JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Biao He,Zhiwei Han,Jingyan Wang,Yaning Li,Jian Li,Saichao Song,Chen Li,Wei Liu,Chengyang Wu
Fluorine-based aluminum thermite have excellent ignition and combustion properties. Nonetheless, its combustion kinetics and energy release are hindered by slow mass diffusion and incomplete reactions. Therefore, this study successfully prepared an Al@PTFE composite with a core-shell structure, utilizing mechanical activation and sintering techniques, to enhance combustion properties and energy release rate. SEM, XRD, FTIR and XPS characterization results demonstrate the unique core-shell structure of the samples and the homogeneous distribution of elements on the surface. In comparison to the physical mixture, the Al@PTFE composite exhibits significantly higher values for P max (2.19 times), P max /Δt (11.30 times), and flame propagation velocity (4.5 times). Furthermore, the combustion duration required to reach the maximum flame height was reduced by 131.75 ms. The adsorption, decomposition and reaction processes of PTFE on the surface of aluminum particles were demonstrated based on RMD simulations. The promotion mechanism of PTFE on combustion in aluminum particles was elucidated.
研究领域:
材料科学
·
燃烧化学
✓ 已验证
DOI
高影响因子
ACS Applied Nano Materials
·
2024
·
IF 5.3
Xin Bao,Ke Zhao,Zhen Tian,Wenquan Sun,Hui Wang,Zixuan Liu,Lijia Zhao,Hui Li,Xi Yuan
Long-lived thermally activated delayed fluorescence (TADF) emission has gained extensive attention due to its potential application in information encryption, illumination, and bioimaging. However, developing visible light-excited TADF materials is still a significant challenge. Herein, visible light triggered TADF emission was achieved by embedding chlorine doped carbon dots (Cl-CDs) into a g-C3N4 nanosheet matrix through a simple microwave treatment. The strong electron-withdrawing effect of the chlorine dropping redshifts the excitation wavelength, and the covalent bonds between Cl-CDs and the matrix significantly stabilize the triplet state. Green TADF with a peak at 520 nm could be obtained in the Cl-CD composite when excited by the UV to visible light, and the afterglow signal can be observed by the naked eye for up to 5 s after a mobile phone flashlight irradiation. The composite also exhibited temperature-responsive color stability under UV light irradiation. Consequently, the Cl-CD composite was successfully employed in concepts of information encryption and single-component time delay WLED development. This research provides materials and strategies that may motivate the visible light-excited TADF applied in advanced information encryption and illumination areas.
研究领域:
材料科学
·
光电技术
·
纳米技术
✓ 已验证
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2024
·
IF 18.5
Wenxuan Sun,Yongqiang Zhang,Guangchao Yin,Siyu Lu
Comprehensive research into afterglow emission in the near-infrared (NIR) region of carbon dots (CDs) is currently lacking. In this study, highly efficient multicolor CDs are synthesized with fluorescence from blue to NIR using Rhodamine 6G. Boron oxide (B 2 O 3 ) is employed as a matrix for encapsulating and confining the CDs, inhibiting triplet exciton quenching. Furthermore, structural rigidity is enhanced due to the formation of carbon-boron (C─B) covalent bonds between CDs and B 2 O 3 , achieving tunable afterglow emission ranging from 463 to 722 nm with lifetimes up to 801 ms. The green–yellow afterglow composite exhibits an impressive quantum yield up to 37.67% while demonstrating thermally activated delayed fluorescence (TADF). Thus, this composite is coated onto a blue alternating-current light-emitting diode (BAC-LED) to fabricate a white AC-LED, which is successfully prepared with Commission Internationale de L'Eclairage (CIE) at coordinates of (0.32, 0.34), accompanied by the color rendering index (CRI) reaching 81.1. The bright afterglow compensates for zero-point flickering in the BAC-LED, resulting in stable and gentle emission. The potential applications of these luminescent materials in optoelectronic devices are undoubtedly widened by this remarkable advancement.
