GLASS PHYSICS AND CHEMISTRY
·
2025
·Vol. 50
·期 5
·511-520
·
IF 0.6
Sihao Jian,Xia Chenkang,Hao Mingyuan,Liu Weihai,Ma Chao,Miao Yang
Silica aerogel has rec eived more and more attention in the field of thermal insulation. However, the poor mechanical properties and high temperature instability of pure silica aerogels seriously restrict the development and application of silica aerogels. Fiber reinforcement is an effective way to improve the mechanical properties of silica aerogels. In this paper, Al 2 O 3 –SiO 2 aerogel was compounded with mullite fiber to prepare silicon–aluminum aerogel fiber felt. When the strain value reaches 30%, the compressive strength of the fiber felt with aerogel content of 50.1 wt % reaches 0.21 MPa, and the thermal conductivity of fiber felt decreases from 0.0425 to 0.0322 W/m K when the aerogel content increases to 50.1 wt %. The thermal insulation performance test of fiber felt also showed that the addition of aerogel could significantly improve the heat insulation of fiber felt, and the cold surface temperature of fiber felt was only about 33°C when the flame exceeding 1000°C calcined the fiber felt for 10 s. This work provides a simple solution to prepare aerogel/nanofiber felt with good mechanical properties and low thermal insulation. Highlights: silicon–aluminum composite aerogel felt (AS/ASNFAs) has been prepared by sol-gel and impregnation method, AS/ASNFAs has good mechanical properties (the compressive strength reaches 0.21 MPa) and thermal insulation (0.0322 W/m K), AS/ASNFAs has good flame retardancy, and it remains stable after being burned at 1000 degrees butane for 10 min.
研究领域:
材料科学
·
纳米技术
·
热工学
·
化学工程
✓ 已验证
DOI
高影响因子
RSC Advances
·
2022
·Vol. 12
·期 19
·11715-11721
·
IF 4.036
Baokang Zou,Yipeng Zhan,Xiuli Xie,TongTong Zhang,Runkai Qiu,Fangming Zhu
Two salalen titanium(IV) complexes ((H-salalen)TiCl2 and (F-salalen)TiCl2) containing hydrogen and fluorine respectively on the phenolate ring close to the imine were synthesized for the copolymerization of ethylene with 1-octene to prepare poly(ethylene-co-1-octene) in the presence of methylaluminoxane (MAO). The (F-salalen)TiCl2/MAO showed higher catalytic activity and better copolymer characteristics such as a higher molecular weight, narrower molecular weight distribution, and higher 1-octene incorporation than (H-salalen)TiCl2/MAO, which revealed that the electron-withdrawing conjugated effect introduced by fluorine substituents led to improvements on catalytic performance and thermal stability. The influences of copolymerization conditions including temperature, Al/Ti molar ratios and comonomer feed ratios on the copolymerization behavior of (F-salalen)TiCl2/MAO and the copolymer microstructure were investigated in detail. Under the activation of MAO, the (F-salalen)TiCl2 could produce ultrahigh molecular weight poly(ethylene-co-1-octene) with 1-octene incorporation ratios in the range of 0.9–3.1 mol% and exhibit relatively high activity. It could be inferred that long ethylene sequences in the copolymer were segregated by the isolated 1-octene units based on the 13C NMR characterization of the copolymer. Moreover, the thermal properties and crystallization of copolymers were determined by DSC and XRD and correlated to the ethylene sequence length distribution. The reactivity ratios calculated by the triad distribution in 13C NMR revealed the random comonomer distribution in the copolymer chain.
研究领域:
高分子化学
·
配位聚合
·
催化化学
·
材料科学
·
高分子物理
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2017
·
IF 3.387
Jiajie Yu,Muzhong Shen,Siyu Liu,Feng Li,Dongping Sun,Tianhe Wang
In this paper, we describe a simple technique for direct growth of gold nanoparticles (GNPs) into a nanostructured porous alumina layer on conductive glass slide (PAOCG). PAOCG was attached firmly with a small piece of steel and was then immersed in a HAuCl 4 solution. Electro-induced electrons from steel were employed to reduce AuCl 4 − on PAOCG. The galvanic replacement reaction (GRR) was adopted as the fundamental mechanism for reducing metal precursors. This mechanism was further studied by open circuit potential-time (OCP-t) experiment and the result demonstrated that steel induced the continuous proceeding of this reaction. This strategy presents a simple and general protocol for preparation of metal nanoparticles (MNPs) on conductive glass substrates. The SERS properties of Au/PAOCG were investigated using aqueous crystal violet (CV) and 4-mercaptopyridine (4-Mpy) as probe molecules. Au/PAOCG allowed as low as 10 −9 M CV and 10 −8 M 4-Mpy to be detected. The reusability of this substrate was achieved by measuring the SERS spectrum of the probe molecules followed with a 400 °C heat treatment for 10 min to remove the residuals. This substrate could be reused for at least ten cycles without any significantly reduced SERS performance. Therefore, this surface can serve as a portable, durable and reusable SERS substrate and has a potential for commercial applications.
