CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Chen Zhang,Xin Wang
In this paper, CaO-B 2 O 3 -SiO 2 (CBS) is utilized as matrix material of microwave coating for the first time to achieve high-performance microwave absorption under high-temperature. A series of FeSiAl (FSA)/CBS composite coatings were prepared via atmospheric plasma spraying. The impact of spraying power on the microstructure, electromagnetic properties, and high-temperature stability of as-sprayed coatings were studied. The experimental results reveal that CBS could effectively suppress the formation of the lamellar structure of FSA as the low initial melting temperature, also form unexpected Fe 2 SiO 4 structure with FSA during the spraying process. The increase in complex permittivity of the coating is primarily attributed to enhanced coating density and the development of Fe-rich regions within the CBS matrix. Furthermore, the dense coating prevents the oxidation of FSA and exhibits high-temperature stability. Our coating of 1 mm thickness has a reflection loss below -5 dB with frequency range of 7–14.8 GHz at 500 °C.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2023
·
IF 4.6
Yuanlu Xu,Yi Zhu,Chunyang Song,Yinan Chen,Chengwen Song,Zaijin You,Xinfei Fan
Oil spills and oily wastewater from various industries caused severe harm to the environment and human life. Then the effective treatment of oily wastewater is extremely urgent. Superhydrophilicity/underwater superoleophobicity membranes are considered as a favorable choice for the separation of oily wastewater. In this work, inspired by mussel adhesive protein chemistry , the SiO 2 /PDA/PTFE membrane (SPP) with hydrophilic chemical components and multi-scale rough structures was prepared by the facile combination of dopamine self-polymerization and sol-gel strategy. The hydrophilic SiO 2 nanoparticles (NPs) and polydopamine layer can be co-deposited on the membrane surface through Michael addition reaction, thus avoiding the problem of coating damage during oil/water separation. Moreover, the SiO 2 /PDA layer has hydrophilic groups and micro/nano rough structure, which makes the SPP membrane possess superhydrophilic and underwater superoleophobic properties. The properties of SPP membrane facilitate the formation of a hydration layer on the membrane surface, thus minimizing direct contact with oil droplets. During the experiment of oil/water separation, SPP membrane demonstrated excellent separation ability, the permeation flux of SPP membrane was measured to be 6183 and 4389 L m −2 h −1 for oil-water mixture and oil-in-water emulsion, respectively. The oil/water separation efficiency had also reached more than 99.7%. In addition, the SPP membrane exhibited brilliant chemical stability under harsh environments. It is worth mentioning that the SPP membrane showed superior cycling and anti-fouling performance in the separation process. These excellent performances demonstrate the great potential of SPP membranes in the industrial applications.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Crystals
·
2023
·Vol. 13
·期 9
·1296
·
IF 2.7
Yan Wang,Jiajing Li,Haipeng Zhu,Qilei Wang,Tulai Sun,Tao Ni,Yanghong Lin,Yu Liu,Minmin Mao,Ji Hu,Bing Liu,Hadi Barzegar Bafrooei,Zhongyan Ma,Yingjie Ren,Feng Shi,Ehsan Taheri-Nassaj,Dawei Wang,Kaixin Song
Mg2SiO4and MgSiO3ceramics with superior microwave dielectric properties are considered to be promising candidates for 5G applications. However, a slight deviation from the stoichiometric Mg/Si ratio will significantly influence their microwave dielectric properties, which will hinder their practical applications. In this work, thexMgO-SiO2(x= 1~2) ceramics were synthesized by a solid-state reaction method. The influence of the Mg/Si ratioxon the crystalline phase, microstructure, and microwave dielectric properties was investigated through X-ray diffraction (XRD), a scanning electron microscope (SEM), and the resonant cavity method. The XRD patterns revealed the coexistence of Mg2SiO4and MgSiO3within thexrange of 1~2, which was further demonstrated by the energy-dispersive X-ray spectra. The SEM images show a typical polycrystalline morphology of ceramics with an inhomogeneous grain size distribution. It is found that the microwave dielectric properties fluctuate at both sides of thexrange while those remain relatively stable with minor changes at the intermediate components, indicating an obvious low composition dependence helpful for practical applications. Further, a demonstrator of a microstrip patch antenna for 5G applications using the 1.5MgO-SiO2ceramic was designed and fabricated, and a return loss of −16.2 dB was demonstrated, which demonstrated the potential applications.Keywords:MgO-SiO2systems;5G application;microwave dielectric ceramics;phase composition
