fe3O4@SiO2 composites with easily-controlled size arranged from 58 to 835 nm could
be synthesized by adjusting the experimental parameters. When TEOS amount is 1 mL and the concentration of magnetic fluid were 30.0 and 10.0 mg/mL respectively, chain-like and peanuts-like well-dispersed Fe3O4@SiO2 particles with clear core–shell structure
were obtained. These size- and shape-controlled Fe3O4@SiO2 composites may have potential application in the field of targeted drug delivery and MRI contrast agent.
研究领域:
材料科学
·
纳米医学
✓ 已验证
DOI
PubMed
高影响因子
MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2016
·Vol. 217
·期 16
·1851-1859
·
IF 2.495
Rui Qi,Yong Jin,Xinfeng Cheng,Hanping Li,Shuangquan Lai,Xiaopeng Sun
Herein, a novel coil-rod-coil triblock copolymer with the coil blocks composed of poly(ethylene glycol) methyl ether and the rigid midterm block alternatively connected with isophorone diisocyanate and isophorone diamine is developed. The triblock copolymer can self-assemble into ellipsoidal micelles in 1-methyl-2-pyrrolidinone. After the addition of a second coil-selective solvent (water) to the micellar solutions, these ellipsoidal micelles can further transform into chain-like nanostructures. The self-assembly behavior is highly influenced by the additional order of the solvents, which is considerably due to the impacts of the hydrogen-bonding urea groups and rigid motifs. The transition of the ellipsoidal micelles to chain-like nanostructures is governed by the water molar fractions. The sizes of the chain-like nanostructures increase first and then decrease with the growth of the water molar fractions in the mixed solutions.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
ChemSusChem
·
2024
·
IF 7.5
Bin Zhu,Qiuge Wang,Jinggang Wang,Xiao Yu,Jian Zhang,Chunlin Chen
Graphical The nitrogen-doped-carbon encapsulated cobalt (Co@NC) chainmail nanowires were synthetized for the electrocatalytic production of 2,5-furandicarboxylic acid (FDCA) from 2,5-bis(hydroxymethyl)furan (BHMF). The Co@NC on Ni foam achieved 97.9 % conversion of BHMF, yielding 93.3 % FDCA at 1.475 V vs. RHE. The superior electrochemical performance of Co@NC/NF can be attributed to its large electrochemically active surface area and excellent kinetic parameters. 2,5-Furandicarboxylic acid (FDCA) has emerged as an important bio-based furanic compound, which has broad application prospects in renewable energy and materials, especially in the preparation of polyethylene 2,5-furandicarboxylate (PEF). While the conventional synthesis of FDCA involves oxidation of 5-hydroxymethylfurfural (HMF) as a substitute, the thermal and chemical instability of HMF due to its aldehyde group poses challenges. A more favorable alternative is the utilization of 2,5-bis(hydroxymethyl)furan (BHMF), a non-aldehyde and more stable precursor. This study pioneeringly reports nitrogen-doped-carbon encapsulated cobalt (Co@NC) chainmail nanowires for the thermal and electrocatalytic oxidation of BHMF to FDCA. The Co@NC/NF achieved a 97.9 % conversion of BHMF with a 93.3 % yield of FDCA at 1.475 V vs. RHE, whereas thermal catalysis only obtained 14.9 % FDCA yield after 10 hours. Kinetic studies indicated that the large electrochemically active surface area and excellent kinetic parameters contribute its superior electrochemical performance. Mechanistic analysis revealed that the migration of inner electrons to the exterior modified the electronic properties of the carbon layer, thereby facilitating the oxidation of BHMF. Furthermore, the in-situ generation of high-valent cobalt species markedly accelerated the BHMF oxidation. This research underscores the potential of carbon-encapsulated metal chainmail catalysts in thermal and electrochemical biomass conversion.
