CRYSTENGCOMM
·
2012
·Vol. 15
·期 5
·1001-1006
·
IF 3.842
Miao Wang,Guoqing Jiang,Yanfeng Tang,Yujun Shi
Without any templates or surfactants, large-scale 3D persimmon-shaped hierarchical LaF3 and LaF3:Ln3+ (Ln = Eu, Tb) have been synthesized via a simple hydrothermal route using organic tetrafluroborate complexes N(C4H9)4BF4 as the fluoride source. The phase and morphology of the products have been characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and selected area electron diffraction (SAED). The SEM and TEM results indicate the 3D persimmon-shaped hierarchical microstructures are constructed by numerous nanodisks with mean thickness of 50 nm. It is found that several factors, including the fluoride sources, molar ratio of reagents and the reaction time, play crucial roles in the formation of the multilayer stacked structures. Detailed studies indicate that the layer-by-layer self-assembly of nanodisks is responsible for the formation of 3D hierarchical structures. The possible mechanism of the crystal growth and assembled procedure are also proposed. Furthermore, the photoluminescent properties of LaF3:Ln3+ (Ln = Eu, Tb) are studied, which exhibit orange-red (Eu3+:5D0–7F1,2,3,4) and green (Tb3+, 5D4–7F3,4,5,6) emission, respectively.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
TRIBOLOGY INTERNATIONAL
·
2021
·
IF 4.872
Ting Xie,Yaru Shi
The friction transfer of polytetrafluoroethylene (PTFE) composites is closely related to their tribological performances . To clarify the effects of LaF 3 /CeF 3 on the friction transfer of PTFE-based composites, the transfer film thickness and coverage were investigated under different loads or speeds. The results show that the addition of LaF 3 /CeF 3 can decrease the transfer film thickness and increase the transfer film coverage to form a thin and uniform transfer film, and the co-filling of LaF 3 and CeF 3 is better in promoting friction transfer of PTFE-based composites than single addition of LaF 3 or CeF 3 . The correlation between transfer film and tribological properties was also analyzed, which indicates that the friction transfer is beneficial for improving the tribological properties of PTFE composites.
研究领域:
材料科学
·
摩擦学
✓ 已验证
产品关联
DOI
高影响因子
SOLID STATE COMMUNICATIONS
·
2015
·
IF 1.897
Lina Liu,Ruirui Sun,Yongsheng Zhang,Ruifei Qin,Dongmei Zhang,Chunjuan Tang,Linfeng Chen,Lishuang Liu
LaF 3 :Ce,Tb@SiO 2 core-shell nanostructures were synthesized using a new one-pot reverse microemulsion strategy. One-pot method facilitates the synthetic process of this kind of core-shell nanostructures. The crystalline phase, size, morphology, pore structure and luminescence properties were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), nitrogen physisorption isotherm, photoluminescence (PL) excitation and emission spectra. The results revealed that the core-shell nanostructures have an average diameter of about 27 nm and cores of about 3 nm, and that these nanostructures contain micropores with an average pore diameter of 0.43 nm. The characteristic emissions of Tb 3+ were observed under the excitation of Ce 3+ 4f–5d transition due to the energy transfer from Ce 3+ to Tb 3+ . LaF 3 :Ce,Tb@SiO 2 nanostructures can disperse well in water and the colloid can emit bright green light under ultraviolet (UV) irradiation.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS LETTERS
·
2020
·
IF 3.204
Ping Huang,Peili Luo,Beiying Zhou,Lianjun Wang,Wan Jiang
Silica glass-ceramics containing highly crystalline LaF 3 :Eu 3+ nanocrystals (NCs) were successfully prepared at a relatively low temperature of 950 °C within a short time of 10 min by Spark Plasma Sintering. The LaF 3 :Eu 3+ NCs were not only well retained without interfacial reaction occurring between LaF 3 :Eu 3+ NCs and silica matrix phases, but also homogeneously dispersed in glass matrix. The luminescence peaks located within reddish-orange spectral scope were registered and identified as the intra-configurational 4 f 6 - 4 f 6 transitions originated from Eu 3+ optically active ions ( 5 D 0 → 7 F J , J = 0–4). By adopting the LaF 3 :Eu 3+ glass-ceramic as color convertor, the fabricated LED shows excellent reddish emission.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
Lubrication Science
·
2024
·
IF 1.8
Cong Liu,Yanguo Yin,Rongrong Li,Haoping Wang,Liang Li
A strategy involving the use the rare-earth compound LaF 3 with good lubrication and stability properties as a filler in the preparation of Cu-based composites was proposed to solve the problem of poor wear resistance in Pb-free Cu-Bi materials. The influence and regulatory mechanism of LaF 3 content on the mechanical and tribological properties of these composites were studied. The results indicate that LaF 3 has a good refining effect on Cu alloy grains, and LaF 3 and Bi are distributed in a network along the grain boundaries of the Cu alloy in the material. As the LaF 3 content increases, the mechanical properties and friction coefficient of the composite gradually decrease, and the wear rate first declines and then increases. The wear resistance of Cu-Bi composite containing LaF 3 mainly depends on the mechanical support provided by the matrix. When the LaF 3 content is higher than 6%, the composite strength is extremely low, and the increase in lubricant content at the friction interface does not play a decisive role in the material wear behaviour. The material wear rate increases with the increase in LaF 3 content. Therefore, using 6% LaF 3 is recommended to improve the wear resistance of the material and maintain a balance among its mechanical properties, antifriction and wear resistance.
