Soft Matter
·
2015
·Vol. 12
·期 3
·867-875
·
IF 4.029
Jiali Xu,Zhiliang Wang,Lingang Wen,Xianju Zhou,Jian Xu,Shuguang Yang
Poly(acrylic acid) (PAA) and lanthanide (Ln) ions, such as Ce3+, Eu3+, and Tb3+, were prepared as dispersed complex colloidal particles through three different protocols with rigorous control of the pH value and mixing ratio. The negatively charged PAA–Ln complex particles were layer-by-layer (LbL) assembled with positively charged poly(diallyldimethyl ammonium) (PDDA) to prepare a thin film. The film thickness growth is much quicker than PDDA/PAA film. Due to the incorporation of Ln3+ ions, the film exhibits fluorescence. During LbL assembly, PDDA–PAA association based on electrostatic force and PAA–Ce association based on coordination are in competition, which leads to the LbL assembly of PDDA and PAA–Ln complex colloidal particles being a complicated dynamic process.
研究领域:
材料科学
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化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nano Research
·
2018
·Vol. 11
·期 3
·1369-1378
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IF 7.994
Yang Shenghong,Sun Xiaohan,Wang Zhaoyan,Wang Xiayan,Guo Guangsheng,Pu Qiaosheng
An anomalous enhancement of fluorescence of carbon dots (CDs) was observed via lanthanum (La) doping. La-doped CDs (La-CDs) were prepared through microwave pyrolysis within 4 min. With La 3+ doping, the emission band shifted from blue to green although La 3+ is non-fluorescent. The quantum yield and fluorescence lifetime improved by about 20% and 35%, respectively. All experiment results indicate that La 3+ doping is an effective way to tune fluorescence and improve the performance of CDs. Another unique attribute of La-CDs is high sensitivity to Fe 3+ . The La-CD-based fluorescence probe was established and used for sensitive and selective detection of Fe 3+ with a limit of detection of 91 nmol/L. The proposed fluorescence probe also was successfully employed to visualize intracellular Fe 3+ in live HeLa cells through cell imaging. It was also shown that yttrium exhibited the same fluorescence enhancement effect as La. The results may provide a new route for preparing CDs with special properties.
研究领域:
材料科学
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生物医学
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分析化学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2014
·
IF 3.766
Xiaocun Qi,Zhiliang Wang,Songmei Ma,Lianjia Wu,Shuguang Yang,Jian Xu
The complexation behavior of PAA and lanthanide (Ln) ions was schematically investigated. As pH increased, the complexation between PAA and Ln ions will greatly strengthen because COO − groups exhibit much stronger interaction with Ln ions than COOH. When the pH values are higher than 2.5, where the ionization of PAA is about 2.0%, the PAA–Ln complex would precipitate out from the solution. The precipitation is a direct indicator for the complexation between PAA and Ln ions. Besides pH values, the complex precipitation is related with the concentration, the molar ratio, and the operation procedure. At the extremely low concentration, there is no polymer–metal complex precipitation but fluorescence spectroscopy reveals that the complexation between PAA and Ln ions still exists when pH value is higher than 2.5. When the molar ratio of PAA and Ln ions exceeds the certain level, it would produce soluble polymer–metal complex, even at the high concentration of Ln ions.