研究领域:
材料科学
·
光学
·
光电子学
✓ 已验证
产品关联
DOI
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
·
2023
·
IF 5.7
Mengbi Zhang,Yun Zhang,Hong Zhong,Liqing Li,Zhanfang Cao
Background Water electrolysis is one of the most competitive approaches to generate hydrogen. The economical stainless steel, which consists of transition metals such as Ni and Fe, has impressive catalytic tunability and tremendous application potential in hydrogen production . Methods In this work, a hydrothermal activation strategy is proposed for breaking the inert oxide layer of stainless steel and producing an active catalytic layer dominated by NiFe 2 O 4 spinel nanoparticles on the surface. The molybdate further complexes with the metal ions, disrupting the initial regular crystals of NiFe 2 O 4 and exposing more defects. At the same time, Mo atoms can further optimize the electronic structure, which is conducive to the kinetic process of the reaction. Significant Findings Consequently, the modified stainless steel requires only 270 mV to achieve a current density of 10 mA·cm −2 , much lower than 387 mV of bare 304 stainless steel (SS304). Moreover, the robust catalytic layer, evolved from the stainless steel's own elements, grows firmly on the surface and shows excellent stability in the test of 120 h. This work provides a novel strategy for developing low-cost stainless steel electrodes with superior performance and stability for oxygen evolution.
研究领域:
材料科学
·
电化学
·
能源转化
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Qingling Zhao,Chunyan Fan,He Bu,Jie Gao,Lanlan Li,Xiaofei Yu,Xiaojing Yang,Zunming Lu,Xinghua Zhang
Solid-state multicolor carbon dots (CDs) have attracted tremendous attention due to their wide applications. However, the fluorescence quenching of solid-state CDs occurs due to the π-π stacking or energy transfer between adjacent carbon dots. In addition, it is difficult to observe the afterglow of solid-state CDs due to their self-quenching and deliquescence. Here, electrochemically prepared multicolor CDs emit the solid-state fluorescence and afterglow emission with lifetimes up to 657 ms by embedding the CDs into urea matrix. More importantly, the surface amino groups and C = O bonds regulate the afterglow emission of CDs from phosphorescence and thermally activated delayed fluorescence at room temperature. Surface amino groups of multicolor CDs can enhance the spin–orbit coupling, increase the intersystem crossing (ISC) and reverse intersystem crossing (RISC). Thus it can promote the generation of triple excited states and regulate the singlet–triplet energy gap value from 0.384 to 0.026 eV. The formation of covalent bonds stabilizes the single and triple excited states and inhibits the non-radiative recombination, which achieves the enhanced fluorescence and visual afterglow of multicolor CDs. The fluorescence and afterglow CDs can be applied to dual signal imaging and anti-counterfeiting, which broadens the practical applications for solid-state CDs via surface state modulation.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Linze Jin,Xu Han,Junxiu Piao,Yuhui Meng,Xiaoran Yang,Lifu Zhang,Zitian Zhang,Chengming Jiang,Sheng Bi
In recent years, smart shape memory materials have garnered significant attention for their potential applications in flexible electronics. However, the exploration of wood, a natural polymer with shape memory capabilities, has been limited, particularly concerning its editable and controllable memory shapes and moveable functions. This study presents a shape memory wood actuator (SMWA) with dual activation capabilities through water and heat. The SMWA is developed by connecting the treated wood with PDMS and LCE for consecutive gesture programming. The controlled contraction of LCE upon thermal activation, combined with strength changes due to reversible hydrogen bonding in the cellulose amorphous region during water activation, enables the SMWA to exhibit continuous shape memory capabilities and programmability. Additionally, the SMWA demonstrates satisfactory mechanical performance (tensile strength of 17.3 MPa when dry and 4.4 MPa when wet) and shape recovery capabilities (over 80 % shape recovery). Notably, the rigidity/flexibility change of SMWA under water-activated conditions, coupled with heat-activated posture control and memory through built-in circuits, allows for practical applications such as object grasping. Such efficient strategy offers a guideline for developing high- performance smart wooden shape memory materials, with promising prospects for applications in soft robotics, flexible sensors and oil–water separation.
