Journal of Materials Chemistry A
·
2020
·Vol. 8
·期 27
·13585-13593
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IF 11.301
Xi Yuan Feng,Kar Wei Ng,Shuang Peng Wang,Wen Zhou Chen,Zhen Zhong Zhang,Wei Chen,Yun Yang Zhao,Bao Tu,Zi Kang Tang,Hui Pan,Zhu Bing He
The amine-induced very fast liquefaction and recrystallization (L&R) process on organic–inorganic hybrid perovskites has been demonstrated to be an effective way to improve the quality of the as-deposited MAPbI3 films and increase the feasibility of preparing large area perovskite solar cells (PSCs). Despite the effectiveness, the reaction mechanism of the L&R process is yet to be well understood. In this work, we investigate the fundamental influences of amines on the structural change of MAPbI3 perovskite by studying the reaction between ammonia and a bulk MAPbI3 crystal. By employing various techniques including in situ X-ray diffraction, Raman spectroscopy and Fourier transform infrared spectroscopy, we find that NH3 effectively substitutes iodine in the perovskite crystal lattice, transforming the 3-dimensional (3D) lattice into a MAPb(NH3)nI3 coordination complex-based system. The resulting coordination complex octahedral structures are only held together by weak forces of attraction, leading to the experimentally observed L&R process. First-principles calculations further confirm the feasibility of such L&R at room temperature. As a proof of concept, we demonstrated the use of liquefaction for substrate recycling of MAPbI3 based solar cells with ammonia. Our results here provide deep insights for understanding the interaction mechanism, which can surely provide important guidance on improving the quality of perovskite films and related devices, as well as the recycling of toxic lead for long-term sustainability.
研究领域:
材料科学
·
物理化学
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DOI
高影响因子
FIBERS AND POLYMERS
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2020
·Vol. 21
·期 6
·1251-1258
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IF 1.797
Liang Huazhe,Cao Meng,Yang Desheng,Sun Tingting,Chu Xiaomeng,Liu Shaojie
A series of polyamidoamine (PAMAM) immobilized TEMPO macromolecular catalysts were prepared by condensation reduction reactions between carbonyl groups in 4-O-TEMPO and primary amines in PAMAM. The macromolecular catalyst and NaBr/NaClO were used as catalytic system for selective oxidation of cellulose in aqueous medium. Effects of various factors, such as TEMPO loading ratios and PAMAM generations, were studied on the catalytic performances. Compared with free TEMPO, the macromolecular catalyst with less than 50 % TEMPO loading ratio had a higher reaction rate in the initial stage of the reaction. Especially, the reaction rate of G1.0 PAMAM with 30 % TEMPO loading ratio was comparable to free TEMPO in the whole reaction process. Its cellulose oxidation degree (or catalytic activity) was also equivalent to the level of free TEMPO. Interestingly, the cellulose depolymerization degree of macromolecular catalyst was not affected by the cellulose oxidation degree and was lower than that of free TEMPO. The macromolecular catalyst could be recycled efficiently by the combination of supernatant circulation and salting-out extraction, and the recycling performance was excellent.
研究领域:
化学工程
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材料科学
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DOI
高影响因子
JOURNAL OF LUMINESCENCE
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2018
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IF 2.732
Yong Kuai,Changchang Zhang,Dule Hao,Xiang Liu,Liang Ma
Organic amines are apt to be oxidized in natural environment. Therefore, preparation of fluorescent materials derived from organic amines should think of the role of oxidized amines. However, this is neglected according to some reports. Herein, first generation poly(amidoamine) ( PAMAM 1.0G ) dendrimers with inherent weak photoluminescence was oxidized by ambient oxygen under heating of 180 °C for 60 min which brought an obvious enhancement of fluorescent quantum yield (QY). The oxidation was proved by both infrared and 1 H nuclear magnetic resonance. Image of transmission electron microscope (TEM) also revealed the aggregation of PAMAM 1.0G after they were suffered from the lasting heating. The enhancement of QY was also observed when the mixture of aqueous solution of PAMAM 1.0G and citric acid were disposed under the same conditions. And the QY reached as high as 64.40%, which is much higher than that of the fluorescent materials derived from sole citric acid. TEM image also exhibited the aggregation of the product. The carboxyl of the aggregated particle could be activated by N-hydroxysuccinimide and could be bonded with bovine serum albumin realizing the fluorescent labeling of BSA finally, which was demonstrated by the image of gel electrophoresis .
