ACS Nano
·
2024
·
IF 15.8
He Ji,Shouhua Feng,Ming Yang
Polymer fibers that combine high toughness and heat resistance are hard to achieve, which, however, hold tremendous promise in demanding applications such as aerospace and military. This prohibitive design task exists due to the opposing property dependencies on chain dynamics because traditional heat-resistant materials with rigid molecular structures typically lack the mechanism of energy dissipation. Aramid nanofibers have received great attention as high-performance nanoscale building units due to their intriguing mechanical and thermal properties, but their distinct structural features are yet to be fully captured. We show that aramid nanofibers form nanoscale crimps during the removal of water, which primarily resides at the defect planes of pleated sheets, where the folding can occur. The precise control of such a structural relaxation can be realized by exerting axial loadings on hydrogel fibers, which allows the emergence of aramid fibers with varying angles of crimps. These crimped fibers integrate high toughness with heat resistance, thanks to the extensible nature of nanoscale crimps with rigid molecular structures of poly(p-phenylene terephthalamide), promising as a template for stable stretchable electronics. The tensile strength/modulus (392–944 MPa/11–29 GPa), stretchability (25–163%), and toughness (154–445 MJ/cm3) are achieved according to the degree of crimping. Intriguingly, a toughness of around 430 MJ/m3 can be maintained after calcination below the relaxation temperature (259 °C) for 50 h. Even after calcination at 300 °C for 10 h, a toughness of 310 MJ/m3 is kept, outperforming existing polymer materials. Our multiscale design strategy based on water-bearing aramid nanofibers provides a potent pathway for tackling the challenge for achieving conflicting property combinations.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Xiaorui Wang,Hao Li,Wenhui Fu,Qiushi Chen,Xuzhong Gong,Zhi Wang,Junhao Liu
Binders provide a straightforward and efficient strategy to mitigate the significant challenge of volume expansion in silicon anodes for lithium-ion batteries. To improve the cycle life of silicon anodes, a cross-linked binder carboxymethyl cellulose–phytic acid–pyrrole (CMC-DP) is designed and synthesized using carboxymethyl cellulose, phytic acid, and pyrrole. The numerous hydroxyl groups in phytic acid provide abundant binding sites for the formation of hydrogen and ester bonds. The formation of hydrogen bonds and covalent bonds enhances the mechanical properties of the adhesive. The amino groups in the binder form N Si O covalent bonds with silicon particles, while the hydroxyl and carboxyl groups form (COO) 2 Cu and (OH) 2 Cu coordination bonds with the copper foil, enhancing interfacial adhesion. When the CMC-DP10 (10 µL pyrrole) binder is applied to silicon nanoparticles (∼30 nm), the specific capacity of the electrode can be maintained at around 1700 mAh/g after 500, whereas the CMC binder achieves only ∼100 mAh/g under the same conditions. This work demonstrates that the CMC-DP binder exhibits strong adhesion to both silicon nanoparticles and copper foil.
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FIBERS AND POLYMERS
·
2025
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IF 2.3
Yan Hongsheng,Xiong Jie,Du Peijian,Wu Ermiao,Pan Tiandi,Li Ni
The construction of semiconductor heterojunctions is an effective way to enhance the photocatalytic activity. In this work, n–p heterojunction composed of ZnO nanorods and polypyrrole (PPy) nanospheres were loaded on polyacrylonitrile (PAN) nanofibers to fabricate ZnO/PPy/PAN nanofiber membranes (ZnO/PPy/PAN NFMs) via electrospinning, hydrothermal synthesis and chemical polymerization. The results showed that the photodegradation rate of ZnO/PPy/PAN NFM was about 4.8 times higher than that of ZnO/PAN NFM. Moreover, the membrane exhibited good cycling stability, which maintained the removal efficiency of rhodamine (RhB) at 79% after five cycles. The enhanced photocatalytic activity was mainly ascribed to the synergistic effect of PAN nanofibers adsorption and n–p heterojunctions catalysis, resulting in a narrow bandgap, an increase in the absorption of visible light and the separation efficiency of electron–hole. Meanwhile, the degradation mechanism of ZnO/PPy/PAN NFMs was proposed. This work provides a promising strategy to construct n–p heterojunction photocatalysts for removing organic pollutants in wastewater.
