POLYMERS FOR ADVANCED TECHNOLOGIES
·
2014
·Vol. 25
·期 3
·329-337
·
IF 1.964
Jiangtao Liu,Guofei Chen,Xingzhong Fang
A series of isomeric poly(thioether ether imide)s (PTEIs) containing both thioether and ether linkages were prepared by nucleophilic substitution reaction of isomeric bis(chlorophthalimide)s with 4,4′-thiobisbenzenethiol. The inherent viscosities of these polymers were in the range of 0.40–0.56 dL/g in m -cresol at 30°C. The T g values of PTEIs were 196–236°C; T 5% values reached up to 509–529°C in nitrogen and 508–534°C in air, which indicated this kind of polyimide possessed excellent thermal stability. The hydrolytic stability was arranged in the order: a > b > c > d > e, and improved with increasing the content of 3-substituted phthalimide unit in the polymer backbone. Flexible films could be cast from the polymer solution with a solid content of 10%. The PTEI films exhibited good mechanical properties with tensile strengths of 90–104 MPa, elongations at break of 6.6–7.9%, and tensile moduli of 2.3–2.6 GPa. The minimum complex viscosity of PTEIs c was about 100 Pa·s at 310°C and the minimum melt viscosity of PTEIs (a–e) decreased with increasing the content of unsymmetrical 3,4′-substituted phthalimide units. Copyright © 2014 John Wiley & Sons, Ltd.
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高影响因子
FORENSIC SCIENCE INTERNATIONAL
·
2018
·
IF 1.974
Ting Wang,Baohua Shen,Hejian Wu,Jingying Hu,Huili Xu,Min Shen,Ping Xiang
Methamphetamine (MA) and amphetamine (AM) are widely abused drugs. These compounds contain a chiral center, and their enantiomers exhibit different pharmacologic, pharmacokinetic, and metabolic properties due to differences in binding affinities to their receptor sites. Until now, there was a lack of information on the decline in the concentration of drugs in hair after abstinence. A simple procedure for the chiral separation and determination of methamphetamine (MA) and its metabolite amphetamine (AM) enantiomers by LC–MS/MS in hair samples has been developed and fully validated. The LODs and LLOQs were 0.02 ng/mg and 0.05 ng/mg for all analytes, respectively. This method was successfully applied to both real hair specimens from chronic MA users and after the discontinuation of MA. The concentration of total MA, and total AM in fifty-eight authentic hair specimens ranged from 7.8 ng/mg to 521.0 ng/mg, and from 0.3 ng/mg to 84.0 ng/mg, respectively. Both enantiomers of MA and/or AM were detected in seven of fifty-eight authentic hair specimens. Hair specimens were from thirteen women with a known history of MA abuse, who went to a rehabilitation center and ceased consuming MA (for 4–5 months). The S -isomers of MA and AM were detected in all the 5–6 cm segments. Both enantiomers of MA were detected in nine of the 5–6 cm segments and the enantiomers of AM were found in only five of the nine samples. Assuming a hair growth rate of 1 cm/month, the mean hair elimination half-lives of S -MA, R -MA, S -AM, and R -AM were 0.64(95% CI, 0.46–0.96), 0.58(95% CI, 0.41–0.93), 0.62(0.49–0.88), and 0.50 months (95% CI, 0.42–0.56), respectively. With the developed method, R/S -MA and R/S -AM could be detected in the hair of former drug users for approximately 4 months after abstinence. S -MA is the most commonly found analyte in hair segments and is principally used by abusers. Our results suggest that to evaluate the discontinuation of MA abuse after a 6-month period of abstinence, a 3-cm proximal hair segment should be free of MA at the SOHT proposed cut-off level.
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PubMed
高影响因子
POLYMER SCIENCE SERIES B
·
2024
·Vol. 65
·期 6
·842-857
·
IF 1
Wanting Zhao,Su Qin,Lyu Ya
Abstract In this paper, tung oil-linseed oil (TO-LSO) and styrene-linseed oil (STY-LSO) were used as raw materials of sulfur-rich copolymers, which were then reversed vulcanized with S 8 at 130°C, and the gel time of the reaction was recorded. At the same time, 1 H NMR, DSC, XRD, sodium sulfite titration and other characterization methods were used to measure the reaction degree, verify the conjugated structure to improve the reaction degree, and study the synthesis mechanism of sulfur-rich copolymer. The results show that the conjugated structure can improve the reaction degree. And when the proportion of TO and STY is 20 and 10% respectively, the reaction gel time is shortened, the reaction degree is greatly deepened, and the effect of promoting polymerization can be significantly obtained. The synthesis mechanism of copolymer is the result of conjugated structure and diallyl group. The self-repair of sulfur-rich copolymers at different temperature and holding time by hot press shows that poly(20-TO-LSO-50S) can realize the S‒S bond self-repair after being compressed at 120°C for 4 h, and the surface of polymer disc was smoother and more uniform. However, poly(10STY-LSO-50S) can be repaired only after being compressed for 8 h. TO can not only enhance the synthesis process, but also enhance the performance of sulfur-rich materials and broaden the application field.
