POLYMER INTERNATIONAL
·
2020
·Vol. 69
·期 5
·457-466
·
IF 2.574
Haoyang Sun,Tao Li,Fan Lei,Meng Yang,Dandan Li,Xianhang Huang,Dazhi Sun
Fluorographene (FG) with layer numbers of 3–4 was successfully prepared through facile microwave-assisted liquid phase exfoliation of raw graphite fluoride (GrF). The raw GrF and the as-prepared FG were then directly incorporated into polyamide 66 (PA66) by melt processing without using any surfactants. Microstructural, mechanical and tribological properties of the prepared PA66 composites were investigated. Various characterization results showed that both GrF and FG, as novel solid lubricants, can effectively improve the mechanical and anti-wear performances of the PA66 matrix. It was also found that FG is better at improving mechanical properties and reducing the friction of PA66 than GrF at low concentrations owing to the large surface–volume ratio. The addition of 0.5 wt% FG into PA66 exhibits a ca 13% increase in tensile modulus, ca 5% increase in tensile strength, ca 18% reduction in coefficient of friction (COF) and ca 43% reduction in wear rate. However, at relatively high concentrations, such as 1.0 wt%, GrF shows a better reinforcement effect than FG owing to a uniform dispersion of GrF in the PA66 matrix. The addition of 1.0 wt% GrF into PA66 exhibits a ca 18% increase in tensile modulus, ca 5% increase in tensile strength, ca 37% reduction in COF and ca 46% reduction in wear rate. Wear tests also show that the excellent wear resistance of the PA66 composites is due to the improved mechanical properties and the lubrication of GrF and FG between the worn surfaces. Our current work demonstrates the tremendous potentials of fluorinated carbon materials for enhancing mechanical and anti-wear properties of polymeric materials. © 2020 Society of Chemical Industry
研究领域:
材料科学
·
高分子化学
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产品关联
DOI
高影响因子
CARBON
·
2015
·
IF 6.196
Guoxin Zhang,Kang Zhou,Ruoyu Xu,Hekai Chen,Xiaoke Ma,Biao Zhang,Zheng Chang,Xiaoming Sun
In this study, we report a potentially scalable strategy for the cost/time-efficient production of water-soluble functionalized few layered graphene (FcG) through the mild defluorination of graphite fluoride (GF) at room temperature (RT). The strategy includes mechanical milling which is of high simplicity and operability, and subsequently water purification . By using heteroatom-containing alkaline such as NaNH 2 and Na 2 S, N or S dopants can be functionalized into the defluorinated graphene, leading to the formation of N- and S-doped FcG, respectively. Our methodology of defluorination of GF allows the fabrication of water soluble FcG in much safer ways relative to the conventional Hummers' method that involves strong acidic/oxidative ambience and disposal of large amount of salt wastes. Meanwhile, the abundance of GF and the simplicity of processibility may also facilitate the practical uses of FcG obtained via our methodology.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
NANO LETTERS
·
2022
·
IF 12.262
Yangqin Liu,Yilong Jiang,Junhui Sun,Yang Wang,Linmao Qian,Seong H. Kim,Lei Chen
Atomically thin two-dimensional (2D) materials are excellent candidates for utilization as a solid lubricant or additive at all length scales from macro-scale mechanical devices to micro/nano-electromechanical systems (MEMS/NEMS). In such applications, wear resistance of ultrathin 2D materials is critical for sustained lubrication performance. Here, we investigated the wear of fluorinated graphene (FG) nanosheets deposited on silicon surfaces using atomic force microscopy (AFM) and discovered that the wear resistance of FG improves as the FG thickness decreases from 4.2 to 0.8 nm (corresponding to seven layers to single layer) and the surface energy of the substrate underneath the FG nanosheets increases. On the basis of density function theory (DFT) calculations, the negative correlation of wear resistance to FG thickness and the positive correlation to substrate surface energy could be explained with the degree of interfacial charge transfer between FG and substrate which affects the strength of FG adhesion to the substrate.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Jian Wang,Yaofeng Mao,Jie Chen,ZiJian Li,Jun Wang,Fude Nie
