CRYSTAL GROWTH & DESIGN
·
2018
·
IF 3.972
Feng Chen,Chunxiang Xu,Qingyu Xu,Yizhi Zhu,Zhu Zhu,Wei Liu,Xiuxiu Dong,Feifei Qin,Zengliang Shi
CH3NH3PbBr3 single crystal, one of organometal halide perovskites, as novel optoelectronic and photovoltaic materials could be easily precipitated using an antisolvent method. Understanding of the growth mechanism will significantly improve reproducibility, quality, and controllability of the single crystals. However, it is difficult to capture the growth process due to the super solubility of CH3NH3PbBr3 crystals in N,N-dimethylformamide solution. Here, filter paper was used to separate the intermediate states of CH3NH3PbBr3 crystals out of N,N-dimethylformamide solution in the growth process. The developed fabrication approach can monitor the morphology evolution of CH3NH3PbBr3 single crystals as a whole. Meanwhile, the precursor solution’s properties and degradation of CH3NH3PbBr3 single crystals were also investigated systematically. It indicates that the CH3NH3PbBr3 single crystal growth process is similar to sodium chloride crystals grown from solution in the presence of nitrilotriacetamide. The results help us to deeply discern the growth mechanism of CH3NH3PbBr3 single crystal in N,N-dimethylformamide solution and design controllable optoelectronic devices.
研究领域:
材料科学
·
光电材料
·
晶体生长
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2018
·
IF 4.427
Xin Liu,Huahua Cai,Jing Zou,Zijun Pang,Baoling Yuan,Zhenming Zhou,Qingfeng Cheng
A sensitive spectrophotometric method (the N,N -diethyl- p -phenylenediamine (DPD) method) was established for the determination of trace permanganate concentration (0–10 μM) in water. The DPD method was based on the oxidative coloration reaction where permanganate could oxidize DPD to form the red colored DPD radical (DPD • + ) with a second-order rate constant of 2.96 × 10 4 M −1 s −1 at pH 6 (50 mM phosphate buffer). The generated DPD • + could be quantitatively measured at 551 nm using an UV–Vis spectrophotometer. There was a good linear relationship (R 2 = 0.999) between the absorbance of DPD • + and permanganate concentration. The DPD method was highly sensitive, and the absorbance of generated DPD • + at 551 nm was as high as 5.70 × 10 4 cm −1 per M (mol L −1 ) of permanganate. The reaction of permanganate with DPD in the pH range of 4.0–8.0 had a stoichiometric coefficient of 1:2.71. The residual absorbance of DPD •+ in ultrapure water and natural waters was fairly stable for 30 min. Limits of detection of the proposed DPD method in ultrapure water and natural waters were calculated to be as low as 0.010 μM and 0.017 μM, respectively. Moreover, trace permanganate concentrations of 0.04 and 0.10 μM were found in natural waters and wastewater by the proposed DPD method. Additionally, the DPD method could be applied to measure the second-order rate constants of the reaction of permanganate with phenol at pH 7.0 (28.2 M −1 s −1 ).
研究领域:
分析化学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANNALS OF MICROBIOLOGY
·
2017
·Vol. 68
·期 1
·27-34
·
IF 1.122
Xiao Yaqing,Li Peijun,Xu Mei,Wang Wu,Chen Conggui
The objective of this study was to evaluate the ability of five strains of meat-borne bacteria to decrease N-nitrosodimethylamine (NDMA) and N-nitrosodiethylamine (NDEA) and to elucidate the mechanism in Mann-Rogosa-Sharp (MRS) broth. Lactobacillus pentosus R3 was found to be the most effective in decreasing the concentration of the two N-nitrosamines (NAs) in MRS broth, with a rate of 22.05% for NDMA and 23.31% for NDEA. The concentration of the two NAs could not be reduced by either extracellular metabolites or intracellular extracts of Lb. pentosus R3 (P > 0.05), and proteinaceous substances in the cell debris were found to be responsible for the decrease. These were surface-layer proteins (SLPs) located on the cell wall. Therefore, the decrease in NDMA and NDEA by Lb. pentosus R3 is associated with its SLPs. Lb. pentosus R3 may be developed as a starter culture in the production of fermented foods with lower NAs.