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ACS Omega
·
2022
·
IF 4.132
Guiting Chen,Hongli Wu,Chuang Feng,Zhikai Deng,Zhuyang Li,Mingxin Nie,Baitian He,Hongqing Hao,Xin Li,Zhicai He
A novel conjugated molecule (PBSON) based on a main chain composed of bis(dibenzothiophene-S,S-dioxide) fused cyclopentadiene and side chains containing amino groups is presented as an efficient cathode buffer material (CBM) for organic solar cells (OSCs). PBSON showed a deep highest occupied molecular orbital (HOMO) energy level of −6.01 eV, which was beneficial for building hole-blocking layers at the cathodes of OSCs. The energy bandgap of PBSON reached 3.17 eV, implying high transmittance to visible and near-infrared light, which meant PBSON should be suitable for the applications to most inverted OSCs. The scanning Kelvin probe microscopy measurement and theoretical calculation on the PBSON/cathode interfacial interaction proved the excellent work function-regulating abilities of PBSON for various cathodes, suggesting that PBSON could promote the formation of Ohmic contacts at the cathodes and thus improve the transport and collection of electron carriers for OSCs. The characterization of electron-only devices demonstrated the good electron-transporting performance of PBSON at the cathodes. In the conventional OSCs, it was hinted that PBSON might restrain the infiltrations of evaporated cathode atoms into the active films, consequently reducing the reverse leakage currents. As a result, PBSON was able to boost the power conversion efficiencies (PCEs) by 58.2 and 56.4% for both conventional and inverted OSCs of the typical PTB7:PC71BM system, respectively, as compared to the unadorned devices. In terms of the classical PTB7-Th:PC71BM system, substantial increases in PCEs could also be found with PBSON interlayers, which were 54.7 and 59.8% for the conventional device and inverted device, respectively. Therefore, PBSON is a kind of promising CBM for realizing both conventional and inverted OSCs of high performance.
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JOURNAL OF SOLID STATE CHEMISTRY
·
2021
·
IF 3.498
Fei Chen,Yiluo Zhang,Qing Hu,Shiyu Cao,Shangbin Song,Xinqi Lu,Qiang Shen
Traditional liquid lithium-sulfur batteries have two key problems: poor safety and shuttle effect . These two challenges can be overcome by using solid-state electrolytes. But poor ionic and electronic conductivity due to solid/solid contact between the electrode and the electrolyte for all-solid-state lithium-sulfur batteries (ASSLSBs). Here, we have synthesized Li 6.4 Ga 0.2 La 3 Zr 2 O 12 (LLZO) conductive ceramics with high ionic conductivity . LLZO is used as the lithium-ion conductor and multi-walled carbon nanotubes (MWCNt) are used as the electronic conductor to form S/MWCNt/LLZO by the thermal diffusion method, resulting in an e − /S/Li + conductive network. The prepared S/MWCNt/LLZO composite material, composite solid electrolyte, and lithium metal are assembled into ASSLSBs. After 50 cycles, the high capacity of 825 mAh·g −1 is maintained with 72.62% capacity retention at 0.2C and 45 °C. The higher capacity indicates the success of forming a conductive network that can improve the electrochemical performance of ASSLSBs. At 0.2C, the capacity of the S/MWCNt/LLZO composite cathode remains at 873 mAh·g −1 after 60 cycles when the operating temperature is increased to 60 °C, indicating good cycle performance.
