POWDER TECHNOLOGY
·
2019
·
IF 3.413
Xuechen Tang,Wanli Kang,Bobo Zhou,Yongbo Gao,Changxiao Cao,Shujun Guo,Muhammad Wassem Iqbal,Hongbin Yang
Polymer/nano-SiO 2 composite microspheres (PNSCMs) were synthesized via inverse suspension polymerization with 3-methacryloxypropyltrimethoxysilane (MPS) modified SiO 2 as the reinforcing filler. The influences of these polymerizable nanoparticles on the swelling behavior, mechanical property, thermal stability, viscoelasticity and dispersion stability were examined in detail. Moreover, the plugging behaviors were investigated by sand pack tests. The results indicate that the introduction of these modified nanoparticles revealed a significant enhancement on the comprehensive properties of PNSCMs. By varying the content of MPS-modified SiO 2 , the environmental sensitivity of the microspheres’ swelling behavior was reduced. Besides, the mechanical property, thermal stability and viscoelasticity were greatly improved by increasing the SiO 2 loading. Compared with SiO 2 -free ones, PNSCMs exhibited better dispersion stability and plugging performance, and the maximum plugging rate reached 93.64%, which was increased by 14.69%. These PNSCMs studied can realize in-depth profile control in reservoirs and have great application prospects in the further enhanced oil recovery research.
研究领域:
石油工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2018
·
IF 3.306
Li-Zhi Zhang,Qian-Wen Su
Membranes of low thermal conductivity (thermal insulation) but high moisture permeability are highly desired in membrane-based humidification-dehumidification (MHDD) seawater desalination technology. The porous membranes with thermal insulation could decrease the heat losses in humidification, thus the system energy performance can be improved. To satisfy this purpose, in this study, a PVDF/SiO 2 (Si aerogel) composite bilayer membrane of low heat conductivity is prepared and analyzed. To solve the problem of cracking in forming SiO 2 layer, the casting solution (TEOS, H 2 O) is doped with a drying control chemical additive (DCCA) N, N -dimethylformamide (DMF) to decrease the surface tensions in the gel. Then performance analysis of the developed membranes are conducted and the membranes are characterized. The results found that the heat conductivity is decreased from 0.08199 W m −1 K −1 to 0.04487 W m −1 K −1 , with a penalty of effective moisture diffusivity sacrificed from 4.93 × 10 −6 m 2 /s to 2.42 × 10 −6 m 2 /s. They are superior to the available SiO 2 blend insulation membranes. Further, the membranes can be optimized by facile structural manipulations such as adjusting the SiO 2 layer thickness to realize the desired performance while balancing the paradox between the permeability and heat conductivity. This is the first time that heat conductivity of membranes can be manipulated for seawater desalination.
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
Scientific Reports
·
2019
·Vol. 9
·期 1
·1-11
·
IF 4.011
Zhu Xiaowei,Yang Kuisuo,Wu Anping,Bai He,Bao Jinrong,Qiao Yan,Yang Yunjiang,Li Wenxian,Liu Ying
The novel submicro-spheres SiO 2 @LaPO 4 :Eu@SiO 2 with core-shell-shell structures were prepared by connecting the SiO 2 submicro-spheres and the rare earth ions through an organosilane HOOCC 6 H 4 N(CONH(CH 2 ) 3 Si(OCH 2 CH 3 ) 3 (MABA-Si). The as-prepared products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and infrared spectroscopy (IR). It is found that the intermediate shell of the submicro-spheres was composed by LaPO 4 :Eu nanoparticles with the size of about 4, 5–7, or 15–34 nm. A possible formation mechanism for the SiO 2 @LaPO 4 :Eu@SiO 2 submicro-spheres has been proposed. The dependence of the photoluminescence intensity on the size of the LaPO 4 :Eu nanoparticles has been investigated. The intensity ratios of electrical dipole transition 5 D 0 → 7 F 2 to magnetic dipole transition 5 D 0 → 7 F 1 of Eu 3+ ions were increased with decreasing the size of LaPO 4 :Eu nanoparticles. According to the Judd-Ofelt (J-O) theory, when the size of LaPO 4 :Eu nanoparticles was about 4, 5–7 and 15–34 nm, the calculated J-O parameter Ω 2 (optical transition intensity parameter) was 2.30 × 10 −20 , 1.80 × 10 −20 and 1.20 × 10 −20 , respectively. The increase of Ω 2 indicates that the symmetry of Eu 3+ in the LaPO 4 lattice was gradually reduced. The photoluminescence intensity of the SiO 2 @LaPO 4 :Eu@SiO 2 submicro-spheres was unquenched in aqueous solution even after 15 days.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