研究领域:
食品科学
·
微生物学
·
毒理学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
·
2025
·
IF 3.3
Zhao Shanshan,Du Shouwen,Guan Yudong,Schlüter Hartmut
The structural instability and electronegativity of sialic acids make N-sialoglycan profiling challenging. We compared commonly used preparation strategies, including native, acetohydrazide-based derivatization, and permethylation, in N-glycomics with nMatch, an R-based bioinformatics tool that ensures full coverage of the detected N-glycans using mass spectrometry. We demonstrated that permethylation leads to efficient detection of not only N-sialoglycans but also other N-glycans and, therefore, provides a valuable reference for the selection of the appropriate N-glycan preparation strategy in future studies.
研究领域:
分析化学
·
糖组学
·
质谱技术
·
生物信息学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Asian Journal of Organic Chemistry
·
2020
·Vol. 9
·期 7
·1076-1080
·
IF 3.13
Siyu Wu,Gengwen Yin,Caihong Cheng,Bo Liang,Haiquan Zhang
Graphical A new product -PDMBPRI-4F was synthesized by one-step method, which has the special property of fluorescence quenching caused by intramolecular charge transfer. Nucleophilic substitution process with loss of one fluorine atom was observed when pentafluorophenyl substituted benzo[ghi]perylene triimide and perylene diimide were heated in N , N -dimethylformamide, in which N , N -dimethylformamide acted both as solvent and nucleophile reagent. Unexpectedly, the obtained product exhibited significant intramolecular charge transfer optical properties in solutions. The mechanism of nucleophilic substitution and the influence of substituent were further studied and proposed in this manuscript.
研究领域:
有机化学
·
材料科学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Ailin Gao,Yang Yang,Changchao Jia,Jian Cui,Bo Wang,Yehai Yan
For the total heat exchange membrane, there is a compromise effect between the moisture permeability and the gas barrier. To overcome this challenge, a new type of total heat exchange membrane was proposed involving a porous polyethylene (PE) membrane and a hydrophilic poly (N, N-dimethyl acrylamide) (PDMAA) hydrogel. A dense PE/PDMAA composite membrane was fabricated via an in situ photoinitiated free-radical polymerization and cross-linking reaction through a pre-permeation of N, N-dimethyl acrylamide (DMAA) monomers in the porous structure of the PE membrane. In this study, we systematically investigated the effect of varying amounts of PDMAA filler on membrane morphology, hydrophilicity, stability, mechanical properties, water vapor transmission rate, gas barrier property, and total heat exchange efficiency. These results demonstrate that a tight, stable PE/PDMAA hybrid membrane with an interlocked structure has been created. Water vapor diffusion channels and an efficient carbon dioxide (CO 2 ) barrier were successfully constructed through the introduction of a cross-linked PDMAA hydrogel. Improvements in water vapor transmission rate and reduction in CO 2 transmission rate were achieved simultaneously with increasing PDMAA filling amount. Excellent mechanical properties and hybrid stability were also observed for the composite membrane obtained. This work provides a novel total heat exchange membrane with convenient production process, low cost and high durability characteristics.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
ULTRASONICS SONOCHEMISTRY
·
2022
·
IF 9.336
Hanyang Gao,Kunkun Pei,Guoxin Hu,Wenxing Liu,Aihua Meng,Hongcheng Wang,Huifeng Shao,Wenxin Li
CO 2 -expanded organic solvent is a kind of important fluid medium and has broad applications in chemical industry, environmental protection and other fields. Ultrasonic cavitation in gas expanded liquids (GXLs) is conducive to enhancing mass transfer and producing many exciting phenomena. In this paper, the ultrasonic cavitations and streaming in the saturated CO 2 -expanded liquid N, N-dimethylformamide (DMF) at 4.2 MPa and 5.2 MPa are observed by a high-speed camera. The cavitation intensity and time trace of pressure pulses are recorded using a PZT hydrophone. The influences of gas–liquid equilibrium pressure and ultrasonic power on the cluster dynamics of transient and stable cavitation are examined. The excess molar enthalpies required for CO 2 dissociation from DMF are calculated by Peng-Robinson