CERAMICS INTERNATIONAL
·
2018
·
IF 3.057
Jingkun Yuan,Peigang He,Xiaomin Liang,Dechang Jia,Lingyu Jia,Delong Cai,Zhihua Yang,Xiaoming Duan,Shengjin Wang,Yu Zhou
In this paper, a high temperature treatment procedure was designed to evaluate the effect of holding temperature on thermal evolution process of Li + substituted Cs-based geopolymer (Cs 0.7 Li 0.3 GP), including the thermal analysis, phase composition and microstructure evolution. With rising of holding temperature, amorphous unheated Cs 0.7 Li 0.3 GP gradually transformed into a multiphase system during the high temperature treatment process, which consisted of pollucite (CsAlSi 2 O 6 ), spodumene (LiAlSi 2 O 6 ) and amorphous glass phase. In the multiphase system, Cs + ions were in the form of pollucite grains, while Li + ions were in the form of spodumene nanocrystallines distributed in amorphous matrix. The pollucite grains gradually coarsened with rise in holding temperature, and the densification of the resulting products were also improved synchronously, which were related to the presence of amorphous glass phases. The amorphous glass phase would be in a molten state when holding temperature over 800 °C. And the presence of molten amorphous phase would make the mass transfer process easier, which could contribute to the growth of the crystal grains and the elimination of the pores.
研究领域:
材料科学
·
地质学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2017
·Vol. 100
·期 10
·4412-4424
·
IF 2.841
Jingkun Yuan,Peigang He,Dechang Jia,Jinsong You,Xuzhao Liu,Yao Zhang,Delong Cai,Zhihua Yang,Xiaoming Duan,Shengjin Wang,Yu Zhou
As part of a series of studies, effects of Na + substitution on the thermal evolution of cesium-based geopolymers on heating were studied. A series of sodium-substituted cesium-based geopolymers, Cs (1− x ) Na x GPs (where x =0, 0.1, 0.2, 0.3, and 0.4), were prepared and treated at 1300°C for 2 hours to obtain the corresponding ceramic products. The thermal evolution process was disclosed by virtue of a variety of technical, including TG-DTA, thermal shrinkage, XRD analysis, SEM, and TEM investigation. The results indicated that unheated Cs (1− x ) Na x GPs was not completely amorphous after the substitution of Na + and the crystallinity of Cs (1− x ) Na x GPs gradually increased with the rise of sodium content. Meanwhile, the average particle sizes of Cs (1− x ) Na x GPs also increased evidently with increases in sodium substitution. The final product after heat treatment mainly consisted of pollucite (CsAlSi 2 O 6 ) and amorphous glass phase. The particle size of pollucite grain gradually decreased as more Cs + were replaced maybe owing to the role of Na + in the nucleation process of pollucite. Two forms of Na + present in the final products: A small portion was present in the pollucite grains due to Na + partial occupied the crystallographic sites of Cs + ; and the rest were present in the amorphous glass phase among the pollucite grains. The average coefficient of thermal expansion (CTE) of resulting Cs (1− x ) Na x GPs ceramics increased from 4.80×10 -6 K −1 ( x =0) to 7.26×10 −6 K −1 ( x =0.4) with increases in sodium substitution, which could be due to the amorphous glass phase had a relatively higher CTE than that of pollucite.