研究领域:
材料科学
·
智能材料
·
生物材料
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale
·
2025
·
IF 5.1
Pengwei Wang,Peixi Cong,Jiachen Chen,Huaiyuan Cao,Qi Yue,Zixiao Xue,Junji Zhang,Long Zhang,Robert S. Weatherup,Jiabin Cui,Jin He
The confined synthesis of carbon dots (CDs) in solid matrixes is a promising avenue for developing new afterglow materials. Benefiting from the advantages of the sol–gel preparation of nanoporous glass, we report transparent glass-confined CDs with tunable afterglow luminescence. Switchable thermally-activated delayed fluorescence (TADF) and room-temperature phosphorescence (RTP) of CDs were achieved by adjusting the sintering temperature and ion doping. Our findings reveal that with an increase in sintering temperature from 500 °C to 600 °C, the energy gap (ΔEST) of CD-nanoporous glass (NG) increased from 0.05 eV to 0.21 eV, while the lifetime increased from 329 ms to 548 ms, which is attributed to the enhanced carbonization degree of the CDs. Pb2+ doping is also shown to achieve switchable TADF and RTP of glass-confined CDs attributed to the alteration of interfacial interactions between the glass and confined CDs. This design concept introduces a new perspective for developing transparent afterglow materials for various unique phosphorescence applications.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2018
·
IF 6.735
Jiangling He,Youling He,Yonghao Chen,Xuejie Zhang,Chaofan Hu,Jianle Zhuang,Bingfu Lei,Yingliang Liu
Fluorescence of carbon dots (CDs) has grown well for substantial applications, but the long-lived photoluminescence, such as room temperature phosphorescence (RTP) and thermally activated delayed fluorescence (TADF), still catch less attention due to the serious deactivation of triplets under ambient conditions, leading to extremely low radiative efficiency. Herein, we simultaneously achieved both of them by incorporating CDs into poly(vinyl alcohol) (PVA) with the assistance of electrospinning technology. Through systematic investigation, ordered mesoporous structure from the electrospun CDs/PVA nanofibers can effectively stabilize the triplet states of CDs , thus enabling the reverse intersystem crossing (RISC) process for TADF and realizing the first example in CDs/polymer system. RTP is closely related to the triplet excited states of the carbonyls located at the surface of CDs and PVA molecule can rigidify these groups with hydrogen bonds, which can prevent quenching from atmospheric oxygen to promote the RTP and TADF behaviors in the air atmosphere. The afterglow spectrum of these nanofibers exhibits dual emission centered at 456 nm and 569 nm, originated from TADF and RTP, respectively. By changing the excitation wavelength or by adjusting the temperature of measurement, the color of the photoluminescence (PL) can be systematically tailored, the white-light emitting is promising. Moreover, these nanofibers show a long average afterglow lifetime of 1.61 s with visually recognizable period of 9 s. Moreover, CDs/PVA composites (nanofibers, solution, film, and aerogel) demonstrate potentialities in optical imaging, writing, anti-counterfeiting, temperature sensing.
