KEY ENGINEERING MATERIALS
·
2015
·
IF 0
Xiao Lin Wu,Jie Lin,Jian Yan Wang,Hang Guo
In this paper composite nanofiber membranes were prepared by electrospinning technology from poly (vinylidene fluoride) (PVDF)-poly (methyl methacrylate) (PMMA)-SiO2 blend solutions with different PMMA and SiO2 contents. It was found that the diameter of electrospun nanofibers was greatly increased with the added PMMA content but decreased with the added SiO2 content, and when both PMMA and SiO2 were added the diameter of electrospun nanofibers was decreased. With a proper ratio of the PMMA and SiO2 added, the electrospum nanofiber membrane could have a suitable diameter with high porosity. The XRD results revealed that electrospun nanofiber membranes contained mainly β-phase crystal structure of PVDF, and its crystalline is reduced with the added PMMA and SiO2 contents due to the inhibited crystallization of the polymer by the inorganic particles and PMMA during the solidification process. These nanofiber membranes exhibited a high electrolyte uptake, around 300%. Moreover, the incorporation of PMMA and SiO2 into the nanofiber membrane improved the ionic conductivity from 1.7×10−3S/cm to 2.0×10−3S/cm at room temperature. Compared with commercial film PE, their cell cycle and charge and discharge performance were also greatly improved.
研究领域:
材料科学
·
电化学
·
储能技术
·
纳米技术
✓ 已验证
DOI
ENERGY & FUELS
·
2019
·
IF 3.021
Di Wang,Shanshan Sun,Kai Cui,Hailan Li,Yejing Gong,Jirui Hou,Zhongzhi Zhang
The wettability condition of a rock’s surface is an enormous parameter for enhanced oil recovery (EOR) in low-permeability reservoirs. It determines the spreading of injected water and the adhesion of residual oil on rock surfaces. In this study, a new nanofluid composed of silica nanoparticles and rhamnolipid in brine was utilized as an effective agent to alter the wettability of a rock’s surface. In order to obtain rock surfaces with different initial wettabilities, hexamethyldisilazane (HMDS) was used for the sample preparation. The measurement of three-phase contact angles for water/air/rock and brine/oil/rock were performed to explore the contact situation between a rock surface and movable fluids, and the spontaneous imbibition test researched the process of oil recovery with nanofluid. By evaluating the experimental measurements, nanofluid showed a significant potential in wettability alteration from oil-wet toward water-wet state, which is an important mechanism for “scraping” oil drops from a rock surface during nano-EOR process. Moreover, a total of nine coreflooding tests were performed to investigate the effects of rock wettability on waterflooding and nanofluid flooding, respectively. The results revealed that an intermediate-wet state of a rock’s surface is in favor of the oil recovery especially for waterflooding, and nanofluid, resulting in an additional 5.3–6.8% increments in oil recovery compared to conventional waterflooding. In conclusion, nanofluids show a significant potential for EOR from low-permeability cores, implying a wide application in oil fields.