研究领域:
化学
·
材料科学
·
可再生资源与环境
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Gels
·
2021
·Vol. 7
·期 4
·210
·
IF 4.702
Shixian Xiong,Yangbiao Hu,Sizhao Zhang,Yunyun Xiao,Zhengquan Li
Cellulose and its derivative aerogels have attracted much attention due to their renewable and biodegradable properties. However, the significant shrinkage in the supercritical drying process causes the relatively high thermal conductivity and low mechanical property of cellulose and its derivatives aerogels. Considering the pearl-necklace-like skeleton network of silica aerogels, which can improve thermal insulation property and mechanical property. Herein, we propose a new strategy for fabricating cellulose diacetate aerogels (CDAAs) with pearl-necklace-like skeletons by using tert-butanol (TBA) as exchange solvent after experiencing the freezing-drying course. CDAAs obtained have the low density of 0.09 g cm−3, the nanopore size in the range of 10–40 nm, the low thermal conductivity of 0.024 W m−1K−1at ambient conditions, and the excellent mechanical properties (0.18 MPa at 3% strain, 0.38 MPa at 5% strain). Ultimately, CDAAs with moderate mechanical property paralleled to cellulose-derived aerogels obtained from supercritical drying process are produced, only simultaneously owning the radial shrinkage of 6.2%. The facile method for fabricating CDAAs could provide a new reference for constructing cellulose/cellulose-derived aerogels and other biomass aerogels.Keywords:cellulose diacetate;aerogels;freezing drying;pearl-necklace-like skeletons
研究领域:
材料科学
·
生物质材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2022
·Vol. 12
·期 49
·31959-31965
·
IF 4.036
Chunde Li,Hua Wei,Xueyan Hu,Zhaoxian Chen,Xin Xie,Guo Chen,Anping Liu,Yingzhou Huang,Weijia Wen
Electrorheological (ER) fluid, containing polarized particles within an insulating liquid, represents a smart material, the mechanical properties of which can be altered mainly by an electric field. In this work, ER fluids based on cauliflower iron(II) oxalate doped titanium particles show excellent rheological and wetting properties by the sample co-precipitation method. The morphology of the particles is observed by SEM and the molecular structure within the particles is obtained via XRD and FTIR. The distribution of elements within the particles is obtained by EDS. Owing to a lower current density than pure iron(II) oxalate, the SEM and optical images show an obvious chain-like structure within the ER fluids with 2 wt% and 5 wt%, respectively, under 2 kV mm−1. Then, the rheological properties of these ER fluids are tested up to 3 kV mm−1 and the results show a gratifying property of resisting shear with different shear rates (0.1–100 s−1), which is attributed to the appearance of a stable chain-like structure. At the same time, the ER efficiency and the switching performance are obtained and the static yield stress fits the relevant electric field strength well. Ultimately, an excellent sedimentation ratio is obtained from 0 h to 600 h.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Shi Liu,Hua Wei,Menghan Xia,Bo Guo,Ziren Wang,Yingzhou Huang,Hua Yu,Xiao-Feng Qian,Weijia Wen
By incorporating polar fibers into the design of electrorheological (ER) fluids, a 130% performance improvement can be achieved with the addition of only 0.8 vol% of polar long fibers. We quantitatively analyzed the impact of relatively long fibers on improving ER performance by measuring the yield stress, shear stress, and current density after adding fibers. Both optical microscopy and transmission electron microscopy were used to observe and analyze the interaction between ER particles and polar fibers. The results indicate that, under the influence of an electric field, the fibers transform the one-dimensional chain-like structure into a two-dimensional mesh structure, greatly improving the ER performance. The transformation of structure induced by the polar fibers in the ER fluids amplifies the ER effect. However, the inclusion of non-polar fibers does not contribute to this enhancement, as a point of comparison. Moreover, to ensure the universality of this method, we used two different types of ER fluids in experiments. The utilization of this method offers a straightforward, environmentally friendly, and highly effective approach. Furthermore, this study provides a novel technical solution aimed at enhancing the performance of ER fluids.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 101