研究领域:
材料科学
·
分析化学
·
纳米技术
·
生物传感
·
表面科学
✓ 已验证
DOI
高影响因子
OPTICS AND LASER TECHNOLOGY
·
2023
·
IF 5
Shizhou Tan,Pengcheng Jian,Maocheng Shan,Yongming Zhao,Zhihua Zheng,Yiming Yang,Yuhui Zeng,Dan Xu,Zhenyu Chen,Changqing Chen,Feng Wu,Jiangnan Dai
In this work, we demonstrated tunable structured AlGaN-based nanoporous (NP) distributed Bragg reflectors (DBRs) with high-reflectivity through one-step vertical-lateral electrochemical etching (ECE). The aperture of nanopores in the doping layer and the size and density of V-pits on the surface of NP-DBRs can be tuned by controlling the etching bias. Furthermore, by further tuning the thickness of alternating layers, we achieved high reflectivity of NP-DBRs at multiple center wavelengths within the wavelength range from 280 to 800 nm. To explore its potential applications, MoS 2 with a photoluminescence (PL) emission in the red light region was grown for the first time on the NP-DBRs. Due to the light localized effect of surface V-pits and the high reflectivity of the bottom DBRs , the PL intensity of MoS 2 was significantly enhanced by a factor of 37.3 compared to the region without NP-DBRs. The PL enhancement of MoS 2 on porous AlGaN and different periodic NP-DBRs further validated the PL enhancement mechanism. The corresponding theoretical simulations also revealed that the PL enhancement should be attributed to the combined effect of enhanced light absorption and NP-DBRs induced emission interference. The fabricated AlGaN-based NP-DBRs provide a new approach for improving the quantum efficiency of two-dimensional layered materials, which holds significant importance for advancing the development of miniaturized and integrated 2D/3D heterogeneous structure systems in the field of optoelectronics.
研究领域:
光电子学
·
半导体材料
·
纳米光子学
·
二维材料
·
固体物理
·
表面科学
·
集成光子器件
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Yuxing Sun,Lei Zhao,Juan Yang,Xiang Wang,Huanjun Peng,Jingdong Peng
Light absorption range, recycling stability and charge transfer efficiency are key to the performance of photocatalytic material. Based on these targets, a Al doped TiO 2 catalyst was synthesized by the evaporation-induced process, after processed by NaBH 4 reduction, the black TiO 2 doped with Al was finally prepared. Uv-vis DRS, EPR and XPS analyses confirm the expanded light absorption window (300 nm - 1000 nm) and the introduction of abundant oxygen vacancy after the reduction process. The final product BTiO 2 /Al-0.5 has a degradation rate of about 84 % over the tetracycline hydrochloride within 60 minutes, the reaction rate constant (k) is 10.6 times higher than the unreduced sample. The dramatic change of photocatalytic ability can be assigned to the broadened visible light absorption , increased charge separation efficiency, narrowed band gap and defect-enriched oxygen vacancy . This work offers insights into the fabrication of TiO 2 catalyst and the introduction of oxygen defect.
研究领域:
材料科学
·
光催化
·
环境功能材料
·
纳米材料
·
表面化学
·
半导体催化
✓ 已验证
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2018
·
IF 2.732
Qinghua Yang,Benxue Jiang,Shuilin Chen,Yiguang Jiang,Pande Zhang,Jun Wang,Shiqing Xu,Long Zhang
Al 2 O 3 : Er 3+ /Yb 3+ transparent ceramics codoped with Zn 2+ ions with intense upconversion and near infrared emission were prepared by conventional solid-state reaction and vacuum and hot isostatic pressing sintering. The effects of Zn 2+ incorporation to the structure, transparent, upconversion and NIR luminescence were discussed in detail. The as prepared Al 2 O 3 ceramics exhibited a total transmittance of ~ 75% in infrared regions (800–3300 nm) and ~ 50% in visible regions (500–800 nm). Under the excitation of a 980 nm laser diode , the as prepared Al 2 O 3 ceramics displayed two tense upconversion emission peaks of a green one centered at 550 nm and a red one centered at 660 nm and a tense near infrared emission peak centered at 1.532 µm, characteristic of Er 3+ emission. Compared with Er 3+ /Yb 3+ doped only, Zn 2+ codoped Al 2 O 3 :Er 3+ /Yb 3+ transparent ceramics showed higher upconversion and near infrared emission of ~ 11 times and ~ 4 times, respectively. The enhancement mechanism due to incorporation of Zn 2+ ions was also discussed in detail.