Boron (B) shows great potential applications in the military and aerospace industry due to its high calorific value. However, the reactivity is limited by the inert oxide layer (B 2 O 3 ) that covers the B particles. Herein, nano-Al, and Fluorographene (FG) are employed as coating materials to enhance the ignition and combustion efficiency of boron. When graphite fluoride (GF) was utilized as an oxidizer (the B/GF mass ratio is 1:9), the maximum heat release of B@nano-Al/GF (∼5.6 kJ/g) and B@FG/GF (∼5.4 kJ/g) were markedly higher than that of raw B/GF (∼2.5 kJ/g), ascribed to the self-activation effect of the coating layer. On this basis, the combustion experiments were performed and their performances were compared and studied. Specifically, the ignition delay time of B@nano-Al/GF and B@FG/GF was decreased to 320 ms 262 ms, respectively, compared with that of raw B/GF (380 ms) with 15 W laser power. This is consistent with the ignition burning test, where the B@6%nano-Al/GF and B@2%FG/GF have higher flame height than raw B/GF. However, the maximum pressure and pressurization rate decreased for B@6%nano-Al/GF and B@2%FG/GF because of the reduced amount of gas caused by decreased boron content. Additionally, the effects of the B/GF mass ratio (1:9, 2:8, 3:7, 4:6) on the combustion performances of composites were fully studied. The pressure output, combustion reaction, and ignition delay time are reduced with B/GF mass ratios increased. This work could provide a general approach to improve the ignition and combustion performance of boron.
研究领域:
材料科学
·
航空航天工程
·
军事技术
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化学工程
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产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2022
·Vol. 139
·期 47
·e53193
·
IF 3.057
Xiuzhou Lin,Qiang Peng,Song Duan,Chunjiang Zhang,Xulei Chen,Zhiqiang Deng,Baojie Dou,Yingjun Zhang,Xiulei Gao,Zhiwen Fang
In this study, ZIF-8 modified fluorinated graphene composite (FG@ZIF-8) was innovatively prepared and used as a novel functional filler to improve the anticorrosion performance of epoxy coating on Q235 carbon steel. The morphology and structure of FG@ZIF-8 composites were characterized by scanning electron microscopy (SEM), x-ray powder diffractometer (XRD), Fourier transform infrared spectrometer (FT-IR), and x-ray photoelectron spectroscopy (XPS) tests. The results showed that the structure and morphology of the composites largely depended on the composition ratio of FG and ZIF-8. The mechanical properties and corrosion resistance of FG@ZIF-8 modified coatings were also investigated. The unique two-dimensional sheet structure and insulation of FG in the FG@ZIF-8 filler can not only inhibit the penetration of corrosive media but also discourage electron migration effectively on the interface of coating/matrix during the electrochemical reaction. Meanwhile, the chemical cross-linking between the amine groups in ZIF-8 and the epoxy group increases the degree of densification of the coatings. Besides, the 2-methylimidazole from the dissolution of ZIF-8 on FG@ZIF-8 will also inhibit the corrosion reaction. These advantages endow the FG@ZIF-8 modified epoxy coatings an excellent long-term corrosion resistance. Our findings may inspire the development of new graphene-based materials with superior protective properties for metallic materials.
研究领域:
材料科学
·
腐蚀与防护
✓ 已验证
产品关联
DOI
高影响因子
TRIBOLOGY INTERNATIONAL
·
2019
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IF 3.517
Xiaojing Ci,Wenjie Zhao,Jun Luo,Yangmin Wu,Tianhao Ge,Lu Shen,Xiulei Gao,Zhiwen Fang
Fluorographene could be used as lubricating additive which is attributed to its high mechanical strength and unique layered structures. However, it is difficult to disperse fluorographene uniformly in base oil due to its low surface energy. Here, we formulated multilayered fluorographene nanosheets (FG i ) by fluorinating graphene and then exfoliated the FG i using chloroform to obtain fluorographene (FG). Tribological results indicated that the coefficient of friction and the wear rate of GTL-8 nanolubricant oil enhanced with 0.3 mg/ml FG were decreased by 35% and 90%. Combining Transmission Electron Microscope images and X-ray photoelectron spectra, it is illustrated that physical transferred film and tribochemical film were generated which were beneficial for the excellent tribological performances of GTL-8 based oil enhanced via FG.