equations of state and the change of surface free energy of CO 2 -expanded DMF is predicted. The results show that the excess enthalpy of the mixture is one of the key factors to control ultrasonic cavitation at high pressurized conditions, while the surface tension is the key factor for low pressure. As the increase of applied ultrasonic power, the formation and collapsing frequency of bubble clusters increases, and the amplitude and cyclic frequency of pressure pulse are enhanced. The transient cavitation intensity increases as it reaches a maximum value at a certain ultrasonic power and then decreases. The change trends of stable cavitation intensity under different pressures are basically same. It can be concluded from the evidence that ultrasonic cavitation in CO 2 -expanded DMF is affected by the combined effect of compression and substitution: compression depresses the nucleation and growth of bubbles, while the high solubility of CO 2 in DMF is conducive to the generation of bubbles in cavitation.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF NANOPARTICLE RESEARCH
·
2023
·Vol. 25
·期 7
·1-16
·
IF 2.5
Shan Chuanfu,Liu Ziyi,Li Fuchao,Jia Wenhan,Cai Gaotuo,Li Ming,Tang Tao,Li Shuai,Wen Jianfeng,Hu Guanghui,Jiang Li,Li Xinyu
TiO 2 -based materials are important photocatalysts but the rapid recombination of photoexcited electron–hole pairs, and the wide band gap both limit their photocatalytic activities. In this work, p-type phosphorus-doped graphene quantum dots (P-GQDs, 5~20 nm) were combined with n-type TiO 2 nanoparticles (20~50 nm) and n-type silver iodide (AgI, 100~200 nm) by a facile sonication and precipitation process to yield a novel ternary photocatalyst TiO 2 /P-GQDs/AgI with n-p-n heterojunctions. The morphologies, structures, optical properties, and chemical environments of photocatalysts were all studied. The resulting ternary photocatalyst exhibited enhanced visible photocatalytic activity toward the degradation of methyl orange (MO), estimated to 70.4-fold that of pure TiO 2 . By contrast, the photocatalytic activities of TiO 2 /GQDs with an n-n heterojunction, TiO 2 /P-GQDs with a p-n heterojunction, and TiO 2 /GQDs/AgI (30%) with an n-n-n heterojunction showed 4.4-fold, 5.3-fold, and 14.2-fold higher than those of TiO 2. The electrochemical and optical measurements revealed that the enhanced photocatalytic activity was linked to promoted charge carrier separation by n-p-n heterojunctions coupled with the increased absorption in the visible region. Overall, the new band structure connected in series p-n heterojunctions looks promising as a highly efficient photodegradation system for future use in decontamination of polluted water. Graphical abstract
研究领域:
材料科学
·
环境科学
·
光催化技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2018
·
IF 6.578
Yuqian Sui,Huayuan Hu,Mitsuru Ueda,Lianjun Wang,Xuan Zhang
In this study, a novel poly[vinyl-(4-benzyl- N , N , N -trimethylammonium bromide) ketone] (QA-PVBK) homopolymer was synthesized by conventional free-radical polymerization, followed by benzyl bromination, and in-situ quaternization reaction, successively. Blend membranes were further constructed between QA-PVBK and commercially available polybenzimidazole (PBI), as novel anion exchange membrane materials. Owing to the short repeating unit of QA-PVBK, the ion-clusters for the ion transport were highly aggregated on the microscale, which significantly contributed to the excellent hydroxide conductivity of the blend membranes. The PBI was introduced as a physical reinforcement, strengthening the membranes’ robustness and suppressing excessive swelling. Membrane PBI/QA-PVBK-OH(70%), with the QA-PVBK-OH (hydroxide form) content of 70% over the entire membrane matrix, exhibited a high hydroxide conductivity of 50.8 mS cm −1 at 60 °C, and, consequently, a good peak power density of 170.6 mW cm −2 at 60 °C/100% relative humidity condition in a H 2 /O 2 single cell test. The blend membranes also demonstrated acceptable chemical stability towards the alkaline condition (1 M NaOH at 60 °C) with the residual conductivity over 59.4% after 168 h. In light of these promising results, the present study demonstrates a facile blending process for simultaneously addressing the ion conductivity and mechanical properties of anion exchange membranes.
