INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2021
·
IF 5.816
Xiaoxiao Chen,Mengyao Liu,Lijuan Zhang,Yunshan Zhou,Enming Ping,Chunyan Ding
ZIF-67@NH 2 –SiO 2 composites were prepared by loading the metal-organic frameworks ZIF-67 on amino modified SiO 2 gel particles (NH 2 –SiO 2 , 80–100 mesh) through layer-by-layer self-assembly method. Systematic investigation on the effects of ZIF-67 loading amounts on NH 2 –SiO 2 packed stainless steel chromatographic column (specification 1.0 m×2.0 mm I.D.), the flow rate of He as carrier gas and the injection amount of mixed gas (H 2 /D 2 ) on the hydrogen isotope H 2 /D 2 separation performance at liquid nitrogen temperature, unraveled the optimal conditions for H 2 /D 2 isotope separation . The results showed that the optimal stationary phase materials under the optimized conditions can effectively separate H 2 and D 2 with separation resolution R = 1.52 and the separation time t = 10.15 min. The superior performance of the ZIF-67 is tentatively thought to be due to kinetic quantum sieving (pore size 3.3 Å) effect and chemical affinity sieving effect of Co ion in ZIF-67.
研究领域:
分析化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES PART B-ENGINEERING
·
2017
·
IF 4.727
Zhengdong Wang,Yonghong Cheng,Mengmeng Yang,Jialiang Huang,Daxian Cao,Siyu Chen,Qian Xie,Wanxi Lou,Hongjing Wu
We report the fabrication of epoxy-based composites using well-designed core/shell Si/SiO 2 (denoted as Si*) and core/shell/shell structured Si/SiO 2 /Polydopamine (denoted as Si*@PDA) particles as fillers, which exhibit improved dielectric properties and thermal conductivity . Using the core-shell Si* and Si*@PDA particles as fillers in the epoxy-based composites, the dielectric loss tangent is remarkably suppressed and the volume resistivity is apparently enhanced, as compared with that using raw Si particles as fillers. Moreover, the Si*@PDA composites have higher dielectric constant and lower loss tangent. For instance, the dielectric constant of Si*@PDA/epoxy composite with 33.8 vol% filler content is up to 19.8 at room temperature at 100 Hz, which is nearly 5.3 times of that of the pure epoxy polymer (3.4), while its loss tangent is only 0.085. Additionally, the core-shell particle-based composites still possess a high thermal conductivity.
研究领域:
材料科学
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电气工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Xiaohui Yuan,Lei Wen,Chao Wang,Yushun Zhao,Yingchun Zhou,Gong Cheng,Chenxi Zhao,Xiaodong He,Chao Sui
Ceramic fiber materials with high mechanical robustness and outstanding thermal stability are highly sought for high-temperature thermal insulation applications. However, the practical use of traditional ceramic fibrous mats has been hindered by their limited tensile strength, resulting in ceramic fibrous mats being easily deformed or broken under actual conditions. In this study, we present the fabrication of biomimetic, cocoon-like Al 2 O 3 -SiO 2 composite fibrous mats incorporating amorphous SiO 2 , γ-Al 2 O 3 , and mullite phases through the centrifugal spinning technique. The maximum tensile strength of these composite mats is determined to be 5.35 MPa, which is superior to most ceramic fiber materials. Additionally, the Al 2 O 3 -SiO 2 composite fibrous mats demonstrate excellent thermal insulation properties, with a thermal conductivity as low as 0.026 W/(m·K) at room temperature and 0.14 W/(m·K) at 1000 °C. These exceptional characteristics position Al 2 O 3 -SiO 2 composite fibrous mats as promising materials for thermal insulation in industrial, aerospace, and other demanding environments.