JOURNAL OF RARE EARTHS
·
2024
·
IF 5.2
Tianhao Xia,Yuwen Yuan,Yunpeng Wang,Pragati Awasthi,Wenkun Dong,Xvsheng Qiao,Dong Chen,Shisheng Ling,Xianping Fan
This study aims to advance the development of magnetic fluorescent polymer microspheres for biomedical detection applications. Conventionally, dopants have utilized europium(III) (Eu(III)) organic complexes due to their high compatibility with polymers and strong fluorescence. However, as the common magnetic material Fe 3 O 4 can quench their fluorescence, it is hard to synthesize Eu complex-doped magnetic fluorescent materials. To maintain fluorescence in the presence of magnetic parts, in this work, we synthesized Eu-doped magnetic microspheres with multi-layered structure. Firstly, poly-(glycidyl methacrylate) (PGMA) microspheres were prepared as templates and subsequently coated with layers of Fe 3 O 4 and SiO 2 . Then, the synthesized Eu(TTA) 3 (TPPO) 2 were added into PGMA@Fe 3 O 4 @SiO 2 microspheres in either basic or acidic conditions, and covered them with an extra sol–gel layer of silica at the same time. The microspheres exhibit a core–shell structure with sub-micron dimensions (580 nm) and possess favorable superparamagnetic properties ( M s = 22.02 A·m 2 /kg, M r = 1.37 A·m 2 /kg, H c = 0.242 A/m). But the fluorescence of Eu 3+ are significantly quenched by Fe 3 O 4 , O–H oscillators, and N–H oscillators. Finally, to exclude the quenching mentioned above, the first pure SiO 2 shielding layer and the second Eu(TTA) 3 (TPPO) 2 -dispersed SiO 2 layer were coated onto PGMA@Fe 3 O 4 microspheres to prevent the energy transfer due to the quenching centers and hold the fluorescence of Eu 3+ . These findings underscore the considerable potential of these microspheres exhibiting rapid magnetic separation and stable fluorescence for bioimaging and biosensing applications.
研究领域:
材料科学
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生物医学工程
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2025
·Vol. 36
·期 16
·1-14
·
IF 2.8
Abdelaty M.,Huanhuan Zhu,Ewais Hassan A.,Morsy Ahmed,Yun Zhao,Qingze Jiao
Poly (m-phenylene isophthalamide) (PMIA) is a high-performance polymer known for its exceptional thermal stability, mechanical strength, and chemical resistance, making it an ideal candidate for advanced material applications. This study presents the synthesis, characterization, and analysis of poly (m-phenylene isophthalamide) (PMIA)/SiO 2 nanocomposites and porous PMIA films. PMIA/SiO 2 nanocomposites were prepared using in situ interfacial polycondensation, incorporating 3-, 5-, and 7-wt% SiO 2 nanoparticles. Nanocomposite films were fabricated through a controlled casting method, followed by etching SiO 2 particles with hydrofluoric acid to create porous PMIA films. Enhancement of the PMIA/SiO 2 nanocomposites exhibited improved inherent viscosity, indicating high molecular weight and efficient polymerization. Fourier Transform Infrared (FTIR) spectroscopy confirmed the successful integration of SiO 2 into the PMIA matrix. Scanning Electron Microscopy (SEM) revealed uniform pore distribution in the porous films, with pore size increasing with higher SiO 2 content. Thermogravimetric analysis (TGA) demonstrated enhanced thermal stability of PMIA/SiO 2 composites, with degradation temperatures increasing from 440 °C for pure PMIA to 460 °C for composites containing 7-wt% SiO 2 . Mechanical testing indicated that PMIA/SiO 2 composites with 5-wt% SiO 2 achieved optimal tensile strength (31.8 MPa) and elongation at break (30.1%), while higher SiO 2 content resulted in reduced mechanical performance due to particle agglomeration. The dielectric constants of these porous films remained consistently lower than those of their nonporous counterparts throughout the frequency range of 1 Hz to 1 MHz. This work highlights the potential of PMIA/SiO 2 nanocomposites and porous PMIA films for advanced applications requiring thermal and mechanical resilience, with tunable properties achieved through SiO 2 content variation.