研究领域:
石油工程
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材料科学
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表面化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2019
·Vol. 125
·期 8
·1-11
·
IF 1.784
Dong Rui,Wang Luming,Zhu Jichao,Liu Lili,Qian Yanling
The nanohybrids of silicon dioxide–graphene oxide (SiO 2 –GO) were prepared by surface modification of graphene oxide (GO) by the hydrolysis of the tetraethoxysilane (TEOS) and then the SiO 2 –GO was added into acrylic resin as reinforcement to prepare acrylic nanocomposites. The structure of SiO 2 –GO was characterized by XRD, FT-IR, Raman and the morphology and dispersion study of SiO 2 –GO were observed by SEM and TEM. The results showed that the SiO 2 –GO was dispersed well in the acrylic resin matrix. Furthermore, the corresponding thermal, mechanical, and chemical resistance properties of the SiO 2 –GO/acrylic resin nanocomposites with mass ratios of SiO 2 –GO to acrylic resin (0.04, 0.06, 0.08, 0.10, and 0.12 wt%) were studied and compared with those of pure acrylic resin and the GO/acrylic resin nanocomposites with the same mass ratios of GO to acrylic resin. The results revealed that the loading of SiO 2 –GO effectively enhanced various properties of acrylic resin, which provides a new method for preparation of graphene nanocomposites.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2019
·Vol. 11
·期 3
·393
·
IF 3.164
Qingguo Chen,Hongda Yang,Xinyu Wang,Heqian Liu,Kai Zhou,Xin Ning
Epoxy resin-impregnated insulation paper (RIP) composites are used as the inner insulation of dry condenser bushing in the ultra-high voltage direct current (UHVDC) power transmission system. To improve the dielectric properties of RIP, nano-SiO2is added to the insulation paper at concentrations of 0–4wt % before impregnation with pure epoxy resin. X-ray diffraction (XRD), scanning electron microscopy observations as well as the typical dielectric properties of relative permittivity, DC volume conductivity, DC breakdown strength, and thermally stimulated depolarization current (TSDC), were obtained. The effects of trap parameters on the breakdown field strength and volume conductivity were investigated. The DC breakdown electric field strength of the sample increased as the trap level increased. The maximum DC breakdown strength of nano-SiO2-modified RIP was increased by 10.6% the nano-SiO2content of 2 wt %. The relative permittivity and DC volume conductivity were first decreased and then increased with increasing nano-SiO2content. These changes occurred near the interfaces between nano-SiO2and RIP. The increased DC breakdown strength was mainly attributed to the increased trap level.Keywords:dry bushing;epoxy resin-impregnated paper;dielectric characteristics;thermally stimulated depolarization current;nanocomposite
研究领域:
电气工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Micro & Nano Letters
·
2019
·Vol. 14
·期 3
·323-328
·
IF 0.975
Jidong Wang,Zhijie Gu,Jialin Zhang,Xin Chen,Mengjuan Li,Yuan Yu,Mingqiao Ge,Xiaoqiang Li
In this work, a mesoporous structure TiO 2 /SiO 2 (M-TS) composite with excellent adsorption and photocatalytic properties was fabricated by a sol–gel process combined with calcination. The structure of the samples was characterised by scanning electron microscopy and Brunauer–Emmett–Teller analysis. The factors influencing the adsorption behaviours of methylene blue (MB) onto M-TS, including ingredient, dosage, initial concentration and temperature were investigated. The M-TS was produced by removing poly(vinylpyrrolidone) from the precursor gel was vital to the excellent adsorption capacity. Furthermore, the isotherm and kinetic data were fitted by using Langmuir and Freundlich isotherm models, pseudo-first-order and pseudo-second-order equations, and the intra-particle diffusion model. The Langmuir isotherm model and the pseudo-second-order kinetics were the most suitable models for describing the adsorption of MB onto M-TS. It was also found that the adsorption capacity of cationic dyes on M-TS is better than that of anionic dyes. The experimental results of adsorption and photodegradation proved that improvement of adsorption capacity enhances the decolourisation efficiency. This work shows that the M-TS could be used as an effective adsorbent and photocatalyst to remove cationic dyes from wastewater.
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
ACS Applied Nano Materials
·
2021
·
IF 5.097
Jiawei Lu,Youran Li,Huilin Zhu,Guiyang Shi
Nanoscale particle-based enzyme immobilization carries a risk of dissolving or breaking the material when applied. One effective strategy to improve the stability and functionality of this type of nanomaterial is compounding with polymers. In this study, Fe3O4 nanoparticles were synthesized and coated with SiO2, after which magnetic hollow composite beads with nanoscale porous structures, named, lipase/Fe3O4/PAN (L/FP), were fabricated by compounding polyacrylonitrile and SiO2-coated Fe3O4 nanoparticles to immobilize Candida antarctica lipase B (CALB) in one step. Fourier transform infrared spectroscopy, scanning electron microscopy, the Brunauer–Emmett–Teller method, vibrating sample magnetometer measurements, and thermogravimetry analysis were used to analyze the structure of hollow beads. It was found that composite beads retained nanoscale channels and had a larger specific surface area (27.2 m2/g), a higher pore volume (0.09 cm3/g), and better saturation magnetization values (9.8 emu/g) than PAN hollow beads (6.2 m2/g, 0.03 cm3/g, and 0 emu/g, respectively). After optimizing fabrication and immobilization conditions, L/FP showed a high lipase capacity (50 mg protein/g support) at 2 mg/mL lipase, and the immobilized yield was up to 98.4% when the mass ratio of the starting lipase and support was 1.3 (mg lipase/g support). The immobilized lipase in L/FP showed greater thermal stability and resistance to alkali than free CALB. L/FP also had good stability in most organic solvents. In all tested cycles, it also had better reusability (78.4, 47.2, and 23.8% retained activity after 10, 20, and 30 cycles, respectively) in ester hydrolysis than CALB-immobilized Fe3O4 nanoparticles or PAN beads and had higher activity than the commercial immobilized lipase (Novo 435).