研究领域:
材料科学
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陶瓷
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热工工程
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机械工程
✓ 已验证
产品关联
DOI
高影响因子
Carbon Energy
·
2024
·
IF 19.5
Xuewen Jiang,Qian Wang,Limeng Song,Hongxia Lu,Hongliang Xu,Gang Shao,Hailong Wang,Rui Zhang,Changan Wang,Bingbing Fan
Material composition and structural design are important factors influencing the electromagnetic wave (EMW) absorption performance of materials. To alleviate the impedance mismatch attributed to the high dielectric constant of Ti 3 C 2 T x MXene, we have successfully synthesized core-shell structured SiO 2 @MXene@MoS 2 nanospheres. This architecture, comprising SiO 2 as the core, MXene as the intermediate layer, and MoS 2 as the outer shell, is achieved through an electrostatic self-assembly method combined with a hydrothermal process. This complex core-shell structure not only provides a variety of loss mechanisms that effectively dissipate electromagnetic energy but also prevents self-aggregation of MXene and MoS 2 nanosheets. Notably, the synergistic combination of SiO 2 and MoS 2 with highly conductive MXene enables the suitable dielectric constant of the composites, ensuring optimal impedance matching. Therefore, the core-shell structured SiO 2 @MXene@MoS 2 nanospheres exhibit excellent EMW absorption performance, featuring a remarkable minimum reflection loss (RL min ) of −52.11 dB (2.4 mm). It is noteworthy that these nanospheres achieve an ultra-wide effective absorption bandwidth (EAB) of 6.72 GHz. This work provides a novel approach for designing and synthesizing high-performance EMW absorbers characterized by “wide bandwidth and strong reflection loss.”
研究领域:
材料科学
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电磁学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
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2015
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IF 3.512
Na Cao,Xin Xie,Yu Zhang,Yanbao Zhao,Liuqin Cao,Lei Sun
Dendritic porous tin oxide/silica (DTS) nanospheres (NSs) were prepared by emulsion-condensation route. DTS NSs have an average diameter of 80 nm and possess accessible center-radial large pore channels, which endow them high surface area, less drug diffusion resistance and more mass transport. SnO 2 quantum dots (QDs) embedded in silica skeleton can be used to track the drug release behavior. DTS NSs were coated by chitosan/polymethacrylic acid and polymer shell would make them achieve great loading capacity and pH-sensitive release for aminomethylbenzoic acid (AMBA).
研究领域:
材料科学
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药学
✓ 已验证
产品关联
DOI
高影响因子
Chemistry-An Asian Journal
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2015
·Vol. 10
·期 3
·759-763
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IF 4.587
Ting Huang,Chao Wang,Xinping Zhang,Chen Wang,Ailing Li,Dong Qiu
Graphical Hybrid hollow sub-microspheres (HHSs) were synthesized by using SiO 2 surfaces. In the presence of SiO 2 particles, the hydrolysis rate of 3-(methacryloyloxy)propyltrimethoxysilane (MPS) accelerated and the condensation rate of the hydrolyzed species decelerated. The preserved hydrolyzed species of MPS emulsified isopentyl acetate to form a steady O/W emulsion. HHSs were obtained by subsequent free radical polymerization and removal of the oil core. A novel method was developed to synthesize organic–inorganic hybrid hollow sub-microspheres (HHSs) through the addition of colloidal SiO 2 . The hydrolysis rate of 3-(methacryloyloxy)propyltrimethoxysilane (MPS) was accelerated by SiO 2 particles; meanwhile, the condensation rate of the hydrolytic species was decelerated. Thus, the hydrolytic monomers and oligomers of MPS were preserved as emulsifiers. These emulsifiers can then emulsify the isopentyl acetate (PEA) to form a steady O/W emulsion. The HHSs were produced by subsequent free radical polymerization and removal of the oil core. The hydrolytic MPS acted as emulsifiers and polymerizable monomers at the emulsification and polymerization stage, respectively. Thus, extra emulsifiers, co-emulsifiers, and organic monomers were omitted, which simplified the synthesis process. The good dispersion of HHSs in water and oil, as well as the EDX results, indicated the organic–inorganic hybrid structure of HHSs.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
DENTAL MATERIALS
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2022
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IF 5.687
Jing Cao,Dan-Lei Yang,Dan Wang,Jie-Xin Wang