✓ 已验证
产品关联
DOI
高影响因子
Chemistry-An Asian Journal
·
2023
·Vol. 18
·期 6
·e202201198
·
IF 4.1
Xuhui Wang,Na Sun,Xufeng Dong,Min Qi,Hao Huang
The development of flexible lithium-ion batteries (FLIBs) is restrained by traditional rigidity anodes. Carbon nanofiber (CNF) is a promising anode material owing to its high specific surface and superior ion transportation capability. However, the low amount of active material loaded on the CNFs and the poor stability during long cycling restrain their applications. Herein, a SiO 2 @carbon sphere/SiO 2 −CNF self-standing anode was prepared via alternate electrospraying-electrospinning. The SiO 2 content of the anode was increased through the electrospraying SiO 2 @carbon spheres layers, and the electrospun SiO 2 −CNFs as robust layers enhanced the stability of the anode. The self-standing anode exhibited 633 mA h g −1 in the initial cycle and maintained a 70% Coulomb efficiency for 1000 cycles at a current density of 100 mA g −1 , which could be applied in FLIB and other electrochemical storage devices.
研究领域:
材料科学
·
储能
·
纳米技术
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL
·
2016
·
IF 3.958
Tao Meng,Pengfei Xie,Hengfei Qin,Huan Liu,Weiming Hua,Xi Li,Zhen Ma
Xie et al. reported that Fe 2 O 3 /SiO 2 spheres with a surface area of 111 m 2 /g could be hydrothermally transformed into Fe 2 O 3 /Silicalite-1 nanowires in the presence of ethylenediamine and triethylamine. The resulting material was found to be active for CO oxidation and N 2 O decomposition due to the presence of small (1–2 nm) Fe 2 O 3 nanoparticles [P.F. Xie et al., Microporous Mesoporous Mater. 200 (2014) 52–60; P.F. Xie et al., J. Mol. Catal. A 409 (2015) 50–58]. In the current work, commercial amorphous SiO 2 spheres with a low specific surface area of 9.5 m 2 /g were found to be transformed into amorphous SiO 2 nanowires via hydrothermal treatment at 200 °C, in the presence of a mixture of ethylenediamine, triethylamine, and Fe(NO 3 ) 3 , for several days. The Fe 3+ species, in the presence of ethylenediamine and triethylamine, not only catalyzed the morphological transformation of SiO 2 , but also got deposited onto the SiO 2 nanowires, forming supported Fe 2 O 3 nanoparticles (2–4 nm in diameter) upon subsequent calcination to remove the organic templates. For comparison, Fe 2 O 3 /SiO 2 spheres prepared by impregnation had big Fe 2 O 3 particles (as large as 50 nm). Both the SiO 2 supports and supported Fe 2 O 3 particles were characterized by various techniques. The catalytic performance was studied, using N 2 O decomposition, CO oxidation, and photocatalytic reduction of Cr(VI) as probe reactions. Implications of the findings are discussed.
研究领域:
材料化学
·
纳米材料
·
催化
·
环境修复
·
无机合成
✓ 已验证
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2019
·
IF 7.723
Haiqiang Lin,Hongyan Qu,Weikun Chen,Kang Xu,Jianwei Zheng,Xinping Duan,Hesheng Zhai,Youzhu Yuan
In gas-phase chemoselective hydrogenation of crotonaldehyde on Ag-based catalysts, zirconia doping on silica supports was found to improve catalytic performance in terms of unsaturated alcohol selectivity, hydrogenation activity, and stability. The surface modification of silica by zirconia doping favors the fine dispersion of Ag species due to the enhanced quantity and strength of surface acid sites, which enable construction of abundant catalytic sites effective for C O bond hydrogenation. High crotyl alcohol selectivity, exceeding 80%, and significant inhibition of monohydrogenation on the C C bond were observed on the optimal Ag/Zr–SiO 2 catalyst. Dynamic O 2 chemisorption measurement revealed that the pure Ag powders did not chemisorb O 2 irreversibly under 323 K, but SiO 2 or Zr–SiO 2 supported Ag catalysts did. The amounts of Ag active for O 2 chemisorption, which are at least one order of magnitude lower than that of surface Ag derived from TEM and XRD characterizations, match well with the perimeter interface Ag of hemispherical particles. A strong correlation between hydrogenation activity and O 2 uptake on those Ag/SiO 2 and Ag/Zr–SiO 2 catalysts with different Ag dispersions and deactivation degrees was observed, implying that the effective catalytic sites for crotonaldehyde chemoselective hydrogenation may originate from accessible interface sites with unique redox properties. Catalyst induction and deactivation were observed on both Ag/SiO 2 and Ag/Zr–SiO 2 catalysts in real catalytic operation. Changes in metal stable interface structure, rather than metal aggregation and coagulation, are assumed to be the main cause of irreversible catalyst deactivation, because the apparent Ag particle sizes changed slightly, but the oxygen chemisorption ability deteriorated considerably. Electropositive Ag sites interacting with neighboring oxygen from oxide supports at the ternary Ag–ZrO 2 –SiO 2 interface are proposed to account for highly selective C O bond hydrogenation to produce the desired unsaturated alcohol.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Han Zhang,Sijia Sun,Hao Ding,Ying Chen
Using amorphous SiO 2 (A-SiO 2 ) and tetrabutyl titanate (TBOT) as raw material, a composite photocatalyst with surface loaded quantum dot size TiO 2 (A-SiO 2 /TiO 2 , AST) was prepared. The degradation of tetracycline hydrochloride as well as mechanism of performance improvement by A-SiO 2 were investigated. The TiO 2 on the composite was anatase with a content of 9.96 wt% and a size of 7–8 nm (quantum dot level). TiO 2 was uniformly distributed and was closely bonded at the interface by chemical bonds. The degradation rate of AST was 95% after 60 min UV exposure, which was comparable to pure nano-TiO 2 . The particle size of TiO 2 in AST was reduced from 20–50 nm to 7–8 nm comparing with pure nano-TiO 2 and changed from a highly agglomerated to a well-dispersed state due to abundant hydroxyl groups on A-SiO 2 surface. TiO 2 bandgap width increased from 3.25 eV to 3.39 eV. These led to the exposing of active sites on TiO 2 and significantly increased photogenerated carrier separation efficiency. This study provides a feasible and simple method to improve TiO 2 nanoparticles’ photocatalytic activity, reduce the usage and achieve recycling to cut the application cost by surface coated.
