APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2023
·Vol. 129
·期 11
·758
·
IF 2.7
Hao Lifeng,Lin Liyu,Jiang Zewen,Zhou Yang,Fang Yujie
Inspired by the fact that nanostructured expandable graphite (denoted as EG), when functionalized with silicon (Si) and boron (B) elements, can significantly enhance thermal insulation performance and improve the strength of char residue layers, the study controllably synthesizes EG supported with boron acid (H 3 BO 3 ) or polyhedral oligomeric silsesquioxane (POSS), using polydopamine (PDA) as a bridging agent. The resulting composites possess specific particle sizes of 80–90 nm and 100–120 nm for H 3 BO 3 -PDA-EG and POSS-PDA-EG, respectively. By formulating ablative-resistant coatings incorporating these composites, significant improvements are achieved in the mechanical properties of the resulting ceramic layers formed during ablation compared to control formulation. The compressive strength of the char residue layer is 0.13 MPa for EG alone, 8.85 MPa for H 3 BO 3 -PDA-EG, and 12.86 MPa for POSS-PDA-EG. Additionally, it is observed that the back surface of the coating with POSS-PDA-EG is approximately 180 ℃, while the back surface of the coating with H 3 BO 3 -PDA-EG is approximately 300 ℃ in a thermal test by a FD-04D/E Wind Tunnel, and compared to the coating with H 3 BO 3 -PDA-EG, the coating with POSS-PDA-EG yields more uniformly expanded and dense residue, which indicated that the coating with POSS-PDA-EG is characterized by better heat insulation and heat-resistant parameters. This is attributed to the improved silicon-boron coordination effect facilitated by the presence of POSS-PDA-EG and boron oxide, promoting ceramization. The resulting graphitized carbon layer, formed through fusion with porous expanded graphite at high temperatures, effectively resists high heat flow erosion over an extended duration. This work introduces an effective approach for enhancing ablation resistance by synergistically catalyzing boric acid or POSS-modified EG with a PDA bridge. The initial decomposition temperature was increased from 189 to 223 ℃, the maximum decomposition temperature was increased from 282 to 287℃, and the residual weight was increased from 51.6 to 63.6%. This can be concluded that the mixture of epoxy resin with either H 3 BO 3 -PDA-EG or POSS-PDA-EG demonstrates outstanding thermal resistance. The utilization of these novel composites and the insights gained from their performance contribute to advancements in the field of ablation-resistant coatings.
研究领域:
材料科学
·
聚合物涂层
·
热防护系统
·
烧蚀材料
·
纳米复合材料
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DOI
高影响因子
Science China-Materials
·
2016
·Vol. 59
·期 5
·337-347
·
IF 0
Zhang Guoxin,Jin Xiuyan,Li Haoyuan,Wang Lin,Hu Cejun,Sun Xiaoming
The crumpled graphene (CrG) was fabricated by applying defluorination of polyvinylidenefluoride (PVDF) on highly curved surface of CaC 2 particle through bottom-up synthetic strategy. The limited reaction depth between PVDF and CaC 2 leads to the formation of CrG with thin layer (3−6 layer graphene) and reasonable high specific surface area (~324.8 m 2 g −1 ). CrG with N incorporation (N-CrG) was applied as electrode material for reducing oxygen (i.e., oxygen reduction reaction, ORR) in alkaline, showing close onset potential to that of Pt/C and better mass-diffusion behavior. Surprisingly, with increased mass loading of catalysts, N-CrG exhibits steady current increase while Pt/C shows clear current plateau. Meanwhile, the N-CrG sample reveals high cycling stability and tolerance to contaminant, demonstrating its high potential for practical applications. Additionally, the bottom-up synthetic pathway to CrG via polymer dehalogenation on solid alkaline may find more applications which require controlled morphology and thickness of deposited thin graphitic carbon layers.
研究领域:
材料科学
·
电化学
·
纳米材料
·
能量存储与转换
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DOI
CHEMICAL PAPERS
·
2018
·Vol. 72
·期 11
·2871-2877
·
IF 0.963
Wang Yazhen,Li Rifang,Jia Hongge,Yang Guoxing,Di Yutao,Xu Chenxi,Ma Liqun,Zhang Hui,Zhou Yongli,Zang Yu,Xu Shuangping,Sun Zhaoyang,Zu Liwu,Yue Chenge,Lan Tianyu
A novel peroxy group-containing silane coupling agent was synthesized and anchored on the surface of titanium dioxide nanoparticles (nano-TiO 2 ) to form an immobilized-initiator-modified nano-TiO 2 species. In this study, the kinetic parameters of the peroxy group-containing silane were tested and assessed using DSC. The pre-exponential factor ( A d ) was 8.973 × 10 8 and the activation energy ( E a ) was 80.736 kJ mol −1 . Moreover, the empirical Arrhenius equation was determined to be ln K d = − 80.736/ RT + ln(8.973 × 10 8 ). To obtain continuous polymers, acrylonitrile (AN) and methyl methacrylate (MMA) were polymerized using the novel peroxy group-containing silane and FeSO 4 as an initiator system. The number average molecular weights ( M n of PAN = 3×10 4 and M n of PMMA = 1.4 × 10 5 ) and polydispersity indexes (PDI of PAN = 2.76 and PDI of PMMA = 1.65) were determined by GPC. It was suggested that the redox initiation system can generate highly reactive species on the surfaces of inorganic nanoparticles. The nano-TiO 2 -grafted polymers were successfully obtained.