研究领域:
材料科学
·
化学工程
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产品关联
DOI
高影响因子
OPTICS EXPRESS
·
2023
·Vol. 31
·期 5
·9123-9134
·
IF 3.8
Hanyu Xu,Zuoling Fu,Yanling Wei
The susceptibility of Cs-based fluorides to deliquescence has led to the fact that lanthanide-doped Cs-based fluorides and their related applications have hardly been reported. Herein, the method to solve the deliquescence of Cs3ErF6 and its excellent temperature measurement performance were discussed in this work. Initially, the soaking experiment of Cs3ErF6 found that water had irreversible damage to the crystallinity of Cs3ErF6. Subsequently, the luminescent intensity was ensured by the successful isolation of Cs3ErF6 from the deliquescence of vapor by the silicon rubber sheet encapsulation at room temperature. In addition, we also removed moisture by heating samples to obtain temperature-dependent spectra. According to spectral results, two luminescent intensity ratio (LIR) temperature sensing modes were designed. The LIR mode which can quickly respond to temperature parameters by monitoring single band Stark level emission named as “rapid mode”. The maximum sensitivity of 7.362%K-1 can be obtained in another “ultra-sensitive mode” thermometer based on the non-thermal coupling energy levels. This work will focus on the deliquescence effect of Cs3ErF6 and the feasibility of silicone rubber encapsulation. At the same time, a dual-mode LIR thermometer is designed for different situations.
研究领域:
材料科学
·
光学
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产品关联
DOI
PubMed
高影响因子
CEMENT & CONCRETE COMPOSITES
·
2022
·
IF 9.93
Wei Chen,Alicia C. Garofalo,Haining Geng,Yan Liu,Dongwen Wang,Qiu Li
Cesium-based geopolymer is more refractory than K + and Na + based geopolymers after the transformation to ceramic material, whose thermal resistance feature is highly appreciated by some industries, especially in the engineering field where the materials in some cases are exposed to environments with high temperatures. In this study, cesium-activated geopolymer composites (CsGPc), with 5–35 wt% cordierite reinforcements, were prepared and evaluated on the high temperature performance. When 35 wt% cordierite was added, the compressive strength increased by 72% compared to the reference plain CsGP. Residual compressive strength (after heating at 1400 °C) of CsGPc with 35 wt% cordierite increased by 106% compared to the specimen before the thermal exposure . After thermal exposure up to 1400 °C, the geopolymer matrix was transformed into a pollucite-based ceramic composite. Amorphous phases in CsGPc gradually crystallized to form pollucite as the main phase with cordierite as secondary phase. The microstructure of CsGPc and the obtained ceramics showed a clear sintering process and crystallization of pollucite. Shrinkage was reduced and the coefficient of thermal expansion (CTE) varied from 4.50 to 1.89 × 10 −6 K −1 with the cordierite inclusion. The performance of obtained ceramic composites was superior compared to the initial CsGPc, which would be excellent for heat resistance applications.
研究领域:
材料科学
·
无机化学
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产品关联
DOI
高影响因子
JOURNAL OF CLUSTER SCIENCE
·
2024
·Vol. 36
·期 1
·1-12
·
IF 2.7
Liu Jiali,Li Chen,Zhang Shen,Liu Xinni,Wei Xiao,Gao Yue,Wang Fei,Yan Mengwei,Wang Jiaqi,Kamuti Diana
All-inorganic perovskite quantum dots have sparked a research boom due to their excellent optical properties, however, their own strong ionicity and lead toxicity have hindered further development in the field of sensing. In this study, we have solved the toxicity problem of lead-based perovskite quantum dots by replacing lead with green metal bismuth. Meanwhile, due to the ligand-passivation effect of oleylamine and oleic acid, we successfully synthesized highly stable bismuth-based perovskite quantum dots(Cs 3 Bi 2 Br 9 PQDs)in ethanol, and constructed the environment-friendly fluorescence sensor for the quantitative detection of oxytetracycline (OTC) for the first time. The results demonstrated that the fluorescence quenching degree of Cs 3 Bi 2 Br 9 PQDs showed a good linear relationship with the concentration of OTC within the range of 2.0 ~ 18 µM, and the detection limit was 0.432 µM. By studying fluorescence lifetime, absorption spectroscopy, and evaluation of internal filtration parameters, it was proved that the sensing mechanism was caused by the inner filter effect owing to the overlapping of fluorescence emission spectrum of Cs 3 Bi 2 Br 9 PQDs and UV absorption spectrum of OTC. Moreover, Cs 3 Bi 2 Br 9 PQDs fluorescent sensor had good selectivity and anti-interference ability. It is believed that this work will open up a new way for lead-free perovskite quantum dots fluorescence sensor in the field of analytical detection.
