COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2022
·
IF 5.518
Jisheng Yang,Han Li,Zede Yi,Murong Liao,Zhiyong Qin
Superhydrophobic treatment of wood is of great significance for improving the service life of wood and expanding its application fields. In this study, two process methods were designed to meet above requirements. Using polydopamine (PDA), 3-mercaptopropyltriethoxysilane (KH580) and nano-Al 2 O 3 as the micro-nano structure maker and octadecyltrichlorosilane (OTS) as a low surface free energy agent to modify rough surface in order to prepare superhydrophobic wood samples (Wood@One-step and Wood@Two-step). The contact angle (CA) and sliding angle (SA) of the Wood@One-step were 155.3° and 4.76°, respectively; the CA and SA of the Wood@Two-step were 152.9° and 7.65°, respectively. Surface electron microscopy (SEM) images showed that the surface of Wood@One-step and Wood@Two-step were honeycomb structure and layered stacking structure respectively. The superhydrophobic properties of Wood@One-step were superior because of its more reasonable micro-nano roughness. Atomic force microscope (AFM) images presented that the nano-Al 2 O 3 particles could effectively provide nano-level roughness. X-ray photoelectron spectroscopy (XPS) analysis showed that KH580 had covalent interaction with PDA. Thermogravimetric (TG) analysis, the immersion of acid-base solution and organic solution revealed that obtained superhydrophobic wood samples had excellent stability in the face of environmental challenges.
研究领域:
材料科学
·
木材科学
·
表面化学
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Shang Gao,Boyu Hu,Xin Song,Zhigang Dong,Renke Kang
Chemical mechanical polishing (CMP) offers promising pathway to smooth 4H-SiC. Dispersion stability of polishing slurry is crucial factor affecting 4H-SiC performance. Particles in polishing slurry can easily agglomerate due to poor dispersion stability, affecting surface quality of wafers. Nano-Al 2 O 3 is common particle in the slurry that directly controls mechanical removal. In this paper, the impact of different dispersants (PEG, (NaPO 3 ) 6 , and NH 4 PAA) on the dispersibility of slurry containing nano-Al 2 O 3 is studied. Results indicate that the slurry containing NH 4 PAA exhibits the greatest dispersion stability with superior 4H-SiC surface quality, with surface roughness (Sa) reaching 1.054 nm. The slurry containing PEG shows poor dispersion, leading to poor SiC surface quality, and the Sa reached 5.314 nm. The dispersion mechanism of different dispersants is also discussed.
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
POLYMER
·
2024
·
IF 4.1
Zhongli Zhang,Zhensheng Wu,Fan Zou,Fuqiang Tian
Polyimide (PI) refers to a polymer containing an imide ring characteristic structure on the main chain. It has excellent thermal stability, insulation properties and other characteristics. The Tesla transformer is the core component of the primary pulse source of the high-current electron beam accelerator. It is also an essential component of the energy storage pulse power supply. Therefore, it has broad application prospects in the fields of national defense and civil industry. If the insulation performance of the turn-to-turn coils of the Tesla transformer does not meet the standards, it will break down during high-voltage corona discharge, causing transformer failure. Therefore, it is crucial to improve the insulation performance of Tesla transformer inter-turn wrapping materials. The incorporation of fluorine-containing groups has proven to be a transformative strategy that significantly enhances the physical, chemical, optical, and electrical properties of PI films. In addition, numerous studies have demonstrated that introducing inorganic fillers into the polyimide matrix can substantially enhance the insulating properties of polyimide films. This paper specifically concentrates on elevating the insulating and thermal attributes of polyimide. Initially, a range of polyimide films was synthesized for performance assessment by employing various fluorinated dianhydride and diamine components, utilizing them as substrates. Then, we used nano-silicon nitride (nano-Si 3 N 4 ) and nano-alumina (nano-Al 2 O 3 ) as doping phases to prepare PI composite films, which reduced the dielectric constant and increased the breakdown strength.
