WEAR
·
2020
·
IF 4.108
Wei Sun,Xiaojun Liu,Kun Liu,Wei Wang,Jiaxin Ye
Nanosized α-phase alumina has been one of the few inorganic fillers that could induce 10 −7 mm 3 /Nm ultralow wear rates of PTFE for the past two decades. We report here two additional oxide fillers, beryllia (BeO) and germania (GeO 2 ) particles, that exhibit comparable wear reduction ability when filled in PTFE. Particle size and surface chemistry analysis revealed that the beryllia and germania particles had different structure and size from the alumina fillers used in this study whereas their composites shared similar ultralow wear rates and carboxylate salt rich tribofilms to the alumina PTFE system. Results in this study support both a particle structure driven and a tribochemistry driven wear reduction hypothesis for the alumina PTFE composite as previously suggested; whereas more systematic investigations are needed to elucidate wear resistance mechanisms in the beryllia and germania filled PTFE composites.
研究领域:
材料科学
·
表面工程
·
摩擦学
✓ 已验证
产品关联
DOI
高影响因子
ACS Nano
·
2024
·
IF 15.8
PeiChi Liao,Haichang Guo,Hongyu Niu,Ruijie Li,Ge Yin,Lei Kang,Liuchen Ren,Ruicong Lv,Huifeng Tian,Shizhuo Liu,Zhixin Yao,Zhenjiang Li,Yihan Wang,Lina Yang Zhang,U Sasaki,Wenxi Li,Yijie Luo,Junjie Guo,Zhi Xu,Lifen Wang,Ruqiang Zou,Shulin Bai,Lei Liu
The rapid development of modern electronic devices increasingly requires thermal management materials with controllable electrical properties, ranging from conductive and dielectric to insulating, to meet the needs of diverse applications. However, highly thermally conductive materials usually have a high electrical conductivity. Intrinsically highly thermally conductive, but electrically insulating materials are still limited to a few kinds of materials. To overcome the electrical-thermal conductance trade-off, here, we report a facile Pechini-based method to prepare multiple core (metal)/shell (metal oxide) engineered fillers, such as aluminum-oxide-coated and beryllium-oxide-coated Ag microspheres. In contrast to the previous in situ growth method which mainly focused on small-sized spheres with specific coating materials, our method combined with ultrafast joule heating treatment is more versatile and robust for varied-sized, especially large-sized core–shell fillers. Through size compounding, the as-synthesized core–shell-filled epoxy composites exhibit high isotropic thermal conductivity (∼3.8 W m–1 K–1) while maintaining high electrical resistivity (∼1012 Ω cm) and good flowability, showing better heat dissipation properties than commercial thermally conductive packaging materials. The successful preparation of these core–shell fillers endows thermally conductive composites with controlled electrical properties for emerging electronic package applications, as demonstrated in circuit board and battery thermal management.
研究领域:
材料科学
·
电气工程
·
热能工程
·
复合材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Zezhen Yin,Yun Zhang,Shihua Ding,Tianxiu Song,Xiaoning Li,Jiaying Dan
The solid-phase method was utilized to synthesize LiAl 1- x Be x O 2- x /2 and LiAl 1- x Ga x O 2 ceramics. By Phillips-Van Vechten-Levine (P-V-L) theory, a strong correlation between chemical bond characteristics and microwave dielectric properties was established. X-ray diffraction (XRD) analysis confirmed that all components formed single-phase solid solution with tetragonal structure. Using Be 2+ and Ga 3+ as substitutes, the differences in ionic radii produced diametrically opposite changes in cell volume. The relative density increased to 97.61 % (98.57 %) with the addition of Be 2+ (Ga 3+ ). According to the P-V-L theory, the variation of ε r was influenced by bond ionization. The introduction of different ions caused bond lengths variations, which in turn affected the lattice energy fluctuations. Importantly, this change more than doubled Q×f from 16,268 GHz to 37,015 GHz. Furthermore, the evolution of τ f can be elucidated by the bond energy. Sintered at 1250 °C, both LiAl 0.96 Be 0.04 O 1.98 and LiAl 0.98 Ga 0.02 O 2 demonstrated outstanding microwave dielectric properties, characterized by ε r = 5.83–6.08, Q×f = 32,727∼37,015 GHz, and τ f = −134.8∼-112.4 ppm/°C.
