Membranes
·
2021
·Vol. 11
·期 11
·803
·
IF 4.106
Qianqian Xu,Yuchao Chen,Tonghu Xiao,Xing Yang
The use of poly(vinylidene fluoride) (PVDF) microfiltration (MF) membranes to purify oily water has received much attention. However, it is challenging to obtain high-performance PVDF microfiltration membranes due to severe surface fouling and rapid decline of permeability. This study explored a new approach to fabricate high-performance PVDF/silica (SiO2) composite membrane via the use of a polymer solution featuring lower critical solution temperature (LCST) characteristics and the non-solvent thermally induced phase separation method (NTIPS). Coupling with morphological observations, the membrane formation kinetics were analyzed in depth to understand the synergistic effect between the LCST solution properties and fabrication conditions in NTIPS. Utilizing such a synergistic effect, the transition from finger-like macrovoid pores to bi-continuous highly connected pores could be flexibly tuned by increasing the PVDF concentration and the weight ratio of SiO2/PVDF in the dope solution and by raising the coagulation temperature to above the LCST of the solution. The filtration experiments with surfactant-stabilized oil-water emulsion showed that the permeation flux of the PVDF/SiO2composite membranes was higher than 318 L·m−2·h−1·bar−1and the rejection above 99.2%. It was also shown that the PVDF/SiO2composite membranes, especially those fabricated above the LCST, demonstrated better hydrophilicity, which resulted in significant enhancement in the anti-fouling properties for oil/water emulsion separation. Compared to the benchmark pure PVDF membrane in oily water purification, the optimal composite membrane T70 was demonstrated via the 3-cycle filtration experiments with a significantly improved flux recovery ratio (Frr) and minimal reduced irreversible fouling (Rir). Overall, with the developed method in this work, facile procedure to tune the membrane morphology and pore structure was demonstrated, resulting in high performance composite membranes suitable for oil/water emulsion separation.Keywords:PVDF/SiO2composite membrane;lower critical solution temperature (LCST);nonsolvent thermally induced phase separation (NTIPS);structural control;oil-in-water emulsion
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Cleaner Production
·
2019
·
IF 6.395
Jiawei Sun,Hengchang Bi,Haiyang Jia,Shi Su,Hui Dong,Xiao Xie,Litao Sun
The pollution of water resource and shortage of clean water have become increasingly severe, developing an urgent demand of reliable, efficient yet low-cost material for everyday water purification . In the present work, a superhydrophobic paper tissue-based SiO 2 /PDMS composite has been prepared for both oil absorption and water-in-oil emulsion separation. The fabrication process is quite simple since it takes the full advantage of tissue that has naturally strong capillary force of which allows the material to absorb oil from water much more rapidly and completely (>99.9%) even under harsh conditions. The study has shown the novel material is exceptionally efficient in separating water-in-oil emulsion under gravity but no need of extraneous pressure. A variety of emulsions has been proven with high flux (>2,000 L m −2 h −1 ) and high separation efficiency (>99.4%). It is believed that this study has proposed a highly reliable and efficient, low cost strategy in both oil absorption and water purification , which shed light on water treatment of both civil use and industry.
研究领域:
环境科学
·
材料科学
·
水处理
·
化学工程
✓ 已验证
DOI
高影响因子
SURFACE & COATINGS TECHNOLOGY
·
2023
·
IF 5.4
Yang Guo,Xiaoying Guo,Haipeng Lu,Xian Jian
Developing high–efficient microwave absorbing (MA) materials with anti–corrosion (AC) properties to tackle the harsh hygrothermal marine conditions remains a challenge. Herein, we employed catalytic chemical vapor deposition and the Stöber technique to fabricate gradient multilayer interface–coupled FeNi@C@SiO 2 composites, guided by the hetero–interface engineering. The resulting composites exhibited exceptional MA properties and AC behavior. Specifically, they showcased a remarkable effective absorption bandwidth of 6.27 GHz at 1.40 mm, outperforming that of FeNi (3.80 GHz). This improved bandwidth was attributed to the electron conduction pathway provided by the C layer, which facilitated electron migration and hopping. The C@SiO 2 layer, containing defects and –OH functional groups, induced abundant dipole polarization and optimizes the impedance matching of FeNi. Furthermore, the RCS reduction value of FeNi@C@SiO 2 could reach 16.73 dB·m 2 . Moreover, the corrosion rate of FeNi@C@SiO 2 was 7.48 × 10 −11 m/s, significantly lower than that of FeNi (1.29 × 10 −10 m/s). This reduction was primarily due to the intrinsic inertness and impermeability of the C@SiO 2 layer, effectively isolating the corrosive medium from the substrate. This investigation presents a novel point of reference for the advancement of bifunctional MA materials intended to cope with extreme environments.