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
高影响因子
POLYMER BULLETIN
·
2020
·Vol. 78
·期 10
·5891-5903
·
IF 2.014
khan Muhammad Zeeshan,Wang Feipeng,Waleed Aashir,Huang Zhengyong,Hassan Muhammad Arshad Shehzad,Khan Asim
In this work, epoxy resin samples incorporated with nano-Al 2 O 3 of various concentrations 0, 1, 3 and 5 wt% were prepared. Surface treatment of nano-Al 2 O 3 was performed by the saline coupling agent of γ-aminopropyltriethoxysilane (KH550) to restrict the aggregation. The thermal gravimetric analysis (TGA) of the epoxy resin/Al 2 O 3 nanocomposites was observed at different filler concentrations. TGA analysis indicated that incorporation of nano-Al 2 O 3 increases the decomposition temperature as compared to pure epoxy resin. Moreover, 3 wt% filler concentration showed increased decomposition temperature because nanoparticles form close connections between molecules due to which thermal stability improved at higher temperatures. Atomic force microscopy was employed for the surface morphology of epoxy resin/Al 2 O 3 nanocomposites which has indicated that surface roughness of epoxy resin/Al 2 O 3 nanocomposites increased slightly with the filler concentration. The distribution of trap energy and trap density obtained by isothermal surface potential decay measurements revealed that 1 wt% filler concentration results in decrease in surface potential decay rate. In addition, significant increase in deep trap energy level and trap density was obvious at 1 wt% filler concentration. AC and DC breakdown strength of the samples was measured to evaluate the effect of filler concentrations on the electrical characteristics of epoxy resin. The results showed that breakdown strength of the epoxy resin/Al 2 O 3 nanocomposites increases with the nano-Al 2 O 3 concentration. Moreover, increase in trap energy results in an increase in the breakdown strength of the nanoparticles.
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2015
·
IF 4.504
Bo Liang,Siqi Tang,Qingbai Jiang,Chuangsheng Chen,Xu Chen,Shengliang Li,Xuehui Yan
This paper presents the preparation and characterization of a series of PEO-PMMA composites containing different lithium salts (LiClO 4 or LiTFSI) with or without nano-Al 2 O 3 . Nano-Al 2 O 3 is added to the polymer electrolytes to alter the morphology, ionic conductivity , interfacial and thermal shrinkage properties. Nano-Al 2 O 3 can effectively improve the stability of the polymer electrolyte membrane interface. The tensile strength of the PEO-PMMA-LiTFSI-Al 2 O 3 electrolyte membrane is 3.24 MPa at room temperature . The study shows that the ion conductivities at room temperature for PEO-PMMA-LiTFSI (EO/Li + = 10) and PEO-PMMA-LiTFSI-Al 2 O 3 (EO/Li + = 10) are 6.71 × 10 −7 S/cm and 9.39 × 10 −7 S/cm, respectively. A good dimensional stability was observed for PEO-PMMA-LiTFSI with a thermal shrinkage of 8.7%. The electrochemical windows of PEO-PMMA-LiTFSI and PEO-PMMA-LiTFSI-Al 2 O 3 are all stable up to 4.6 V versus Li + /Li, which makes them good electrolyte candidates of lithium ion batteries with high-potential cathodes.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Xiaoxuan Pang,Yajiang Xian,Wei Wang,Pengcheng Zhang
Aluminum matrix Boron carbide composites is an important thermal neutron shielding material. In order to prepare 12 wt% B 4 C/6061Al composite with higher mechanical properties by powder metallurgy method, the new composite reinforced by Nano-Al 2 O 3 particles was fabricated by hot isostatic pressing in the semi-solid temperature range. The tensile properties and strengthening effects of the composite were investigated in this research. The tensile stress-strain curve of the composites was tested by material testing machine, and the microstructure and tensile fracture morphology of composites were analyzed by scanning electron microscopy (SEM) and transmission electron microscopes (TEM). The results indicated that the tensile strength of the composite was greatly improved by the addition of Nano-Al 2 O 3 , but the elongation decreased obviously. Nano-Al 2 O 3 particles had seriously affected the microstructure and fracture morphology of the composite and lead to the more obvious brittle fracture characteristics . Strengthening mechanisms of Nano-Al 2 O 3 particles reinforced 6061Al/B 4 C composite have been discussed, which reveals that grain boundary strengthening mainly plays the most important role.