研究领域:
高分子化学
·
材料科学
·
纳米技术
·
表面改性
·
引发剂设计
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DOI
高影响因子
APPLIED PHYSICS B-LASERS AND OPTICS
·
2024
·Vol. 130
·期 3
·38
·
IF 2
Ran Qiu-Yue,Lian Yu-Long,Tang Yong,Hao Jian-Hong,Bai Yun-Feng
FIR temperature measurement based on thermally coupled levels of rare earth ions has been widely studied, but its sensitivity is limited by the thermal coupling levels’ spacing. In this letter, a transition from non-thermally coupled levels of Ho 3+ to thermally coupled levels is reported for the first time. It can effectively improve the sensitivity of temperature measurement based on thermal coupling levels. The Ho 3+ /Yb 3+ co-doped Y 2 O 3 millimeter crystals have been prepared by laser annealing. The fluorescence properties of laser-annealed Ho 3+ /Yb 3+ co-doped Y 2 O 3 millimeter crystals were investigated as a function of temperature. It was found that the I 667nm / I 549nm show non-thermal coupling below 453K, but changes to thermal coupling above 453K. The maximum relative sensitivity of I 667nm / I 549nm in thermal coupling is greater than the relative sensitivity of any known thermal coupling energy levels of Ho 3+ . It provides a new way to improve the sensitivity of thermally coupled FIR temperature measurement.
研究领域:
材料科学
·
光学传感
·
稀土掺杂
·
激光加工
·
温度测量
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DOI
高影响因子
IONICS
·
2026
·
IF 3.4
Jie Yuxin,Wang Wenhai,He Maowei,Yang Can,Wang Linyu
Hexavalent chromium (Cr(VI)) poses serious risks to human health and ecological environment due to its high toxicity and non-biodegradability. Therefore, developing highly sensitive detection methods for Cr(VI) is of significant importance. Here, a colorimetric sensing platform based on hollow cobalt and nitrogen co-doped porous carbon (H-Co, NPC) was proposed for the sensitive detection of Cr(VI). H-Co, NPC was synthesized by high-temperature calcination of a ZIF-8@ZIF-67 precursor, and it exhibited excellent peroxidase-like and oxidase-like activities. The hollow structure significantly enhances the accessibility of active sites and facilitates mass transport, while the co-doping of Co and N effectively improves electron transfer capability and substrate affinity. These synergistic effects make H-Co, NPC a promising candidate for colorimetric sensing applications. The sensing platform demonstrated excellent detection capabilities toward Cr(VI), including low detection limit (5 nM), wide linear range (0.015-1.5 µM), outstanding reproducibility and anti-interference ability. Moreover, it exhibited satisfactory detection performance of Cr(VI) in real samples. This work would provide new insights into the development of highly sensitive colorimetric sensing platforms.
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DOI
高影响因子
Advanced Composites and Hybrid Materials
·
2022
·Vol. 6
·期 1
·1-9
·
IF 11.806
Wu Yufeng,Wu Jianbo,Lin Yan,Liu Junchen,Pan Xiaolong,He Xian,Bi Ke,Lei Ming
In recent years, due to the development of flexible electronics, flexible sensors have been widely concerned and applied in intelligent robots, brain-computer interfaces, and wearable electronic devices. In this paper, we propose a low-cost and high-efficiency sensor component preparation method. The sensor component tetrathiafulvalene-tetracyanoquinodimethane/melamine sponge (TTMS) takes a melamine sponge as a flexible substrate. And the sponge is metallized with the tetrathiafulvalene-tetracyanoquinodimethane (TTF-TCNQ) which is an organic conducting molecule to construct a conductive pathway. The physical load approach is used to ensure the advantages of low cost and efficient manufacturing. TTMS can withstand 8000 compression cycles which exhibits its good mechanical stability. And 1000 cycles of cyclic voltammetry scanning proved it also had good electrical stability. TTMS can distinguish pressure changes of 100 Pa and respond quickly to pressure application and release. The TTMS can be assembled to form an array of sensors that can distinguish the position and intensity of pressure. Therefore, the excellent performance of the sensor is expected to promote the commercial application of the piezoresistive sensor.