研究领域:
化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
·
2016
·Vol. 34
·期 4
·399-406
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IF 1.811
Wang Zhi-liang,Xu Jia-li,Yuan Qian,Shibraen Mahmoud H. M. A.,Xu Jian,Yang Shu-guang
Hydrothermal processing of polyamide 6 (PA6) with the presence of lanthanum chloride (LaCl 3 ) was studied in the temperature region from 160 °C to 250 °C. PA6 will be dissolved in the superheated water when temperature is above 160 °C. And as PA6 is dissolved, hydrolysis will happen, which makes PA6 chains degrade. By adding LaCl 3 in the hydrothermal environment, the PA6 hydrolysis will intensify, especially when the hydrothermal temperature is higher than 200 °C. When the hydrothermal system cools down, the hydrolyzed PA6 segments will crystallize from the solution or remain dissolved in the solution depending on molecular weight. In addition, the hydrolyzed compound of LaCl 3 would affect the crystallization of PA6 segments with proper size, and γ phase would be presented.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2022
·Vol. 23
·期 18
·10542
·
IF 6.208
Yuheng Qiu,Kaiqi Ding,Liwen Tang,Ziyu Qin,Mengting Li,Xueqiong Yin
The demand for rare earth metal increases rapidly in the modern high-tech industry and therefore the accumulation of rare earth metal ions from an aqueous environment becomes a significant concern worldwide. In this paper, a water-recyclable chitosan-based La3+-imprinted thermoresponsive hydrogel (CLIT) was prepared to accumulate La3+from solution. The CLIT was characterized by DSC, FITR, Raman spectroscopy, XPS, and SEM, which revealed obvious reversible thermosensitivity and imprinted sites of La3+ions. An adsorption capacity of 112.21 mg/g to La3+ions was achieved on CLIT under its optimum adsorption conditions (pH 5, 50 °C, 60 min). The adsorption could be well illustrated by second-order kinetics and Freundlich isotherm models. The La3+-adsorbed CLIT could be recycled only by rinsing with 10 °C cold water, with a desorption rate of 96.72%. After ten cycles of adsorption-desorption, CLIT retained good adsorption capability. In the solution containing six ions, the adsorption coefficients kLa3+/Mn+of CLIT were 2.04–3.51 times that of non-imprinted hydrogel, with kLa3+/Y3+, kLa3+/Gd3+, kLa3+/Al3+, kLa3+/Fe3+and kLa3+/Cu2+being 1.67, 2.04, 3.15, 2.72 and 4.84, respectively.Keywords:thermoresponsive hydrogel;La3+-imprinting;rare earth metal
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF RARE EARTHS
·
2022
·
IF 4.632
Yu Wang,Xiao-Hui Yang,Jian Cui,Guo-Hua Zhang
Rare-earth hexaborides (REB 6 ) are vital raw materials for cathode materials and high temperature structural ceramics that are widely applied as high-frequency electron tubes and ceramics adaptive for extreme environment, respectively. In this work, single phase substitutional solid solution REB 6 (LaB 6 , La 0.75 Ce 0.25 B 6 , La 0.5 Ce 0.5 B 6 , La 0.25 Ce 0.75 B 6 and CeB 6 ) powders were prepared with the raw materials of La 2 O 3 , CeO 2 , B 4 C and Al powders, after calcining at 1773 K for 4 h and the following alkaline leaching. All substitutional solid solution products have homogeneous distributions of La and Ce in particles. Through microscopic morphology analysis, it is discovered that the formation of solid solution is beneficial for reducing the particle size of product, relative to LaB 6 and CeB 6 . Moreover, Al flux plays an important role in decarbonizing reaction, and C contents of all products are below 0.4 wt%.