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SENSORS AND ACTUATORS B-CHEMICAL
·
2017
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IF 5.401
Wanqing Zhang,Lukuan Zong,Guangwei Geng,Yuanchao Li,Yuping Zhang
A novel MIP/MIL-101 (Cr)/MoS 2 /GCE sensor was fabricated for the determination of quercetin (Qu), based on MIL-101 (Cr)/MoS 2 modified GCE , followed by molecularly imprinted polymer (MIP) immobilized on modified electrode. Nanoscale materials of MIL-101 (Cr) and MoS 2 as electrochemical sensor modifiers were synthesized via hydrothermal methods The physical characterizations of the prepared MIL-101 (Cr), MoS 2 and MIL-101 (Cr)/MoS 2 were examined by FTIR, XRD, BET and TEM. The influencing parameters controlling the performance of the prepared sensor were in detailed studied. Under the optimized conditions, the electrochemical behavior of Qu at the MIP/MIL-101 (Cr)/MoS 2 /GCE sensor was investigated by using differential pulse voltammetry (DPV) method. The proposed sensor possessed desirable linear relationship between the peak currents and the Qu concentrations. Two linear concentration ranges can be observed at the MIP/MIL-101 (Cr)/MoS 2 /GCE sensor in the ranges of 0.1 to 10.5 μM and 10.5 to 700 μM, with a detection limit of 0.06 μM in phosphate buffer solution (PBS, pH = 3.5) (S/N = 3). Additionally, the MIP sensor presented excellent reproducibility, stability and selectivity. Furthermore, the imprinted sensor was also successfully applied for the determination of Qu in honey samples and received satisfactory recoveries.
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CARBON
·
2017
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IF 6.337
Qi Li,Dan Xu,Jiangna Guo,Xu Ou,Feng Yan
Preparation of high-performance carbon materials with an abundance of heteroatoms, edges, and defects for sustainable energy-conversion technologies, such as supercapacitors and oxygen reaction reduction (ORR), are still a challenge. Herein, we reported a facile strategy for the large-scale synthesis of nitrogen-doped porous carbon via carbonization of core-shell structured protonated g-C 3 N 4 @polypyrrole (P- g -C 3 N 4 @PPy) nanocomposites . Polypyrrole provided both the carbon and heteroatom sources, while P-g-C 3 N 4 acted not only as a sacrificial template but also as nitrogen sources. Porous carbon derived from P-g-C 3 N 4 @PPy (denoted as PCN@PPy-C-900) exhibited a specific capacitance of 350 F g −1 at a current density of 5 A g −1 and a high-rate capability (320 F g −1 ) at 20 A g −1 in 6 M KOH aqueous solution, as well as good long-term stability after 1000 cycles. In addition, PCN@PPy-C-900 also displayed excellent electrocatalytic performances in ORR in 0.1 M KOH aqueous solution. The excellent electrochemical performances provide guidance for the structure design of this promising class of multifunctional carbon-based materials which can be large scale applied to supercapacitors, ORR, and other fields.
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ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2017
·Vol. 409
·期 30
·7133-7144
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IF 3.431
Zhang Chao,She Yongxin,Li Tengfei,Zhao Fengnian,Jin Maojun,Guo Yirong,Zheng Lufei,Wang Shanshan,Jin Fen,Shao Hua,Liu Haijin,Wang Jing
An electrochemical sensor based on molecularly imprinted polypyrrole (MIPPy) was developed for selective and sensitive detection of the herbicide glyphosate (Gly) in cucumber and tap water samples. The sensor was prepared via synthesis of molecularly imprinted polymers on a gold electrode in the presence of Gly as the template molecule and pyrrole as the functional monomer by cyclic voltammetry (CV). The sensor preparation conditions including the ratio of template to functional monomers, number of CV cycles in the electropolymerization process, the method of template removal, incubation time, and pH were optimized. Under the optimal experimental conditions, the DPV peak currents of hexacyanoferrate/hexacyanoferrite changed linearly with Gly concentration in the range from 5 to 800 ng mL −1 , with a detection limit of 0.27 ng mL −1 ( S/N = 3). The sensor was used to detect the concentration of Gly in cucumber and tap water samples, with recoveries ranging from 72.70 to 98.96%. The proposed sensor showed excellent selectivity, good stability and reversibility, and could detect the Gly in real samples rapidly and sensitively.
