POLYMER COMPOSITES
·
2024
·
IF 4.8
Dayu Liang,Xiang Li,Yixiang Zhang,Jianlei Qi,Zhimin Lu
In this paper, carboxyl-terminated nitrile rubber (CTBN) and Nano cerium oxide (n-CeO 2 ) were used to toughen epoxy resin (EP), and the effects of toughening agents on the mechanical and thermal properties of EP were studied. Orthogonal experiments determined that the ideal toughener proportions are 20 wt% CTBN and 1 wt% n-CeO 2 , under which the resin demonstrated superior mechanical characteristics. The combined application of CTBN and n-CeO 2 significantly enhanced the resin's mechanical properties, surpassing the effects of individual particle toughening. Compared with pure EP, the impact, flexural, and tensile strengths of the resin-cured product synergistically toughened by CTBN and n-CeO 2 increased by 462%, 136%, and 110%, respectively, and the flexural and Young's moduli increased by 38% and 35%, respectively. Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) were used to characterize the cured resin. The results indicate that incorporating CTBN and n-CeO 2 reduces the reaction activation energy, thereby accelerating the curing reaction and facilitating its progression. The addition of nanoparticles enhances the maximum weight loss temperature of the cured resin, thereby improving its thermal stability. CTBN and n-CeO 2 particles create a uniform phase separation structure within the resin, enhancing its toughness and strength. Furthermore, the impact fracture mode of the cured resin transitions from brittle to tough fracture, demonstrating a significant toughening effect. This provides an effective method for the toughening modification of EP. Highlights The synergistic use of CTBN and n-CeO 2 enhances the toughness of EP. The incorporation of nanoparticles improves the thermal stability of the cured resin. The addition of CTBN and n-CeO 2 accelerates the curing reaction rate. The inclusion of toughening agents transforms the fracture mode of the cured resin from brittle to tough fracture.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Coatings
·
2024
·Vol. 14
·期 12
·1572
·
IF 2.9
Yuqin Zhu,Jia Liu,Liang Li,Weikang Sun,Wei Tang,Lei Wang
To improve lubricant performance and extend the service life of machinery, the friction reduction and anti-wear performance of nano-cerium oxide (nano-CeO2) and nitrogen-containing heterocyclic borate (BNH2) composite additives were studied in this work, with the goal of obtaining better lubrication effects than a single additive. The results showed that the nano-CeO2modified with Span80 had good dispersion stability in the base oil. The optimal addition mass fractions of single nano-CeO2and BNH2 were 0.6 wt% and 1.0 wt%, respectively. Compared with the base oil, 0.6 wt% nano-CeO2reduced the coefficient of friction by 44.9% and the wear spot diameter by 27.8%, while 1.0 wt% BNH2 reduced the coefficient of friction by 49.1% and the wear spot diameter by 32.8%. Compared with the single additions of nano-CeO2and BNH2, the compound nano-CeO2/BNH2 further improved the friction reduction and anti-wear performance of the lubricating oil. Compared with the base oil, the 0.8 wt% nano-CeO2/1.0 wt% BNH2 composite additive reduced the coefficient of friction by 55.9% and the diameter of the abrasive spot by 48%. Physicochemical analysis of the wear surface revealed that the combination of nano-CeO2and BNH2 had excellent synergistic effects. The generated lubricant films of nano-CeO2/BNH2 contained a chemical reactive layer of organic nitride (C–N), Fe2O3, FeO, and B2O3and a physical adsorbent layer of CeO2that provided great friction reduction and anti-wear effects during friction.