Objective The objective of this study is to develop novel CaF 2 /SiO 2 nanoclusters (NCs) fillers, which can endow the dental resin composites (DRCs) with excellent mechanical properties , stable and sustained fluoride ion release, and good antibacterial activity . Methods The CaF 2 /SiO 2 NCs were efficiently fabricated by assembling CaF 2 /SiO 2 nanoparticles (NPs) as building blocks with a spray-drying technology. CaF 2 /SiO 2 NCs with different SiO 2 coating amounts (20 wt%, 50 wt% and 80 wt%) were incorporated into the DRCs at the filler content of 55 wt% for the measurement of mechanical properties including flexural strength , flexural modulus, compressive strength , and hardness. The effect of the filling amount of CaF 2 /50SiO 2 NCs (50 represents 50 wt% SiO 2 coating amount) in the DRCs was investigated, while CaF 2 /50SiO 2 NPs were adopted as comparison group. The fluoride ion release and antibacterial activity of the DRCs with the optimal mechanical performances were evaluated. Furthermore, the statistical analyses were performed for mechanical properties. Results Spherical CaF 2 /50SiO 2 NCs with an average size of 2.4 µm were obtained at the feed rate of 7.4 mL/min and the CaF 2 /50SiO 2 NPs solid content of 2 wt% in the suspension. The optimum comprehensive performances of the DRCs can be achieved by filling 55 wt% CaF 2 /50SiO 2 NCs. Compared with CaF 2 /50SiO 2 NPs, the filling amount of CaF 2 /50SiO 2 NCs was increased by 5 wt% (50–55 wt%), and under the same filling amount of 50 wt%, the flexural strength, flexural modulus, compressive strength, and hardness of the DRCs containing CaF 2 /50SiO 2 NCs were improved by 9.8%, 17.7%, 7.5% and 69.8%, respectively. Furthermore, the DRCs filled with 50 wt% CaF 2 /50SiO 2 NCs exhibited more cumulative F-release by 126% and more stable F-release rate than the counterpart filled with 50 wt% CaF 2 /50SiO 2 NPs after immersed for 1800 h. And 55 wt% CaF 2 /50SiO 2 NCs filled DRCs could inhibit the growth of S. mutans, reaching an antibacterial ratio of 93%. Significance The spray-dried CaF 2 /50SiO 2 NCs are promising fillers for the development of high-performance multifunctional DRCs.
研究领域:
材料科学
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牙科学
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生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF NON-CRYSTALLINE SOLIDS
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2017
·
IF 2.124
Ren Gao,Huanping Wang,Qingong Zhu,Qinghua Yang,Xingguo Sun,Bingpeng Li,Shiqing Xu,Xianghua Zhang
The glasses of 93.9% ( x SiO 2 - y Al 2 O 3 - z MgO)-5% CaO-1% B 2 O 3 -0.1% Fe 2 O 3 were prepared, and the relationship between mechanical properties and structural stability were characterized by means of Raman spectroscopy and optical band gap values. The glass forming region is found to be x = 50–70%, y = 10–25% and z = 15–32%. As x = 65%, y = 10% and z = 25% (SAM-4), the investigated glass possesses the optimum volume density, oxygen packing density, optical band gap, banding strength , compression strength and compression modulus, which are 2.517 g/cm 3 , 77.047 mol/l, 3.56 eV, 77.04 MPa, 202.74 MPa and 106.70 GPa, respectively. Meanwhile, starting from the representative point of SAM-4 to radiate around, the volume density, oxygen density, Raman intensity and mechanical properties of the glasses are all decreasing constantly, and the optical band gap of the glasses is increasing on the contrary. Moreover, the optical band gap value and Raman spectroscopy of SAM-4 all prove that the number of oxygen bonds in the bridge reach the maximum and the highest structural stability is achieved, which further shows that it is an important reason why its mechanical properties is significantly improved.
研究领域:
材料科学
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玻璃科学
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光谱学
✓ 已验证
产品关联
DOI
高影响因子
SURFACE & COATINGS TECHNOLOGY
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2017
·
IF 2.589
Xue-Ling Wei,Na Li,Wen Jun Yi,Li-Jun Li,Zi-Sheng Chao
The super-hydrophobic (SH) porous ceramics material with good stability was successfully prepared via the hydrothermal growth of CeO 2 micro/nano-structure and the subsequent dip-coating of low surface energy substance 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PFDTES) over the surfaces of ZrO 2 -SiO 2 porous ceramics substrate. The surface morphology , chemical composition and wettability of material were investigated by means of SEM, EDS, XRD , FT-IR, and contact angle measurement. It was found that a layer of CeO 2 nano-flowers had been attached over the surfaces of ZrO 2 -SiO 2 porous ceramics substrate, using the optimized concentration of CeNO3 precursor, and after the grafting of PFDTES, the super hydrophobicity of the obtained material was achieved, with the water contact angle being as high as 162° and sliding angle being approximately 0°. Particularly, the super hydrophobicity was found to occur also in the pores of the obtained material. The obtained material was found to possess the significantly large thermal and chemical stabilities.
