Polymer Chemistry
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2018
·Vol. 9
·期 9
·1095-1108
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IF 4.927
Xiaoqi Zhao,Wentao Wu,Jian Zhang,Wenxue Dai,Youliang Zhao
Multicomponent miktoarm stars with multifunctional Y junctions may provide us with new insights into their physicochemical properties and prospective applications. Considering the unique role of a gas stimulus in smart materials and the promising gradient-type properties induced by combined stimuli, this study aims at the synthesis, thermoresponsive and self-assembly behaviors of an O2-, redox-, thermo-, and pH-responsive 3-miktoarm star quarterpolymer. A robust method involving controlled polymerization, amine–thiol–ene conjugation and hydrolysis was developed to achieve a poly(N-isopropylacrylamide-co-4-(2-(2,2,2-trifluoroethylcarbamoyl)ethylthio)-2-(acrylamido)-N-(2-hydroxyethyl)butanamide)-arm-poly(ε-caprolactone)-arm-poly(acrylic acid) star. Owing to the changes in amphiphilicity, chemical composition and mutual interactions, a single stimulus or various stimuli combinations could lead to switchable LCSTs and morphological transformations. Upon increasing pH, O2 treatment and oxidation, the copolymer solution was liable to exhibit enhanced LCST due to the improved hydrophilicity. The star quarterpolymer could self-assemble into multicompartment vesicles (pH 3.0), vesicles (pH 5.9) and small micelle/vesicle mixtures (pH 10) at ambient temperature. Upon thermo, redox and O2 stimuli, the assemblies formed at different pHs could be further converted into some other morphologies such as compound micelles and nanocapsules with hollow caves. Our research affords a general route to synthesize MMSs with tailored Y junctions, and the combination of the O2 stimulus with other stimuli may potentially expand the scope of multi-triggered properties and applications of star copolymers.
研究领域:
高分子化学
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材料科学
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高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Zhengyi Qian,Baoyu Sun,Lei Du,Shuaifeng Lou,Chunyu Du,Pengjian Zuo,Yulin Ma,Xinqun Cheng,YunZhi Gao,Geping Yin
Since electrode surfaces primarily house the sites of oxygen reduction/evolution reactions, surface chemistry is pivotal for both charge and discharge processes of Li–O 2 batteries . Herein, we introduce oxygen-containing functional groups associated with defects on the carbon fiber papers (functionalization) via acid treatment and investigate their effects on the rechargeable nonaqueous Li–O 2 batteries. The discharge platform increases from 2.68 V to 2.79 V, meanwhile the decreased charge overpotential (a drop of 0.84 V) is also observed after functionalization. It is found that the discharge products formed on pristine carbon fiber exhibit a huge toroidal-like structure, in contrast to the porous flake clusters with much smaller size on the functionalized carbon fiber. On the other hand, the smaller product clusters are found to be much easier to be oxidized, leading to remarkably reduced charge overpotential. In this regard, the decomposition of electrolyte and corrosion of carbon cathode are dramatically alleviated, thus leading to greatly promoted cycling performance. All the experimental facts suggest that the oxygen functional groups associated with defects could provide tremendous active sites for the nucleation of discharge products and result in remarkably decreased overpotential for both the oxygen reduction and the oxygen evolution reaction in our cases.
研究领域:
材料科学
·
电化学
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高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
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2017
·Vol. 164
·期 13
·G112
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IF 3.259
Yuchen Hui,Xiaoyan Ma,Fengjin Qu,Fang Chen,Ying Chen
A practical strategy is developed to fabricate stable glucose/O2 biofuel cells with high power density assembled by enzymatic bio-electrodes based on three-dimensional nickel foam. The porous three-dimensional nickel foam is used as a substrate to enhance the enzyme loading, while the reduced graphene oxide and gold nanoparticles decorating on the nickel foam are employed as the direct electron transfer system for bio-anodes and bio-cathodes. The ferrocenecarboxylic acid serves for the mediated electron transfer to further increase electron transfer rate for glucose oxidase electrodes. Covalent bond is employed to immobilize the mediator and enzymes for improving the stability of bio-electrodes and biofuel cells. As the results, the surface glucose oxidase loading reaches to 4.03 × 10−7 mol cm−2 with good enzymatic activity. Additionally, the obtained glucose/O2 biofuel cells exhibit an outstanding maximum power density of 2.84 ± 0.09 mW cm−2, with a remarkable long-term operational stability for retaining 85.5% of its performance after 70 days. In human blood, the biofuel cell shows a favorable output performance of 0.39 ± 0.04 mW cm−2, implying the appropriateness for practical applications.