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2022
·Vol. 16
·期 1
·387
·
IF 3.748
Kezhu Xu,Qunling Fang,Jing Wang,Ailing Hui,Shouhu Xuan
Due to the abuse of antibiotics, the sensitivity of patients to antibiotics is gradually reduced. This work develops a Fe3O4@SiO2@Au/PDA nanochain which shows an interesting magnetic-field-induced improvement of its photothermal antibacterial property. First, SiO2was wrapped on Fe3O4nanospheres assembled in a chain to form a Fe3O4@SiO2nanocomposite with a chain-like nanostructure. Then, the magnetic Fe3O4@SiO2@Au/PDA nanochains were prepared using in situ redox-oxidization polymerization. Under the irradiation of an 808 nm NIR laser, the temperature rise of the Fe3O4@SiO2@Au/PDA nanochain dispersion was obvious, indicating that they possessed a good photothermal effect. Originating from the Fe3O4, the Fe3O4@SiO2@Au/PDA nanochain showed a typical soft magnetic behavior. Both the NIR and magnetic field affected the antimicrobial performance of the Fe3O4@SiO2@Au/PDA nanochains.Escherichia coliandStaphylococcus aureuswere used as models to verify the antibacterial properties. The experimental results showed that the Fe3O4@SiO2@Au/PDA nanochains exhibited good antibacterial properties under photothermal conditions. After applying a magnetic field, the bactericidal effect was further significantly enhanced. The above results show that the material has a broad application prospect in inhibiting the growth of bacteria.
研究领域:
材料科学
·
生物医学工程
·
微生物学
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2024
·
IF 4.7
Xiaofei Li,Lili Geng,Haifeng Shi,Songshou Ye,Ley Boon Sim,Jinbao Zheng,Nuowei Zhang,Binghui Chen
In this study, we utilized a sol-gel method to prepare Ni-HPW/SiO 2 catalysts with varying citric acid (CA):Ni molar ratios ranging from 0 to 5.0. The catalysts demonstrated different levels of activity in the hydrogenation of ethylbenzene , which correlated to their respective CA:Ni ratios. Introducing citric acid in the preparation process of nickel-based catalysts yielded mesopore formation and reduced NiO particle size, producing a more uniform NiO dispersion on SiO 2 , which was confirmed by BET, XRD, and TEM analyses. The results of H 2 -TPR, H 2 -TPD, NH 3 -TPD, and Py-IR analyses suggested that the addition of citric acid augmented the interaction between phosphotungstic acid (HPW), Ni species, and SiO 2 . Citric acid improved Ni species and HPW dispersion, fostering increased HPW-Ni species formation. This, in turn, generated additional electron-deficient Ni ions , stemming from semi-reduced HPW-Ni species, which acted as Lewis acid sites, enhancing Ni + species effectiveness in activating aromatic rings. The better-dispersed, non-HPW-bound NiO, which, upon complete reduction to Ni, led to a substantial rise in H 2 bond cleavage, thereby facilitating more hydrogen spillover. Overall, the infusion of citric acid into fabricating Ni-HPW/SiO 2 catalysts sparked a significant surge in their aromatic hydrogenation ability.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2016
·
IF 6.333
Hang Wang,Xiaojie Li,Xupin Zhuang,Bowen Cheng,Wei Wang,Weimin Kang,Lei Shi,Hongjun Li
Proton currents are an integral part of the most important energy-converting structures in biology. We prepared a new type of bioinspired Nafion (Bio-Nafion) membrane composited of biofunctional SiO 2 (Bio-SiO 2 ) nanofiber and Nafion matrix . SiO 2 nanofibers were prepared by electrospinning silica sol prepared from tetraethyl orthosilicate . Meanwhile, Bio-SiO 2 nanofibers were synthesized by immobilizing amino acids (cysteine, serine , lysine, and glycine) on SiO 2 nanofibers, which acted as efficient proton-conducting pathways that involved numerous H + transport sites. In our study, the SiO 2 nanofibers biofunctionalized with cysteine were further oxidized, and the composite membranes were designated as Nafion-Cys, Nafion-Lys, Nafion-Ser, and Nafion-Gly, respectively. We then investigated the different polar groups ( SO 3 H, OH, and NH 2 ) of the amino acids that contributed to membrane properties of thermal stability, water uptake (WU), dimensional stability, proton conductivity , and methanol permeability . Nafion-Cys exhibited the highest proton conductivity of 0.2424 S/cm (80 °C). Nafion-Gly showed the lowest proton conductivity and WU because glycine contains the least number of hydrophilic groups among the amino acids. Overall, the introduction of Bio-SiO 2 nanofiber to composite membranes significantly improved proton conductivity, dimensional stability, and methanol permeability.