研究领域:
材料科学
·
力学
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产品关联
DOI
高影响因子
JOURNAL OF WUHAN UNIVERSITY OF TECHNOLOGY-MATERIALS SCIENCE EDITION
·
2020
·Vol. 35
·期 3
·514-519
·
IF 0.64
Liu Tingling,Pang Xiaoxuan,Xian Yajiang,Luo Hao,Zhang Pengcheng
Aluminum-matrix boron carbide (B 4 C p /Al) is a kind of neutron absorbing material widely used in nuclear spent fuel storage. In order to improve the tensile property of B 4 C p /Al composites, a new type of nano-Al 2 O 3 particle (Al 2 O 3np ) reinforced B 4 C p /Al + Al 2 O 3np composites were prepared by powder metallurgy method. The Monte Carlo particle transport program (MCNP) was used to determine the influence of Al 2 O 3np on the thermal neutron absorptivity of composites. The universal material testing machine and scanning electron microscope (SEM) were used to study the mechanical properties, microstructure and fracture morphology of B 4 C p /Al composites. The results indicated that the neutron absorption properties of B 4 C p /Al composites were not affected by the addition of nano-Al 2 O 3 particles in the range of 1 wt%–15 wt%. The addition of Al 2 O 3np can obviously reduce the grain size of B 4 C p /Al matrix metals thus improve the tensile strength of the composites. The addition threshold of Al 2 O 3np is about 2.5 wt%. Both B 4 C p and Al 2 O 3np change the fracture characteristics of the composites from toughness to brittleness, and the latter is more important.
研究领域:
材料科学
·
核工程
✓ 已验证
DOI
高影响因子
Heliyon
·
2023
·
IF 4
Honglin Zhang,Ke Zhang,Zhiguo Zhiguo,Jian Hao
In this work, the metalloporphyrin film of PtOEP/Poly (St-co-TFEMA) modified by nano Al 2 O 3 powder was prepared, and the enhancement performance of oxygen sensing was studied in detail. It was verified that the modified film extended the residence time of oxygen through the characterization of SEM. The phosphorescence intensity changes with the content of Al 2 O 3 and PtOEP were studied. The Stern-Volmer equations before and after modification of Al 2 O 3 powder was compared. It was found that the linearity of the calibration curve was still high, but the oxygen sensitivity value of K SV was significantly improved due to the increase of quenching probability between indicator and oxygen. Finally, the stability test shows that the Al 2 O 3 @PtOEP/Poly (St-co-TFEMA) oxygen sensing film presents a strong anti-photo-bleaching ability, and the response time is shortened.
研究领域:
材料科学
·
化学传感器
·
光学检测
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2022
·
IF 14.224
Tingting Zhang,Dan Li,Xuan Zhu,Minglu Zhang,Jianhua Guo,Jianmin Chen
Nano-Al 2 O 3 has been widely used in various consumer products and water treatment processes because of its unique physicochemical properties . The probability of human exposure to nano-Al 2 O 3 increases significantly, of which oral ingestion is an important route. However, effects and underlying mechanisms of nano-Al 2 O 3 on gut microbiota and resistome are still not well delineated. Here, we systematically investigated the effects of nano-Al 2 O 3 on the human gut microbiome by an in vitro simulator of human colon microbial ecosystem. Results indicated that nano-Al 2 O 3 interfered with the gut microbiota, and significantly suppressed the short-chain fatty acids metabolism, which might pose adverse effects on the host. More seriously, high level of nano-Al 2 O 3 (50 mg/L) was more destructive to the gut flora, though the damage might be temporary. In addition, sub-inhibitory low-dose of nano-Al 2 O 3 (0.1 mg/L) significantly enhanced the abundance of antibiotic resistance genes (ARGs) after 7-day exposure. This is attributed to that low concentration of nano-Al 2 O 3 can promote horizontal transfer of ARGs by increasing cell membrane permeability and relative abundance of transposase (e.g. tnpA , IS613 , and Tp614 ). Our findings confirmed the adverse effects of nano-Al 2 O 3 on the human gut resistome and emphasized the necessity to assess potential risks of nanomaterials on the human gut health.