研究领域:
生物化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL PHYSICS LETTERS
·
2018
·
IF 1.686
Lianji Li,Yanan Hao,Jiaqi Guo,Yilin Wang,Li Yu
The fabrication of nanocomposite structures for Nano-Optics is facing many challenges due to the special performance requirements. In this work, a novel Ag nanoprism@SiO 2 @QD composite nanostructure is designed and fabricated to meet the desire of optical experiments. This material has good morphology and high monodispersity, and quantum dots can stably attach to the silica layer through chemical bonds. Simulation results confirm that this nanostructure can generates a Rabi splitting with a maximum value of 112 meV. Our coupling system creates a new combination of Ag nanoprisms and quantum dots, providing a high performance nanostructure for future photonic systems.
研究领域:
纳米光学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Mingxing Wang,Xiutong Wang,Youbo Nan,Hui Xu,Hui Zhou,Yanan Sun,Peijia Yi,Teng Yu
Raindrops are an abundant micromechanical renewable energy source in nature, and raindrop energy harvesting has always been a research hotspot. Traditional hydropower generation is not suitable for low-frequency energy harvesting, and it is difficult to realize distributed energy harvesting. The development of triboelectric nanogenerator (TENG) is a promising strategy for converting raindrop energy in the environment into electrical energy. Polydimethylsiloxane (PDMS) composite has received much attention due to its excellent chemical stability and insulating properties for TENG. However, the deficiency of the low output performance and insufficient hydrophobicity of PDMS limits the application of PDMS in droplet energy capture. Modification of PDMS can improve the droplet energy collection capability of the liquid–solid contact triboelectric (LS-TENG). In this work, a new approach to modifying polydimethylsiloxane (PDMS) as a hydrophobic negative triboelectric material using a high dielectric constant MXene and a hydrophobic nano-SiO 2 was reported. The as-prepared composites′ permittivity and triboelectric performance were remarkably promoted as compared to composites without interfacial modification. In addition, the use of composites for TENG assembly improved the open-circuit voltage and short-circuit current by a factor of 47.5 and 25.21, respectively, compared to pure PDMS. Application of the composite to the assembled TENG was employed as energy harvester to light up LEDs and charge a capacitor. In addition, a cathodic protection system was designed to demonstrate its potential application in the field of electrochemistry. This provides guidance for the practical implementation of TENGs in the field of electrochemical cathodic protection.
✓ 已验证
产品关联
DOI
高影响因子
Defence Technology
·
2023
·
IF 5.1
Xinli Ye,Hao Yu,Kai Zheng,Shan Li,Xiaomin Ma,Bangxiao Mao,Junxiong Zhang
The well-designed composite with satisfactory electromagnetic microwave absorption at high temperatures remains a serious challenge. Herein, we fabricated a resorcinol-formaldehyde/silica dioxide composite aerogel (RF/SiO 2 ) with a three-dimensional network structure using sol-gel, atmospheric pressure drying technique as well as heat-treated processes to achieve enhanced microwave absorption capabilities in the low frequency range. The pristine RF/SiO 2 aerogel presented a typical micropores structure with a surface area, porous volume, and density of 146.82 m 2 /g, 62.40%, and 0.28 cm 3 /g, respectively. Remarkably, the RF/SiO 2 aerogel showed an effective absorption bandwidth of 3.56 GHz and a minimum reflection loss value of −46.10 dB at 2.25 mm after being heat-treated at 1500 °C, while the maximum effective absorption bandwidth was 3.60 GHz at 2.30 mm. The intricate three-dimensional networks possessed remarkable impedance matching, multiple attenuation mechanisms, interfacial polarization, and dielectric loss, which were attributed to the exceptional ability to absorb electromagnetic microwaves. It offered a fresh approach to creating adaptable and effective microwave absorption materials in military defense.