·99072-99080
·
IF 3.289
Xiaosong Guo,Xiaoguang Yu,Yulu Chen,Zijia Feng,Qinglin Li,Zhenheng Sun,Guicun Li,Chuncheng Hao,Qingquan Lei
Hollow TiO2 nanospheres were fabricated and adopted as dispersing materials in ER fluids with different viscosities in order to investigate variation of polarized particles before and after the formation of chainlike structure in electrorheological (ER) fluids. Results showed that the ER fluid with low viscosity had better ER efficiency than that with high viscosity, which was ascribed to the better ability of low viscosity ER fluid in maintaining chainlike structures. From an analysis of dielectric properties, it was found that increase of permittivity of ER fluids at low frequency should result from the distribution change of polarized particles in ER fluids. Distribution variation of polarized particles would induce the increase of electric field strength in the region of chainlike structure, which was called “secondary polarization”. This secondary polarization led to an increase of the number of charges on the surface of polarized particles, causing further enhancement of electrostatic interactions between polarized particles. Moreover, the magnitude of polarized charge caused by secondary polarization was much larger than that caused by interface polarization, which suggested that the secondary polarization played an important role in the ER phenomenon. A novel model with detailed explanation about the ER effect is proposed. Furthermore, relationships among the polarizability of dispersed particles, characteristic of dielectric spectrum at low frequency, and ER properties are discussed in detail.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2020
·
IF 4.65
Daile Zhang,Jianghua Zhang,Mingdi Pan,Yun Wang,Ting Sun
Electrochemical deposition is a facile technique to fabricate metal organic frameworks (MOFs) based materials in a short reaction time under mild conditions. In this work, novel necklace-like zeolitic imidazole framework@multiwalled carbon nanotubes (ZIF-8@MWCNTs) composite was synthesized by electrochemical method for the first time and then used as precursor for subsequent carbonization and acid treatment. The resultant porous carbon material (C-ZIF-8@MWCNTs) maintained the necklace-like structure with a high surface area of 1063.2 m 2 g −1 . When used as electrode material for supercapacitor , the C-ZIF-8@MWCNTs demonstrated a high specific capacitance of 259.2 F g −1 at the current density of 0.5 A g −1 . Further, the capacitance retention could reach 92% after 5000 cycles under the current density of 15 A g −1 . Due to the large specific surface area of the porous carbon derived from ZIF-8 and the intrinsic high conductivity, the C-ZIF-8@MWCNTs displayed good rate ability and cycle performance. The current work can expand the method to synthesize functional MOFs-based materials for advanced applications.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES COMMUNICATIONS
·
2025
·
IF 7.7
Xiaofeng Shi,Lei Wang,Lin Chen,Qiaoling Xu,Zhengting Du,Deqing Shi,Zhenfa Zi,Renchao Che
Chain-like magnetic-dielectric composites have become an ideal choice for electromagnetic (EM) wave absorption materials due to their excellent component adjustment and structural optimization. Here, the chain-like CoNi@C heterojunction was obtained via multi-step reaction combining the solvothermal reaction, polymerization reaction, and annealing treatment. Magnetic chain-like CoNi alloy was firstly synthesized under application magnetic field, where offered the polymerization surfaces for the dopamine monomer. Then, as-prepared CoNi@PDA composites were undergoing the annealing treatment at N 2 atmosphere to obtain the chain-like CoNi@C heterojunction. The EM parameters and impedance match properties of the CoNi@C composites can be efficiently regulated via tunning the carbon shell. Combining with the magnetic-dielectric balance and synergy loss absorption, chain-like CoNi@C heterojunction exhibited outstanding EM wave performance. Optimized CoNi@C-7 heterojunction exhibited the minimum reflection loss (RL min ) value can reach to −50.3 dB at 11.92 GHz when the thickness is 1.95 mm and the effective absorption bandwidth (EAB) can up to 4.16 GHz from 13.84 GHz to 18 GHz at only 1.5 mm thickness. Therefore, the chain-like magnetic-dielectric CoNi@C composites provided a new design ideal to fabricate the EM wave absorption materials.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2022
