CHINESE JOURNAL OF POLYMER SCIENCE
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2021
·Vol. 39
·期 8
·966-974
·
IF 3.603
Feng Li-Dong,Bian Xin-Chao,Li Gao,Chen Xue-Si
The effect of exogenous hydroxyl, carboxyl groups and/or Sn 2+ on pyrolysis reactions of poly(L-lactide) (PLLA) was investigated by thermogravimetric analysis (TGA). The activation energy ( E a ) of pyrolysis reactions was estimated by the Kissinger-Akahira-Sunose method. The kinetic models were also explored by the Malek method, and the random degradation behavior was determined by comparing the plots of In{-In[1 - (1 - w ) 0.5 ]} versus 1/ T for experimental data from TGA with model reactions. The pyrolysis reaction rate of PLLA was affected slightly by exogenous hydroxyl and carboxyl groups at lower levels of Sn with 65–70 mg·kg -1 but increased appreciably in the presence of extraneous Sn 2+ , -COOH/Sn 2+ , or -OH/Sn 2+ . The E a values for the pyrolysis reactions of the PLLAs that provided lactide were different under the catalysis of Sn 2+ in different chemical environments because Sn 2+ can form the new Sn-carboxylate and Sn-alkoxide with exogenous carboxyl and hydroxyl groups, which were different in steric hindrance for the formation of activated complex between Sn 2+ and PLLA. Under the catalysis of Sn 2+ , a lactide molecule can be directly eliminated selectively at a random position of PLLA molecular chains, and the molecular chain of PLLA cannot change two PLLA fragments at the elimination site of lactide. However, it was regenerated into a new PLLA molecule with the molecular weight reduced by 144 g·mol -1 .
研究领域:
材料科学
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化学工程
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DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2018
·
IF 3.794
Biao Lu,Yingbang Yao,Xiaodong Jian,Tao Tao,Bo Liang,Q.M. Zhang,Sheng-Guo Lu
The electrocaloric effect (ECE) in gadolinium and tin ions doped lead lanthanum zirconate titanate ceramics was investigated. Five samples with different compositions and hence different relaxor behaviors and polarization properties were prepared via a conventional solid-state reaction process. The ECE was measured directly by a high resolution thermometer from 293 K to 423 K. The results show that the ECE is mainly determined by the number of polarization states and polar-correlation strength . Furthermore, the results reveal that the temperature variation of ECE around Curie temperature is associated with the generation rate, activation energy , size and freezing temperature of polar nanoregions. As a result, Sn doped PLZT composition exhibits the best ECE, i.e. , a peak ΔT > 2 K obtained at 5 MV/m, and ΔT > 1.78 K achieved in the whole temperature range measured at the same field, which are very attractive for high performance ECE devices.
研究领域:
材料科学
·
物理学
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DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Xiao Jin,Min Zheng
In view of the important influence of Sn 4+ and ascorbic acid (AA) on environmental pollution and human health, the establishment of an effective method to achieve rapid and highly sensitive detection is urgently needed. Herein, orange fluorescent (FL) carbon dots (CDs) were successfully prepared from 1,2,4,5-benzenetetramine tetrahydrochloride and thiourea via solvothermal approach. CDs can serve as FL sensors for detecting Sn 4+ and AA, the detection limit is 0.13 and 0.41 μM, respectively, through a signal on–off–on mode. Furthermore, the practicability of CDs nanoprobes is validated by the successful identification of Sn 4+ and AA in live cells, real water samples and medicine. The present work comfirms the feasibility of employing CDs as FL probes to effectively and selectively detect Sn 4+ and AA, which presents a potential approach for on-site detection of Sn 4+ and AA in various environment and biological systems with exceptional sensitivity.