研究领域:
材料科学
·
光学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2022
·
IF 5.6
Shuai Sun,Lei Wang,Han Xu
Reduced graphite oxide membrane (RGOM) with different thickness were prepared and used as electric double layer capacitor (EDLC) electrodes with aqueous electrolyte. According to quantum and molecular dynamic simulations, it was difficult for K + and OH − to diffuse into graphene sheets due to dense structure, which made the RGOM electrodes show poor EDLC behaviors. Electrochemical tests showed that controlling the thickness of electrodes and modifying the dense structure could improve the specific capacitance of EDLC. Further studies indicated that during galvanostatic charge/discharge processes, if the EDLC were heated at 70 °C for one cycle and then cooled down to room temperature, the specific capacitance could be increased further. Additionally, according to 10,000 times cycling tests at 5000 mA g −1 , the improved capacitance could be maintained for long time (154–167 F g −1 during test process), indicating that the hot activation could make RGOM electrodes obtain good and stable EDLC performances.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Haoran Song,Rui Zhou,Shiting Pan,Yuwei Wang,Yang Cai,Qingyun Li,Ting Wu,Yongming Shen,Changping Li
Treatment of landfill leachate and recovery of recycled water in photothermal activation of peroxydisulfate (PDS) process using iron nanoparticles/MXene-coated polyurethane sponge module (Fe NPs/MXene@PU) were investigated from lab to pilot scale for the first time. In the module preparation process, nanoscale zero-valent iron (NZVI) and iron oxides were in situ generated on Ti 3 C 2 MXene surface. Fe NPs/MXene@PU module reached the 147.7 °C interfacial temperature due to the synergistic effect of MXene and in-situ generated Fe NPs. Sulfate radical (SO 4 •- ) and hydroxyl radical (HO • ) were generated in photothermal activation of PDS process. Under optimized reaction conditions, almost complete removal of chemical oxygen demand (COD), nitrate nitrogen (NO 3 – ), ammonia nitrogen (NH 3 -N) and total phosphorus (TP) of landfill leachate was achieved after about 40 d pilot-scale experiment in the open air. The recycled water collected by natural condensation was also purified, which contained ultralow concentrations of COD, NH 3 -N, NO 3 – , TP and heavy metals and met the discharge limits of various countries. This study provides an eco-friendly and energy-efficient technology for treatment of landfill leachate and recovery of recycled water.
研究领域:
环境科学
·
材料科学
·
水处理工程
✓ 已验证
产品关联
DOI
高影响因子
Advanced Science
·
2023
·Vol. 10
·期 15
·2300139
·
IF 15.1
Zhen Zhang,Zhenguang Wang,Xiao Liu,Yu-e Shi,Zhiqiang Li,Yanli Zhao
Inorganic boric acid (BA) is generally not considered an efficient afterglow material, and several groups have reported its extremely weak room-temperature phosphorescence (RTP) in the blue spectral region. It is discovered that heat treatment of BA results in increased afterglow intensity (27-fold increase) and prolonged emission lifetime (from 0.83 to 1.59 s), attributed to enhanced through-space conjugation (TSC) of BA. The afterglow intensity of BA can be increased further (≈415 folds) by introducing p-hydroxybenzoic acid (PHA), which contains a conjugated molecular motif, to further promote the TSC of the BA system. This combination results in the production of afterglow materials with a photoluminescence quantum yield of 83.8% and an emission lifetime of 2.01 s. In addition, a tunable multicolor afterglow in the 420–490 nm range is achieved owing to the enhancement of the RTP and thermally activated delayed fluorescence of PHA, where BA exerts a confinement effect on the guest molecules. Thus, this study demonstrates promising afterglow materials produced from extremely abundant and simple precursor materials for various applications.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
PubMed
高影响因子
Advanced Optical Materials
·
2022
·Vol. 10
·期 18
·2200629
·
IF 10.05
Donghui Wang,Zhangdi Lu,Xiaoman Qin,Zhen Zhang,Yu-e Shi,Jacky W. Y. Lam,Zhenguang Wang,Ben Zhong Tang
The construction of highly luminescent solid-state materials with long-lived afterglow through a straightforward method is promising but still a challenging task. Herein, a heat-treatment strategy is proposed to embed levofloxacin (Lev) in the matrix of boric acid (BA) to produce a complex with a photoluminescence quantum yield of 63.8% and an emission lifetime of 0.74 s (afterglow: >5 s). Detailed investigations suggest that the unique photophysical properties of the complex are attributed to the confinement effect of BA matrix to Lev, which reduces the probability of nonradiative relaxation and activates the radiative decays to result in the promoted emission efficiency. In addition, thermally activated delayed fluorescence is also activated due to the alteration of the π transition of Lev by the formation of boron–carbon bonds. The emission color and lifetime are also modulated through controlling the synthetic conditions, which endow their applications both in light-emitting diodes and information encryption. Thus, the present results are significant for the construction of solid-state luminescent materials, including fluorescence and room-temperature phosphorescence, and also provide a solid and universal theory to clarify their detailed emission profiles.
研究领域:
材料科学
·
光学
·
化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）