研究领域:
材料科学
·
机械工程
·
表面工程
✓ 已验证
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2022
·
IF 8.129
Yiling Wan,Kuan Ding,Jason Chun-Ho Lam,Daoxu Zhong,Shu Zhang
Catalytic pyrolysis of biomass over CeO 2 to prepare ketonic chemicals is an important way to achieve carbon emission reduction, whereas the role of catalyst structure has long been overlooked. In this work, nano-CeO 2 with different crystal shapes, namely nanorods (R-CeO 2 ), nano-polyhedra (P-CeO 2 ), and nanocubes (C-CeO 2 ), were synthesized and then tested in catalytic ketonization of xylan . Results showed that among all the three catalysts, C-CeO 2 produced the highest yield of ketones . Characterization results revealed that C-CeO 2 presented the lowest content of oxygen vacancies while exhibiting the highest proportion of {100} facets, proving that the {100} facets made a greater contribution to the total yield of ketones . On the other hand, P-CeO 2 and R-CeO 2 displayed a better selectivity to linear ketones, which was beneficial to improving the product quality. The relative contents of {111} facets of these catalysts were higher than C-CeO 2 , demonstrating that the {111} facets could selectively produce linear ketones. The proposed mechanism indicated that P-CeO 2 and R-CeO 2 principally enhanced the ketonic deoxygenation reactions, while C-CeO 2 also promoted the recyclization reaction, producing more cyclic ketones . These findings disclose that the {111} facets of CeO 2 are more favorable to producing valuable linear ketones.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
FLUID PHASE EQUILIBRIA
·
2020
·
IF 2.838
Zixiang Cui,Jiaojiao Chen,Yongqiang Xue,Junzhen Gan,Xinghui Chen,Huijuan Duan,Rong Zhang,Jiayi Liu,Jie Hao
The surface tension and surface thermodynamic properties play a decisive role in research and applications of nano materials , but they are difficult to be determined, as there is no precise method to measure these properties of nano materials. Herein, we derived the relations between the molar surface thermodynamic functions, surface heat capacity , and particle size. On this basis, a new low-temperature heat capacity method for determining the surface tension and the surface thermodynamic functions of nano materials was proposed. We measured the low temperature heat capacities of nano-CeO 2 and bulk CeO 2 in temperature range from 1.9 K to 300 K at constant pressure by the Physical Property Measurement System (PPMS). The surface tensions and corresponding temperature coefficients of nano-CeO 2 were calculated at different temperatures, and then the surface thermodynamic functions were obtained. The results show that the molar heat capacities of nano-CeO 2 are greater than that of the corresponding bulk CeO 2 in temperature range from 1.9 K to 300 K. The molar surface enthalpy and molar surface entropy of nano-CeO 2 increase with the increase of temperature, while surface tension, temperature coefficient, and molar surface Gibbs energy decrease with the increase of temperature. The proposed low temperature heat capacity method can not only accurately measure surface tension, temperature coefficient, and surface thermodynamic functions of nanoparticles at different temperatures, it also provides a reliable and an accurate experimental method for solving the thermodynamic problems of nanoparticles.
研究领域:
材料科学
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热力学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
·
2023
·
IF 6.1
Chuan Li,Xinxin Wang,Qiangqiang Zhang,Xu Tan,Yefeng Liu,Honglin Li,Hao Liu,Enzhu Hu,Xianguo Hu
This study fabricated nano-CeO 2 /biodiesel carbon soot (BCS) composites using the raw material BCS, which is the byproduct of biodiesel combustion and cerium salt and used as a novel lubricant additive to PAO6 for steel/steel contact. Oleylamine modified nano-CeO 2 /BCS composites comprise abundant lipophilic groups, and thus nano-CeO 2 /BCS composites exhibit good dispersion in PAO6. The tribological results showed that nano-CeO 2 /BCS composites significantly improved the lubricating performances of PAO6. In case of 0.1 wt% nano-CeO 2 /BCS composites dispersed in PAO6, the friction coefficient and wear volume were reduced by 17.3 and 35.2%, respectively. The improved tribological properties were attributed to the composites rolling and forming of a lubricating film on the friction surface and the presence of BCS and CeO 2 in composites exerting a synergistic lubricating effect, which simultaneously improved the tribological properties of PAO6. This discovery contributes to the conversion of BCS into valuables and promotes the high value utilization of BCS as a lubricating additive.