研究领域:
生物化学
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材料科学
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能源技术
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高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2017
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IF 3.359
Cheng Tan,Lei Li,Kongzhai Li,Dapeng Zhong
A novel method to separate As from high As-Sb dust using Fe 2 O 3 as a fixative under an O 2 -N 2 atmosphere is proposed. Here, Sb is oxidised and converted to Sb 2 O 4 and FeSbO 4 that remain in the roasted residue, and As is volatilized in the form of As 4 O 6 . The Sb 2 O 3 can be selectively oxidised from the dust by using 21 vol% O 2 , but the formation of amorphous substance (As-Sb-O) hinders the effective separation of As and Sb. Adding Fe 2 O 3 hinders the amorphous substance formation and destroys the structure of the solid solution ((Sb, As) 2 O 3 ) in the raw material by converting the Sb component in it to FeSbO 4 . Therefore, the volatilization rates of As and Sb can reach up to 90.53% and only 13.20%, respectively at a roasting temperature of 723 K, roasting time of 90 min, an Fe 2 O 3 dosage of 15 mass%, and O 2 content of 21 vol%.
研究领域:
冶金学
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环境科学
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高影响因子
CHEMICAL ENGINEERING JOURNAL
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2023
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IF 15.1
Daming Yang,Guiru Sun,Xinru Wang,Fengyang Li,Ze Gao,Pingli Zhang,Wei Lu,Ming Feng
The photo-assisted lithium-oxygen (Li-O 2 ) cell is widely concerned due to its low overpotential. However, rapid recombination rate of photogenerated electrons and holes remains a fundamental challenge for photo-assisted Li-O 2 cells. Herein, we design an optical and magnetic fields co-assisted Li-O 2 cell based on α-Fe 2 O 3 nanospindles. We employed PL spectrum and I-t curve confirm that under the magnetic field, the photogenerated electrons and holes are driven via the opposite Lorentz forces in photo-assisted Li-O 2 cells, which is beneficial to accelerating the formation and decomposition of Li 2 O 2 . The optical and magnetic fields co-assisted Li-O 2 cell based on α-Fe 2 O 3 nanospindles achieves an ultra-high discharge platform of 3.47 V and a low charge platform of 3.57 V, as well as a surprising energy efficiency of 97.2%. In addition, the optical and magnetic fields co-assisted Li-O 2 cell can stably cycle for over 25 cycles. This study offers a reference for improving the electrochemical kinetics of photo-assisted Li-O 2 cell by introducing magnetic field, which opens up a new avenue for the development of high-performance Li-O 2 cells.
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JOURNAL OF ELECTROANALYTICAL CHEMISTRY
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2023
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IF 4.5
Chaoyang Sun,Fenglong Xiao,Di Wu,Gang Lian,Deliang Cui,Qilong Wang,Haohai Yu
Rechargeable Li-O 2 batteries show great potential due to their superior high energy density. However, the practical application is still limited by the sluggish kinetics, resulting in poor cycling performance and high overpotentials. Herein, highly dispersed Co nanoparticles embedded into porous N -doped carbon matrix (DCo-NC) with carbon nanotubes is explored through the pyrolysis of a bimetallic leaf-shaped ZnCo-ZIFs. The evaporation of Zn species and porous carbon matrix derived from ZIFs prevents the Co nanoparticles aggregation, exposes more Co-N active sites and provides abundant pores. They facilitate Li + and electron transfer, prevent Co nanoparticles from deactivation and provide enough space for Li 2 O 2 , thereby accelerating oxygen reduction reaction (ORR)/oxygen evolution reaction (OER) kinetics. Accordingly, the Li-O 2 batteries with DCo-NC cathode exhibit reduced overpotential, high discharge capacity (10,490 mA h g −1 at 100 mA g −1 current density) and improved cycling performance (258 cycles at 500 mA g −1 with a limited capacity of 500 mA h g −1 , 103 cycles at 500 mA g −1 with a limited capacity of 1000 mA h g −1 ).
