CHEMOSPHERE
·
2022
·
IF 8.943
Ning Hou,Xin Zhao,Ziyi Han,Xinxin Jiang,Yongping Fang,Yun Chen,Dapeng Li
The inability to demulsify oil-in-water emulsions via green and efficient processes is a challenging problem in many industrial processes. As a novel biodemulsifier, protein demulsifiers display excellent dispersibility and stability, but their demulsification mechanisms are not clear, which severely restricts their large-scale production and application. In this study, the demulsification mechanism of the high-efficiency protein biodemulsifier oxalate decarboxylase (Bacm OxdC), which is secreted by the Bacillus mojavensis XH1 strain, for an oil-in-water emulsion was analyzed. The results showed that Bacm OxdC was spontaneously adsorbed at the oil-water interface and turned its hydrophobic amino acids outward to increase its hydrophobicity and break the emulsified system. Furthermore, it effectively reduced the oil-water interfacial tension and interfacial film strength, thereby reducing the oil-water interfacial energy and finally enabling demulsification. To further improve the demulsification efficiency and reusability, Fe 3 O 4 @SiO 2 @OxdC-DDSA was prepared. This method provided a magnetic response for Bacm OxdC and enabled efficient demulsification. The demulsification rate of Fe 3 O 4 @SiO 2 @OxdC-DDSA reached 98.1% at 24 h, which was 30.7% higher than that of the original Bacm OxdC. After three cycles, the demulsification rate still reached 89.3%, proving it has excellent recyclability . This work is the first study on the demulsification mechanism of protein biodemulsifiers and provides useful insights into the demulsification mechanism of biodemulsifiers for oil-in-water emulsions. In addition, a promising high-efficiency modification technique for protein biodemulsifiers was proposed, which provided information for the development of biodemulsifiers for oil-water separation.
研究领域:
生物化学
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环境科学
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材料科学
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DOI
PubMed
高影响因子
MICROCHIMICA ACTA
·
2022
·Vol. 189
·期 12
·1-10
·
IF 6.408
Dai Yin,Jiang Wei,Zheng Yani,He Pei,Zhu Ruizhi,Fei Jianwen,Xu Wei,Liu Chunbo,Hong Junli
A selective method for the determination of myosmine (a tobacco alkaloid) was developed using molecularly imprinted polymers (MIPs) based on Fe 3 O 4 @SiO 2 and PAMAM dendrimers. Fe 3 O 4 @SiO 2 with excellent magnetism and rapid separation performance was chosen as carrier for the MIPs. Moreover, the MIPs modified with PAMAM dendrimers exhibited a regular structure and abundant functional groups, which improve the efficiency of imprinting sites. The myosmine concentration was measured by HPLC with PDA detector, and the UV detection wavelength was set to 200 nm. The linear range of this assay was 13.2–400 mg/L with a correlation coefficient of 0.999, and the detection limit was 4.0 mg/L (S/N = 3). The MIPs have been used for the determination of myosmine in cigarettes, and the recovery range was 84.2–93.5%, with RSD values in the range 0.41–3.1%. In conclusion, our MIPs combine advantages of simple preparation and remarkable selectivity, which gives them excellent application prospects for the sensitive determination of trace myosmine in tobacco products. Graphical abstract
研究领域:
分析化学
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材料科学
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烟草研究
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2023
·
IF 8.2
Sisi Ma,Wenying Shi,Hongbin Li,Yifeng Zhang
Inspired by the natural nacre structure, we propose a new strategy to fabricate mineralized, multiple crosslinked hydrogel membranes with the “rigid silica in soft polymer” nacre-like structure. In-situ SiO 2 nanoparticles (NPs) and polyvinyl alcohol/sodium alginate (PVA/NaAlg) are used to simulate the rigid “bricks” and soft “mortar” compositions of nacre, respectively. The nacre-like mineralized (PVA/CaAlg/SiO 2 ) membrane showed a higher tensile strength of 4.1 ± 0.08 MPa, excellent pure water flux of 170 ± 3 L/m 2 h, and an oil/water rejection rate of 99 %. The interwoven hierarchal structure, similar to nacre, was determined by SEM analysis . In addition, incorporating SiO 2 NPs increases the anti-swelling, roughness, and hydrophilicity of the membranes. PVA/CaAlg/SiO 2 membrane exhibited excellent superhydrophilicity (WCA value was 0°) and superoleophobicity underwater (OCA value was 162°). PVA/CaAlg/SiO 2 membrane also showed excellent separation performance for water-soluble organic pollutants and can be used for dye separation with rejection efficiencies of 99.5 %, 99.1 %, and 98.3 % for Congo red (CR), Alizarin red (AR), and Sunset yellow (SY), respectively. Moreover, PVA/CaAlg/SiO 2 membrane had outstanding long-term filtration and antifouling performance. The biomineralization-inspired structure provides a promising technique that can be used to prepare high-performance organic-inorganic membranes with great promise for wastewater separation application.
