Materials Research Express
·
2019
·Vol. 6
·期 5
·056547
·
IF 1.449
Yinqun Hua,Bochen Jiang,Ruifang Chen,Jiangdong Cao,Wenwen Shuai,Ruitao Li
In this study, Gd2Zr2O7 -X TiSi2 (X = 0, 2.5, 5 and 7.5 wt% TiSi2) ceramics were synthesized by solid state reaction method at 1550 °C for 12 h in air. The influences of TiSi2 content on the phase, microstructure, thermophysical properties, hardness and fracture toughness were investigated. Gd2Zr2O7- X TiSi2 (X = 7.5 wt%) ceramic mainly consists of a defect fluorite phase; while Gd2Zr2O7 -X TiSi2 (X = 0, 2.5 and 5 wt% TiSi2) ceramics have an ordered pyrochlore phase. In addition, the degree of structural order decreased with the increasing TiSi2 content. The microstructure of the doped ceramic materials exhibited grain refinement. The doping of TiSi2 decreased the thermal conductivity while improved the thermal expansion coefficient, the hardness and the fracture toughness enhanced significantly. With these improved properties, the TiSi2 doped Gd2Zr2O7 ceramic materials can be a very promising material for ceramic layers of thermal barrier coating.
研究领域:
材料科学
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热障涂层研究
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产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Yan-Chan Wei,Gui-Xiang Liu,Ling Zhang,Wen-Zhe Xu,Shuangquan Liao,Ming-Chao Luo
Mechanical strength and toughness are usually mutually exclusive, but they can both appear in natural rubber (NR). Previous studies ascribe such excellent properties to highly cis stereoregularity of NR. To our surprise, after the removal of non-rubber components (NRC) by centrifugation, the strength and toughness of NR decrease dramatically. It is still a challenge for us to make out for the problem of how NRC affect the properties of NR. Our group ascribes the superior mechanical robustness of NR to NRC. To further verify such a viewpoint, we add phospholipids (phosphatidylcholines) into NR without NRC. Phosphatidylcholines construct a sacrificial network, which ruptures preferentially upon deformation to dissipate energy. Moreover, some of phosphatidylcholines participate in the vulcanization reaction, which further improves the mechanical strength and energy dissipation. As a result, the mechanical strength and toughness of samples are as high as 21.1 MPa and 49.6 kJ/m2, respectively, which have reached the same level as that of NR. Therefore, this work not only imitates the excellent mechanical robustness of NR but also further provides a rational design for elastomers with excellent mechanical robustness.
研究领域:
材料科学
·
高分子化学
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DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·Vol. 141
·期 27
·e55617
·
IF 2.7
Luze Wang,Boyu Cai,Wendi Xu,Zhonglin Luo,Biaobing Wang
Currently, the flame retardancy of epoxy resin (EP) was achieved at the expenses of the transparency and/or toughness. In the present work, a phosphorus/nitrogen-containing compound (FDNP) was synthesized by one-pot method using 9,10-dihydro-9-oxa-10-phospha-phenanthrene-10-oxide, furfural and N-phenyl-p-phenylenediamine as raw materials, and further adopted as a functional agent for epoxy resin. The results demonstrated that the FDNP remarkably improved the fire safety of EP. The incorporation of 4 wt% FDNP enabled EP to pass UL-94 V-0 rating test and achieve a limiting oxygen index value of 35.5%; meanwhile, the peak heat release rate, total heat release rate and total smoke release were significantly reduced by 41.3%, 41.6% and 72.5% as compared with the pure EP, respectively. What is more, the EP/4 wt% FDNP composite kept almost the same transparency of the pure EP, simultaneously its impact strength was more than doubled as that of the pure EP. Herein, the improved flame retardancy is contributed to a synergistic biphasic flame retardant effect including the formation of a compact protective carbon layer and the release of both non-combustible gases and phosphorus-containing radicals.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
Soft Matter
·
2018
·Vol. 14
·期 28
·5888-5897
·
IF 3.709
Si Yu Zheng,Ye Tian,Xin Ning Zhang,Miao Du,Yihu Song,Zi Liang Wu,Qiang Zheng
Hydrogel films have promising applications in medical dressings, flexible electronics, etc. However, it is challenging to fabricate ultrathin hydrogel films with high toughness and controllable thickness. Here, we report a facile approach to prepare tough physical hydrogel films by spin-coating of a poly(acrylic acid-co-acrylamide) (P(AAc-co-AAm)) solution and subsequent gelation in FeCl3 solution to form carboxyl–Fe3+ coordination complexes. The thickness of the obtained gel films, ranging from several to hundreds of micrometers, was easily tunable by adjusting the spin conditions and polymer concentration. The thus obtained hydrogel films showed excellent mechanical properties, with tensile breaking strengths of 0.6–14.5 MPa, breaking strains of 140–840%, Young's moduli of 0.1–61.7 MPa, and tearing fracture energies of 300–1300 J m−2. Based on this approach, responsive tough hydrogel films can also be prepared by spin-coating of a poly(acrylic acid-co-N-isopropylacrylamide) (P(AAc-co-NIPAm)) solution. The obtained gel films showed a fast response (<60 s) and a large output force (∼0.2 MPa) triggered by a concentrated saline solution, making them an ideal material in the design of chemomechanical devices. Furthermore, a bilayer hydrogel film was fabricated by two-step spin-coating of P(AAc-co-NIPAm) and P(AAc-co-AAm) solutions, which showed reversible bending deformation under external stimuli. This simple yet effective approach should be applicable to other systems to prepare versatile hydrogel films with tunable thickness and promising applications in diverse areas.