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高影响因子
APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Chang Cheng,Xunchang Wang,Feng Wang
Two analogous positional polymers P16PySO and P27PySO have been synthesized via the copolymerization from dibenzothiophene-S,S-dioxide and pyrene building blocks. The effect of the linking pattern on the molecular packing, photophysical and photocatalytic properties of the two isomers was investigated. It was interestingly found that a minor change at the substitution position of pyrene unit was demonstrated to largely influence the photocatalytic properties of the two isomers. P16PySO exhibited an encouraging average hydrogen evolution rate (HER) of 619.5 μmol h −1 and the maximum HER of 774 μmol h −1 , much higher than that of 2,7-counterpart with a moderate rate of 282 μmol h −1 . The increased photocatalytic activity of P16PySO is mainly ascribed to its more ordered molecular packing, broader absorption region, better wettability , and higher photo-generated charge mobilities. Moreover, the optimum HER was increased from 774 to 1013 μmol h −1 when the amount of the photocatalyst P16PySO was increased from 50 to 100 mg, which is among the top solar-to‑hydrogen conversion efficiencies reported so far for the polymeric photocatalysts.
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高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2025
·
IF 8.3
Jingting Sun,Shangshang Wang,Xingyu Liu,Huan Yu,Jiaming Li,Chao Liu,Qinfang Zhang,Zhigang Zou
Photocatalytic hydrogen production (PHE) technology has emerged as a sustainable approach to convert solar energy into hydrogen energy, exhibiting significant potential for clean energy applications. In this study, an ultrasonic-assisted method was adopted to fabricate S-scheme MoSe 2 /Mn 0.5 Cd 0.5 S (MoSe 2 /MCS) composites, where intimate heterostructures are formed through interfacial Mo–S bonds between MCS and MoSe 2 . The atomic-level Mo–S bonds establish charge transport pathways and enable directional control of charge transfer. The as-constructed S-scheme MoSe 2 /MCS photocatalysts exhibit two critical advantages: enhanced charge carrier separation rate and improved overall redox capacity. Under visible-light irradiation, the MoSe 2 /MCS composites significantly outperform pure MCS in PHE performance. The optimal 5-MoSe 2 /MCS composite demonstrates the superior PHE activity, achieving an apparent quantum yield value of 71.16 % at 400 nm and remarkable photocatalytic stability. Key characterization techniques, including (solution-based) time-resolved photoluminescence technique, theoretical calculation, photoelectrochemical measurements, were employed to elucidate the positive correlation between ion-carrier interaction and charge separation efficiency, thereby enhancing the PHE performance. Based on experimental analysis and theoretical calculation, a plausible PHE mechanism for the S-scheme MCS composites is revealed and discussed in detail. These findings provide valuable insights for designing high-efficiency S-scheme heterostructured composites with interfacial chemical bonds.
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高影响因子
Materials Chemistry Frontiers
·
2023
·Vol. 7
·期 6
·1072-1081
·
IF 7
Yanan Zhu,Yuanfu Deng,Guohua Chen
Carbon materials with large exposed surfaces and heteroatom doping have great potential in suppressing the shuttle effect in Li–S batteries. In this study, crosslinked triazine frameworks were successfully utilized to synthesize heteroatom-doped carbon nanosheets utilizing g-C3N4 nanosheets as the hard template and porogen. Characterization studies show that the nanosheets were highly crinkled and interconnected with a large surface area (1060 m2 g−1) and pore volume (2.14 cm3 g−1), and with highly dispersed N, O and S. After coating them on commercial Celgard separators, batteries with the modified separators showed a low self-discharge and an improved rate performance even at 4 C. At 0.5 C, the initial discharge capacity was 1240 mA h g−1 with a capacity decay of 0.059% per cycle for over 1000 cycles. Moreover, excellent cycling performances at 2 C for 500 cycles were also achieved. The excellent performance can be attributed to the large surface area and porous structure of NOS-C, the superior wettability toward the electrolyte, enhanced Li+ diffusion, strong interactions between polysulfides and doped atoms, and the accelerated redox kinetics of polysulfides.
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高影响因子
Materials Research Express
·
2021
·Vol. 8
·期 8
·085002
·
IF 1.62
Xiangming Liu,Xiaoshi Peng,Tao Xu,Yulong Li,Huiyue Wei,Zanyang Guan,Feng Wang
Ternary Ag-In-S and quaternary Ag-In-Zn-S nanoparticles with different ratio of Ag/In/Zn/S are synthesized. The incorporation of Zn into Ag-In-S nanoparticles leads to the increase in the optical bandgap and the blue shift of photoluminescence (PL). The optical properties of these nanoparticles are significantly dependent on the chemical composition of nanoparticles. Time-resolved PL spectroscopy in nanosecond time regime is used to study the recombination processes of carriers, which involve the surface states and intrinsic crystallographic defects. These measurements support the donor-acceptor model, in which the PL is achieved by radiative recombination of the localized electron and hole.