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
Journal of Water Process Engineering
·
2023
·
IF 7
Guanfeng Lin,Yongzhi Xiong,Guilong Wang,Simin Li,Rongyuan Jiang,Beili Lu,Yandan Chen,Biao Huang
Adsorption and selective adsorption are effective means of separating rare earths (REs) from aqueous solutions and reducing heavy metal contamination. In this work, bagasse was used as carbon source and phytic acid as phosphorus source and activator, and a simple synthesis strategy was applied to prepare the effective adsorbent P-doped porous carbon (PC) of lanthanum ions (La 3+ ). Doping of P was helpful to enhance the adsorption and selectivity of porous carbon to La 3+ . Compared with the samples without P-doping, the adsorption capacity of PC on La 3+ was increased by >4 times, and the theoretical maximum adsorption capacity is as high as 342.2 mg g −1 , which was greater than that of other reported carbon-based materials. In addition, the selective adsorption of PC on La 3+ was as high as 96.07 % and 71.07 % not only in the multi-ion coexistence system of La 3+ , Ni 2+ , Zn 2+ , Co 2+ , Ca 2+ , and Na + , but also in the La 3+ /Na + (1:50) coexistence system with very low La 3+ content, respectively. The adsorption of La 3+ on PC-800 is mainly chemisorption , where C-P-O, C/P=O and C-O-P groups are the main active sites for adsorption and improves the selectivity. This work can furnish some useful message on designing and synthesizing of carbon-based adsorbent, which has excellent adsorption selectivity in polyionic and low La 3+ coexistence systems.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2023
·
IF 4.2
Lin Mei,Chao Feng,Yuzhong Wang,Qiang Yu,Wenjie Xin,Weifeng Chu,Yanan Wang,Xiangxue Zhu,Shenglin Liu,Hongxia Wang,Longya Xu
Synthesis of acetonitrile (ACN) by way of ethanol dehydroamination process was performed over copper-, zinc-, nickel-, and cobalt-based catalysts in a fixed-bed reactor, by which 20Co/Al2O3 was found to be the best one and ready for subsequent La, Ce, and Pr doping. Then, catalytic tests and a series of characterizations such as XRD, XRF, XPS, TEM, TG-DTA, IGA, NH3-TPD, and N2 adsorption–desorption were carried out. The results demonstrate that rare-earth-modified 20Co/Al2O3 catalysts have improved the catalytic performance for ethanol dehydroamination remarkably; the addition of La leads to better dispersion of cobalt species, the higher surface area of 20Co/Al2O3 catalyst, and fast adsorption for ACN, as well as better resistance to carbon deposition. In the meantime, the La-doped catalyst seems to prefer the route of acetaldehyde imine to ACN rather than to ethylamine, and consequently, a highly selective synthesis of ACN with excellent catalytic stability was obtained with the formation of ethylamine being suppressed..
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF RARE EARTHS
·
2017
·
IF 2.429
Yanran XUN,Xinxin HE,Han YAN,Ziwang GAO,Zhao JIN,Chunjiang JIA
In this paper, a series of Fe- and Co-doped lanthanum (hydr)oxides catalysts were prepared by a simple coprecipitation-hydrothermal method. The as-prepared catalysts were characterized with various techniques including powder X-ray diffraction (XRD), N 2 adsorption/desorption, inductively coupled plasma (ICP) and transmission electron microscopy (TEM). The Fe-based catalysts exhibited consecutive phase changes of amorphous FeO x →FeLaO 3 →Fe 2 N under different stages (as-prepared→calcination→ammonia decomposition reaction); as for Co-based catalysts, the phase transformation followed a sequence of Co(OH) 2 → Co 3 O 4 →metallic Co. It was revealed that Fe 2 N and metallic Co were most probably the active crystalline phase respectively for Fe- and Co-based catalysts in the decomposition of ammonia.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2025
·
IF 9.5
Chang'an Wang,Zuoshuai Xi,Tao Ban,Zhiyuan Liu,Yibin Luo,Hongyi Gao,Ge Wang,Xingtian Shu
The fine design and regulation of the microenvironment surrounding active sites in metal–organic frameworks (MOFs) are crucial for optimizing electron distribution and enhancing oxygen activation, thereby achieving superior catalytic performance in epoxidation reactions. In this study, we focus on the synergistic modulation of the cobalt (Co) microenvironment in MOF-74 through the introduction of lanthanum (La) sites and defect engineering. The incorporation of rare-earth La species effectively redirects the electron density of Co sites, enhancing their oxygen activation capabilities. Additionally, the presence of coordination-unsaturated Co sites facilitates rapid electron transfer from active sites to substrates, promoting the generation of superoxide radicals. Notably, the Co0.50La0.50-MOF-74-4eq sample demonstrates