研究领域:
材料科学
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生物医学工程
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Kejia Kang,Rong Tu,Guoqiang Luo,Jian Zhang,Jiawen Zhu,Qiang Shen,Lianmeng Zhang
In this study, Re alloying and self-generated hard phase enhancement were used to improve the strength and toughness of W. The arc-melting W-based composite with 10 wt% Re and 1 wt% SiC addition is composed of toughening W-Re matrix and ceramic particles (W 2 C and W 5 Si 3 ). This composite having high strain capacity (37.1%) at room temperature (more than 5 times of W), exhibits the excellent hardness (5.04 GPa), yield strength (0.92 GPa) and fracture strength (1.78 GPa) due to the synergetic mechanism, grain refinement, and good interfaces bonding state. The synergetic mechanism of Re and SiC addition on strength and toughness was proposed.
研究领域:
材料科学
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力学
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DOI
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 14
·7645-7651
·
IF 3.049
Xin Wang,Min Xue,Songbai Liu,Kuo Jiang,Zhuli Zhang
Herein, powders composed of La2Zr2O7 (LZ) and ZrO2 phases were synthesized by an in situ reaction using a sol-spray pyrolysis method; moreover, 24 mol% LaO1.5–ZrO2 (volume ratio = 1 : 1) powders were characterized by XRD, Raman spectroscopy, SEM, and TEM. XRD and Raman results showed that the samples maintained a tetragonal ZrO2 and a pyrochlore LZ phase from 900 to 1100 °C. The addition of LZ could be helpful in the stabilization of t-ZrO2 and decreasing the grain size of ZrO2. The SEM results revealed that the LZ and ZrO2 phases were homogeneously distributed in the sintered bulk. The HRTEM results suggested that the crystal orientations of the nano-LZ and nano-ZrO2 phases were accordant; this was in agreement with the characteristics of the coherent boundaries. The fracture toughness of LZ–ZrO2 was markedly improved by the transformation toughening of the ZrO2 phase, and a value that was 2.2-fold that of the LZ prepared by a similar technique was achieved.
研究领域:
材料科学
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陶瓷学
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DOI
PubMed
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 53
·42362-42368
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IF 3.84
Zhengguang Heng,Yang Chen,Huawei Zou,Mei Liang
A PEG-b-CTBN diblock copolymer was synthesized via the esterification reaction of hydroxy terminated methoxypolyethylene glycols (PEG) in the presence of a carboxyl-terminated butadiene-co-acrylonitrile copolymer (CTBN) with 4-dimethylaminopyridine (DMAP) as the catalyst. Epoxy thermosets were modified via the formation of a nanostructure. The result of transmission electronic microscopy (TEM) shows spherical domains were homogeneously dispersed into the continuous epoxy matrix and the size is nano-scale. It was noted that the glass transition temperatures decreased with an increase in the content of PEG-b-CTBN, which was evidenced by Dynamic Mechanical Analysis (DMA) and a Differential Scanning Calorimeter (DSC). Through mechanical tests, we found the tensile strength and fracture toughness of epoxy resins were simultaneously enhanced by nanostructured PEG-b-CTBN.
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
COMPOSITES COMMUNICATIONS
·
2017
·
IF 0
Yiqi Sun,Shuai Sun,Lei Chen,Lina Liu,Pingan Song,Wei Li,Youming Yu,Lu Fengzhu,Jun Qian,Hao Wang
Although the flammability of biodegradable poly(lactic acid) (PLA) has been effectively addressed so far, the resultant flame retardant PLA still displays a high brittleness , extremely restricting its wide applications in electrical, automobile and aerospace fields. In this work, we have demonstrated the fabrication of flame retardant and tough PLA composites by combining ammonia polyphosphate (APP) and poly(ethylene glycol) (PEG) with a molecular weight of 20,000 via the melt-blending strategy. The results show that the peak heat release rate of PLA can reduce by 14% in cone tests and a V-0 rating is achieved in vertical burning tests by adding 7 wt% of APP and 14 wt% PEG. Moreover, such PLA composite shows a high strain at break of 280% and impact strength of 14.9 kJ/m 2 , respectively increasing by thirty-eight-fold and two-fold relative to the PLA bulk. The results strongly indicate that flammability and brittleness of the PLA are strikingly reduced. This work provides an integrated strategy for creating advanced green polymer composites with exceptional flame resistance and toughness.