研究领域:
材料科学
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化学
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DOI
高影响因子
Inorganic Chemistry Frontiers
·
2019
·Vol. 7
·期 1
·82-90
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IF 5.934
Xiao Chen,Shuhua Han,Dongdong Yin,Changhai Liang
Based on the isolation of the active sites in the crystal structure as well as the strong alteration of the electronic structure in comparison to elemental metals, metal silicides as typical intermetallic compounds have boosted their applications in catalysis. Heterogeneous Ni2Si/SiCN as a promising and low-cost catalyst alternative to noble-metals has been successfully synthesized via the chemical modification of a polysilazane precursor at a molecular level by the use of metal complexes followed by its temperature-programmed pyrolysis. In the one-pot tandem synthesis of imines and secondary amines via the reductive coupling of nitrobenzene and benzaldehyde, the as-prepared Ni2Si/SiCN-1000 catalyst exhibits excellent catalytic performance (conversion >99% and selectivity to aromatic amine >92%) and excellent recyclability under optimal reaction conditions. Due to the reduction induction support–metal strong interactions and the formation of intermetallic Ni2Si, the electronic structure of the metallic Ni active site has been modified, which may tone the catalytic performance and enhance the stability of the catalyst.
研究领域:
材料科学
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催化化学
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DOI
高影响因子
PLoS One
·
2014
·Vol. 9
·期 11
·e113087
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IF 3.534
Ping Zhou,Yi Deng,Beier Lyu,Ranran Zhang,Hai Zhang,Hongwei Ma,Yalin Lyu,Shicheng Wei
Polydopamine (PDA) coating provides a promising approach for immobilization of biomolecules onto almost all kinds of solid substrates. However, the deposition kinetics of PDA coating as a function of temperature and reaction method is not well elucidated. Since dopamine self-polymerization usually takes a long time, therefore, rapid-formation of PDA film becomes imperative for surface modification of biomaterials and medical devices. In the present study, a practical method for preparation of rapidly-deposited PDA coating was developed using a uniquely designed device, and the kinetics of dopamine self-polymerization was investigated by QCM sensor system. It was found that high temperature and vigorous stirring could dramatically speed up the formation of PDA film on QCM chip surface. Surface characterization, BSA binding study, cell viability assay and antibacterial test demonstrates that the polydopamine coating after polymerization for 30 min by our approach exhibits similar properties to those of 24 h counterpart. The method has a great potential for rapid-deposition of polydopamine films to modify biomaterial surfaces.
研究领域:
生物材料学
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表面化学
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医学工程
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DOI
PubMed
高影响因子
EUROPEAN JOURNAL OF PHARMACEUTICAL SCIENCES
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2015
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IF 3.35
Yu Gao,Zhihong Li,Xiaodong Xie,Chaoqun Wang,Jiali You,Fan Mo,Biyu Jin,Jianzhong Chen,Jingwei Shao,Haijun Chen,Lee Jia
The anticancer efficacy of ursolic acid (UA) was limited by poor water solubility, non-specific tumor distribution, and low bioavailability. To overcome this problem, polyamidoamine (PAMAM) conjugated with UA and folic acid (FA) as novel dendrimeric prodrugs were designed and successfully synthesized by a concise one-pot synthetic approach. Both FA and UA were covalently conjugated to the surface of PAMAM through acid-labile ester bonds and the covalently linked UA could be hydrolysed either in acidic (pH 5.4) or in neutral (pH 7.4) PBS solution. The cellular uptake study indicated that the presence of FA enhanced uptake of the dendrimeric prodrugs in folate receptor (FR) over-expressing Hela cells. The enhanced cellular uptake could be due to the electrostatic absorptive endocytosis and FR-mediated endocytosis. In contrast, for HepG2 cells, a FR-negative cell line, FA conjugation on the surface of the dendrimer showed no effect on the cellular uptake. In MTT assay and cell cycle analysis, FA-modified dendrimeric prodrugs showed significantly enhanced toxicity than non-FA-modified ones in Hela cells. These results suggested that FA-modified dendrimeric UA prodrugs have the potential for targeted delivery of UA into cancer cells to improve its anti-tumor efficacy.