Schematic illustration of the experimental procedure to detect Gly using the MIPPy electrode
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IONICS
·
2017
·Vol. 24
·期 3
·845-859
·
IF 2.062
Xiao Qi,Feng Mengmeng,Liu Yi,Lu Shuangyan,He Yingzi,Huang Shan
A sensitive and selective electrochemical sensor based on carboxyl graphene (CG), polypyrrole (PPy), and chitosan (CS) nanocomposite-modified glassy carbon electrode (GCE) has been developed for nitrite determination. The electrochemical performances of CG/PPy/CS/GCE were characterized by cyclic voltammetry and electrochemical impedance spectroscopy. Under the optimum experimental conditions, CG/PPy/CS/GCE exhibited excellent differential pulse voltammetry (DPV) response of nitrite. A linear relationship between DPV peak current and the concentration of nitrite was obtained in the range of 0.2 to 1000 μM. The limit of detection of nitrite was estimated to be 0.02 μM. Using such modified electrodes, our method is quite reproducible for nitrite determination, even for real water samples.
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JOURNAL OF APPLIED POLYMER SCIENCE
·
2017
·Vol. 134
·期 35
·45235
·
IF 1.86
Wei Yuan,Gaoyi Han,Yaoming Xiao,Yunzhen Chang,Ying Zhang,Hua Song
Polypyrrole deposited on titanium mesh (PPy–TiM) was fabricated via a galvanostatic method with titanium mesh as the substrate to electrochemically deposit polypyrrole (PPy) doped with p -toluene sulfonate anions. The influence of the deposition time on the characteristics of the PPy–TiM samples was investigated. Then, semitransparent flexible electrochemical capacitors were assembled with the optimal samples of PPy–TiM as electrodes and H 3 PO 4 –poly(vinyl alcohol) as the gel electrolyte. The testing results show that PPy in the optimal PPy–TiM electrode had a specific capacitance of about 326 F/g, and the capacitance of the assembled cells still remained unchanged or up even after 20,000 cycles. Just as expected, the cells possessed semitransparent and good flexibility, and three cells connected in series could drive an LED device. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2017
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Frontiers in Environmental Science
·
2024
·
IF 3.3
Ma Rong,Yu Shuangshuang,Li Yafang,Lin Yan,Ma Xiaodong
Background: With the growing use of nitrogen-containing pesticides in agriculture, their residues in the environment have raised significant public health concerns.Objective: This study aimed to develop a novel PPy-DBSA/IT-SPME coating to enhance the detection efficiency of polar nitrogen-containing pesticides in water matrices.Methods: The preparation conditions were optimized, including pyrrole concentration at 7.0 mol/L, DBSA concentration at 0.014 mol/L, oxidant concentration at 0.35 mol/L, and a coating cycle repeated 10 times. High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was employed for detection.Results: The novel coating effectively adsorbed 19 different categories of polar nitrogen-containing pesticides, including sulfonylureas, triazolopyrimidines, diphenyl ether herbicides, benzoylurea insecticides, and phenylurea herbicides, with unadsorbed rates below 10%. The analytical method achieved an average recovery rate of 61.92% to 115.21%, with an RSD below 5.0%. Detection and quantification limits ranged from 0.012 to 0.524 μg/L and 0.127 to 5.243 μg/L, respectively.Conclusion: The developed method is green, efficient, simple, and cost-effective. It offers an environmentally friendly and user-friendly approach for the detection of polar nitrogen-containing pesticide residues, demonstrating good recovery and precision. This method holds potential for wide application in environmental monitoring and food safety.