研究领域:
分析化学
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环境科学
·
生物医学
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产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2019
·
IF 8.456
Fanghao Ye,Huijun Zhang,Pang Wang,Wei Li,Donghui Li,Baocai Du,Dan Liu,Tao Wang
Two-dimensional (2D)/three-dimensional (3D) perovskites have been successfully applied in high-efficiency light-emitting diodes (LEDs) because of their large exciton binding energy (Eb) caused by the quantum and dielectric confinements. Thermal annealing and antisolvent treatments are usually executed in order to promote the crystallization and film quality of perovskites, which add complexity to the device fabrication process. Here, the cesium-based 2D/3D perovskite was prepared by introducing ammonium halide benzamidine hydrochloride (BMCl) as the additive. By further introducing an appropriate amount of MABr and PbBr2, BM2(Cs1–xMAxPbBr3)n−1PbBr4 crystals can be formed rapidly without any additional treatments, while inhibiting the formation of the unfavorable Cs4PbBr6 phase. The optimized 2D/3D perovskite-based LEDs achieved a maximum luminance of 12 367 Cd/m2, a current efficiency of 17.4 Cd/A, and an external quantum efficiency of 5.2%. Our results suggest that appropriate perovskite crystallization can be achieved at room temperature by the regulation of precursor solution, making the perovskite crystallization process easier to control with reduced processing complexity.
研究领域:
材料科学
·
光电工程
✓ 已验证
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Ran Ran,Hanwen Yan,Guoliang Zhang,Zengxi Li,Gang Wang,Gongying Wang,Weiguang Su,Chunshan Li
Supported Cs-based catalysts are considered as potential candidates for methyl methacrylate (MMA) synthesis via one-step aldol condensation, but they suffer from low activity. In this paper, the acid–base properties of the Cs/SiO2 catalyst were modulated by loading different amounts of the Al element. The changes in structural and physicochemical properties following Al introduction were revealed by a series of characterizations. In-depth investigation of the catalytic mechanism through in situ DRIFT combined with DFT calculations unveiled the synergistic effects between the Al and Cs components on the promotion of catalytic performance. The results showed that the presence of Al species facilitated the formation of weak and medium acid and base sites, along with the dispersion of the active Cs component, leading to an improvement of MMA yield. Additionally, the kinetic studies indicated that the addition of Al efficiently reduced the activation energy in comparison to pristine Cs/SiO2.
研究领域:
化学工程
·
催化科学
✓ 已验证
DOI
高影响因子
Theranostics
·
2016
·
IF 8.854
Yuxin Liu,Luoyuan Li,Quanwei Guo,Lu Wang,Dongdong Liu,Ziwei Wei,Jing Zhou
Lanthanide-based contrast agents have attracted increasing attention for their unique properties and potential applications in cancer theranostics. To date, many of these agents have been studied extensively in cells and small animal models. However, performance of these theranostic nanoparticles requires further improvement. In this study, a novel CsLu 2 F 7 :Yb,Er,Tm-based visual therapeutic platform was developed for imaging-guided synergistic cancer therapy. Due to the presence of the heavy alkali metal Cesium (Cs) in host lattice, the nanoplatform can provide a higher resolution X-ray CT imaging than many other reported lanthanide-based CT contrast agents. Furthermore, by using the targeted RGD motif, chemotherapy drug alpha-tocopheryl succinate ( α -TOS), and photothermal coupling agent ICG, this nanoplatform simultaneously provides multifunctional imaging and targeted synergistic therapy. To demonstrate the theranostic performance of this novel nanoplatform in vivo , visual diagnosis in the small animal model was realized by UCL/CT imaging which was further integrated with targeted chemo-photothermal synergistic therapy. These results provided evidence for the successful construction of a novel lanthanide-based nanoplatform coupled with multimodal imaging diagnosis and potential application in synergistic cancer theranostics.