研究领域:
材料科学
·
无机化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMISTRY OF MATERIALS
·
2024
·
IF 7.2
Yi-Gang Chen,Xiwei Hu,Yao Guo,Sangen Zhao,Bingbing Zhang,Xia Zhang,Xian-Ming Zhang
A challenging topic for tetrahedra-based deep-ultraviolet (deep-UV, wavelength λ < 200 nm) birefringence crystals is how to generate both large birefringence and high deep-UV transmittance. Edge-sharing tetrahedra can induce large structural distortion and thus could produce strong optical polarization anisotropy to realize the challenging topic, but edge-sharing tetrahedra frequently require extreme synthesis conditions to overcome large repulsion interaction between tetrahedra. Herein, under mild hydrothermal conditions, an α-Be3(H2O)2(PO4)2 crystal with edge-sharing BeO4 and its polymorph β-Be3(H2O)2(PO4)2 with common corner-sharing BeO4 were synthesized, both featuring a three-dimensional stable structure constructed by BeO4, BeO2(H2O)2, and PO4 tetrahedral units. Remarkably, α-Be3(H2O)2(PO4)2 manifests superior birefringence of 0.101 and high deep-UV transmittance of 167 nm, with the largest birefringent quality factor (BQF) of 0.75 among the known tetrahedra-based deep-UV materials. By contrast, β-Be3(H2O)2(PO4)2 manifests a small birefringence of 0.019 and 160 nm deep-UV transmittance, with only a mediocre BQF of 0.15. Further, computational investigations reveal that edge-sharing BeO4 makes a dominant contribution to the great birefringence. This study could push the synthesis of edge-sharing-tetrahedra materials and offers an alternative strategy toward designing high-performance tetrahedra-based deep-UV birefringence materials.
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 RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2024
·
IF 1.5
Xia Hongyang,Zheng Boyuan,Zhao Xu,Huang Yanting,Wang Hongqiang,Hu Eming,Lei Zhiwu,Hu Fang,Wang Qingliang
Uranium (U) and beryllium (Be) are strategic critical metals. It is imperative to realize the comprehensive utilization of U or Be poly-metallic resources. This study employed solvent extraction to separate and recover U and Be from a simulated acidic sulphate leachate from a U-Be associated ore. The results indicated that the mixture extractant system containing bis-(2-ethylhexyl) phosphoric acid (D2EHPA) and tributyl phosphate (TBP) had affinity for U, and the selectivity of U towards Be was dependent on the hydrogen ion concentration of the solution. 99.74% U and 6.98% Be were extracted with a two-stage counter-current extraction at sulfuric acid concentration of 1.58 mol/L. By using 2 mol/L Na 2 CO 3 solution as the stripping solution, 94.79% U was stripped from the U-loaded organic phase with a one-stage stripping process. After adjusting the pH of the raffinate to 2, with D2EHPA as extractant, 99.76% Be was recovered by performing a two-stage counter-current extraction. Besides, Be could be well stripped from the Be-loaded organic phase with 3 mol/L NaOH solution. And the stripping rate of Be reached 98.85% with a one-stage stripping process. The established method to separate U and Be from sulphate solutions with high acidity has several advantages, including recyclable, reliable, and environmentally friendliness, providing a promising new pathway for the green recovery of U and Be from poly-metallic resources.
研究领域:
化学工程
·
冶金学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Canglong Wang,Zhaocang Meng,Jianke Tian,Yiwen Liu,Yafeng Shu,Haibo Wu,Lei Yang
Given the wide prospects for SiC ceramic with high thermal conductivity, high-throughput screening of SiC containing BeO-Y 2 O 3 -Al 2 O 3 -MgO additives has been implemented by the experimental and multiscale simulation investigation. About 16 groups of SiC prepared by SPS are composed of 4H-SiC, 6H-SiC, 3C-SiC, BeO and yttrium aluminum garnet phases, and exhibit equiaxed and columnar microstructures. It was verified by the density functional theory simulation that these dopants (Be, O, Mg, Al and Y) can migrate spontaneously towards the Σ13 (150) [001] GB. The ceramics with thermal conductivity higher than 120 W/(m·K) were screened out. Especially, the annealed SiC with 5%BeO-10 % additive exhibits the maximum thermal conductivity of 206.5 W/(m·K). The Vickers hardness about 16.89 GPa can be predicted by the macro finite element model simulation, which is accorded with the experimental result. This work provides an economically feasible project for the large-scale production of SiC ceramics with high thermal conductivity.