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高影响因子
Frontiers in Bioengineering and Biotechnology
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2023
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IF 5.7
Yujia Liang,Zhengmin Cai,Yamei Tang,Chenglin Su,Liye Xie,Yan Li,Xinqiang Liang
Introduction: Reactive oxygen species (ROS)-mediated therapies have typically been considered as noninvasive tumor treatments owing to their high selectivity and efficiency. However, the harsh tumor microenvironment severely impairs their efficiency. Methods: Herein, the biodegradable Cu-doped zeolitic imidazolate framework-8 (ZIF-8) was synthesized for loading photosensitizer Chlorin e6 (Ce6) and CaO 2 nanoparticles, followed by surface decoration by hyaluronic acid (HA), obtaining HA/CaO 2 -Ce6@Cu-ZIF nano platform. Results and Discussion: Once HA/CaO 2 -Ce6@Cu-ZIF targets tumor sites, the degradation of Ce6 and CaO 2 release from the HA/CaO 2 -Ce6@Cu-ZIF in response to the acid environment, while the Cu 2+ active sites on Cu-ZIF are exposed. The released CaO 2 decompose to generate hydrogen peroxide (H 2 O 2 ) and oxygen (O 2 ), which alleviate the insufficiency of intracellular H 2 O 2 and hypoxia in tumor microenvironment (TME), effectively enhancing the production of hydroxyl radical (•OH) and singlet oxygen ( 1 O 2 ) in Cu 2+ -mediated chemodynamic therapy (CDT) and Ce6-induced photodynamic therapy (PDT), respectively. Importantly, Ca 2+ originating from CaO 2 could further enhance oxidative stress and result in mitochondrial dysfunction induced by Ca 2+ overloading. Conclusion: Thus, the H 2 O 2 /O 2 self-supplying and Ca 2+ overloading ZIF-based nanoplatform for cascade-amplified CDT/PDT synergistic strategy is promising for highly efficient anticancer therapy.
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DOI
PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2023
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IF 9.5
Hongyong Zhao,Ting Song,Xiaoli Ding,Ruyi Cai,Xiaoyao Tan,Yuzhong Zhang
Membrane technology for O 2 /N 2 separation is a mature industrial unit. Membranes with excellent permeation-separation performance are still one of the critical requirements. The cobalt-based compounds have been well known for their good affinity for O 2 , which can facilitate O 2 transfer and improve the O 2 /N 2 selectivity in membranes. The cobalt-based compounds, moreover, have a magnetic responsive effect, which can lead to a further improvement in O 2 /N 2 separation under a magnetic field. A class of PIM-1 mixed matrix membranes (MMMs), containing cobalt-based ionic liquid (CILs)@polyarylate (aromatic polyester) (PAR) (core-shell) composite nanospheres (CILs@PAR (c-s) CNPs), were prepared. Chemical compositions of CILs@PAR (core-shell) CNPs were determined by Fourier transform infrared spectroscopy (FTIR). Morphologies and structures of CILs@PAR (core-shell) CNPs were observed by transmission electron microscopy (TEM). Gas adsorption properties of CILs@PAR (core-shell) CNPs were tested. Thermal properties of the (CILs@PAR (c-s) CNPs)/PIM MMMs were investigated by simultaneous thermal analysis (TGA-DSC). Gas permeation-separation performances of the (CILs@PAR (c-s) CNPs)/PIM MMMs were also reported. Compared with the original PIM-1 membrane, the (CILs@PAR (c-s) CNPs)/PIM MMMs display higher O 2 /N 2 selectivity because of cobalt-based ionic liquid as O 2 carrier, coupled with a reduction in O 2 permeability. With increasing the content of the CILs@PAR (c-s) CNPs, the O 2 /N 2 selectivity increases, and the O 2 permeability decreases. It is also found that, as a magnetic field on the MMMs, the O 2 /N 2 selectivity further increases; and it increases more, as a higher content of CILs@PAR (c-s) CNPs. Therefore, the (CILs@PAR (c-s) CNPs)/PIM MMMs exhibit excellent O 2 /N 2 selectivity of ∼5 coupled with good O 2 permeability of ∼140 Barrer under a 180 mT magnetic field and show great potential for air separation.
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高影响因子
FUEL
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2023
·
IF 7.4
Qi Rong,Wenkai Huang,Fuhua Xu,Yanlan Wang,Changlong Wang,Xiang Liu
In spite of significant developments are accomplished in the exploration of H 2 and O 2 evolution upon water electrolysis/photolysis, this remains a challenge to design and develop ideal catalytic systems for this reaction and to isolate H 2 from H 2 -O 2 mixture with membranes. Herein, a series of ZIF-67-supported transition metal nanoparticles (TMNPs/ZIF-67), including Pt, Ir, Pd, Rh, Au and Ag, via immobilization of ultrafine TMNPs at the surface of ZIF-67, have been designed and developed for the selective H 2 generation from NH 3 BH 3 hydrolysis and O 2 evolution upon H 2 O 2 decomposition. In particular, the optimized nanocatalyst Pt/ZIF-67 presents the super-high catalytic property in the both H 2 evolution upon NH 3 BH 3 hydrolysis (689 mol(H 2 )·mol Pt -1 ·min −1 ) and O 2 evolution upon H 2 O 2 decomposition (979 mol(O 2 )·mol Pt -1 ·min −1) at 30 °C. Importantly, the selective “on–off” control for demand-based H 2 generation from NH 3 BH 3 hydrolysis was successfully realized by Zn 2+ /EDTA-2Na system. This highly efficient Pt/ZIF-67 proposed a new method for the promising potential application of ammonia borane and hydrogen peroxide as an economic and safe H 2 resp. O 2 carrier for fuel cell.