✓ 已验证
产品关联
DOI
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2024
·
IF 4.5
Jianfu Wang,Yi Lin,Wei Bing,Huichao Jin,Jie Zhao,Limei Tian
Superhydrophobic materials can solve the problem of oil pollution in water resources. In this paper, superhydrophobic PDMS-SiO 2 with macro-micro-nano multi-level structures was prepared by impregnation method. The superhydrophobic PDMS-SiO 2 material has good physical and chemical stability, and retains its superhydrophobicity after sandpaper abrasion, tape peeling, water immersion, acid or alkali immersion, and high temperature baking. The superhydrophobic PDMS-SiO 2 material has a high oil-water separation efficiency, with the highest oil-water separation efficiency reaching more than 99%, and the oil-water separation efficiency of different oils all exceeding 96%. The preparation of superhydrophobic PDMS-SiO 2 material is simple, inexpensive and environmentally friendly, which can achieve fast and large-area preparation, with good engineering application prospects.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2017
·
IF 3.981
Lili Lian,Jinyi Lv,Xiyue Wang,Dawei Lou
A novel magnetic solid–phase extraction approach was proposed for extraction of potential residues of tetracyclines (TCs) in tap and river water samples, based on Fe 3 O 4 @SiO 2 @FeO magnetic nanocomposite. Characterized results showed that the received Fe 3 O 4 @SiO 2 @FeO had distinguished magnetism and core–shell structure. Modified FeO nanoparticles with an ∼5 nm size distribution were homogeneously dispersed on the surface of the silica shell. Owing to the strong surface affinity of Fe (II) toward TCs, the magnetic nanocomposite could be applied to efficiently extract three TCs antibiotics, namely, oxytetracycline, tetracycline and chlortetracycline from water samples. Several factors, such as sorbent amount, pH condition, adsorption and desorption time, desorption solvent, selectivity and sample volume, influencing the extraction performance of TCs were investigated and optimized. The developed method showed excellent linearity (R > 0.9992) in the range of 0.133–333 μg L −1 , under optimized conditions. The limits of detection were between 0.027 and 0.107 μg L −1 for oxytetracycline, tetracycline and chlortetracycline, respectively. The feasibility of this method was evaluated by analysis of tap and river water samples. The recoveries at the spiked concentration levels ranged from 91.0% to 104.6% with favorable reproducibility (RSD < 4%).
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ISIJ INTERNATIONAL
·
2018
·Vol. 58
·期 7
·1361-1367
·
IF 1.35
Jia-yun Wang,Hong-juan Li,Lei Li,Hua Wang,Yu Wang,Yong Yu
A process of removing iron from copper-based alloy scraps using oxidation slagging method is researched, in which the iron is oxidized to FeO and then reacted with SiO2 forming Fe2SiO4 and enter into the slag phase. The addition of SiO2 could restrict the Fe3O4 generation through the transformation of FeO to 2FeO·SiO2 in a certain O2 pressure, which is favorable to decreasing the melt viscosity and increasing the separation efficiency of Cu and Fe. Under optimized conditions of O2 flow rate of 40 ml/min, temperature of 1673 K, oxygenation time of 8 min, and SiO2 amount of 2.17 mass%, Fe content in the metal phase is decreased to 0.0030 mass% with Cu loss rate being of 1.14%.
研究领域:
冶金工程
·
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）