exceptional molecular oxygen utilization and epoxidation performance, achieving a cyclohexene conversion of 92.2% with a selectivity of 93.9% for 1,2-epoxycyclohexane at 40 °C within 1 hour. Furthermore, this catalyst exhibits broad applicability across different substrates. Density functional theory calculations, complemented by in situ analysis, confirm that molecular oxygen activation occurs at Co sites while suppressing the allylic oxidation pathway, thus favoring the conversion of cyclohexene to epoxides. This work elucidates how strategically tailoring the electronic properties around catalytic sites can dramatically influence catalytic behavior in heterogeneous catalysis, providing new insights for the rational design of advanced catalysts.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2022
·
IF 10.319
Zeya Xu,Bin Lin,Chaoqian Zhao,Yanjin Lu,Tingting Huang,Yan Chen,Jungang Li,Rongcan Wu,Wenge Liu,Jinxin Lin
Lanthanum (La) has tremendous potential in the treatment and prevention of bone diseases especially osteoporosis and metabolic disorders. However, controlling its distribution and keeping the release of La 3+ ions sustained and steady in the body is still a big challenge. In this study, we prepared La-OCP powders via co-precipitation method, and further prepared La-OCP/PLA porous scaffolds by 3D printing . La 3+ was successfully introduced into the OCP crystal structure and substituted Ca 2+ at the Ca-5 and Ca-8 sites. In particular, some La 3+ ions were deposited on the crystal surface in the form of nanoparticles. Both octacalcium phosphate (OCP, Ca 8 H 2 (PO 4 ) 6 ·5H 2 O) crystals and nanoparticles played as the carriers for La 3+ ions. The La-OCP/PLA scaffolds displayed obvious mineralization effects and sustained release of La 3+ . The scaffolds contained a uniform structure with rough micro surface topography which acted as a suitable pathway for BMSCs cells to adhere, grow and proliferation. At a certain La 3+ concentration, the extracts from La-OCP/PLA scaffolds increased the expression of osteogenesis-related genes, thus promoting the osteogenic differentiation of BMSCs. Moreover, the extracts regulated the immune responses. The experiment in vivo proved that La-OCP/PLA porous scaffolds were safe and could enhance bone defect regeneration in vivo . These findings suggest that 3D printed La-OCP/PLA porous scaffolds have promising potentials in bone tissue engineering.
研究领域:
生物材料学
·
骨科医学
·
组织工程学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Weijun Gui,Mingzhe Du,Xianmin Zhang,Miroslav Almáši,Lijia Wan,Lu Gan,Zhenxi Wang,Suhang Wu
The limited luminescence efficiency and poor stability of lanthanide-based metal-organic frameworks (Ln-MOFs) are the key factors restricting their practical applications. It is well known that high-temperature annealing can significantly enhance the photoelectric properties of inorganic materials, but it seems unfeasible for Ln-MOFs due to the existence of organic components. To overcome this dilemma, MOF-76 was synthesized by hydrothermal method and then hydrothermally annealed at 140 °C for 4 h. As a result, the annealing not only significantly improves the crystallinity of MOFs but also promotes their transition from the original tetragonal phase to the monoclinic phase. The annealed MOFs ( a MOF) exhibit about 3-fold emission enhancement and show better stability, especially under alkaline conditions or in water or saturated alkanes, such as cyclohexane, and dichloromethane. The total emission intensity of the as-prepared (AP) MOF is reduced to less than 1/10 compared to the a MOF due to the influence of water molecules. When the material was immersed in a mixture of ammonia and water, the a MOF emission remained stable, while the AP MOF emission rapidly decreased to approximately 12 % with an increasing volume ratio. Additionally, a notably enhanced 5 D 0 → 7 F 1 transition of Eu 3+ ions in MOF-76 has been observed for the first time. It was found that after hydrothermal annealing, the photoluminescence quantum yield of the MOF increases from 10.86 % to 61.48 %, and its synthesis yield can reach 73.8 %. The properties described above remarkably enhance the application values of the a MOFs. Interestingly, MOFs can also be solvothermal annealed, thus the schemes presented in this context open up novel approaches to significantly improve/modify the performance of other MOF materials. Finally, the obtained green and red emitting a MOFs combined with the N-CDs@starch were applied to warm white LED with the colour coordinates (CIE) of (0.3662, 0.3544), colour rendering index (CRI) of 88.5 and correlated colour temperature (CCT) of 4261 K.
研究领域:
材料科学
·
光学
✓ 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）