RSC Advances
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2015
·Vol. 5
·期 51
·40588-40594
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IF 3.84
Dan-Dan Liu,Hua Su,Qian Cao,Xue-Yi Le,Zong-Wan Mao
Carbon nanodots (C-Dots) have recently been proposed as promising alternatives to traditional semiconductor quantum dots and organic fluorophores. However, C-Dots were often prepared and studied as a mixture, and the ignorance of the real composition significantly limits the accurate understanding and control of physical/chemical properties of C-Dots and further practical applications. Herein, we demonstrated and identified for the first time the co-existence of highly-fluorescent carboxylic group-rich C-Dots (CR-C-Dots) and amine group-rich C-Dots (AR-C-Dots) during the one-pot pyrolysis of citric acid and branched polyethylenimine precursors. Transmission electron microscopy demonstrated that the average size of CR-C-Dots was slightly smaller than that of amine group-rich C-Dots (AR-C-Dots), 1.5 nm vs. 1.9 nm. Photophysical characterization indicated that CR-C-Dots had a longer fluorescence lifetime and higher quantum yields (QYs) than the AR-C-Dots, despite the same excitation-independent emission at 445 nm, unlike most previous reports, which stated that amine group passivation enhanced the QYs of C-Dots. Both the C-Dots showed excellent biocompatibility and great potential for cellular imaging. A fluorescence- and electron spin resonance-responsive dual-model probe for ascorbic acid detection was also constructed, further proving the existence of CR-C-Dots. This study facilitates the understanding of the nucleation/surface passivation process during C-Dots formation and the development of a new synthetic and purification strategy for C-Dots.
研究领域:
材料科学
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生物医学工程
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DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2016
·
IF 3.782
Rui Zhao,Xiang Li,Bolun Sun,He Ji,Ce Wang
An environmentally benign and efficient hydrothermal carbonization method is widely applied for the preparation of carbon-based adsorbents. However, the adsorption capacity toward anionic species would be influenced due to the negatively charged surface of the traditional hydrothermal carbonaceous materials ; moreover most of the carbonaceous materials were in the form of powder which restricted the practical applications. Herein, amino-rich hydrothermal carbon-coated electrospun polyacrylonitrile fiber (PAN@NC) adsorbents were obtained through one-step hydrothermal carbonization approach assisted by diethylenetriamine using polyacrylonitrile (PAN) fibers as the templates, which showed highly efficient adsorption for anionic pollutants. The PAN@NC fibers were characterized in detail to confirm their structures and composition . The flexible and robust PAN@NC fiber membrane exhibited high adsorption capacity and good regeneration and recycling ability toward the anionic metal ion Cr(VI) and herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). According to the Langmuir model, the adsorption behaviors showed monolayer adsorption capacities of 290.70 mg/g and 164.47 mg/g for Cr(VI) and 2,4- D , respectively, which were higher than that of many other adsorbents. Recycling study indicated that the removal efficiencies for both pollutants retained above 90% after five cycles. These findings demonstrate that PAN@NC fibers are promising adsorbents for the removal of anionic pollutants from wastewater solutions.
研究领域:
环境科学
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材料科学
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DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Fangfang Wei,Feng Qi,Yangyang Li,Weiyu Dou,Tangye Zeng,Jing Wang,Zhikan Yao,Lin Zhang,Zhe Tang
Bilirubin is a serious toxin in the blood of liver failure patients, and the development of bilirubin adsorbent with high removal efficiency, excellent hemocompatibility is crucial to improve the efficacy of hemoperfusion therapy. Herein, PAN/PEI nanofiber membrane (NFM) with amino-rich and smooth surface structure was prepared through a more facile co-blended electrospun method. During simulated adsorption experiments in vitro , PAN/PEI NFMs exhibited a high adsorption capacity of 142.79 mg g −1 for free bilirubin at clinical bilirubin concentration (100 mg L -1 ) in patients with liver failure. In addition, the bilirubin removal efficiency in static adsorption exceeded 96% when the PAN/PEI NFMs addition was greater than 120 mg. In particular, PAN/PEI NFMs displayed excellent hemocompatibility, presented a low hemolysis rate (0.4%), favorable anti-adhesion properties for hemocyte and plasma protein, and had no significant effect on coagulation. The development of this facile method promotes the feasibility of nanofibrous membranes for the treatment of hyperbilirubinemia with significant implications for improving therapeutic efficacy.