研究领域:
材料科学
·
能源科学
·
生物仿生学
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2015
·
IF 2.752
Zeyu Guan,Yajie Shu,Yongwen Ma,Jinquan Wan
A novel core–shell amino-functionalized silica coated nanoscale zero valent iron (NH 2 –SiO 2 @NZVI) was prepared by the combination of liquid phase reducing method and improved Stöber method. The surface, structure and characteristics of the nanoparticles (NPs) were investigated by transmission electron microscope (TEM), scanning electron microscopy (SEM), powder X-ray diffraction (XRD), and the elemental analysis. It was found that the appropriate dropping rate of NaBF 4 and the proper usage of 3-aminopropyl trimethoxysilane (APTMS) were the crucial and key step for the formation of highly uniform and desirable NH 2 –SiO 2 @NZVI particles. SEM, XRD results showed that the obtained NH 2 –SiO 2 @NZVI NPs has a good dispersibility and antioxidant capacity with the particle size around 120 nm, BET surface area around 123.38 m 2 /g when NaBH 4 dropping speed was 1 ml/min and the usage of APTMS was 0.3 ml/ml tetraethyl orthosilicate (TEOS). NH 2 –SiO 2 @NZVI particles can effectively adsorb TCP with the first-order rate constant k obs of 0.0204 h −1 in 18 h and remove with a removal efficiency of 45.62% in 48 h.
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 Environmental Chemical Engineering
·
2022
·
IF 7.968
Tiantian Feng,Qing Liu,Can Yang,Guiju Li,Jin Liu
Considering the stability and hazard of chromium complexes, their removal and recovery from industrial wastewater is a worthy goal. Membrane capacitive deionization (MCDI) can effectively reduce co-ion adsorption compared with CDI technology and has been demonstrated to be a promising deionization technology. In this study, functionalized activated carbon (AC@SiO 2 -NH 2 ) was applied as a MCDI eletrode. The AC@SiO 2 -NH 2 adsorbs chromium complexes (Cr(Ⅲ)-EDTA) through electrostatic gravitation of protonated amino groups (-NH 3 + ). With applied voltage of 1.2 V, solution flow rate of 20 mL min −1 and initial concentration of 300 mg L −1 , the electrosorption capacity of the AC@SiO 2 -NH 2 electrode for Cr(Ⅲ)-EDTA was 17.70 mg g −1 . The Ragone curves verified that the electrosorption rate (SER) of the AC@SiO 2 -NH 2 electrode was positively correlated with voltage and initial concentration. Moreover, the effects of competing ions (K + , Na + , and Mg 2+ ) in a series of single electrolyte solution by the AC@SiO 2 -NH 2 electrode were investigated. It was also verified that the optimum pH was 3 for electrostatic attraction. The energy consumption of the MCDI process is calculated as 0.251 kWh m 3 and 0.039 kWh g −1 Cr at 1.2 V. We envisage that the use of AC@SiO 2 -NH 2 electrodes will pave the way for efficient operation of MCDI as well as the preferential recovery of Cr(Ⅲ)-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
Processes
·
2023
·Vol. 11
·期 4
·1159
·
IF 3.5
ZhengNan Sun,Biao Yan,GuoLin Jing,YiHai Yang,HongJing Li,FuNing Zhang
Differences in the synthesis methods can affect the performance of nanocomposite materials. The synthesis methods of SiO2-based nanocomposite pour point depressants synthesized by chemical hybrid are mostly in situ polymerization and chemical grafting. However, there are still some gaps in the synthesis of nanocomposites using chemical grafting. In this paper, the amino-modified Nano-SiO2and octamethyl methacrylate-maleic anhydride copolymer was used to prepare PM18-g-NSiO2by an amidation reaction, and the product was compared with PM18/SiO2prepared by the solution blending method. The characterization results of FT-IR and SEM showed that the chemical bond formed between PM18 and NSiO2and PM18-g-NSiO2showed a more regular morphology structure. The results of rheological tests showed that the optimal concentration of PM18-g-NSiO2and PM18/SiO2is 300 mg·kg−1, but the decrease of PM18-g-NSiO2is 19 °C, while the decrease of PM18/SiO2is only 13 °C. The lowest viscosity of model oil added PM18-g-NSiO2was only 214 mPa·s while PM18/SiO2reached 453 mPa·s. The wax crystal structure after adding PM18-g-NSiO2is also more regular and smaller compared to PM18/SiO2. We concluded that differences in the synthesis methods may lead to the different coverage of the polymer on the surface of the nanoparticle.Keywords:nano-SiO2;polymethacrylate;nanocomposite pour point depressant;flow properties;wax crystal
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY COMMUNICATIONS
·
2024
·
IF 4.4