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高影响因子
COLLOIDS AND SURFACES B-BIOINTERFACES
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2023
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IF 5.8
Shuo Liu,Huiqi Yang,Liguo Zhang,Alberto Bianco,Baojin Ma,Shaohua Ge
The injured bone microenvironment is typically characterized by high-level reactive oxygen species (ROS, mainly H 2 O 2 ) and low content of oxygen. The former can cause cell apoptosis, induce immune imbalance and inflammation, inhibit osteogenic differentiation, and delay bone repair . In this work, barrier membranes made of a combination of hydroxyapatite nanowires (HAp NWs) and polylactic acid (PLA) loaded with manganese dioxide nanosheets (NSs) ( [email protected] ) were prepared to guide bone regeneration (GBR). Due to the catalytic function of MnO 2 , [email protected] membranes are able to effectively decompose H 2 O 2 to generate O 2 . In vitro experiments demonstrated [email protected] membranes inhibited the apoptotic process caused by high level of H 2 O 2 , decreased intracellular oxidative stress , suppressed inflammation-related gene/protein expression, and inhibited macrophage M1 polarization. The nanostructured HAp stimulated osteogenic differentiation, and the loading of MnO 2 NSs played a synergistic effect. In addition, the barrier function of PLA could hamper the epithelium overgrowth, providing the development space for periodontal regeneration. By scavenging H 2 O 2 , generating O 2 , eliminating inflammation, and regulating immune response, [email protected] membranes efficiently promoted bone regeneration. Our results confirmed that composite membranes have great potential for application in GBR, and provide a reference for future design of bone repair materials.
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SEPARATION AND PURIFICATION TECHNOLOGY
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2022
·
IF 9.136
Wei Zhou,Liang Xie,Yan Wang,Yani Ding,Xiaoxiao Meng,Fei Sun,Jihui Gao,Guangbo Zhao
Large-scale application of H 2 O 2 production through 2-electron oxygen reduction reaction (2eORR) greatly depends on the cost of electrode materials and configuration. In this work, engineered coal-derived oxygen-rich hierarchical activated coke (AC), which is low-cost and highly tunable in porosity and surface chemistry, was used as catalyst to fabricate gas diffusion electrodes (GDEs) for efficient H 2 O 2 production. Results showed that Fenton’s reagents treatment could significantly increase the contents of C O and –COOH on AC, leading to an increased hydrophilicity. However, the higher O contents do not necessarily enhance the selectivity of AC towards 2eORR (i.e., F-5-AC, F-10-AC), especially that F-20-AC exhibited a complete 4e pathway. GDEs were then fabricated with AC and oxidized AC as catalyst, key fabrication parameters including the PTFE binder and AC particle size, and operating parameters such as current intensity, electrolyte pH, and O 2 flow rate were optimized. Up to 747 mg/L H 2 O 2 were generated within 90 min. Results showed that oxidized AC exhibited a decreased H 2 O 2 yield, due to the flooding of GDEs caused by super-hydrophilicity property. Finally, DFT calculations were employed to reveal the synergistic effect of different O groups considering the fact of high O contents on AC.
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高影响因子
BIOELECTROCHEMISTRY
·
2022
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IF 5.76
Yanjing Yun,Zhisong Lu,Xiaodan Jiao,Peng Xue,Wei Sun,Yan Qiao,Yang Liu
Relationship between mycotoxin-induced hormesis and reactive oxygen species (ROS) has not been systematically investigated due to the lack of an effective analysis method. To monitor cellular release and intracellular level of O 2 ·− , carboxymethyl cellulose-Mn 3 (PO 4 ) 2 nanocomposite was synthesized to fabricate an electrochemical biosensor, which selectively detects O 2 ·− over the range of 57.50 nM ∼ 2.95 μM (R 2 = 0.99) with the sensitivity of 78.67 μA μM −1 cm −2 and the detection limit of 8.47 nM. Transient exposure to zearalenone (ZEA) induces the enhancement on cell viability, immediate O 2 ·− release from cells, and reduction of intracellular O 2 ·− level. After post-treatment culture, intracellular O 2 ·− initially increases to a high level and then decreases to the normal level. Concurrently, the ZEA-induced hormesis disappears. Based on the findings, we propose a mechanism, involving the ROS release, increase of succinate dehydrogenase activity and recovery of intracellular ROS, to explain the occurrence and disappearance of hormesis in intestinal porcine enterocytes.
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高影响因子
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