研究领域:
材料科学
·
摩擦学
·
能源与环境
✓ 已验证
产品关联
DOI
高影响因子
Nanotechnology Reviews
·
2021
·Vol. 10
·期 1
·385-400
·
IF 7.848
Shengli Liang,Shuang Liu,Yi Zhang,Meng Zhou,Baohong Tian,Yongfeng Geng,Yong Liu,Yanlin Jia,Xu Li,Alex A. Volinsky
The graphene oxide (GO)-doped nano-CeO 2 was introduced into Cu30Cr10W electrical contact composites by ball milling dispersion, freeze-drying, and spark plasma sintering, resulting in excellent mechanical strength and high arc erosion resistance. The effects of GO and CeO 2 on the microstructure and properties of the composites were investigated. The arc erosion behavior was investigated by the JF04C electrical contact testing apparatus. Consequently, the uniform distribution of CeO 2 nanoparticles hinders the movement of dislocations, GO transformed into reduced graphene oxide (rGO) during high-temperature sintering, and the in situ formation of Cr 3 C 2 between trace carbon atoms and chromium particles at the C–Cu interface, which enhanced the interface combination. Compared with Cu30Cr10W composites, the tensile strength of the two composites was increased by 47 and 36% by importing GO and nano-CeO 2 , respectively. Finally, electrode material migrated from the cathode to the anode, and the rGO delayed the formation of pits and sharp bumps on the contact surface of the electrode and inhibited diffusion of molten metal; when compared with Cu30Cr10W, the GO/CeO 2 –Cu30Cr10W composites have better welding force.
Graphical abstract
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE
·
2021
·Vol. 30
·期 5
·3795-3805
·
IF 1.819
Mao Xisong,Xia Xuewen,Li Junqi,Chen Chaoyi,Zhang Junshan,Ning Deyang,Lan Yuan-Pei
Homogeneously rare-earth (RE=La, Sm and Y) ions doped CeO 2 nanoparticles (NPs) with enhanced photocatalytic performance were synthesized by a facile KOH-NaOH molten flux method. XRD, TEM, EDS mapping and XPS results demonstrate that RE cations have been successfully doped into the CeO 2 lattice, which leads to the lattice expansion/shrinking, and more oxygen vacancies are generated after RE ions doping. The UV-Vis DRS and PL spectra indicate that RE-doped CeO 2 samples have slightly narrower band gaps and significantly reduced photo-generated electron-hole recombination rates. 5% RE ions doped CeO 2 NPs show excellent photocatalytic performances and the photodegradation ratio of methylene blue (MB) increases from 71.63% of undoped CeO 2 to 76.35%, 77.51% and 77.37% for 5%-La, 5%-Sm and 5%-Y-doped CeO 2 NPs, respectively. The obviously reduced recombination rate of e − /h + pairs after RE ions doping may be the critical factor for the enhanced photocatalytic performance.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Yangkai Xiong,Zhiqiang Fang,Daxiong Hu,Hao Jiang,Lei Huang,Qitong Mao,Guoqing Wang,Jipeng Li,Zhenzhong Liu,Chunxin Ma
Although many antibiofouling materials have been developed based on either bacterial-killing or antiadhesion effects, the integration of both the effects in one material remains challenging for achieving highly enhanced synergistic antibiofouling. In this study, we have explored a nano-CeO2-loaded double-network hydrogel by introducing CeO2 nanorods into a polyzwitterionic hydrogel via a simple one-pot method for achieving highly efficient antifouling. First, the CeO2 nanorods dispersed in the hydrogel, as an outstanding nanozyme, have highly efficient bacterial-killing performance. Second, the superhydrophilic polyzwitterionic hydrogel provides a dense hydrated layer on the surface and subsequently excellent broad-spectrum antiadhesion behavior. Most importantly, the bacterial killing and antiadhesion of this hydrogel can work synergistically to largely improve the marine-antifouling performance. Moreover, the double-network structure of this hydrogel, including the covalently cross-linked polyzwitterion hard network and the physically cross-linked poly(vinyl alcohol) soft network, can provide greatly improved mechanical properties (2.44 MPa of tensile strength reaches and 21.87 MPa of compressive strength). As a result, among the existing marine-antifouling hydrogels, the CeO2-loaded polyzwitterionic double-network hydrogel can achieve outstanding antifouling performance, which can sustain for over 6 months in a real marine environment. This work provides a promising marine-antifouling hydrogel, which will also inspire antifouling research of a new strategy and materials.