研究领域:
环境科学
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分析化学
·
生物医学
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DOI
高影响因子
JOURNAL OF CHEMICAL RESEARCH
·
2022
·
IF 1.097
Ruiji Li,Dong Wang,Xiaoyun Li,Zehui Zhang,Wei Li
Visible-light-excited fluorescent probes with excellent water solubility are of significant research importance in the biomedical field. In this work, a series of visible-light-responsive carbocyanine fluorescent compounds [DiSCn(3)] are synthesized from 2-methylbenzothiazole and are employed as fluorescent probes for detecting tin(II) ions. Upon addition of tin(II) ions to an aqueous solution of compounds DiSCn(3)-3 and 4, both exhibit considerable changes in their absorption and fluorescent intensity, respectively. These spectral changes may correspond to the binding between tin(II) ions and the sulfur atom in the benzothiazole unit to form a metal complex. This indicates that DiSCn(3)-3 and 4 can be used as promising fluorescent chemical sensors for detecting tin(II) ions in aqueous solution via visible-light excitation.
研究领域:
分析化学
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生物医学
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DOI
高影响因子
Materials Horizons
·
2025
·
IF 10.7
Mengjie Si,Yueman Tang,Chen Xu,Chen Yu Li,Kaishun Xia,Wei Xu,Ji Lin,Zhen Jiang,Jintao Yang,Si Yu Zheng
Developing hydrogels with high conductivity and toughness via a facile strategy is important yet challenging. Herein, we proposed a new strategy to develop conductive hydrogels by growing metal dendrites. Water-soluble Sn2+ ions were soaked into the gel and then converted to Sn dendrites via an electrochemical reaction; the excessive Sn2+ ions were finally removed by water dialysis, accompanied by dramatic shrinkage of the gel. Based on in situ transformation from metal ions to dendrites, the method integrated the advantages of ionic conductive fillers, such as LiCl (uniform dispersion), and electrical fillers, such as metal particles (high conductivity). Additionally, the morphology of metal dendrites combined advantages of 1D nanowires (large aspect ratio of the branches) and 2D nanosheets (large specific surface area of the skeleton). The strategy was found to be effective across diverse gel systems (non-ionic, anionic, cationic and zwitterionic). The dense, highly conductive and branched Sn dendrites not only formed a conductive pathway but also interacted with the polymer network to transfer stress and dissipate energy. The resultant gel exhibited a high conductivity of 12.5 S m−1, fracture energy of 1334.0 J m−2, and fatigue threshold of 720 J m−2. Additionally, the gel exhibited excellent sensitivity when used as a wearable strain sensor and bioelectrode. We believe this strategy offers new insights into the development of conductive hydrogels.
研究领域:
材料科学
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生物医学工程
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化学工程
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产品关联
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
·
2022
·
IF 5.304
Shan Pu,Chengyan Xia,Lan Wu,Kailai Xu
In this study, polyvinylpyrrolidone (PVP) supported and cysteine (Cys) modified copper nanoclusters (Cys-PVP-CuNCs) with high fluorescence intensity have been synthesized and used to establish a simple and sensitive assay for the determination of trace Sn 4+ . The presence of Sn 4+ can lead to fluorescence quenching based on the aggregation of PVP-CuNCs caused by the coordination of Sn 4+ and oxygen atoms. For Cys-PVP-CuNCs, the ligand Cys can transfer electrons to the metal center of the cluster, resulting in strong fluorescence enhancement of CuNCs and intensification of fluorescence quenching after interaction with Sn 4+ , which is conducive to more sensitive visual detection. The proposed assay allows for the detection of Sn 4+ in a linear range from 5 μg L −1 to 100 μg L −1 , with a detection limit as low as 4.5 μg L −1 at a signal-to-noise ratio of 3. Moreover, under UV light, the obvious fluorescent color change can be observed by naked eyes at Sn 4+ concentration ranging from as low as 5 μg L −1 to 200 μg L −1 . Benefiting from the high sensitivity of this assay, satisfactory test results have been obtained when using only 10 mg of canned food samples with rapid digestion. The proposed Cys-PVP-CuNCs fluorescent probe shows excellent stability, simple operation, good selectivity, and high sensitivity, and thus it is expected to be used in the real-time field detection of Sn 4+ .