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DOI
高影响因子
JOURNAL OF POLYMER RESEARCH
·
2022
·Vol. 29
·期 12
·1-15
·
IF 3.061
Olonisakin Kehinde,Li Ran,He Suping,Aishi Wen,Lifei Feng,Mengting Cao,Xin-Xiang Zhang,Ruohai Jiang,Yang Wenbin
The mountmorinollite (MMT) nano clay, microcrystalline cellulose (MCC), and poly(Lactic acid) (PLA (MMT/MCC/PLA) composites with reinforced strength and toughness were prepared. This study aimed to develop MMT/MCC/PLA composite with improved thermal stability and flame rating based on reinforced strength and toughness. A simple and efficient method to hydrophobize MCC and intercalate the interlayer of MMT by mobilising cerium oxide nanoparticles (CeO 2 NP) bearing long-chain saturated fatty acid (Myristic acid; MA) to enhance compatibility with the PLA was adopted. The modified MCC (mMCC) and MMT (mMMT) were incorporated into PLA at different wt%. The flaming rating was studied by adding fire retardant (FR) into the composite. The mMCC, mMMT and their composites were characterised by Fourier Transformed Infrared spectroscopy(FTIR), Scanning Electron Microscopy(SEM), X-ray diffraction, Thermogravimetric analysis(TGA), UL-94 test, Limiting Oxygen Index(LOI), and mechanical analysis. FTIR and XRD confirmed the intercalation of MMT with the CeO 2 -MA and the mobilisation of CeO 2 -MA onto the surface of mMCC. SEM study showed the homogenous distribution of mMCC in the PLA matrix and revealed the layered clay structure with the deposition of nanoparticles into the clay interlayer space. The compatibility effect of the MA significantly improved the strength and toughness with more than 100% improvement in tensile strength of mMCC/PLA compared to neat PLA. The flame rating resulted in a 58.8% improvement in the LOI with the addition of the FR. The thermal stability was enhanced by the mMMT and mobility of CeO 2 NP into the interlayer space of the clay. The composite of mMCC/PLA, mMMT/PLA, and mMCC/mMMT/FR/PLA attained a V2, V1 and V0 rating in the UL-94 at a low FR addition. The improvement in fire retardancy did not significantly compromise the mechanical properties. The high mechanical performance of the mMCC/PLA presented MA as a potential fiber-matrix compatibiliser.
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DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2022
·Vol. 30
·期 5
·12125-12137
·
IF 5.19
Yan Jin,Zou Ying,Zhang Fengrui,Zhang Shenghua,Huang Xinyue,Benoit Gaboury
Although the addition of triclosan (TCS) in consumer products has been strictly restricted, its continuous applications in hospitals and other medical facilities and its numerous residues still pose a potential risk to aquatic organisms and aquatic ecosystems. In this study, we investigated the growth, biochemical alterations, and physiological responses of Chlorella vulgaris exposed to different concentrations of TCS. The potential toxicity mechanisms associated with excessive production of reactive oxygen species (ROS) and disruption of photosynthetic system II (PSII) were also analyzed. The results indicated that the growth, cellular ultrastructure, and physiology of C. vulgaris were severely affected by TCS in a dose-effect dependent manner. TCS inhibited the growth of C. vulgaris , leading to mitochondria enlargement, the disordering of the arrangement of thylakoids, cell wall rupture, organelles loss, and the cytoplasm lysis. TCS induced severe oxidative damage characterized by ROS accumulation, elevated malondialdehyde (MDA), and up-regulation of antioxidant enzyme activities. Moreover, in TCS-induced algal cells, the main sites of ROS accumulation were chloroplasts, mitochondria, and cell membranes, with ROS accumulating most in the mitochondria. In addition, TCS caused damage to the reaction center (RC inactivation), donor side (OEC damage), and accepted side (electron transport from Q A to Q B ) of PSII in C. vulgaris , leading to inhibition of photosynthetic activity. These results could provide novel insights into the mechanisms of TCS-induced ROS accumulation and photosynthetic inhibition in C. vulgaris , which would contribute to a deep understanding of TCS toxicity on algae.
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DOI
PubMed
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
·
2022
·Vol. 41
·期 1
·67-74
·
IF 3.815
Yang Xiao,Niu Yan-Fang,Wei Meng-Xiao,Zhang Jun-Ning,Liu Ke-Liang,Du Xin,Gu Zhong-Ze
In this study, we investigate the effect of the exposure dose on the mechanical property of the photoresins generated with acrylate self-polymerization and thiol-ene polymerization. The results indicate that the mechanical performance of the thiol-ene photoresin is highly depended on the exposure dose during the solidification process. With 350-fold exposure dose change, the stiffness of the thiol-ene photoresin reached more that 700-fold change compare to 14-fold of the acrylate photoresin. We developed a TPL photoresist based on our results and show the capability to fabricate microstrucutres with high resolution and variable mechanical performances using this method.