研究领域:
材料科学
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机械工程
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2013
·Vol. 4
·期 5
·2550-2556
·
IF 2.562
Liuting Zhang,Xuezhang Xiao,Xiulin Fan,Shouquan Li,Hongwei Ge,Qidong Wang,Lixin Chen
A simple approach to dramatically enhance the dehydrogenation properties of sodium borohydride is achieved by ball milling NaBH4 with fluorographite (FGi). It was found that the ball-milled NaBH4–FGi composite starts to release hydrogen without impurity gas at a lower temperature of 125 °C, and obtains a hydrogen desorption capacity of ca. 4.8 wt% below 130 °C in seconds, which is improved markedly compared to the ball-milled pristine NaBH4. The significant thermodynamic and kinetic improvement of the NaBH4–FGi composite can be ascribed to the reaction between NaBH4 and FGi as well as the formation of micro-scale NaBH4. Moreover, since the dehydrogenation process of NaBH4–FGi composite is exothermal, the fully reverse reaction is not feasible. In-depth investigations show that the partial rehydrogenation is due to the formation of Na2B12H12 and another new borohydride.
研究领域:
材料科学
·
能源化学
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纳米科技
·
物理化学
✓ 已验证
DOI
高影响因子
LANGMUIR
·
2024
·
IF 3.7
Ding Wang,Xiaohua Jia,Zhiqiang Shan,Li Gao,Jin Yang,Zhaofeng Wang,Haojie Song
Fluorinated graphene (FG) among numerous two-dimensional materials has enormous potential in improving antifriction properties. However, they being susceptible to thermal oxidation and prone to wear hinder practical applications. Herein, UIO-66-NH2 (Zr-MOF) enjoying good chemical and thermal stabilities was assembled on the surface of FG nanosheets under covalent bonds and van der Waals forces. The Zr-MOF@FG composite was successfully synthesized and used as a lubricant additive. It can be seen that Zr-MOF@FG composites offer a synergistic lubricant mechanism at the friction interface. Moreover, due to the adsorption and purification performance of Zr-MOF, the obtained Zr-MOF@FG composite adsorbs the abrasive rust during the friction process, thereby realizing the purification of the lubricant. These findings suggest that Zr-MOF@FG shows tremendous potential as a lubricant additive.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ADVANCED MATERIALS
·
2020
·Vol. 33
·期 3
·2006118
·
IF 27.398
Zhengping Ding,Chen Yang,Jian Zou,Shulin Chen,Ke Qu,Xiumei Ma,Jingmin Zhang,Jing Lu,Weifeng Wei,Peng Gao,Liping Wang
Fluorographites (CF x ) are ultrahigh-energy-density cathode materials for alkaline-metal primary batteries. However, they are generally not rechargeable. To elucidate the reaction mechanism of CF x cathodes, in situ transmission electron microscopy characterizations and ab initio calculations are employed. It is found that it is a two-phase mechanism upon K/Na/Li ion insertion; crystalline KF (crystalline NaF nanoparticles and amorphous LiF) is generated uniformly within the amorphous carbon matrix, retaining an unchanged volume during the discharge process. The diffusivity for K/Na/Li ion migration within the CF x is ≈2.2–2.5 × 10 –12 , 3.4–5.3 × 10 –12 , and 1.8–2.5 × 10 –11 cm 2 s –1 , respectively, which is comparable to the diffusivity of K/Na/Li ions in liquid-state cells. Encouraged by the in situ transmission electron microscopy (TEM) results, a new rechargeable all-solid-state Li/CF x battery is further designed that shows a part of the reversible specific discharge capacity at the 2nd cycle. These findings demonstrate that a solid-state electrolyte provides a different reaction process compared with a conventional liquid electrolyte, and enables CF x to be partly rechargeable in solid-state Li batteries.
