JOURNAL OF MATERIALS SCIENCE
·
2016
·Vol. 52
·期 4
·1823-1830
·
IF 2.302
Liu Zhi,Ang Koon Keong Jeremy,He Jihuan
Point discharge is a natural phenomenon which principle and application are both under active investigation. In this work, a needle-disk electrode spinneret was designed through the combination of the point discharge concept and the merits of typical needleless electrospinning (disk as spinneret). The desired outcome for point electrode system is to produce a controllable process of jet formation, with respect to the control of jet site and amount of jets under a lower applied voltage value. Two comparisons were used: (i) in comparison to the typical needleless electrospinning method (disk electrospinning), the needle-disk electrospinning produce finer and more uniform nanofibers. Further numerical simulation results confirmed that the needle-disk electrode induced electric field intensity which is 5.33 times higher than that of disk electrode under the same parameters; (ii) both the numerical simulation and experimental results showed that needle-disk electrospinning can produce competitive quality of nanofibers accompanied by enhanced throughput, compared with the traditional single-needle electrospinning method. Finally, we demonstrate that needle-disk electrospinning produces nanofiber with super-high throughput of 13.5 g/h, which is 183 times higher than traditional electrospinning under similar spinning conditions.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Hailan Qin,Yushan Zhang,Shuaijun He,Zeyu Guan,Yintao Shi,Xinyi Xie,Dongsheng Xia,Dongya Li,Haiming Xu
Increasing the migration and separation efficiencies of photogenerated carriers can enormously enhance photocatalytic properties. Thus, a novel CQDs/BiOCl nanocomposite with rich oxygen vacancies (OVs) was effectively synthesized via a hydrothermal method by using maltitol as a carbon source to address these issues. The photocatalysts were characterized by XRD, SEM, TEM, FT-IR, BET, XPS, PL, EIS, I-t, DRS and ESR. The experimental results demonstrate that BOC-1 can purify 72% tetracycline hydrochloride (10 mg/L, TC-HCl) within 60 min, which is 4 times higher than pure BiOCl. Moreover, photocatalytic mechanism was thoroughly studied and verified that the cooperation of point discharge effect (PDE) and rational OVs concentration induced by carbon quantum dots (CQDs) can significantly enhance the migration and separation of photo-induced carriers, thereby leading to high photocatalytic activity of the as-prepared nanocomposites. In addition, the contribution of the free radicals was comprehensively calculated based on trapping experiments. the contributions of ·OH, ·O 2 - and 1 O 2 are 6.38%, 48.94% and 8.51%, respectively. This study provides a promising strategy to boosting the photoinduced carrier transfer properties by the coupling of point discharge effect and defect engineering.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2018
·
IF 6.042
Yuan Yang,Qing Tan,Yao Lin,Yunfei Tian,Li Wu,Xiandeng Hou,Chengbin Zheng
Speciation analysis of mercury in hair facilitates accurate evaluation of mercury exposure to humans and insights into the intertransformation of different mercury species in the human body. However, conventional hyphenated techniques used for mercury speciation analysis usually require expensive instruments and a complex interface. In this work, a compact and miniaturized point discharge (PD) atomic emission spectrometer was utilized as a detector of gas chromatography for the speciation analysis of mercury. Mercury species extracted from hair were derivatized to their volatile species with NaBEt4 and subsequently preconcentrated by headspace solid-phase microextraction (HS-SPME) prior to their speciation analysis. Under the optimized conditions, limits of detection of 0.35 μg kg–1 (0.035 ng) and 1.0 μg kg–1 (0.10 ng) were obtained for IHg and MeHg, respectively, with a relative standard deviation (RSD) of better than 3.5%. Because of the compact and miniature conformation, high excitation capability, low power consumption of PD-OES, and efficient preconcentration of mercury species by HS-SPME, the proposed system not only overcomes the shortcomings associated with the conventional hyphenated techniques but also provides several unique advantages, including significant simplification of experimental setup, reduction of dead volume, and improvement of sensitivity. The accuracy of this system was validated by speciation analysis of mercury in a Certified Reference Material (GBW09101b, human hair) and 10 human hair samples collected from different people in the population.
研究领域:
环境科学
·
分析化学
✓ 已验证
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2024
·
IF 10.8
Tian Ren,Yuanyuan Li,Xi Wang,Yurong Deng,Chengbin Zheng
Rapid and in situ identification of specific polymers is a challenging and crucial step in plastic recycling. However, conventional techniques continue to exhibit significant limitations in the rapid and field classification of plastic products, especially with the wide range of commercially available color polymers because of their large size, high energy consumption, and slow and complicated analysis procedures. In this work, a simple analytical system integrating a miniature and low power consumption (22.3 W) pyrolyzer (Pyr) and a low temperature, atmospheric pressure point discharge optical emission spectrometer (μPD-OES) was fabricated for rapidly identifying polymer types. Plastic debris is decomposed in the portable pyrolyzer to yield volatile products, which are then swept into the μPD-OES instrument for monitoring the optical emission patterns of the thermal pyrolysis products. With machine learning, five extensively used raw polymers and their consumer plastics were classified with an accuracy of ≥97.8%. Furthermore, the proposed method was applied to the identification of the aged polymers and plastic samples collected from a garbage recycling station, indicating its great potential for identification of environmentally weathered plastics. This portable Pyr-μPD-OES system provides a cost-effective tool for rapid and field identification of polymer types of recycled plastic for proper management and resource recycling.
研究领域:
环境科学
·
材料科学
·
人工智能
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FOOD CHEMISTRY
·
2025
·
IF 9.8
Yuan Yang,Xiaoli Wu,Qiuyi Yan,Hongling Zhou,Yurong Deng,Chengbin Zheng
Furans, recognized as carcinogenic contaminants generated during thermal food processing, pose significant food safety concerns, necessitating sensitive and cost-effective detection methods. Traditional GC-FID/MS methods are often constrained by high costs and complex instrumentation. Herein, a point discharge molecular emission spectrometer (PD-MES) was developed as a highly sensitive GC detector, specifically by monitoring CN molecular emission at 388.3 nm for the analysis of furans in food samples. Furans were extracted using headspace solid-phase microextraction (HS-SPME) prior to detection. Compared to conventional carbon atomic emission at 193.0 nm, the CN-based method demonstrated up to a 211.42-fold improvement in sensitivity and achieved detection limits of 0.02–0.08 ng/g with excellent precision (RSD < 4.9 %). Practical validation across ten diverse food matrices yielded satisfactory recoveries (83.4 %–114.5 %). This system offers a robust, highly sensitive, reliable, and economical alternative for the routine monitoring of furan compounds in foods, particularly in resource-limited settings.
研究领域:
食品安全
·
分析化学
·
光谱学
·
环境卫生
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）