研究领域:
材料科学
·
海洋生物学
·
生物医学工程
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BIOMACROMOLECULES
·
2023
·
IF 6.2
Jing Hu,Xin Liu,Qun Gao,Chunfa Ouyang,Kangsheng Zheng,Xiaoqian Shan
Chronic wounds are prone to produce excessive reactive oxygen species (ROS), which are the main reason for multiple bacterial infections and ulcers at the wound. Therefore, regulating ROS is the key in the process of wound healing. Herein, a new type of thermosensitive hydrogels is developed to improve the scavenging efficiency of ROS and accelerate wound repair. Nano-CeO2 was uniformly dispersed on the surface of mesoporous silica (MSN). The nanocomposite particles were physically crosslinked with poly(N-isopropylacrylamide) (PNIPAM) to form a MSN-CeO2@PNIPAM thermoresponsive hydrogel (PMCTH). The stability, temperature sensitivity, rheological properties, biocompatibility, and wound healing ability of the PMCTH were evaluated in detail. The results showed that the hydrogel could not only maintain the stability of the system for a long time with low biological toxicity but also have a phase transition temperature close to the human body temperature. In addition, the PMCTH was directly applied onto the skin surface. The MSN-CeO2 nanoparticles would be dispersed in the hydrogel to restrict ROS exacerbation effects and promoted the formation of blood vessels as well as surrounding tissues, accelerating the wound healing. More importantly, animal experiments showed that when the mass ratio of CeO2 to MSN was 40%, the wound healing rate reached up to 78% on the 10th day, which was far higher than that of other experimental groups. This study provides a new strategy and experimental basis for the applications of functional hydrogels in wound repair.
研究领域:
材料科学
·
生物医学工程
·
伤口愈合
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2024
·
IF 11.2
Haoyuan Zheng,Yuxiao Jia,Chen Jin,Hang Che,Chia-TseLee,Guang Liu,Li Wang,Yuyuan Zhao,Shixuan He,Haizhen Liu,Xinhua Wang,Yifeng Yu,Mi Yan
The magnesium based metal hydrogen storage composite system Mg(NH 2 ) 2 -2LiH has a theoretical hydrogen storage capacity of 5.6 wt.% and is a promising hydrogen storage material for vehicles. However, its application is limited due to serious thermodynamic and kinetic barriers. Introducing efficient catalysts is an effective method to improve the hydrogen storage performance of Mg(NH 2 ) 2 -2LiH. This article investigates for the first time the use of nano rare earth oxide CeO 2 (∼44.5 nm) as an efficient modifier, achieving comprehensive regulation of the hydrogen storage performance of Mg(NH 2 ) 2 -2LiH composite system through oxygen vacancy driven catalysis. The modification mechanism of nano CeO 2 is also systematically studied using density functional theory (DFT) calculations and experimental results. Research has shown that the comprehensive hydrogen storage performance of the Mg(NH 2 ) 2 -2LiH-5 wt.% CeO 2 composite system is optimal, with high hydrogen absorption and desorption kinetics and reversible performance. The initial hydrogen absorption and desorption temperatures of the composite system were significantly reduced from 110/130°C to 65/80°C, and the release of by-product ammonia was significantly inhibited. Under the conditions of 170°C/50 min and 180°C/100 min, 4.37 wt.% of hydrogen can be rapidly absorbed and released. After 10 cycles of hydrogen release, the hydrogen cycle retention rate increased from 85% to nearly 100%. Further mechanistic studies have shown that the nano CeO 2− x generated in situ during hydrogen evolution can effectively weaken the Mg–N and N–H bonds of Mg(NH 2 ) 2 , exhibiting good catalytic effects. Meanwhile, oxygen vacancies provide a fast pathway for the diffusion of hydrogen atoms in the composite system. In addition, nano CeO 2− x can effectively inhibit the polycrystalline transformation of the hydrogen evolving product Li 2 MgN 2 H 2 in the system at high temperatures, reducing the difficulty of re-hydrogenation of the system. This study provides an innovative perspective for the efficient modification of magnesium based metal hydrogen storage composite materials using rare earth based catalysts, and also provides a reference for regulating the comprehensive hydrogen storage performance of hydrogen storage materials using rare earth catalysts with oxygen vacancies.
研究领域:
材料科学
·
催化
·
氢气存储
·
纳米技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）