✓ 已验证
产品关联
DOI
高影响因子
FIBERS AND POLYMERS
·
2023
·Vol. 24
·期 12
·4279-4286
·
IF 2.5
Zhou Jianhua,Niu Zhuanli,Xiao Anguo,Li Xiang
Materials with passive daytime radiative cooling (PDRC) have drawn more attention as a result of their potential for energy savings. We prepared SiO 2 -encapsulated ZnO@ZIF-8 (ZZS) particles and a radiative cooling coating containing ZZS particles. Owing to the polyhedron structure and the phonon-polarization resonance of ZZS particles, the ZZS fabric coating could reflect sunlight with 83% and radiate heat to outer space with 0.96. Compared with the ambient air, its average temperature decreased by 6.4 °C, and the human body under direct sunlight could avoid overheating 3.9 °C. In addition, the ZZS coated fabric after rubbing still had good PDRC and its average temperature increased by 1.38℃ higher than the original ZZS coated fabric. Owing to good PDRC property, hydrophobicity, mechanical properties and simple methods, the widespread usage of ZZS coated fabric for personal thermal management appears to be promising.
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS COMMUNICATIONS
·
2020
·
IF 3.612
Jiyuan Li,Zhuxiu Zhang,Mifen Cui,Qing Liu,Zhaoyang Fei,Xian Chen,Jihai Tang,Xu Qiao
The acid-catalyzed Markovnikov addition of isobutene is affected by the concomitant isobutene oligomerization. Herein, a solid acid catalyst consisting of the sulfonated silica modified with crystalline ZrSiO 4 was prepared, and the ZrSiO 4 /SiO 2 -SO 3 H catalyst went beyond conventional acid catalysts in the hydroacetoxylation of isobutene. The structure of the catalyst was well-characterized, and the role of ZrSiO 4 in suppressing the dimerization of isobutene was discussed in terms of both kinetic study and in-situ DRIFT analysis. Moreover, this catalyst also showed general applicability for a broad substrate scope, further highlighting the necessity of ZrSiO 4 in the solid acid catalyst.
研究领域:
化学工程
·
催化科学
✓ 已验证
DOI
高影响因子
NANO
·
2020
·
IF 1.566
Yanhong Wang,Xiuli Wang,Cuihong Wu,Xiaomei Wang,Xu Zhang
A hybrid adsorbent with inverse opal (IO) structure was prepared for removing Cd(II) from aqueous solution. The functional polymeric chains were grafted from the pore wall of IO silica to prepare the porous hybrid material by surface-initiated atom-transfer radical polymerization. Furthermore, the amidation reaction was carried out to obtain diethylenetriamine-modified hybrid adsorbent (IO SiO 2 -g-PAA-DETA). Batch adsorption of removing Cd(II) onto IO SiO 2 -g-PAA-DETA was studied as the effect of solution pH, adsorbent doses, contact time, ionic concentration, and temperature. When the grafted amount was 73%, the maximum adsorption capacity was obtained. The optimum adsorbent dose and pH value for adsorbing Cd(II) were found to be 5 g/L and 0.5 g/L, respectively. The adsorption capacity was almost unaffected by Na + at low concentrations. The adsorption data was depicted by the corresponding models and the results displayed that adsorbing Cd(II) on IO SiO 2 -g-PAA-DETA followed the Freundlich and pseudo-first-order model. In addition, after six adsorption–desorption cycles, IO adsorbent could remain above 80% of the first adsorption ability while it was washed using 0.025 M EDTA.
研究领域:
环境科学
·
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）