·Vol. 15
·期 4
·1412
·
IF 3.748
Jingyuan Bai,Xuejiao Wang,Meilin Zhang,Jin Zhang,Xiaolin Chen,Yanan An,Renguo Guan
Novel porous magnetic soft materials (pMSMs) based on a poly (vinyl alcohol) (PVA) porous matrix filled with CuNi nanoparticles (NPs) of around 70 nm were synthesized. Initially, magnetic CuNi NPs were fabricated by the reduction of Ni and Cu ions with hydrazine hydrate in ethylene glycol medium in the absence of other capping agents. The pMSMs are subsequently fabricated by mixing CuNi NPs and PVA through freezing-drying process. The as-obtained pMSMs can respond to a magnetic field, i.e., the compressive modulus increase under a magnetic field of 0.23 T. The experimental results indicate that CuNi NPs can easily move to form chain-like structures under the application of a magnetic field. A combination of direct observation and finite element modeling has shown that under the influence of a magnetic field, chain-like aggregates of CuNi NPs lead to self-reinforcement of the pMSMs and, thus, to the increased compressive modulus. From a technological point of view, these materials with good magnetic responsiveness and moderate mechanical strength have potential applications in artificial muscle, soft actuators and drug release, to name a few.
研究领域:
材料科学
·
力学
·
纳米技术
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2020
·
IF 4.939
Qiao Wu,Tianle Li,Wenju Wang,Yupeng Xiao
Oxygen evolution reaction (OER) is a key part of water electrolysis for hydrogen production . Non-noble-metal catalysts with high activity, stability, but low cost are prerequisites for practical application. In this work, sucrose char was synthesized and then chainmail catalysts were produced by in situ growth method, defined as M@C (M = Fe, Co and FeCo). FeCo@C showed great OER performance in both catalytic activity and durability tests. The overpotentials were 302 mV (at the current density of 10 mA cm −2 ) and 423 mV (at 50 mA cm −2 ), with a lowest Tafel slope of 75 mV dec −1 . The electrochemical surface area of catalysts were also analyzed by calculating the capacitance of the double layer to further investigate the catalytic activity. Furthermore, FeCo@C showed superior stability after 30 h test or 10,000 cycles of cyclic voltammetry . Theoretical calculation based on density functional theory (DFT) demonstrated that the overpotential of OER was determined by the Gibbs free energies of reaction intermediates HO∗, O∗ and HOO∗. The adsorption of HO∗ radicals onto the FeCo@C was weaker than Fe@C, which was favorable for reducing the overpotential, as the rate-determining step of the OER process over these catalysts was that HO∗ dehydrogenated to form O∗.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2018
·
IF 2.011
Teng-Fei Zheng,Xue-Mei Tian,Shu-Li Yao,Chen Cao,Jin-Bao Cai,Sui-Jun Liu
Two Ln III complexes derived from one aromatic monocarboxylate ligand, namely [Tb 2 (mnba) 6 (H 2 O) 4 ] n ( 1 ) and [Dy 2 (mnba) 4 ( μ 3 -OH) 2 (H 2 O)] n ( 2 ) (Hmnba = m -nitrobenzoic acid), have been prepared by similar synthetic procedures and structurally characterized. Complex 1 contains two identical one-dimensional (1D) chains with the syn,syn -carboxylate as linkers, while complex 2 takes the 1D chain structure with μ 3 - - OH and carboxylate as bridge. Magnetic studies indicate that ferromagnetic interactions between intra-chain metal centers exist in 1 and 2 and only complex 2 exhibits field-induced slow magnetic relaxation behavior.
研究领域:
化学
·
材料科学
✓ 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）