研究领域:
生物医学工程
·
分子影像学
·
癌症治疗
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COMBUSTION AND FLAME
·
2024
·
IF 5.8
Zhiwen Wang,Hui Wang,Lian Li,Qianyi Zhang,Feng Li,Ruiqi Shen,Yinghua Ye,Wei Zhang
The high-temperature plume of solid propellant has spawned considerable amount of highly ionized plasma, which can be used to increase the specific impulse of propellant with the external physical field, as well as serve as the charged particles for the magnetohydrodynamic (MHD) generator on the thruster. Unfortunately, the deficiency of workable deal to promote the electrical performance of the plume hinders the development of the above technologies. In this work, cesium-based composite solid propellants (CCSP) were designed and fabricated by introducing cesium-based oxidants into the AP/HTPB/Al propellant as the highly ionized seed. The propulsion properties and plume conductivity of CCSP were preliminarily calculated through theoretical method. The comprehensive combustion-plasma characteristics (plume conductivity, flame morphology and combustion temperature) of CCSP were further investigated, utilizing plume-plasma diagnostic system. Profiting from the high electron derailment capacity of cesium atom with high temperature, the density of charged particles in the plume of CCSP significantly multiplied. The conductivity of CCSP plume with a value of >1000 S/m presented several orders of magnitude enhancement compared with the plume of baseline propellant (3.9 S/m). Additionally, partially replacing AP with CN/CP contributed to the combustion adequacy of Al MPs. The investigation on the burning rate pressure-index of CCSP and baseline using the high-pressure combustion chamber indicated that 0< n baseline < n CCSP <1, proving the application ability on SRM and the ability to regulate the burning rate over a wide pressure range for CCSP. Overall, the presented work provided a novel method for improving the plume-plasma performance of propellant, exhibiting the admirable application prospects for Rocket-MHD generator technology and enhancement technology of thrust/specific impulse by physical energy field.
研究领域:
航空航天工程
·
等离子体物理
·
推进技术
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2025
·
IF 4.3
Kai Zhao,Senlin Deng,Chenxi Feng,Jie Li,Kaipeng Cao,Gang Wang,Chunshan Li
Coal-based aldol condensation of methyl acetate with formaldehyde on Cs-based catalyst is a promising atom-economic route for methyl acrylate production, where the pore structure plays a critical role in addition to the acid and base properties. Herein, series of Cs-Zr-Al/SiO 2 catalysts with similar acid-base properties but different porous structure, were synthesized via hydrothermal and co-impregnation method for synthesis of methyl acrylate. The physicochemical characteristics of as-prepared catalysts were comprehensively analyzed by physical N 2 adsorption and desorption isotherms, XRD, and CO 2 /NH 3 -TPD. The structures of disordered mesopores, two-dimensional hexagonal straight channels, three-dimensional cubic cage pores, and three-dimensional interconnected pores exhibit significant effect on the reactant/product diffusion and transformative process. In situ DRIFTS revealed the reactants and product show the Knudsen diffusion behavior, with diffusion coefficients showing strong positive correlation to pore diameter, indicating that mass transfer efficiency is pore-structure-dependent. Accelerated diffusion in the optimal pore structure would enhance methyl acetate conversion while improve selectivity for methyl acrylate diffusion by suppression of side reactions. Among which, the Cs-Al-Zr/SiO 2 (KIT-6) featuring a three-dimensional interconnected pore structure with an average diameter of 7.4 nm, demonstrated the exceptional performance in the aldol condensation reaction, achieving 25.9 % methyl acetate conversion, 92.7 % methyl acrylate selectivity, and a space–time yield of 2.69 mmol MA /g Cat /h. Furthermore, it showed considerable catalytic stability and regeneration capability.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2016