研究领域:
材料科学
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环境工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Cleaner Production
·
2020
·
IF 7.246
Bao Liu,Kexuan Lyu,Yongqiang Chen,Baozhong Ma,Chengyan Wang
Manganese electrodeposition experiments were performed in an anion-exchange membrane (AEM) electrolysis reactor using Ti/IrO 2 –RuO 2 –SiO 2 anode. The influence of Mn 2+ concentration, cathode current density (CCD), (NH 4 ) 2 SO 4 concentration, SeO 2 concentration and electrolysis time on the cell voltage (CV), cathode current efficiency (CE) and specific energy consumption (SEC) of manganese electrodeposition was investigated. The crystalline structure, chemical composition and morphology of the deposited manganese metal and the generated dark mass were analyzed using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM) and energy dispersive spectroscopy (EDS) measurements. The obtained results reveal that the crystalline structure of the deposited manganese metal was α-Mn. The dark mass of MnOOH would be generated and precipitated on the surface of the cathode, inhibiting the electrodeposition of manganese metal when the operating condition was not well controlled. Considering the CE, SEC and environmental aspect, the operating condition of Mn 2+ concentration = 30 g L −1 , CCD = 350 A m −2 , (NH 4 ) 2 SO 4 concentration = 110 g L −1 and SeO 2 concentration = 0.03 g L −1 was regarded as the best condition for manganese electrodeposition. Under this condition, the CE was 78.3% and the SEC was 4346–4433 kW h t −1 after electrolyzing for 24 h. Compared with the traditional approach, the CE increased by about 10% and the SEC decreased by about 27%. In addition, the electrolytic manganese anode slime was not generated during the manganese electrodeposition process . This approach is recommended as it will reduce the energy consumption and the quantities of solid waste discharge of manganese electrodeposition.
研究领域:
材料科学
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电化学工程
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DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2017
·
IF 3.133
Liuting Shi,Jia Hu,XuDong Lin,Liang Fang,Fang Wu,Jiao Xie,FanMing Meng
Composite coatings consisting of polyphenylene sulfide (PPS), polytetrafluoroethylene (PTFE) and 40 nm silicon dioxide (SiO 2 ) nanoparticles (PPS-PTFE/SiO 2 ) with SiO 2 in the range of 0–4 g/l were successfully prepared on AZ31 Mg alloys by a simple spray process. The morphology, composition, water contact angle (WCA), wear behavior and corrosion properties of the composite coatings were measured by using SEM, FT-IR, OCA20, sandpaper abrasion and electrochemical workstation, respectively. Effects of SiO 2 content on the wear behavior and corrosion properties of the coatings were studied. It is found that micro-sized protrusions distribute on the surface of the coatings, and a fibrous-network structure of PTFE arranges on the protrusions. WCAs of the PPS-PTFE/SiO 2 (0–4 g/l) coating are in the range of (152°–145.5°) ± 0.3° and the sliding angles (SAs) are less than 5°. The WCAs of the un-abraded and 10 m-abraded-on-sandpaper PPS-PTFE/SiO 2 (4 g/l) coating are 145.5°±0.3° and 142.5°±0.3°, respectively, implying the PPS-PTFE/SiO 2 coating is a robust superhydrophobic one with good wear resistance. Due to the superhydrophobic characteristics, the PPS-PTFE-based coatings show superior corrosion resistance in 3.5 wt% NaCl solution to pristine AZ31 Mg alloys. Owing to the excellent superhydrophobicity, wear resistance and corrosion resistance properties, the robust PPS-PTFE/SiO 2 coating is regarded to possess great potential to be applied in automobiles and navigation industries in future.
研究领域:
材料科学
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表面工程
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腐蚀与防护
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产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2024
·
IF 9.4
Kefa Sheng,Hongyu Xia,Jianping Ge
Selective hydrogenation of nitroaromatics is a crucial industrial reaction, but there are still challenges in developing nanocatalysts with stable active centers, yet easily recyclable characteristics. Here, a magnetically separable Pd/Fe 3 O 4 @SiO 2 nanocatalyst was prepared through the seeding growth of silica on the Fe 3 O 4 nanocrystal cluster (NC) followed by in situ reduction of Pd nanoparticles (NPs) on the amino group modified Fe 3 O 4 @SiO 2 nannotube (NT). The nanocatalyst showed good activity and stability in the hydrogenation of a series of nitroaromatics as the Pd NPs were highly dispersed on the nanotubes. Meanwhile, it could be easily separated from the reaction solution and well-redispersed in the solvent for the next-round reaction due to the superparamagnetic property of the Fe 3 O 4 NC and the good dispersibility of silica in many organic solvents. The magnetically separable nanocatalyst combined the high activity of the nanocatalyst and the convenient separation of a traditional heterogeneous catalyst, which effectively promote the practical application of nanomaterials in catalysis.