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产品关联
DOI
高影响因子
Advanced Composites and Hybrid Materials
·
2023
·Vol. 6
·期 1
·1-9
·
IF 20.1
Du Peng,Lin Chaoliang,He Xian,Zheng Zhichuan,Xie Xinyu,Huang Kai,Lei Ming,Tang Haolin
Developing relatively cost-effective and high-performance Ru-based composites as electrocatalysts for acidic oxygen evolution has become the critical step toward emerging renewable energy conversion, in which exploring controllable synthetic strategies and investigating the intrinsic nature by non-metallic interfacial modulation is highly desirable. In this work, a facile tandem process is proposed by ball-milling and thermal annealing for the scalable synthesis of Ru–O–Se nanocomposites with in-situ formed crystalline RuSe 2 and metallic Ru heterostructures on a RuO 2 substrate. The optimized RuO x Se y -800 sample has been proved to have an excellent OER activity and long-term stability in an acidic electrolyte due to its suitable microscopic morphology and phase composition, along with a relatively smaller Tafel slope of 45.4 mV dec −1 compared with commercial RuO 2 and most similar catalysts reported in the literature. The outstanding acidic OER performance can be ascribed to the enhanced electron transfer and more active site exposure by controllable selenization. This work paves a novel way for the design and large-scale production of various non-metallic modified composite catalysts for extensive applications of energy conversion and storage.
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DOI
高影响因子
Science China-Chemistry
·
2023
·Vol. 66
·期 3
·853-862
·
IF 9.6
Yang Lei,Liu Zenghe,Neisiany Rasoul Esmaeely,Lou Jiaming,Guo Yifan,Zhang Luzhi,Liu Huijie,Chen Shuo,Gu Shijia,You Zhengwei
It is exceedingly desired, but difficult to construct self-healing materials with both excellent mechanical properties and healing efficiency, which are usually realized by using mutually exclusive methods. Here, we reconcile this contradiction by utilizing copper-bis-(imidazole-2-yl)-methane-urea (Cu-BIMU) locked units based on novel designed dynamic imidazole-urea bonds with coupled multiple noncovalent bonds (coordination bonds, π − π stacking bonds, and hydrogen bonds). The coordination of Cu(II) greatly reduces the electron-cloud density of imidazole, which lowers the free energy barrier of imidazole-urea bonds and promotes their reversible dissociation, as demonstrated by the density functional theory and small-molecule model reaction. The topological design of Cu-BIMU polyurethane (Cu-BIMU-PU), which concentrates multiple crosslinking-in-one locked unit to avoid the formation of excessive crosslinking sites to ensure high chain mobility, facilitates self-healing. Accumulative extensive intermolecular interactions endowed excellent mechanical properties to the resulting Cu-BIMU-PU elastomer with a tensile strength of 65.3 MPa, among the highest ever-reported value. This work provides a novel molecular design principle for fabricating high-performance dynamic polymers.
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DOI
高影响因子
JOURNAL OF POROUS MATERIALS
·
2023
·Vol. 30
·期 4
·1295-1302
·
IF 2.6
Wang Xu,Xu Gen,Zhou Zhiwei,Qin Xiaojuan,Su Yuansha,Zhang Xianbin,Wu Wenliang
New Cu 2 O@TiO 2 core-shell microspheres were successfully prepared for the first time in this paper. The XRD, N 2 adsorption-desorption, SEM, TEM, EDX and XPS characterizations were utilized to investigate the physical and chemical properties. The liquid phase oxidation of naphthalene was also carried out to test their catalytic performance. The characterization results indicating that the Cu 2 O microspheres were firstly formed by hydrothermal treatment and the rutile TiO 2 coating on the surface would be formed by the hydrolysis of tetrabutyl titanate. The Cu 2 O@TiO 2 - 5.0 catalyst with the molar ratio of copper to titanium species as high as 5.0 has the largest surface area and maximum pore volume resulting from the integrated microspheres with rougher surface thickness of about 6.3 nm, and it showed higher catalytic performance in the liquid phase oxidation of naphthalene. Naphthalene conversion of 43.2%, 1, 4-naphthoquinone selectivity of 26.7% and phthalic anhydride selectivity of 53.4% can be obtained, and it only slightly decreased even after repeated use for 5 times. The method would provide a valuable theoretic reference for the hindrance of Cu 2 O rapid deactivation and the industrial application of the naphthalene oxidation to produce high valuable chemicals.
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DOI
高影响因子
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