·Vol. 99
·期 11
·3784-3791
·
IF 2.787
Jingkun Yuan,Peigang He,Chao Yang,Dechang Jia,Jinsong You,Shu Yan,Delong Cai,Zhihua Yang,Xiaoming Duan,Shengjin Wang,Jiahuan Xu,Yu Zhou
The purpose of this work was to study the role of lithium in cesium-based geopolymers and the thermal evolution during heat treatment together with thermal expansion behavior of the resulting geopolymer ceramic. A series of lithium-substituted cesium-based geopolymers, Cs (1− x ) Li x GP (where x = 0, 0.1, 0.2, and 0.3), were prepared. All the geopolymer samples were heated at 1300°C for 2 h and thermal evolution on heating was studied by a variety of techniques. Phase composition, microstructure evolution, and thermal expansion behaviors of the ceramics derived from the geopolymers were characterized. All the geopolymer specimens exhibited similar thermal evolutionary trends. With increases in lithium content, overall mass loss increased gradually due to the higher hydration energy of Li + than Cs + . Thermal shrinkage of these specimens can be divided into four stages, i.e., structural resilience, dehydration, dehydroxylation, and sintering, according to the dilatometer results. The introduction of Li results in two-step sintering behavior for the lithium-substituted cesium-based geopolymers. The average thermal expansion coefficient (CTE) of Cs (1− x ) Li x GP ceramics decreased from 4.80 × 10 −6 K −1 ( x = 0) to 3.61 × 10 −6 K −1 ( x = 0.3) with increase in lithium substitution. The reason can be attributed to the presence of spodumene after thermal treatment, which has a relatively low thermal expansion coefficient compared with pollucite. Meanwhile, molten spodumene could serve as a buffer phase between pollucite crystals also conducive to the decline of CTE of this system.
研究领域:
材料科学
·
无机非金属材料
·
陶瓷学
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热物理性能
·
固废资源化
✓ 已验证
DOI
高影响因子
Journal of Marine Science and Engineering
·
2023
·Vol. 11
·期 5
·1001
·
IF 2.9
Yuefeng Gao,Baojiu Chen
Seawater pollution caused by heavy metal ions is a growing concern among the public. Perovskite quantum dots (PeQDs) are ideal probes for detecting metal ions due to their exceptional sensing characteristics, including remarkable sensitivity, low detection limit, and good selectivity. However, traditional lead-based PeQDs exhibit drawbacks related to lead toxicity and poor water stability. Herein, lead-free halide PeQDs Cs3Bi2Br9were synthesized using Bi3+instead of Pb2+via the ligand-assisted reprecipitation method. The luminescence performance of the precursor is analyzed with respect to the reaction conditions. The results reveal that the optimal reaction temperature is 80 °C, the ideal octylamine dosage is 35 μL, and the most effective reaction time is 10 min. Photoluminescence spectra of Cs3Bi2Br9are analyzed at various temperatures and demonstrate that fluorescence intensity decreases as temperature increases. The value of the exciton binding energy (Eb) is determined to be 88.6 meV. Cs3Bi2Br9PeQDs synthesized under the optimum reaction conditions are utilized as fluorescent probes to detect copper ions in seawater. Results from experiments demonstrate that the presence of copper ions markedly quenched the photoluminescence of Cs3Bi2Br9owing to the effective transfer of electrons from Cs3Bi2Br9to Cu2+. A strong linear correlation between the degree of quenching and the contents of Cu2+is observed. Cs3Bi2Br9PeQDs demonstrate a sensitivity and detection limit of 1.21 μM−1and 98.3 nM, respectively. Furthermore, this probe exhibits good photostability, water stability, and selectivity for copper ions, thereby indicating its potential for detecting marine heavy metal contaminants.
研究领域:
环境科学
·
材料科学
·
分析化学
✓ 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）