研究领域:
材料科学
·
摩擦学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2020
·
IF 5.162
Yuhan Zhong,Qing Wang,Guangxue Chen
In this experiment, sodium carboxymethyl cellulose (CMC) was used as raw material, rare earth chloride was used as inorganic nano luminescent material to prepare a series of lanthanide rare earth ions-doped composite materials. The photoluminescent materials were prepared via in-situ chemical deposition of rare earth ions onto CMC surface with the help of carboxyl groups contained on the surface of CMC. The structure, fluorescence properties, surface morphology, surface elements, crystalline structure and thermal stability of CMC before and after surface modification were characterized by FT-IR spectra (FTIR), photoluminescence spectra (PL), field emission scanning electron microscope (FESEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and thermal gravimetric analyses (TGA), respectively. The results showed that CMC/LaF 3 :Eu 3+ composites were successfully prepared, and the fluorescence intensity can be organically controlled by the reaction temperature, doping ratio and doping concentration of rare earth ions. The method has mild reaction conditions, facile process without expensive material equipment. Moreover, the as-prepared transparent anti-counterfeiting film possessed good fluorescence intensity, transparency and excellent mechanical properties, which can be used for large-scale functional packaging films.
研究领域:
材料科学
·
光学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Lubrication Science
·
2025
·
IF 1.9
Tao Wu,Shuguang Fan,Ningning Song,Chuanping Gao,Shengmao Zhang,Yujuan Zhang
This study aims to explore the potential application of LaF 3 nanoparticles as high-performance gear oil additives. Lanthanum trifluoride nanoparticles modified by di(2-ethylhexyl) phosphoric acid (D2EHPA) [denoted as LaF 3 -D2EHPA], which exhibited excellent dispersion stability, were prepared using a liquid-phase chemical method. The tribological properties of LaF 3 -D2EHPA nanoparticles in weakly polar mineral base oil (150 N), polyalphaolefin (PAO6), and strongly polar synthetic ester oil diisooctyl sebacate (DIOS) were investigated using a four-ball friction and wear tester. In combination with the adsorption experiments using a dissipative quartz crystal microbalance (QCM-D), the compatibility and action mechanisms of LaF 3 -D2EHPA nanoparticles with extreme-pressure and anti-wear additives for typical gear oils were further investigated. The results indicate that when the mass fraction of LaF 3 -D2EHPA nanoparticles is 0.2%, the tribological properties of all three base oils are improved to the greatest extent. When LaF 3 -D2EHPA nanoparticles are mixed with gear oil additives T321 (sulfurized isobutylene) and T307 (ammonium thiophosphate), they exhibit high film-forming rates and anti-wear properties, forming a boundary lubricating film on the worn surface. This film consists of a tribochemical reaction film containing sulfur and phosphorus, as well as LaF 3 -D2EHPA nanoparticles that have been deposited.
研究领域:
纳米技术
·
润滑工程
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 54
·期 4
·2897-2907
·
IF 2.993
Wu Honge,Fang Ming,Fei Guang Tao,Hu Ze Min,De Zhang Li
LaF 3 nanocrystals (NCs) are usually used as good host matrix for down-conversion phosphors owing to their impressive photophysical properties. In this study, Pr 3+ -activated LaF 3 with hollow hexagon nanostructures (HHNs) is achieved by a green and eco-friendly hydrothermal method without any catalyst, template, or surfactant. The pore structure of the LaF 3 HHNs is greatly affected by the content of Pr 3+ ions and hydrothermal reaction time. The LaF 3 : Pr 3+ NCs excited by 467 nm light show strong emission peaks locating in visible light region (centered at 612 and 635 nm) and the first biological window region (existed in 689 and 721 nm), respectively. The relative photoluminescence (PL) intensity of LaF 3 : Pr 3+ NCs from 20 to 60 °C (biological temperature) decreases slightly and decreases only 20% at 120 °C. The PL emission intensity could reach the maximal value with doping ~ 1.5% Pr 3+ ions. Based on the outstanding photophysical properties, LaF 3 : Pr 3+ NCs will be used for both warm white light-emitting diodes and bio-imaging.