研究领域:
分析化学
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环境科学
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材料科学
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Xiaoman Li,Pengfei Zhai,Xinyu Liu,Guangqiang Liu,Rongfei Wei,Hai Guo
A series of novel Sn 2+ doped boroaluminate glasses were prepared by the traditional melt quenching method in this work. Their glass network structure, luminescent properties, and mechanisms were studied in detail. The main framework of the glass network was dependent on the glass network former (B 2 O 3 ) and intermediate (Al 2 O 3 ), and was characterized by the 11 B and 27 Al NMR spectra . Broadband tunable blue-violet emissions ranging from 320 to 550 nm were realized by regulating the glass network structure through optical basicity. The quantitative relationship between optical basicity and emission/excitation peak positions and intensities, FWHM, and Stokes-Shift of this Sn 2+ -doped glass were revealed, according to which the luminescent properties of Sn 2+ could be modulated and even predicted in the future. This work will enrich our understanding of the luminescent properties of Sn 2+ ions and the variations of glass network structure, guiding the design of efficient and tunable luminescent boroaluminate glass.
研究领域:
材料科学
·
光学
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DOI
高影响因子
JOURNAL OF NANOPARTICLE RESEARCH
·
2020
·Vol. 22
·期 9
·1-11
·
IF 2.132
Zhao Yubin,Li Meng,Matras-Postolek Katarzyna,Yang Ping
Sn 2+ ions were introduced in Cs-Pb-Br nanocrystals (NCs) to test the change of crystal structure and photoluminescence (PL) property. In the cases of Sn/Pb ratios less than 20%, the CsPb 1- x Sn x Br 3 NCs revealed CsPbBr 3 crystal structure. With increasing the Sn/Pb ratio, Cs-Pb-Sn-Br NCs exhibited a mixture phase of CsPbBr 3 and Cs 4 PbBr 6 . The NCs show bright PLQYs (87%) for Sn/Pb molar ratio of 30%. This is ascribed to little amount Cs 4 PbBr 6 decreased the electrons and holes non-radiation recombination of CsPbBr 3 . With increasing the Sn/Pb ratio to 80%, the Cs 4 Pb 1- x Sn x Br 6 NCs exhibited pure Cs 4 PbBr 6 phase structure. Furthermore, a weak blue-emitting peak around 450 nm was observed for the Cs 4 Pb 1- x Sn x Br 6 NCs. This confirms that Sn 2+ ions were successfully introduced into Cs 4 PbBr 6 structure. The morphologies of samples changed from initial cubic to hexagonal with increasing Sn/Pb ratios from 20 to 80%. The excitons and free carrier dynamics of the NCs were discussed. Graphical abstract
研究领域:
材料科学
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光学
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DOI
高影响因子
Environmental Science-Nano
·
2022
·Vol. 9
·期 7
·2417-2426
·
IF 9.473
Zhenting Yuan,Wenrou Tian,Tingting Ren,Jun Han,Najun Li,Dongyun Chen,Jianmei Lu
Highly conductive Sn2+-anchored Ti3C2 quantum dots (Sn-TQDs) prepared by electrostatic attraction between Sn2+ and Ti3C2 quantum dots (TQDs) have a vital ability to transfer electrons. Herein, WO3/Sn-TQDs/In2S3 heterojunctions have been fabricated for the first time by introducing Sn-TQDs as electron mediators to shuttle electrons from WO3 to In2S3 efficiently, further realizing the rapid reduction of low-concentration Cr(VI) and H2 generation by water splitting under visible light. The Cr(VI) reduction efficiency and H2 evolution rate over WO3/Sn-TQDs/In2S3 were 2.1 and 5.5 times that of WO3/TQDs/In2S3, respectively. The enhanced photocatalytic activity of WO3/Sn-TQDs/In2S3 can be attributed to the positively charged Sn2+ anchored around the negatively charged TQDs, facilitating the improvement of photogenerated electron transfer efficiency. Finally, the possible photocatalytic mechanism of Cr(VI) reduction and H2 generation by WO3/Sn-TQDs/In2S3 was proposed. This provides a new perspective on the surface modification of Ti3C2 quantum dots in photocatalysis.