研究领域:
材料科学
·
电化学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
E-POLYMERS
·
2020
·Vol. 20
·期 1
·273-281
·
IF 1.675
Shengzhu Zhou,Qiang Zhou,Chang Lu,Zhihui Zhang,Luquan Ren
The intelligent poly N , N -dimethylacrylamide hydrogel material system with high mechanical strength and the 3D printable property was prepared via in situ free radical polymerization under vacuum successfully. With the increase in nanofibrillated cellulose (NFC) content, stress and strain of hydrogels increased gradually. As the effective reinforcement, NFC enhanced the crosslinking density, which realized the controllable regulation of rheology behaviors including viscosity, storage modulus, and loss modulus of hydrogels. Combined with the swelling rate and the existence of the gel–sol transition point, a hydrogel with 10 mg/mL NFC was treated as the 3D printing ink of hydrogel actuators. Variation of printing parameters significantly affected self-driven deformations. The hydrogel actuators with 90°/0° and 45°/135° configurations owned bending and spiral deformations, respectively. Actuators with a larger length–width ratio owned a lower pitch value. The precise anisotropic swelling property of the printed bilayer structure was the self-driven deformation mechanism of hydrogel actuators, which provided material candidates for the preparation of soft robots and actuators.
研究领域:
材料科学
·
软体机器人
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2013
·Vol. 3
·期 43
·20877-20882
·
IF 2.562
Changqing Liu,Guoxin Hu
Supercritical fluid exfoliation of layered titanate is an efficient way to prepare titania nanosheets. However, a phase transition may occur under high temperature and high pressure conditions. We have studied the phase transition process of H1.07Ti1.73O4·H2O in two solvents (N,N-dimethylformamide (DMF) and water) under supercritical conditions by XRD measurements. Experimental results show that exfoliation is found in supercritical DMF, while in supercritical water exfoliation and the phase transition occur concurrently, transforming it into anatase. An interpretation of the phase transition is proposed: as water is a protic solvent, it can supply H+ under high temperature and high pressure conditions; the phase transition is caused by dissolution and recrystallization, which is confirmed by XRD and SEM results. The suitable solvents shall be selected for the preparation of titania nanosheets by supercritical exfoliation.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CELLULOSE
·
2020
·Vol. 27
·期 12
·6861-6870
·
IF 4.21
Zeng Tong,Ke Xun,Li Lijuan,Cheng Xinlei,Ni Yonghao,Ouyang Xinhua,Zhang Xingye,Chen Lihui,Huang Liulian,Hu Hui-Chao
Abstract This work developed a novel method for the determination of N-methyl morpholine N-oxide (NMMO) in the solution of biorefining, such as lyocell or biomass pretreatment. Copper hydride in situ (CuH) was generated in alkaline solution from sodium borohydride and cupric ion to completely reduce NMMO to N-methyl morpholine (NMM). Finally, the generated volatile NMM was analyzed by headspace gas chromatography. The generation of in situ CuH, complete reduction of NMMO, and the gas–liquid equilibration of NMM can be synchronously completed at 80 °C in 30 min, with a cupric ion concentration of 20 μmol, sodium hydroxide (0.8 mmol), sodium borohydride (3.0 mg), and 1.0 mL 30% ammonium hydroxide in 5.0 mL aqueous solution. The lowest limit of NMMO quantification was 42 mg/L in the present method, with good precision (standard deviation = 5.62%) and accuracy (recoveries from 95.9 to 106%). The present method has high accuracy, sensitivity, and throughput. It should be a useful tool to determine the content of NMMO and allow optimize the cost efficiency. Graphic abstract
研究领域:
分析化学
·
生物工程
✓ 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）