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JOURNAL OF SOLID STATE ELECTROCHEMISTRY
·
2024
·
IF 2.6
Ravichandran Balamurali,Narayanan Naresh,Ravichandran Sabarinathan,Liu Huiyuan,Zhang Weiqi,Bhuvanendran Narayanamoorthy,Su Huaneng
In this study, PtCo alloy nanoparticles (NPs) were successfully synthesized and deposited on nitrogen-rich carbon nanosheets derived from Polypyrrole-g-C 3 N 4 using a chemical reduction method. This electrocatalyst not only offers enhanced catalytic efficiency but also significantly improves the stability for the oxygen reduction reaction (ORR) in in acidic medium. In terms of electrocatalytic performance, the PtCo/CN@PPY-g-C 3 N 4 catalyst demonstrated a mass activity of 0.378 mA µg Pt −1 at 0.85 V, 0.131 mA µg Pt −1 at 0.9 V and a specific activity of 2.900 mA cm Pt −2 at 0.85 V, 1.004 mA cm Pt −2 at 0.9 V which are respectively 2.3, 2.8 and 10, 12 times higher than those of a commercial 20% Pt/C catalyst (0.166 mA µg Pt −1 at 0.85 V, 0.046 mA µg Pt −1 at 0.9 V and 0.285 mA cm Pt −2 at 0.85 V, 0.079 mA cm Pt −2 at 0.9 V). This indicates superior catalytic activity. Furthermore, after 5000 cycles, the PtCo/CN@PPY-g-C 3 N 4 retained approximately 77% at 0.85 V and 83% at 0.9 V of its initial mass activity, with only a 14 mV decrease in the half-wave potential, whereas commercial 20% Pt/C catalyst retained only 40% at0.85 V and 30% at 0.9 V of its initial mass activity. These enhancements can be attributed to the synergistic effects and strong interactions between the Pt–Co alloy nanoparticles and the carbon nitride support. The findings of this study underscore the potential of PtCo/CN@PPY-g-C 3 N 4 as a viable and efficient alternative to traditional catalysts in electrochemical applications.
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RARE METALS
·
2024
·Vol. 43
·期 7
·3185-3193
·
IF 9.6
Yuan Jing-Bo,Feng Zhi-Hong,Li Dong-Chan,Luo Yang,Zhou Yun-Lei
Electronic textiles, an emerging class of electronic technology, offer exciting opportunities for seamless integration with the human body. Numerous applications have been developed based on electronic textiles. However, researches on integrating multiple electronic textile-based devices are still few. In this study, we present a system integrated with an electrocardiogram monitoring sensor and an electroluminescence device based on stretchable and washable conductive microtextiles. The signal is acquired by an electrocardiograph amplifier and displayed by a dual-color electroluminescence device based on the processed results. The integrated electronic device has excellent moisture permeability and comfort for long-term wearing. The system reported in this study opens a new avenue for the application of electronic textiles in health monitoring, robotic prosthetics, and competitive sports. Graphical abstract
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JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·
IF 2.7
Miaotian Long,Zerui Zhang,Long Yan,Liang Yi
For effectively strengthening the comprehensive properties of intumescent flame-retardant epoxy resins (EPs), a microencapsulating γ-Fe 2 O 3 by polypyrrole (PPy) named PPy-Fe 2 O 3 was synthesized and used as a synergist to simultaneously enhance the flame retardancy, smoke toxicity suppression and mechanical strength of EP composites containing diaminodiphenylmethane modified ammonium polyphosphate (DDP). The results demonstrate that the mixture of PPy-Fe 2 O 3 and DDP exhibits a surprising synergistic effect on strengthening the comprehensive properties of EP composites. Specifically, EP composite containing 0.2 wt% PPy-Fe 2 O 3 and 9.8 wt% DDP achieves the UL94 V-0 rating with a limiting oxygen index (LOI) value of 35.5%, while 10 wt% DDP only imparts a UL94 V-1 rating and a LOI value of 34.0% to EP. Furthermore, 0.2 wt% PPy-Fe 2 O 3 shows a 11.0% reduction in peak smoke production rate and a 12.3% reduction in peak heat release rate of the EP/DDP system. The enhanced fire security of EP/DDP/PPy-Fe 2 O 3 is attributed to the formation of more phosphorus-rich structures retained in the char, thus reducing the release of harmful gases including NH 3 , CO, and CO 2 , and generating more incombustible gases including H 2 O to weaken burning intensity. Meanwhile, the satisfactory compatibility of PPy-Fe 2 O 3 with epoxy matrix imparts a superior mechanical strength to EP composites.
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