研究领域:
材料科学
·
电化学
·
能源存储
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2023
·Vol. 140
·期 12
·e53637
·
IF 3
Xiuzhou Lin,Xulei Chen,Shixiong Zhao,Baojie Dou,Qiang Peng,Zhiqiang Deng,Wilfred Emori,Xiulei Gao,Zhiwen Fang
Fluorinated graphene (FG) is a derivative of graphene with excellent insulating properties, however, the dispersion performance of FG in organic coatings is still a challenge in anti-corrosion applications. This study aims to propose a simple strategy to effectively improve the dispersion of FG towards enhancing its interfacial compatibility with epoxy resins. FG was modified with amino-containing 3-aminopropyl triethoxysilane (APTES) and epoxy terminated 3-glycidoxypropyl trimethoxysilane (GPTMS). The chemical compositions and microstructures of FG and the silane-modified FGs were effectively characterized. Moreover, the corrosion resistance and anticorrosion mechanisms of the epoxy coatings modified by FG and silane-modified FG were systematically studied, and the results showed that the silane coupling agent effectively improved the dispersion of FG in the epoxy coating and enhanced the interface interaction between FG and the epoxy resin, thereby improving the barrier properties of the epoxy coating and preventing the penetration of the corrosive medium. Electrochemical and tribological analyses showed that the APTES-modified FG (AFG) coating exhibited better anti-corrosion properties than the GPTMS-modified FG (GFG) coating, which is attributed to the improvement of its crosslinking density and barrier properties by the reactions between the amino groups on AFG and the epoxy resin.
研究领域:
材料科学
·
化学工程
·
腐蚀与防护
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Guolong Wang,Zhuofan Yang,Leyuan Li,Junwen Ren,Jiamei Liu,Lei Li
Modern electrical applications urgently need flexible polymer films with a high dielectric constant (εr) and low loss. Recently, the MXene-filled percolative composite has emerged as a potential material choice because of the promised high εr. Nevertheless, the typically accompanied high dielectric loss hinders its applications. Herein, a facile and effective surface modification strategy of cladding Ti3C2Tx MXene (T = F or O; FMX) with fluorographene (FG) via self-assembly is proposed. The obtained FMX@FG hybrid yields high εr (up to 108 @1 kHz) and low loss (loss tangent tan δ = 1.16 @ 1 kHz) in a ferroelectric polymer composite at a low loading level (the equivalent of 1.5 wt % FMX), which is superior to its counterparts in our work (e.g., FMX: εr = 104, tan δ = 10.71) and other studies. It is found that the FG layer outside FMX plays a critical role in both the high dielectric constant and low loss from experimental characterizations and finite element simulations. For one thing, FG with a high F/C ratio would induce a favorable structure of high β-phase crystallinity, extensive microcapacitor networks, and abundant interfacial dipoles in polymer composites that account for the high εr. For another, FG, as a highly insulating layer, can inhibit the formation of conductive networks and inter-FMX electron tunneling, which is responsible for conduction loss. The results demonstrate the potential of a self-assembled FMX@FG hybrid for high εr and low loss polymer composite films and offer a new strategy for designing advanced polymer composite dielectrics.
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2020
·Vol. 138
·期 6
·49801
·
IF 2.52
Fan Zhang,Jinhui Li,Tao Wang,Chao Huang,Fei Ji,Liang Shan,Guoping Zhang,Rong Sun,Ching-ping Wong
Low dielectric constant and low dissipation factor, superior hydrophobicity, excellent thermal and mechanical property, and good optical performance are desired for advanced electronic packaging of fan-out wafer level package (FO-WLP). An effective approach was introduced to fabricate novel fluorinated graphene/polyimide(FG/PI) nanocomposite films in this paper. FG nanosheets exhibit excellent dispersion in the PI matrix due to their high surface area with some oxygen-containing functional groups, and individual graphitized planar structure. Besides, the effects of the addition of FG on the dielectric, optical, mechanical, thermal properties as well as the hydrophobicity of the films are investigated with controlled amounts of FG. The dielectric constant and loss can be as low as 2.64 (at 10 6 Hz) and 0.00176 for PI-0.5wt% FG. And with the increase of the loading of FG, the thermal stability ( T 5 = 514°C) and mechanical property (tensile modulus = 2.11GPa, tensile strength = 93.23 MPa, elongation at break = 11.60%) has been improved successfully. Besides, the contact angles have been increased from 83° to 92° showing a superior hydrophobicity which is essential for the FO-WLP. Moreover, the incorporation of FG also proved excellent optical performance of 88% transmittance at 550 nm. Therefore, with the excellent comprehensive performance, the as-prepared FG/PI films possess widespread applications in the microelectronics especially in FO-WLP.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）