研究领域:
材料科学
·
纳米复合材料
·
表面工程
·
电磁功能材料
·
腐蚀防护
✓ 已验证
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2022
·
IF 7.968
Zhijun An,Yufeng Hu,Di Zhang,Hao Zhou,Jingjing Zhan,Minghuo Wu
Fenton-like reaction was considered one of the most prospective advanced oxidation processes in the removal of organic pollutants . To achieve efficient degradation of sulfonamides (SAs) in water, MoS 2 /SiO 2 composites (M@Si) were fabricated by a simple “one-pot” process and packed as fixed-bed reactors (FBR) for Fenton-like reaction. The SEM and XRD results showed the nano-sized MoS 2 particles (400 – 600 nm) were attached to the SiO 2 particles, confirming the successful fabrication of M@Si composites. The operation conditions for the M@Si FBR were systematically optimized, including H 2 O 2 concentration, Fe 2+ concentration, pH, bed height and flow rate, and the degradation rate of > 95% was realized for sulfisoxazole (20 mg/L) at a residence time of 15 s. M@Si Fenton FBR could enhance the Fe 3+ /Fe 2+ cycle for producing hydroxyl radicals (·OH) and self-generate singlet oxygen ( 1 O 2 ) from the interaction between H 2 O 2 and MoS 2 . Moreover, the M@Si FBR could be operated for over six days without the plunge of degradation efficiency. Finally, M@Si FBR was successfully applied in the degradation of SAs in pond water, demonstrating the application prospect of this reactor. This system presented a simple MoS 2 based Fenton catalyst for the efficient activation of hydrogen peroxide for the removal of antibiotics in continuous flow mode.
研究领域:
环境工程
·
水处理
·
催化
·
材料科学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 82
·67031-67040
·
IF 3.84
Z. Y. Wu,X. A. Fan,G. Q. Li,J. Wang,Z. H. Gan
Core–shell structured Fe-6.5 wt% Si/SiO2 particles and intergranular insulated Fe-6.5 wt% Si/SiO2 composite compacts with tunable insulating layer thickness were prepared by in situ chemical deposition combined with a subsequent spark plasma sintering process. Most of conductive Fe-6.5 wt% Si alloy particles were coated with a SiO2 insulating layer in the Fe-6.5 wt% Si/SiO2 composite compacts. The SiO2 insulating layer could increase the electrical resistivity and reduce the effective radius of the eddy current in Fe-6.5 wt% Si/SiO2 composite compacts. Therefore, the intergranular insulated Fe-6.5 wt% Si/SiO2 composite compacts presented lower core loss than those of Fe-6.5 wt% Si compacts without SiO2 insulating layer. Based on this, several types of Fe-6.5 wt% Si/SiO2 core–shell particles and intergranular insulated Fe-6.5 wt% Si/SiO2 composite compacts (with various SiO2 insulating layer thicknesses) were selectively prepared by simply varying the TEOS concentration (the volume of TEOS for each gram of Fe-6.5 wt% Si particles, ml g−1). The results indicated that the thickness of the SiO2 layer and electrical resistivity of Fe-6.5 wt% Si/SiO2 composite compacts increased with increasing the TEOS concentration from 0.1 to 0.4 ml g−1, while saturation magnetization, relative permeability and core loss displayed the reverse tendencies. The as-prepared intergranular insulated Fe-6.5 wt% Si/SiO2 composite compacts exhibited excellent magnetic properties, which inspire us to develop new high silicon containing soft magnetic cores which can be widely used in various electromagnetic devices.
研究领域:
材料科学
·
电磁学
·
冶金学
✓ 已验证
产品关联
DOI
高影响因子
Small
·
2024
·
IF 13
Jiahui Lin,Jintao Huang,Zhanhu Guo,Ben Bin Xu,Yan Cao,Juanna Ren,Hua Hou,Yongshuang Xiao,Mustafa Elashiry,Zeinhom M. El-Bahy,Yonggang Min
With the rapid development of electronic industry, it's pressing to develop multifunctional electromagnetic interference (EMI) shielding materials to ensure the stable operation of electronic devices. Herein, multilayered flexible PEG@PAN/MXene (Ti 3 C 2 T x )/PVDF@SiO 2 (PMF) composite film has been constructed from the level of microstructure design via coaxial electrospinning, coating spraying, and uniaxial electrospinning strategies. Benefiting from the effective encapsulation for PEG and high conductivity of MXene coating, PEG@PAN/MXene composite film with MXene coating loading density of 0.70 mg cm −2 exhibits high thermal energy storage density of 120.77 J g −1 and great EMI shielding performance (EMI SE of 34.409 dB and SSE of 49.086 dB cm 3 g −1 ) in X-band (8–12 GHz). Therefore, this advanced composite film can not only help electronic devices prevent the influence of electromagnetic pollution in the X-band but also play an important role in electronic device thermal management. Additionally, the deposition of nano PVDF@SiO 2 fibers (289 ± 128 nm) endowed the PMF composite film with great hydrophobic properties (water contact angle of 126.5°) to ensure the stable working of hydrophilic MXene coating, thereby breaks the limitation of humid application environments. The finding paves a new way for the development of novel multifunctional EMI shielding composite films for electronic devices.