研究领域:
材料科学
·
光学材料
·
无机非金属材料
·
发光材料
·
陶瓷工程
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2021
·
IF 8.128
Xin-yu Hu,Mao-xiang Jing,Hua Yang,Quan-yao Liu,Fei Chen,Wei-yong Yuan,Le Kang,Dong-hong Li,Xiang-qian Shen
Poor room-temperature ionic conductivity and lithium dendrite formation are the main issues of solid electrolytes. In this work, rod-shaped alumina incorporation and graphite coating were simultaneously applied to poly (propylene carbonate) (PPC)-based polymer solid electrolytes (Wang et al., 2018). The obtained alumina modified solid electrolyte membrane (Al-SE) achieves a high ionic conductivity of 3.48 × 10 −4 S/cm at room temperature with a wide electrochemical window of 4.6 V. The assembled NCM622/Al-SE/Li solid-state battery exhibits initial discharge capacities of 198.2 mAh/g and 177.5 mAh/g at the current density of 0.1 C and 0.5 C, with the remaining capacities of 165.8 mAh/g and 161.3 mAh/g after 100 cycles respectively. The rod-shaped structure of Al 2 O 3 provides fast transport channels for lithium ions and its Lewis acidity promotes the dissociation of lithium salts and release of free lithium ions. The lithiophilic Al 2 O 3 and Graphite form intimate contact with metallic Li and create fast Li + conductive layers of Li-Al-O layer and LiC 6 layer, thus facilitating the uniform deposition of Li and inhibiting Li dendrite formation during long-term cycling. This kind of composite Al-SE is expected to provide a promising alternative for practical application in solid electrolytes.
研究领域:
材料科学
·
电化学
·
能源存储
·
固态离子学
·
纳米复合材料
·
锂金属电池
✓ 已验证
DOI
高影响因子
Journal of Environmental Sciences
·
2018
·
IF 3.12
Fan Bu,Baoyu Gao,Qinyan Yue,Xue Shen,Wenyu Wang
Coagulation–ultrafiltration (C–UF) is widely used for surface water treatment. With the removal of pollutants, the characteristics of organic matter change and affect the final treatment efficiency and the development of membrane fouling . In this study, we built a dynamic C–UF set-up to carry out the treatment of micro-polluted surface water, to investigate the characteristics of dissolved organic matter from different units. The influences of poly aluminum chloride and poly dimethyldiallylammonium chloride (PDMDAAC) on removal efficiency and membrane fouling were also investigated. Results showed that the dosage of PDMDAAC evidently increased the UV 254 and dissolved organic carbon removal efficiencies, and thereby alleviated membrane fouling in the C–UF process. Most hydrophobic bases (HoB) and hydrophobic neutral fractions could be removed by coagulation. Similarly, UF was good at removing HoB compared to hydrophilic substances (HiS) and hydrophobic acid (HoA) fractions. HiS and HoA fractions with low molecule weight accumulated on the surface of the membrane, causing the increase of transmembrane pressure (TMP). Membrane fouling was mainly caused by a removable cake layer, and mechanical cleaning was an efficient way to decrease the TMP.
研究领域:
环境工程
·
水处理技术
·
膜分离
·
有机地球化学
·
给水处理
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Peibo Li,Guoqiang Luo,Xiaoshan Zhang,Xiao Wang,Zhihao Wu,Yi Sun,Qiang Shen
As one of the most commonly used binary alloys , the effect of intermetallic compounds (IMCs) of Al-Cu alloys in powder metallurgy on their structure and properties is instructive for tailoring Al-Cu alloys for different applications. In this investigation, a series of Al-Cu-Ag alloys with varying Cu compositions were fabricated via hot pressing. TEM analysis identified CuAl 2 as the primary intermetallic compounds , with Ag existing in forms including Ag 2 Al, elemental Ag, and an Ag-(Cu) solid solution . The modulation of Cu content influenced the state of Ag and the mechanical behaviors of the Al-Cu-Ag alloy. Particularly, the high Al/Cu alloy, benefiting from a synergistic effect comprising stacking faults, nanoscale precipitates, and solid solutions, exhibited outstanding mechanical properties. Conversely, the Al-50Cu-3Ag alloys displayed significant brittleness , attributed to the adverse impact of large-scale intermetallic compounds and increased grain size due to the formation of CuAl 2 . The incorporation of nanoparticles effectively mitigated the grain size in high Al/Cu alloys. This study elucidates the correlation between the evolution of intermetallic compounds and composition in Al-Cu alloys, offering novel insights into the reinforcement of both Al-based and Cu-based alloys.