研究领域:
微生物学
·
环境科学
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED PHYSICS LETTERS
·
2016
·Vol. 109
·期 9
·
IF 3.142
Yao Manwen,Peng Yong,Xiao Ruihua,Li Qiuxia,Yao Xi
SrTiO 3 /nano Al 2 O 3 inorganic nanocomposites were prepared by using a conventional sol-gel spin coating process. For comparison, SrTiO 3 films doped by equivalent amount of sol-Al 2 O 3 have also been investigated. Aluminum deposited by using vacuum evaporation was used as the top electrode. The nanocomposites exhibited a significantly enhanced dielectric strength of 506.9 MV/m, which was increased by 97.4% as compared with the SrTiO 3 films doped with sol-Al 2 O 3 . The leakage current maintained of the same order of microampere until the ultimate breakdown of the nanocomposites. The excellent electrical performances are ascribed to the anodic oxidation reaction in origin, which can repair the internal and/or surface defects of the films.
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Yu He,Yunxiang Cai,Ling Zhang,Kaige Liu,Gang Liu,Bingxi Xiang,Jianpang Zhai,Ling Bing Kong,Tianshu Zhang,Yin Liu
Al 2 O 3 transparent ceramics have important applications in electronics, solid-state lighting, military and 5G industries. At present, thin and large-size Al 2 O 3 ceramics are urgently required by enterprises. Tape casting method has emerged as a powerful tool in producing transparent ceramics, but the preparation of the slurries is generally very time consuming. In this study, a one-step ball milling process was proposed to fabricate Al 2 O 3 transparent ceramics through non-aqueous tape casting, in which green tapes were obtained with uniform texture and no distortion. Thickness of the Al 2 O 3 transparent ceramics approached 0.1 mm. The effects of dry pressing on single and double-layer tapes were also compared. It was found that dry pressing has essentially no effect on monolayer samples, but contributed to improve the densification and promoted grain growth of the bilayer samples. Our results could be used as reference for the preparation of extremely thin Al 2 O 3 transparent ceramic wafers.
研究领域:
材料科学
·
陶瓷
·
电子
·
固态照明
·
军事
·
5G产业
✓ 已验证
产品关联
DOI
高影响因子
IONICS
·
2021
·Vol. 28
·期 2
·767-777
·
IF 2.817
Zang Guojing,He Min,Liao Youhao,Li Minsui,Hong Mingyao,Li Weishan
To improve the comprehensive performance of fibrous membrane based on poly(methyl vinyl ether-alt-maleic anhydride) P(MVE-MA)- and poly(vinylidene fluoride-co-hexafluoropropylene) P(VdF-HFP)-blended copolymers, a small amount of nano-Al 2 O 3 was doped by electrospinning technique to apply for high-energy-density cathode material of nickel-rich LiNi 0.8 Co 0.15 Al 0.05 O 2 (NCA) based Li-ion battery. The results indicated that the electrospinning membrane and corresponding gel polymer electrolyte (GPE) only doped with 3.0 wt.% nano-Al 2 O 3 presented the proper structure and delivered the best electrochemical characterization. Due to the uniform distribution of nanoparticles on the fibers with higher density, the specific surface area and porosity of the fiber membrane were increased, leading to the improved fracture stress of 172.0 MPa for the membrane and ionic conductivity of 2.1 × 10 −3 S cm −1 for the GPE at room temperature. Contributed from the proper pore structure and the enhanced interfacial stability, the capacity retention of 89.4% was achieved for the Li/GPE/NCA coin cell after 200 cycles in the voltage range of 3.0 V and 4.3 V under room temperature using the GPE doped with 3 wt.% Al 2 O 3 , compared with that of 63.6% for the GPE without nanoparticles. Similarly, the discharge capacity of the coin cell under 7 C rate (123.2 mAh g −1 ) maintained 65% of that at 0.3 C (189.4 mAh g −1 ), showing good rate performance of the developed GPE. Therefore, the significant improvement in electrochemical stability of the GPE achieved by doping a small number of nanoparticles provided a simple and feasible solution for the development of high-energy-density Li-ion batteries.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）