研究领域:
材料科学
·
电气工程
·
纳米技术
·
高分子科学
·
热工程
·
电磁兼容
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
·
2023
·
IF 4.1
Xuefeng Bai,Han Zhang,Sijia Sun,Jie Wang,Yu Tu,Hao Ding
Defect engineering and heterojunction are the two dominant methods to improve the efficiency of semiconductor photocatalysis . Loading can also improve the performance of photocatalysts and solve the problems of photocatalyst agglomeration and difficult recovery in water. In this paper, a ternary ZnIn 2 S 4 /TiO 2 /MS-SiO 2 composite photocatalyst (EG-ZIS/TS) was constructed by sequentially loading nano-TiO 2 and defective state ZnIn 2 S 4 (EG-ZIS) on industrial by-product SiO 2 microspheres (MS-SiO 2 ). Among them, EG-ZIS was prepared with ethylene glycol as a solvent. Compared with EG-ZIS/T (unloaded MS-SiO 2 ) and ZIS/TS (non-defected state ZnIn 2 S 4 ), the degradation performance of methyl orange (MO) solution and the reduction performance of hexavalent chromium under simulated daylight irradiation were substantially improved. As a result, Zn defects enhanced the photocatalytic performance of ZnIn 2 S 4 and the heterojunction between ZnIn 2 S 4 and TiO 2 , and this enhancement was achieved by adjusting the work function of the system and promoting interface electronic transmission. The loading of MS-SiO 2 further produced a synergistic effect of enhancing the heterojunction photocatalytic efficiency by improving the dispersion and immobilization of TiO 2 and EG-ZIS. The effect of ethylene glycol on the curvature and surface Zn defectivity of ZnIn 2 S 4 nanosheets was also investigated in this study. This study provides an innovative approach to improve the oxidation and reduction performance of photocatalysts by combining semiconductor defect, heterojunction, and loading on the carrier surface and finds that the loading of photocatalysts on the SiO 2 carrier surface has an enhancement effect on the performance of the formed heterojunction. This thesis is useful and informative for related research.
研究领域:
材料科学
·
环境科学
·
化学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2020
·
IF 3.99
Qi Jiang,Jian Huang,Baoguo Ma,Zhengcai Yang,Ting Zhang,Xin Wang
TiO 2 @SiO 2 composite microspheres (TS) were prepared by the deposition of TiO 2 on the raspberry-like SiO 2 @polystyrene microspheres (PSS). The hollow microspheres with hierarchical microtopography possess both improved photocatalytic activity and stabilized TiO 2 particle structure. The results of energy dispersion spectrum (EDS) mapping, X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) showed that after calcination, anatase TiO 2 nanoparticles has formed on the raspberry-like PSS template with preferred deposition among interstitials of the drupelet-like structure. The thermal degradation of the polystyrene (PS) core during calcination led to the hollow microspheres. The photocatalytic experiments indicated that the raspberry-like TiO 2 @SiO 2 composite microspheres (TS1-TS3) had higher photocatalytic efficiency than the smooth ones (TS0), due to the hierarchical and hollow structure. The sample TS2 prepared with a moderate ammonia concentration (3 %) not only had relatively more intact hollow spherical structure, but also enhanced photocatalytic activity. The hollow TiO 2 @SiO 2 composite microspheres (TS3) prepared with 4 % ammonia showed the best photocatalytic efficiency. However, the higher ammonia concentration made the drupelet-like structure unstable and the microspheres tend to disintegrate. The raspberry-like microstructure showed a protective effect on the loaded TiO 2 , which resulted in better recyclability with persistent photocatalytic activity. The hierarchical composite microspheres shed light on the potential effective utilization strategy of nano-photocatalyst.
研究领域:
材料科学
·
化学
·
纳米技术
·
环境科学
✓ 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）