研究领域:
材料科学
·
金属学与热处理
·
粉末冶金
·
结构材料
·
合金设计
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2018
·
IF 3.141
Wei Bi,Yanjie Hu,Wenge Li,Hao Jiang,Chunzhong Li
In this work, a nanoreactor combining layers of facile traditional two-dimensional (2D) material, hexagonal boron nitride (h-BN, which often called the white graphene) with Pt/Al2O3 catalyst was designed to exhibit higher stability, activity, and selectivity in automobile exhaust treatment. Characterization revealed that h-BN does coat on the surface of platinum and forms a distinct Pt@h-BN/Al2O3 core–shell nanostructure. This as-prepared catalyst possesses good thermal stability and selectivity, because of the excellent high-temperature tolerance and the multidefected structure of the h-BN shell; that is, small molecules such as CO and O2 can easily intercalate into the nanoreactor, while large molecules such as propylene are blocked out. Meanwhile, the intercalated reactants can achieve the conversion of CO to CO2 faster (ΔT100 = 20 °C) with the confinement effect. The study indicates that constructing a nanoscale confined environment with two-dimensional (2D) coating can enhance the performance of the catalyst in multiple aspects and simultaneously provide a good example for designing nanostructured catalysts with multifaceted improvement.
研究领域:
催化化学
·
纳米材料科学
·
环境催化
·
能源化学
·
表面科学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2023
·Vol. 107
·期 1
·475-487
·
IF 3.9
Ling He,Ling Pan,Wei Zhou,Maolin Chen,Qinzhao Zhang,Wenqian Pan,Peng Xiao,Yang Li
The interaction and infiltration behavior between typical calcium–ferrum–alumina–silicate (CFAS) and Yb 4 Hf 3 O 12 ceramics at 1300, 1400, and 1500°C for different duration times were investigated. At 1300°C, the CFAS melt first crystallized and then generated massive anorthite with high-melting point, reducing the wettability of CFAS melt and physically blocking CFAS penetration paths. As the temperature increased to 1400°C and 1500°C, the wettability of the molten CFAS correspondingly increases. A continuous reaction layer, composed of apatite, fluorite, and garnet, was formed over Yb 4 Hf 3 O 12 ceramic due to the penetration of CFAS melt. Furthermore, the infiltration rate of CFAS decreases with increasing corrosion time because of the barrier effect primarily derived from the as-mentioned continuous reaction layer.
研究领域:
材料科学
·
陶瓷材料
·
高温材料
·
无机化学
·
表面化学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2018
·
IF 8.097
Kaihua Wen,Yanlei Wang,Shimou Chen,Xi Wang,Suojiang Zhang,Lynden A. Archer
Rechargeable lithium (Li) metal batteries are considered the most promising of Li-based energy storage technologies. However, tree-like dendrite produced by irregular Li+ electrodeposition restricts it wide applications. Herein, based on a cation-microphase-regulation strategy, we create solid–liquid electrolytes (SLEs) by absorbing commercial liquid electrolytes into polyethylene glycol (PEG) engineered nanoporous Al2O3 ceramic membranes. By means of molecular dynamics simulations and comprehensive experiments, we show that Li ions are regulated and promoted in the two microphases, the channel phase and nonchannel phase, respectively. The channel phase can achieve homogeneous Li+ flux distribution by multiple mechanisms, including its uniform array of nanochannels and ability to suppress lateral dendrite growth by its high modulus. In the nonchannel phase, PEG chains swollen by electrolyte facilitate desolvation and fast conduction of Li+. As a result, the studied SLEs exhibit high ionic conductivity, low interfacial resistance, and the unique ability to stabilize deposition at the Li anode. By means of galvanostatic cycling studies in symmetric Li cells and Li/Li4Ti5O12 cells, we further show that the materials open a path to Li metal batteries with excellent cycling performance.
研究领域:
材料科学
·
电化学
·
能源存储
·
纳米技术
·
电池技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）