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高影响因子
Forensic Toxicology
·
2018
·Vol. 37
·期 1
·121-131
·
IF 3.924
Chen Lizhu,Yu Yingjia,Wang Yang,Xiang Ping,Duan Gengli
Purpose It is crucial for forensic analysis to differentiate clinical use from illegal abuse. Selegiline (SG) is mainly metabolized to desmethylselegiline (DM-SG), R -(−)-methamphetamine (R-MA) and R-(−)amphetamine (R-AM); while abused methamphetamine and amphetamine mainly contain the S -(+)-form. The aim of this study was to simultaneously determine SG, DM-SG, R / S -MA, and R / S -AM in human oral fluid (OF) and to differentiate clinical use from illegal use. We also aim to apply the present method to the OF samples from authentic cases in forensic toxicology. Methods Liquid–liquid extraction and liquid chromatography-tandem mass spectrometry operating in positive ion multiple-reaction monitoring mode were utilized. The chromatographic system consisted of a Chirobiotic TM V2 column (2.1 mm × 250 mm, 5 μm) and a mobile phase of methanol containing 0.1% (v/v) glacial acetic acid and 0.02% (v/v) ammonium hydroxide. Results and conclusions The calibration curves were linear from 1 to 100 ng/mL, and r > 0.995 for all analytes with imprecisions ≤ 15% and accuracy between 85 and 115%. Extraction recoveries ranged from 46.3 to 104.7% with coefficient of variation (CV) ≤ 10.3% and matrix effects (MEs) ranged from 47.4 to 114.8% with CV ≤ 12.9%. The lower limit of quantification was 0.2 ng/mL for SG and DM-SG and 1.0 ng/mL for S-MA, R-MA, S-AM and R-AM. The present method is simple, rapid (accomplished in 12 min), sensitive, and validated by authentic samples.
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高影响因子
APPLIED SURFACE SCIENCE
·
2025
·
IF 6.9
Xiaoying Xu,Shaofeng Dong,Jialong Lv,Guocheng Huang,Qiaoshan Chen,Jinhong Bi
The carrier transfer mechanism of S-scheme heterojunctions has been extensively explored, yet their impact on light absorption performance remains ambiguous. In this work, a finely designed S-scheme heterojunction was developed by coupling oxidation photocatalyst a specific covalent organic framework (COF)-TaTp, and reduction photocatalyst SnS 2 (SS) for in-situ H 2 O 2 photo-production and sterilization. The optimized 10% SS/TaTp achieved a 3.45- and 16.87-fold enhancement in H 2 O 2 generation than pure TaTp and SS, respectively, with significant improvements under visible and near-infrared (NIR) light. In-situ XPS, EPR, and Kelvin probe force microscopy (KPFM) verified the S-scheme charge transfer mechanism, underscoring accelerated photo-induced electrons migration and strengthened redox capacity. The internal electric field of 10% SS/TaTp was calculated to be 2.14 and 4.63 times stronger than TaTp and SS. Intriguingly, the electron localization function and partial density of states analyses revealed that the interfacial C-N-S covalent bonds finely tuned the energy band structure and generated hybrid energy levels in the heterojunction, thus improving light harvesting and catalytic performance in both visible-light and NIR region. This work highlights the role of interfacial covalent interactions in tuning energy levels in COF-based S-scheme photocatalysts.
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高影响因子
NEW JOURNAL OF CHEMISTRY
·
2017
·Vol. 41
·期 4
·1696-1703
·
IF 3.269
Guiting Chen,Ruifeng He,Wei Yang,Bin Zhang
Two novel water-soluble π-conjugated small molecules based on dibenzothiophene-S,S-dioxide and bispyridinium salts, named FSOPyCl and FSOmiCl, were successfully synthesized. Both molecules showed deep blue light emission, with photoluminescence peaks at about 408 and 405 nm in aqueous solution, respectively. Their photoluminescence quantum yields (PLQYs) in aqueous solution were as high as 68.9% and 50.3%, respectively. Electrochemical measurements suggested that they have excellent electron affinity, with lowest unoccupied molecular orbital (LUMO) energy levels at −3.78 and −3.94 eV, respectively. Due to their unique properties including large planarity, good thermal stability, excellent electron affinity and high fluorescence efficiency, FSOPyCl and FSOmiCl may be promising construction units for preparing water/alcohol-soluble conjugated materials with good optoelectronic performance.
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高影响因子
危险品化学品经营许可证（带存储）