研究领域:
材料科学
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催化化学
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产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2014
·Vol. 2
·期 38
·15931-15937
·
IF 0
Zhongyang Zhang,Qingzhong Xue,Yonggang Du,Cuicui Ling,Wei Xing
Graphene nanoribbons (GNRs) have been of great interest in a wide range of device applications for their novel physical, electronic and spin transport properties. Here we study the hydrogen (H2) sensing properties of GNRs decorated with palladium (Pd) nanoparticles by a one-step chemical modification and reduction process. A novel Pd-GNR film/SiO2/Si structure was fabricated by transferring a Pd-GNR film onto a heavily doped Si substrate with a native oxide layer. It is demonstrated that the Pd-GNR film/SiO2/Si structure exhibits highly enhanced responses to H2 than the pristine Pd-GNR film at parts-per-million (ppm) concentration levels at room temperature. For example, the Pd-GNR film/SiO2/p-Si structure shows an excellent response (ΔR/Rair) of ∼94% to 100 ppm H2 in air. The sensing mechanism was proposed to explain these H2 sensing characteristics based on p–n junction theory. Our findings demonstrate the incorporation of nanoparticles in GNR-based gas sensors through chemical functionalization and present a novel strategy for the application of GNRs in high performance gas sensors.
研究领域:
材料科学
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传感器技术
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纳米科技
✓ 已验证
DOI
Materials Research Express
·
2020
·Vol. 7
·期 9
·095012
·
IF 1.929
Menghui Wan,Haodong Zhao,Zhihua Wang,Yanbao Zhao,Lei Sun
In this paper, a convenient method to fabricate flexible and free-standing surface-enhanced Raman scatting (SERS) substrates for direct bacteria detection without aptamer bonding is presented. SiO2 nanofibers were prepared via electrospinning and calcination by using tetraethyl orthosilicate as the precursor. Subsequently, it was coated with polydopamine (PDA) by self-polymerization. Finally, Ag@PDA@SiO2 nanofibrous membranes were obtained through in situ growth of Ag nanoparticles in Tollens' reagents. The as-prepared Ag@PDA@SiO2 composite nanofibrous membranes were characterized by techniques of scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction, energy-dispersive x-ray spectroscopy and thermo gravimetric analysis. The flexibility of the as-prepared nanofibrous membranes were verified simply through manual folding. Small molecule probes of 4-mercaptophenol (4-MPh) and 4-mercaptobenzoic acid (4-MBA) were chosen to investigate the SERS sensitivity of the as-prepared Ag@PDA@SiO2 as free-standing substrates. Furthermore, Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), as typical strains of Gram-negative and Gram-positive bacteria, were performed to directly SERS detection by dropping bacteria suspension onto the fibrous membranes without any previous treatment, such as aptamer combination. In addition, the antimicrobial properties of the as-prepared Ag@PDA@SiO2 electrospinning nanofibrous membranes were tested by inhibition zone and turbidity methods. The results show that Ag nanoparticles with an average diameter of 50 nm are uniformly deposited on the surface of electrospinning nanofibers, and the as-prepared Ag@PDA@SiO2 nanofibrous membranes are flexible. As SERS substrates, it shows a rather high detection limitation of 10−11 mol l−1 for 4-MPh and 4-MBA. More importantly, this substrate can be applied for bacteria label-free SERS detection, i.e., complicated procedures are avoided. Meanwihile, the as-prepared Ag@PDA@SiO2 nanofibrous membranes exhibit excellent antibacterial properties. Thus, it has application prospects in trace bacteria detection and water purification.
研究领域:
材料科学
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生物医学工程
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分析化学
✓ 已验证
DOI
高影响因子
Surfaces and Interfaces
·
2021
·
IF 4.837
Sixun Niu,Xiaobin Dong,Weifen Zhang,Xiansong Li,Shiquan Liu
SiO 2 -Cu x O composites may have potential applications in antibacterial and dye degradation . However, it is still a challenge to prepare SiO 2 -Cu x O films with well crystallized Cu x O nanoparticles and high Cu/Si molar ratios under alkaline condition at relatively low temperature. Herein, by using PVP stabilized alkaline silica sol and ethanolic solution of copper acetate, a series of SiO 2 -Cu x O composite films with high Cu/Si molar ratios were successfully prepared via a facile two-step process of dip coating and annealing. The microstructure and crystalline phase of the composite films were finely controlled by changing the amount of PVP, the concentration of copper solution and the calcination temperature. The results showed that film prepared with 1 mol/L copper acetate solution and calcined at 500 °C exhibited the best antibacterial activity , adsorption and photocatalytic performance toward methylene blue in solutions. The prepared films could be conveniently used in antibacterial field and the treatment of organic wastewater.