研究领域:
材料科学
·
生物材料
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产品关联
DOI
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2022
·
IF 9.965
Xia Zhou,Fukai Chu,Zhoumei Xu,Shuilai Qiu,Yuan Hu
Aiming at enhancing the toughness and fire safety of bismaleimide (BMI), BMI monomers containing phosphate and phosphonate structure (BDTP and BDTDP) were designed and prepared. With incorporation of 5 wt% BDTP and BDTDP, the peak value of heat release rate (PHRR) of BMI/BDTP-5 and BMI/BDTDP-5 decrease by 59.4% and 52.4%, respectively. The total smoke production (TSP) of BMI/BDTP-5 and BMI/BDTDP-5 are of 8.3% and 13.1% reduction, respectively. Meanwhile, BMI/BDTP-5 and BMI/BDTDP-5 possess UL-94V-0 rating, which indicates that BMI is endowed with better flame retardant performance by modification of designed BMI monomers. Besides, the impact strength of BMI/BDTP-5 and BMI/BDTDP-5 increase by 146.3% and 90.2%, respectively. The comprehensive performance of BMI/BDTP-5 is better than that of BMI/BDTDP-5. And the effect of phenyl phosphate structure in BDTP and phenyl phosphonate structure in BDTDP on BMI performance is explored.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER
·
2022
·
IF 4.432
Ning Zhang,Zhicheng Pan,Chao Li,Juan Wang,Yao Jin,Shaofeng Song,Mingwang Pan,Jinfeng Yuan
Self-repairing materials with damage self-healing ability have attracted much attention because of their potentials to improve the reliability, durability, and life of materials. However, its poor self-repair performance in the ambient environment still faces the challenge for waterborne polyurethane (WPU) broad range of applications. In this work, to break through the limitation of chain stiffness and improve the self-healing ability, we choose glycylglycine methyl ester as a functional end-capping reagent to seal the WPU chain (WPUG) and provide triple intermolecular hydrogen bonds . It is found that the chain-end triple hydrogen bonds act a unique role in WPUG, which can serve as a "bridge" to connect soft segments, endowing the molecular chain with more flexibility and fluidity . As a result, the self-healing efficiency of WPUG in the surrounding environment can reach 91.5% within a short time. This work suggests a new point of view on the role and interaction mechanism of chain-end hydrogen bonding in WPUs.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Research and Technology-JMR&T
·
2021
·
IF 5.039
Xiayun Zhang,Ting-Ting Li,Yuxiao Wang,Bing-Chiuan Shiu,Hao-Kai Peng,Ching-Wen Lou,Jia-Horng Lin
In order to prepare a new high-performance and flexibility stab-resistant composite material, one type of high-toughness and high-strength hydrogel is combined with aramid fabric. In this paper, the nanocomposite (NC) hydrogels are prepared using Pluronic F127 Diacrylate (PF127DA) as the crosslinking agent, acrylamide as the monomer and nano-silica as nano additive. The influence of the addition amount of nano-silica on the toughness and strength of nano-composite hydrogels is discussed. The strength and toughness of the NC hydrogels with nano silica are higher than that of the acrylamide hydrogel without nano particles. The NC hydrogel with the best strength is made as a composite with aramid fabric and the effect of nanocomposite hydrogel on the stab resistance of the stab-resistant composite material is studied. The research shows that the stab resistance performance of the composite material prepared by aramid fabric and nanocomposite hydrogel is effectively improved in comparison with aramid fabric, and the yarn pulling force is also improved. The composite material with high stab resistance can be used as the stab-resistant layer of armor, cut-resistant gloves and stab-resistant base material of shoes. This work provided a possibility for preparing a kind of lightweight composite material with high stab resistance.
研究领域:
材料科学
·
复合材料
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产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2023
·Vol. 11
·期 24
·12735-12745
·
IF 11.9
Nana Xu,Xiaoshan Zhang,Haiyan Liu,Hui Xu,Shuang Wu,Bing Wang,Yingde Wang
Oxide ceramic fibers with softness and toughness are key materials in emerging fields like wearable devices and membrane technologies. However, the brittle failure of oxide ceramic fibers after thermal cycling leads to the loss of membrane architectures, which limits their long-term applications at high temperature. Here, we report a scalable approach of sol–gel electrospinning to synthesize a flexible and tough pyrochlore La1.85Al0.15Zr2O7 (L5AZO) nanofiber membrane (NFM) involving self-assembled 3D networks. The interactions between the nanoscale constituents lead to the assembled networks with high nodal connectivity and strong crosslinking between nanofibers, which may promote an enhancement of macroscopic mechanical properties by orders of magnitude. Ultrasonic dispersion and an amorphous secondary phase drive the formation of numerous L5AZO nuclei and soft grain boundaries, thus effectively refining grains and inhibiting crystallite growth. Indeed, the L5AZO NFM achieves both a high specific tensile modulus of ∼11.4 MPa cm3 g−1 and fracture toughness of ∼1032 J m−2, as well as high-temperature resistance above 1100 °C, which are advantageous for diverse structural applications. Furthermore, the simple processing technique of the NFM allows it to be fabricated into various functional devices, such as aerogels, thermal camouflage, and filtration membranes at high temperature. The mechanistic insights and manufacturability provided by this flexible and tough oxide NFM may create further opportunities for materials design and technological innovation.
研究领域:
材料科学
·
纳米技术
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）