研究领域:
材料科学
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环境科学
·
化学
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DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2021
·Vol. 139
·期 9
·51724
·
IF 3.125
Xiaoqing Qiu,Daqian Wang,Qing Li,Xiaoyue Li,Xiaowei Zhao,Zhiwei Li,Xiaohong Li,Zhijun Zhang
Melamine-formaldehyde (MF) foam has wide applications due to good flame retardancy, excellent sound absorption, and high thermal stability. However, the recycling of MF foam wastes remains a challenge due to its thermosetting nature. Here, we demonstrate a new strategy for discarded foams as solid adsorbents for removing tin ions in simulated tin-containing wastewater. Results showed that the removal rate of tin in simulated wastewater is as high as 99.996%. Moreover, after simple calcination, as-obtained products can be used as high-efficiency flame retardants for flexible poly(vinyl chloride) (PVC), reducing the peak of heat release rate and total smoke production of PVC by 51.8% and 45.8%, respectively, under the condition of 2.5 wt.% addition. In short, this strategy successfully converted MF foam and tin wastewater to valuable flame retardants, opening the way for the environmentally friendly recycling of MF waste and the simultaneous treatment of tin-containing wastewater.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2018
·Vol. 6
·期 20
·5506-5513
·
IF 5.976
Meng Li,Xiao Zhang,Katarzyna Matras-Postolek,Hsueh-Shih Chen,Ping Yang
Fast and efficient ion-exchange reactions endow CsPbX3 nanocrystals (NCs) with superior photoluminescence (PL) properties. In this study, SnX2 (X = I, Cl) was used as a Sn precursor to conduct the cation exchange reaction, which was promoted by anion exchange between the parent CsPbBr3 NCs and the guest X in SnX2. The anion-driven cation exchange reaction occurred efficiently (10 min). CsSnI3 NCs were created by ion-exchange reactions between CsPbBr3 NCs and the SnI2 precursor. The CsSnI3 NCs retained the initial morphology of CsPbBr3 NCs and revealed a high PL efficiency (59%) and prolonged PL lifetime. In contrast, the exchange reaction of Sn2+ ions in CsPbBr3 NCs did not occur in a short time using SnBr2 as a precursor. After the cation exchange reaction, the 4f peaks of Pb ions in X-ray photoelectron spectroscopy spectra shifted to low binding energies as compared to those of the parent CsPbX3 NCs. This is ascribed to the increase in the number of Pb–oleate (Pb–OA) species. Contrary to the hot-injection method used to synthesize CsSnI3 NCs, the kinetically controlled ion exchange reactions lead to the synthesis of CsSnI3 NCs with a high structural stability. Thus, an anion-exchange-promoted cation exchange reaction is a particularly efficient versatile tool to dope Sn2+ into CsPbX3 NCs.
研究领域:
材料科学
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光学
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DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2021
·
IF 9.127
Min Yang,Xiaojuan Huang,Liquan Yao,Limei Lin,Aicheng Chen,Yongqing Chen,Yuliang Che,Shuiyuan Chen,Xiangkai Kong,Guilin Chen
Molecular solution with the metal-thiourea complex is a facile and effective route for Cu 2 SnS 3 (CTS) thin film deposition . However, its stability is still challenging due to flexible metal salts precursors. Here we report a strategy to enhance the stability of the Cu–Sn–S molecular solution that use bivalent Sn to suppress the oxidation of the S 2- of thiourea via the redox reaction . The self-stabilizing mechanism has been carefully revealed by the systematic experiments and confirmed by the spontaneous reaction process of metal-thiourea system. It demonstrates that Sn with a low valence state weakens the transfer of lone pair electrons from thiourea to Cu 2+ and Sn 4+ ions, alleviating the sulfur precipitates from thiourea oxidation because of the easily reducible character of Sn 2+ ion. The solution with Sn 2+ antioxidant additive can be stored for a long time under air ambient, which is then spin-coated and sulfurized with Sn powder compensation. The uniform CTS thin film with composition control is finally achieved and delivers a device efficiency of 1.15%. This work provides a guide on stabilizing the solution precursor for chalcogenide thin film deposition.
研究领域:
材料科学
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化学
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产品关联
DOI
高影响因子
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