研究领域:
材料科学
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环境科学
·
微生物学
✓ 已验证
产品关联
DOI
高影响因子
Nano Select
·
2024
·
IF 0
Zhiyu Zhang,Fei Long,Yanhong Guo,Yunxiao Liang,Jing Wang,Yong Ren
The large-sized nanofilm-constructed hierarchical porous SiO 2 (LNCHPS) is successfully prepared by the dual templating approach and subsequently used as the support for g-C 3 N 4 . A series of characterization techniques are conducted to evaluate the structure and property of the as-prepared materials. The LNCHPS possesses two sets of explicated successive pass-through macropores (0.5–1.0 µm) with large specific surface area. In addition, the macropore wall is constructed by uniform mesoporous nanofilms with the thickness ranging from 35 to 50 nm. Then, the photocatalytic property is investigated by degradations towards Rhodamine B (RhB) under simulated sunlight, in which experiments have been performed through controlling the g-C 3 N 4 loading contents, solution pH values, and photocatalyst dosages. The apparent rate constant of g-C 3 N 4 /LNCHPS could reach 0.03 min −1 under optimum conditions, showing 6.0 times that of the bulk g-C 3 N 4 . In addition, g-C 3 N 4 /LNCHPS also exhibits significantly enhanced performance in H 2 evolution (39.9 µmol h −1 ) compared to that of the bulk g-C 3 N 4 . High light absorption and utilization, enhanced adsorption capability and quick electron hole separation can render this fine structure excellent photocatalytic performance. Our work enables a facile route for large-scale preparation of g-C 3 N 4 /LNCHPS for addressing the wastewater treatment and hydrogen energy production simultaneously.
研究领域:
材料科学
·
环境科学
·
能源技术
✓ 已验证
DOI
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
·
2021
·
IF 7.664
Yuhuan Yuan,Cong Peng,Duo Chen,Zhanjun Wu,Shichao Li,Tao Sun,Xin liu
SiO 2 nanoparticles (NPs) were modified with as-synthesized coupling agent containing isocyanate-terminated polyurethane (PUCA) to enhance the interaction between SiO 2 NPs and DGEBA/DDM matrix in purpose of promoting the dispersion condition of the SiO 2 NPs in cured resin. Uniform dispersion of the PUCA-SiO 2 NPs was observed in the cured resin which was in obvious contrast with that of the raw SiO 2 NPs and the IPTS-SiO 2 NPs according to the visible light transmittance and TEM observation. The tensile behaviors of the PUCA-SiO 2 composites were found obviously promoted than that of the raw SiO 2 and IPTS-SiO 2 composites. DMA results showed that the T g of the PUCA-SiO 2 composite was 8.9 °C and 5.8 °C higher than that of the raw, IPTS-SiO 2 composite. SEM observation of the fracture surfaces showed that PUCA-SiO 2 composite possessed the densest crack texture. This work showed that grafting the polyurethane chain to the surface of the inorganic NPs is an effective way to obtain uniform dispersion of the inorganic NPs in resin matrix.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2023
·
IF 5.7
Sheng-Jin He,Ling-Feng Su,Chuang-Tian Zhan,Xiu-Bin Chen,Wei-Ming Guo,Shi-Kuan Sun,Li-Xiang Wu,Jia-Xiang Xue,Hua-Tay Lin
Low-temperature joining of SiC ceramics using raw CaO-Al 2 O 3 -MgO-SiO 2 mixed powders (CAMS-P) and CaO-Al 2 O 3 -MgO-SiO 2 glass (CAMS-G) as additives for the liquid-phase sintering of SiC nanopowders (NITE phase) in combination with surface oxidation was studied. Using CAMS-P as an additive for SiC joining required 1650 °C and produced a lower shear strength of 77.2 ± 3.5 MPa, compared to untreated SiC (108.2 ± 15.8 MPa). Using CAMS-G as an additive, the compactness of SiC joints obtained at 1550 °C was higher than that of NITE joints obtained at 1650 °C with CAMS-P as an additive. Nonetheless, the low joining temperature resulted in gaps and delaminations at the interface, and the joints strength was only 48.3 ± 5.6 MPa. Incorporating CAMS-G as an additive and surface oxidation achieved reliable NITE phase joining at 1550 °C, with no observed gaps or delaminations at the interface. The resulting joints strength was as high as 100.0 ± 0.8 MPa. The joining mechanism was discussed and compared, involving microstructural analysis .
研究领域:
材料科学
·
陶瓷工程
✓ 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）