研究领域:
药理学
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肿瘤学
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DOI
PubMed
高影响因子
Reaction Kinetics Mechanisms and Catalysis
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2013
·Vol. 109
·期 2
·551-562
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IF 1.104
Cui Wenjing,Zhu Huaiyong,Jia Meilin,Ao Wulan,Zhang Yulin,Zhaorigetu Bao
Imines were synthesized from benzyl alcohol and amines by using catalysts of gold nanoparticles supported on ZrO 2 (Au/ZrO 2 ). The effects of reaction time, temperature, gold loadings and base were investigated. High yields were achieved under moderate conditions (60 °C) in the presence of KOCH 3 . For instance, the yield of N -benzylidenebenzylamine produced from benzyl alcohol and benzylamine on 3 wt% Au/ZrO 2 is 87 %. The synthesis of imine involves two reaction steps: selective oxidation of benzyl alcohol to benzaldehyde and the coupling reaction of amines with benzaldehyde. In the first step, the base promotes the selective oxidation. The reactions of benzyl alcohol with three different amines, aniline, n -butylamine and benzylamine, were conducted to produce corresponding imines. The results show that the amine with stronger nucleophilicity has better ability to react with benzaldehyde in the second step, resulting in higher yield of the corresponding imine. We proposed a tentative mechanism for the synthesis process.
研究领域:
催化化学
·
有机合成
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DOI
高影响因子
MACROMOLECULES
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2017
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IF 5.835
Ziyang Sun,Huahua Huang,Le Li,Lixin Liu,Yongming Chen
Sulfur-containing polymers have renewed widespread attention due to their fascinating properties like high refractive index and semiconducting character. However, examples of direct polymerization involving elemental sulfur are limited. Herein, a new strategy to prepare polythioamide (PTA) by direct polymerization of aliphatic primary diamines in the presence of sulfur is reported. The polymerization of p-xylylenediamine (1) and sulfur at 110 °C in N-methyl-2-pyrrolidinone afforded PTA1 of high Mw and high yield when the feed ratio of [1]:[S] ranged from 1:2 to 1:3. 1H NMR and 13C NMR spectra confirmed that there are three kinds of structural units among the PTA1 chains. Moreover, different diamines including m-xylylenediamine (2), 1,6-hexanediamine (3), ethylenediamine (4), and 1,4-cyclohexanediamine (5) were copolymerized with 1 in the presence of sulfur to obtain PTA copolymers. With an increase in 5 content, the copolymer PTA1/5 with an alternating sequence in the range of 56%–94% was prepared. Solubility and thermal properties of homopolymers and copolymers were studied. Meanwhile, the copolymers PTA1/3 and PTA1/5 possessed a high refractive index as high as 1.7.
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 Environmental Sciences
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2022
·
IF 6.796
Shuang Zhang,Yi-Li Lin,Tian-Yang Zhang,Chen-Yan Hu,Zhi Liu,Zheng-Yu Dong,Meng-Yuan Xu,Bin Xu
In this study, the formation of iodinated trihalomethanes (I-THMs) was systematically evaluated and compared for three treatment processes - (i) chlorination, (ii) monochloramine, and (iii) dichloramination - under different pH conditions. The results demonstrated that I-THM formation decreased in the order of monochloramination > dichloramination > chlorination in acidic and neutral pH. However, the generation of I-THMs increased in the dichloramination < chlorination < monochloramination order in alkaline condition. Specifically, the formation of I-THMs increased as pH increased from 5 to 9 during chlorination and monochloramination processes, while the maximum I-THM formation occurred at pH 7 during dichloramination. The discrepancy could be mainly related to the stability of the three chlor (am) ine disinfectants at different pH conditions. Moreover, in order to gain a thorough insight into the mechanisms of I-THM formation during dichloramination, further investigation was conducted on the influencing factors of DOC concentration and Br − /I − molar ratio. I-THM formation exhibited an increasing and then decreasing trend as the concentration of DOC increased from 1 to 7 mg-C/L, while the yield of I-THMs increased with increasing Br − /I − molar ratio from 5:0 to 5:10. During the three processes mentioned above, similar I-THM formation results were also obtained in real water, which indicates that the excessive generation of I-THMs should be paid special attention during the disinfection of iodide-containing water.