研究领域:
材料科学
·
计算材料学
✓ 已验证
产品关联
DOI
高影响因子
Inorganic Chemistry Frontiers
·
2025
·Vol. 12
·期 8
·3179-3185
·
IF 6.4
Xinyi Wang,Xin Wen,Yuchen Yan,Jindong Chen,Guangsai Yang,Guang Peng,Ning Ye
Beryllium-based selenites have rarely been reported. Herein, the first two alkaline earth metal beryllium-based selenites, Ca3Be(SeO3)4 and SrBe(SeO3)2, have been synthesized using a mild hydrothermal method. In both crystals, Be is connected to four [SeO3]2− groups. Due to the different arrangements of [SeO3]2− groups, these two crystals exhibit significantly different optical anisotropy. From Ca3Be(SeO3)4 to SrBe(SeO3)2, the birefringence ranges from 0.005@546 nm to 0.058@546 nm. Theoretical calculations confirmed the dominant role of [SeO3]2− in the optical anisotropy of these two crystals. In addition, both of them exhibited large band gaps (5.40 and 5.28 eV) and high thermal stability (596 and 570 °C). This work demonstrates that the introduction of beryllium can effectively increase the band gap of selenites to over 5 eV and offers new ideas for the development of large-bandgap selenites.
研究领域:
无机化学
·
材料科学
·
光学材料
·
固态化学
✓ 已验证
产品关联
DOI
高影响因子
Sustainable Energy & Fuels
·
2024
·Vol. 8
·期 6
·1304-1313
·
IF 5
Hongfeng Liu,Yingshuai Wang,Xiangyu Ding,Yusong Wang,Feng Wu,Hongcai Gao
Layered transition metal oxides are the most promising cathode materials for sodium-ion batteries, however, the cycling stability and rate performance of this type of cathode materials are very limited. Herein, a solid-state reaction method is developed to synthesize micrometer-sized bulk crystals of the P2-type cathode of Na0.85Li0.12Ni0.198Be0.011Mg0.011Mn0.66O2 (denoted as NLNBMMO-5%) via configurational entropy. The high-entropy layered oxide cathode exhibits superior rate capability, delivers a high reversible capacity of 102.6 mA h g−1 at 1C with a capacity retention of 94.2% after 100 cycles, and maintains a capacity of 78.2 mA h g−1 at 5C with a capacity retention of 78.3% after 300 cycles. This new strategy reduces the ratio of Mn3+/Mn4+, which alleviates the Jahn-Teller distortion effect and enhances the structural stability. Moreover, it expands the interlayer spacing that ensures the excellent rate performance of the cathode, as confirmed by the XPS, the Rietveld refinement of the XRD and the GITT measurement. This work demonstrates that the new composition cathode NLNBMMO-5% is promising for rechargeable sodium-ion batteries with a long cycling life and excellent rate performance.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
SOLID STATE SCIENCES
·
2018
·
IF 1.861
Jie Lu,Linjiang Shen
Recently, developing free rare-earth (RE) doped afterglow phosphors has received great attentions in the lighting field. In this work, we prepare and report a RE-free phosphor, Na 2 BeGeO 4 :Mn 2+ , which can simultaneously emit the green fluorescence and afterglow luminescence upon excitation at UV light. Our results reveal that the as-prepared samples crystallize in orthorhombic type with the space group of Pmn 2 1 (31). The green emission is a broad band centered at 525 nm, corresponds to the 4 T 1 ( 4 G)- 6 A 1 ( 6 S) transition of Mn 2+ ions. After exposing to a 254 nm UV lamp for 10 min, the green afterglow luminescence seen with naked eyes can last more than 5 h. Together with the structural analysis and thermoluminescence (TL) spectra, the afterglow luminescence mechanism is also discussed in this work.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY
·
2019
·
IF 4.85
Yi-Gang Chen,Meiling Xing,Yao Guo,Zheshuai Lin,Xiujun Fan,Xian-Ming Zhang
Beryllium (Be) has high ionization energy (9.32 eV) with the greatest degree of covalency in the group IIA elements, and BeO4 tetrahedra (and BeO3 triangles) with covalent character are generally presented in beryllates. An unprecedented BeO6 trigonal prism with ultralong Be–O bonds as well as a BeO4 common tetrahedron is discovered in a new deep ultraviolet crystal Li13BeBe6B9O27 (LBeBBO) with a ∞2[Be6B9O33] double-layer framework. The BeO6 unit and its bond character are verified by an isostructural crystal Li13(Mg0.45Be0.55)Be6B9O27, while the orbital theory and charge density difference further clarify the ionic character of the BeO6 unit. Phonon dispersion confirms the structural stability of LBeBBO.
研究领域:
材料科学
·
晶体学
✓ 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）