研究领域:
材料科学
·
表面工程
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2017
·
IF 3.582
Lian-Kui Wu,Jie Xia,Hua-Zhen Cao,Yi-Ping Tang,Guang-Ya Hou,Guo-Qu Zheng
The sluggish kinetics of oxygen evolution reaction (OER) is the most challenging technical problem in water splitting. Here, we reported a new type of cauliflower-like NiCo 2 O 4 (CF-NiCo 2 O 4 ) film which was co-electrodeposited with silica for oxygen evolution reaction. Structure and morphology of the obtained films were characterized using X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscopy and transmission electron microscopy . Electrochemical properties of the CF-NiCo 2 O 4 film were evaluated by quasi-steady state polarization curve , cyclic voltammetry and electrochemical impedance spectroscopy . Results show that the enhanced electrocatalytic activity of the CF-NiCo 2 O 4 film toward OER is a synergistic effect of improved intrinsic catalytic activity and increased surface area.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS COMMUNICATIONS
·
2014
·
IF 3.32
Xuanduong Le,Zhengping Dong,Zhicheng Jin,Qingqing Wang,Jiantai Ma
In this study, a novel Pd(II) complex functionalized core–shell magnetic mesoporous catalyst (Fe 3 O 4 @SiO 2 @mSiO 2 –Pd(II)) was synthesized by a simple cost effective procedure. It was characterized by transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, vibrating sample magnetometer, and nitrogen physical adsorption. The Fe 3 O 4 @SiO 2 @mSiO 2 –Pd(II) catalyst offered high surface area and exhibited excellent activity towards Suzuki–Miyaura cross-coupling reaction of halides with aryl boronic acids in ethanol in air. The Fe 3 O 4 @SiO 2 @mSiO 2 –Pd(II) catalyst was stable, reusable, and conveniently recovered by applying an external magnetic field. Moreover, it provided 91% conversion after the sixth catalytic run. The Fe 3 O 4 @SiO 2 @mSiO 2 –Pd(II) catalyst examined in this study combined both the efficiency of a homogeneous catalyst and the durability of a heterogeneous catalyst. The results revealed that the Fe 3 O 4 @SiO 2 @mSiO 2 –Pd(II) catalyst is promising as a candidate for various Pd-based catalytic applications.
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Wanzheng Ren,Jian Pan,Wenqiang Gai,Xinyu Pan,Haimei Chen,Jiao Li,Lilan Huang
A crucial step in the purification and recycling of industrial waste oil is the separation and removal of trace water from emulsified oil. After optimizing the polymer content, solvent composition, and SiO 2 nanoparticle addition amount of the spinning precursor solution, a Polyvinylidene fluoride- co -trifluoroethylene chloride (PVDF-CTFE)/SiO 2 nanofibrous membrane with micro and nano-rough structure was prepared by electrospinning. Using scanning electron microscopy, a pore size analyzer, a contact angle tester, a single-fiber strength tester, and a gravity separation experiment, the influence of SiO 2 addition on the morphology, pore size distribution , wettability , mechanical, and separation properties of the modified membranes was characterized. The results demonstrated that the water contact angle of the nanofibrous membrane was increased to 151.3° of superhydrophobic when SiO 2 was added at a concentration of 2.5 wt%. The nanofibrous membranes exhibited outstanding separation performance (>99%) for water-in-oil mixtures and emulsions, as well as for various oil-water systems. Moreover, the PVDF-CTFE/SiO 2 nanofibrous membranes exhibited superior multi-cycle performance and consistent chemical resistance. This research yielded a novel material and a straightforward method for fabricating superhydrophobic nanofibrous membranes, which demonstrated greater application potential in oil-water separation.
研究领域:
材料科学
·
环境工程
✓ 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）