研究领域:
材料科学
·
光学
·
生物医学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2013
·
IF 2.144
Ying Ji,Xiaoyang Liu,Benxian Li,Jingchao Zhang,Xiaofeng Wang
Mild molten salt synthesis (MSS) method was utilized to synthesize rare earth fluorides nanocrystals with favorable fluorescence efficiency. LaF 3 nanocrystals were achieved through this modified MSS method by only using La(NO 3 ) 3 ·6H 2 O and NH 4 HF 2 as starting materials. NH 4 HF 2 is difunctionality as both fluorine source and the flux. The effects of reaction time and temperature to the synthesis of LaF 3 nanocrystals were discussed in detail. The fluorescence of LaF 3 nanocrystals was detected with excitation wavelength of 360 nm, the results showed a broad band emission centered at 475 nm. The photoluminescence properties of pure LaF 3 nanocrystals and Eu 3+ doped samples were also investigated. In our work, white light emission was achieved in single element (Eu 3+ ) doped LaF 3 nanocrystals by adjusting the concentration of Eu 3+ ions. This would be the combination of broad emission of LaF 3 nanocrystals and sharp line emission of Eu 3+ in the LaF 3 :Eu 3+ nanocrystals.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2022
·
IF 4.171
Zuodong Liu,Qilong Shen,Yue Cao,Siya Li,Xue Chen,Jiashun Wang,Yongsheng Yu,Bingchu Mei,Qiangshan Jing,Peng Liu
Pr, La:SrF 2 ceramics co-doped with various amounts of LaF 3 were fabricated by hot-pressing (HP) sintering in a vacuum environment. The transmittance of the Pr, La:SrF 2 ceramics was gradually improved with the increase in sintering temperature , and the sintering temperature of 1000 °C was adequate to fabricate highly transparent ceramics without rapid grain growth. Residual pores and undissolved PrF 3 /LaF 3 fluorides were identified as light scattering defects within the ceramic sintered at 830 °C. The effect of LaF 3 on the microstructural, transmittance, and spectroscopic characteristics of ceramics was studied systematically. The luminescence intensity of the Pr, La:SrF 2 ceramics was drastically enhanced through LaF 3 co-doping, while the optical transmittance first slightly increased and then decreased. The ceramic sample co-doped with 1 wt% LaF 3 exhibits the highest transmittance with the smallest grain size of 43.4 μm, and the transmittance reaches 87.8% at 400 nm and 87.2% at 1100 nm.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale
·
2012
·Vol. 4
·期 18
·5619-5626
·
IF 5.914
Suwen Li,Xiao Zhang,Zhiyao Hou,Ziyong Cheng,Pingan Ma,Jun Lin
Uniform, ultra-small-sized and well-water-dispersible LaF3 nanoparticles doped with trivalent rare earth (RE) ions (Eu3+ or Tb3+) have been synthesized by a simple, low temperature synthesis route. The nanoparticles, with sizes of about 3.2 nm (for those doped with Eu3+) and 3.0 nm (for those doped with Tb3+), are roughly spherical and monodisperse. 1,2,4,5-Benzenetetracarboxylic acid (labeled as BA) as sensitizer has been bonded to the surface of the nanoparticles, which can sensitize the emission of RE3+ in the LaF3 nanoparticles. The BA–LaF3:RE3+ (RE = Eu or Tb) nanoparticles have a broad absorption band in the UV domain, and show enhanced luminescence of RE3+ based on an energy transfer from BA ligands to RE3+ ions (i.e. the so-called “antenna effect”). Due to the dual protection of organic ligands (BA) and inorganic matrices (LaF3), BA–LaF3:RE3+ (RE = Eu or Tb) nanoparticles have longer excited state lifetimes than LaF3:RE3+ (RE = Eu or Tb) nanoparticles as well as lanthanide coordination polymers of BA.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Solar RRL
·
2020
·Vol. 4
·期 6
·2000126
·
IF 7.527
Hanjin Jiang,Hairui Fang,Dong Wang,Jianbo Sun
Due to its promising potential applications in seawater desalination and purification, solar steam conversion has attracted tremendous attention recently. The light-to-heat conversion capacity of solar absorbers directly affects the rate at which freshwater is produced by the evaporation system. Herein, an efficient double-layer evaporator is developed using MoS 2 /LaF 3 /PDMS ink as an absorber that is printed onto a commercial PTFE membrane by the controlled ink-spray method. The LaF 3 nanoparticles-decorated MoS 2 nanoflowers nanocomposite exhibits enhanced adsorption of sunlight due to semiconductor/solid electrolyte interface synergetic effect-induced broadband absorption ability. Combining the advantages of local heating and rapid vapor emission, the water evaporation rate of the evaporator with spray ink in sunlight is 1.76 kg m −2 h −1 and the corresponding high light-to-heat conversion efficiency is 91%. Also, the membrane module has good operability, certain mechanical strength, and good long-term stability. The synergistic effect of a rare-earth solid electrolyte and semiconductor provides new ideas for the design and development of materials with high light-to-heat conversion efficiency and good thermal stability.
研究领域:
材料科学
·
能源工程
·
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）