研究领域:
环境科学
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水处理工程
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DOI
PubMed
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
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2022
·
IF 4.831
Xin Liu,Wei Yu,Xiaowei Mu,Wei Zhang,Xinghua Wang,Qiang Gu
A rapid and sensitive strategy for sensing dopamine (DA) was proposed based on the fluorescence quenching effects of polydopamine (PDA) on carbon dots (CDs). The green-emission fluorescence CDs were synthesized via a facile one-pot hydrothermal approach by employing p-phenylenediamine and ethanol as reagents. In alkaline environments, DA would polymerize to form PDA on surface of CDs, resulting in the fluorescence quenching of the detection system owing to the effects of fluorescence resonance energy transfer (FERT) and inner filter effect (IFE). The proposed fluorescence probe exhibits good selectivity and sensitivity to DA in the concentration range of 0.1–15 μM, with a limit of detection (LOD) of 37 nM. Results of detecting DA in serum samples indicate the broad potential of the proposed strategy for future application in diagnosis of DA-related diseases.
研究领域:
分析化学
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医学诊断
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生物传感
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DOI
PubMed
高影响因子
MOLECULES
·
2023
·Vol. 28
·期 13
·4889
·
IF 4.6
Meng Lian,Feng Zheng,Lingbin Meng,Fei Zhao,Jun Liu,Jimei Song,Qinghua Lu
Heteroaromatic polyimides (PIs) containing benzimidazole have attracted tremendous attention due to their positive impact on the properties of PIs. Some research on PIs containing 4,4′-[5,5′-bi-1H-benzimidazole]-2,2′-diylbis-benzenamine (4-AB) has been reported. However, reports are lacking on homo-polyimides (homo-PIs) containing 3,3′-[5,5′-bi-1H-benzimidazole]-2,2′-diylbis-benzenamine (3-AB), which is one of the isomers of4-AB. In this paper, the influence of amino groups’ positions on the performance of homo-PIs was investigated. It was found that the net charge of the amine N group in4-ABwas lower than that of3-AB, resulting in higher reactivity of4-AB. Consequently, PIs containing4-ABdisplayed better mechanical performance. Molecular simulation confirmed that3-ABand its corresponding PI chain exhibited distorted conformation, leading to the PI films containing3-ABhaving a lighter color. In addition, the3-ABstructure was calculated to have higher rotational energy compared to4-AB, resulting in a higher glass transition temperature (Tg) in PIs prepared from3-AB. On the other hand, PIs containing4-ABexhibited a higher level of molecular linearity, leading to a lower coefficient of thermal expansion (CTE) compared to PIs prepared from3-AB. Furthermore, all PIs showed higher thermal stability with a 5% weight loss temperature above 530 °C andTghigher than 400 °C.Keywords:heteroaromatic polyimides;isomeric diamine;bis-benzimidazole
研究领域:
材料科学
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化学工程
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DOI
PubMed
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2025
·
IF 6.2
Ming-Hui Yi,Heng-Ji Wang,Bing-Jie Wang,Meng-Yu Wang,Zi Tang,Qing-Qi Meng,Yao Shi,Wen-Lin Li,Xiao-Lan Liao,Li Shi
Tiorantraniliprole is a novel diamide insecticide, and the resistance level and mechanism of Spodoptera litura to tiorantraniliprole and the multiresistance mechanism with other diamide insecticides are still unknown. In this study, bioassays showed that field S. litura developed high and medium levels of resistance to tiorantraniliprole, chlorantraniliprole, and cyantraniliprole. Enzyme activity and synergist bioassay indicated that P450s was the main factor leading to metabolic resistance to tiorantraniliprole. Transcriptome sequencing and qPCR showed that CYP6B50 was upregulated by tiorantraniliprole induction and overexpressed in the field-resistant strain. RNA interference and transgenic fruit fly indicated that CYP6B50 was involved in multiresistance to tiorantraniliprole, chlorantraniliprole, and cyantraniliprole. In addition, a target mutation site I4723M in RyR was detected in the field-resistant strain. Further genetic crossing and insecticides docking confirmed that the I4723M mutation involved in chlorantraniliprole and cyantraniliprole resistance also mediated resistance to tiorantraniliprole. This study comprehensively elucidated the mechanisms of resistance to diamide insecticides from both metabolic and target-site resistance in S. litura.
研究领域:
昆虫学
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分子生物学
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农药科学
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DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）