研究领域:
材料科学
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生物医学工程
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血液透析
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DOI
高影响因子
NANOTECHNOLOGY
·
2022
·Vol. 33
·期 17
·175705
·
IF 3.953
Qian He,Junkai Ren,Yaodong Liu
In this study, carbon dots (CDs) synthesized by hydrothermal method with amino-rich surface exhibit tunable fluorescence across entire visible range by simply controlling the concentration. A comprehensive comparison has been performed for the first time between concentration-induced aggregation of the single-type CDs and electrostatic-induced agglomeration of opposite-charged CDs in terms of their fluorescence properties. Experimental results show that both the aggregation of CDs and internal absorption filtration are possible causes of the concentration-dependent fluorescence emission. Subsequently, the inter distance of adjacent CDs in their aggregates was enlarged by forming rigid double-stranded DNA (dsDNA) between adjacent CDs through base pairing. It is clear that the contact of CDs induces the changes of fluorescence emission and light absorption. Through a better understanding of the mechanisms behind concentration-induced multicolor emission, this work can provide a novel strategy to develop the advanced applications of CDs.
研究领域:
材料科学
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纳米技术
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光学
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化学
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DOI
PubMed
高影响因子
SN Applied Sciences
·
2019
·Vol. 1
·期 10
·1-11
·
IF 0
Geng Yuqing,Wang Zhiwei,Wang Yahuan,Song Jiayang,Chen Zhimin,Chen Jiafu,Chen Yong,Fu Jianwei
The development of excellent dye adsorbent with high adsorption capacity and good separation function is imperative to clean the wastewater. Herein, an innovative magnetic Fe–Fe 2 O 3 @poly(cyclotriphosphazene- co -polyethyleneimine) (named as Fe–Fe 2 O 3 @PCP) composite was fabricated through a facile copolymerization between hexachlorocyclotriphosphazene and polyethyleneimine in the presence of Fe–Fe 2 O 3 nanoparticles. With the help of scanning electron microscope, transmission electron microscope, Fourier transform infrared spectroscope and vibrating sample magnetometer, the microstructure of the resulting magnetic Fe–Fe 2 O 3 @PCP composite was characterized. Then, the adsorption performance of magnetic Fe–Fe 2 O 3 @PCP composite was evaluated by removing anionic dye acid chrome blue K (ACBK) from aqueous solution. The effects of contact time, initial solution pH and temperature on the adsorption of ACBK onto magnetic Fe–Fe 2 O 3 @PCP composite were systematically studied. The kinetics, isotherms and mechanism of the adsorption process were analyzed. Results show that the maximum adsorption capacity of the magnetic Fe–Fe 2 O 3 @PCP toward ACBK dye could be up to 260 mg g −1 at 25 °C in neutral solution. The adsorption kinetics follows both the pseudo-second-order kinetic model and the Weber’s intraparticle diffusion model well. And the Freundlich isotherm model can nicely fit the adsorption equilibrium data. The electrostatic attraction between Fe–Fe 2 O 3 @PCP and ACBK plays a dominant role in the adsorption process. Moreover, the magnetic Fe–Fe 2 O 3 @PCP composite owns a high saturation magnetization of 30.1 emu g −1 , rendering it rapid magnetic separability and good reusability. After five adsorption–desorption cycles, the magnetic composite still kept 75% of removal efficiency with the adsorption capacity of 195 mg g −1 . The excellent adsorption capacity and good magnetic separability make the magnetic Fe–Fe 2 O 3 @PCP composite a promising adsorbent for efficient removal of anionic dyes including ACBK from contaminated wastewater.
研究领域:
环境科学
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材料科学
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化学工程
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DOI
COMPOSITES PART B-ENGINEERING
·
2022
·
IF 11.322
Qian Guo,Gang Li,Pengli Zhu,Zhen Xu,Tao Zhao,Rong Sun,Ching-ping Wong
As electronic devices move toward miniaturization and high-degree integration, it becomes imperative to use nano-sized silica as a reinforcing filler for epoxy resin in modern electronics packaging industries. However, the use of silica nanoparticles (SNPs) brings about new challenges in filler dispersion and in the balance between the rheology and thermal mechanical performance of epoxy nanocomposites . This study presents a novel strategy aiming to address the above challenges by interface engineering with amino-rich branched polyethyleneimine (PEI) polymer molecules through a facile self-assembly process. This not only enables a considerable decrease (by 79.7%) in viscosity accompanied by a significant improvement in viscosity stability (only 2.7 times increase after 24 h) but also leads to a further CTE reduction of 4.8 ppm/ ° C (equivalent to the effects of around 10 wt% SNPs) relative to the SNPs. This work offers a new direction and efficient approach to develop high-performance epoxy composites for electrical packaging applications as well as provides some fresh insights into the interface-property relationships.
研究领域:
材料科学
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纳米技术
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聚合物科学
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电子工程
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）