Haijiao Jia,Xinyu Xu,Yuchen Cui,Mengqi Cheng,Guirong Borjihan,Xiao Zhang,Shengbo Yang,Youxin Li
A novel magnetic heterogeneous ruthenium catalyst (Fe 3 O 4 @SiO 2 -DTPA-Ru) was prepared by using magnetic silicon spheres as support, ethylenediaminepentaacetic acid (DTPA) as functional ligands, ruthenium chloride as catalyst precursor. The results obtained after a series of characterizations showed that the catalyst Fe 3 O 4 @SiO 2 -DTPA-Ru was 5–15 nm in size with a 0.205 nm lattice and contained 0.31 mmol Ru/g catalyst. It also had a good thermal stability under 232°C which was verified by thermal filtration method. Besides, the saturation magnetic intensity was as high as 20.54 emu/g. The catalyst Fe 3 O 4 @SiO 2 -DTPA-Ru was applied for the first time into thirteen oxidation reactions of aromatic alcohols and showed good catalytic activity even the yields of eleven aromatic alcohols were all over 90%. In catalyzing 1-phenylethanol to acetophenone, its TOF and TON were 9677 h −1 and 6991, respectively. The Fe 3 O 4 @SiO 2 -DTPA-Ru catalyst could still maintain good reusability and catalytic performance after 15 cycles of 1-phenylethanol oxidation, which was superior to many reported catalysts and had great potential in future industrial production.
研究领域:
化学
·
催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
NANO
·
2018
·
IF 1.1
Chang Liu,Qianqian Su,Li Li,Jie Sun,Jian Dong,Weiping Qian
In this work, we designed a simple substrate-immersed solvothermal route for the one-step synthesis of novel ordered SiO 2 /Ag arrays, employing SiO 2 colloidal crystals as templates and alcohol as reducing agent. The Ag nanoparticles were uniformly deposited in situ onto SiO 2 colloidal crystals, which exhibited high surface enhanced Raman spectroscopy (SERS) activity and uniform SERS intensity. It was found that ordered SiO 2 /Ag arrays could rapidly scavenge the absorbed-Nile blue A (NBA) molecules from the surfaces with the assistance of H 2 O 2 , while the SERS signals of NBA decreased sharply and almost completely disappeared within four minutes. This can be attributed to the superior catalytic activity of Ag nanoparticles. After five times of re-immersion and re-absorbing process of NBA, the substrates could still keep ∼ 74.8% SERS intensity versus the original. The high activity and durability of the as-prepared SiO 2 /Ag SERS substrate endow them as a promising candidate for trace detection.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Xiaoyu Wang,Dong Zhang,Jiahui Wu,Iryna Protsak,Shihua Mao,Chunxin Ma,Meng Ma,Mingqiang Zhong,Jun Tan,Jintao Yang
Continuously growing interest in the controlled and tunable transport or separation of target molecules has attracted more attention recently. However, traditional “on–off” stimuli-responsive membranes are limited to nongradient feedback, which manifests as filtration efficiency that cannot be increased or decreased gradually along with the different stimuli conditions; indeed, only the transformation of on/off state is visible. Herein, we design and fabricate a series of robust salt-responsive SiO2@cellulose membranes (SRMs) by simply combining salt-responsive poly[3-(dimethyl(4-vinylbenzyl)ammonium)propyl sulfonate] (polyDVBAPS)-modified SiO2 nanoparticles and cellulose membranes under negative-pressure filtering. The antipolyelectrolyte effect induces stretch/shrinkage of polyDVBAPS chains inside the channels and facilities the directional aperture size and surface wettability variation, greatly enhancing the variability of interfacial transport and separation efficiency. Due to the linear salt-responsive feedback mechanism, the optimal SRMs achieve highly efficient target macromolecule separation (>75%) and rapid oil/saline separation (>97%) with a continuous gradient and adjustable permeability, instead of simply an “on–off” switch. The salt-responsive factors (SiO2-polyDVBAPS) could be reversibly separated or self-assembled to membrane substrates; thus, SRMs achieved unprecedented repeatability and reusability even after long-term cyclic testing, which exceeds those of currently reported membranes. Such SRMs possess simultaneously a superfast responsive time, a controllable gradient permeability, a high gating ratio, and an excellent reusability, making our strategy a potentially exciting approach for efficient osmotic transportation and target molecule separation in a more controllable manner.
研究领域:
材料科学
·
环境工程
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）