Composites Part C: Open Access
·
2021
·
IF 0
Anthony Chun Yin Yuen,Timothy Bo Yuan Chen,Bo Lin,Wei Yang,Imrana I. Kabir,Ivan Miguel De Cachinho Cordeiro,Andrew E. Whitten,Jitendra Mata,Bin Yu,Hong-Dian Lu,Guan Heng Yeoh
MXene is a class of 2D materials exfoliated from ternary carbide and nitride ceramics. During synthesis, etching and delamination conditions affect the quality, overall crystallinity, defects and surface functionalization of MXene flakes. In this article, the morphological structure of MXene (Ti 3 C 2 ) nanosheets under temperature between 20 °C and 60 °C were investigated with the application of Small-Angle Neutron Scattering (SANS) combined with several complementary techniques, such as Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) and X-ray Photoelectron Spectroscopy (XPS). The SANS analysis enabled structural information to be obtained about the Ti 3 C 2 nanosheets, which consists of layers of transition metal carbides in a multilayer lamella morphology. The results showed that a single Ti 3 C 2 layer is approximately 11.4 – 11.8 Å (1.14 – 1.18 nm) in thickness with a 20.3 – 21.5 Å (2.03 – 2.15 nm) interstacking layer gaps. This results in a total thickness of approximately 32 Å (3.2 nm), which was consistent with the model-dependent lamella model analysis. Furthermore, the thickness of the Ti 3 C 2 layer increased by approximately ~2 Å (0.2 nm) when the temperature increased from 20 - 40 to 50 - 60 °C.
研究领域:
材料科学
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纳米技术
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物理化学
✓ 已验证
产品关联
DOI
Surfaces and Interfaces
·
2023
·
IF 6.2
Li-Zhao Huang,Chao-Wen Yang,Kun Song,Ting-Ting Yang,Jia-Zhuang Xu,Guang-Ai Sun,Zhong-Ming Li,Dong Liu
The effects of various fillers on the hierarchical structures and reinforcement of silica filled silicone rubbers were investigated using contrast matching small-angle neutron scattering (SANS) and low-field nuclear magnetic resonance (NMR). Raw (R), modified (M), and grafted (G) surface were designed on colloidal silica particles with sizes of 20 and 80 nm. The reinforcement effects of colloidal silica on silicone rubber were compared with those of industrial (fumed and precipitated) silica. The power-law decay d f,agg of fumed and precipitated filler aggregate were 2.6 and 2.4, respectively, suggesting that the fractal aggregates determined the formation of a connective filler network. The bound rubber (BR) thickness measured via CM-SANS were 8.2, 7.9, and 7.9 nm for 20 nm colloidal silica with G, M, and R surfaces, respectively. NMR results indicated that grafting could promote BR formation, resulting in the highest modulus (3.4 MPa) among those of analyzed samples. All samples had similar D res /2π values (close to 210 Hz) but different σ/ D res values, implying that the aggregate influenced the crosslinking distribution rather than the crosslinking density. Combined with the hierarchical structures and mechanical properties , the synergistic effects of the aggregate and BR networks on the reinforcing performance of silica-filled silicone rubbers have been discussed.
研究领域:
材料科学
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高分子化学
✓ 已验证
产品关联
DOI
高影响因子
Nature Communications
·
2022
·Vol. 13
·期 1
·1-9
·
IF 17.694
Ren Qingyong,Qi Ji,Yu Dehong,Zhang Zhe,Song Ruiqi,Song Wenli,Yuan Bao,Wang Tianhao,Ren Weijun,Zhang Zhidong,Tong Xin,Li Bing
One of the greatest obstacles to the real application of solid-state refrigeration is the huge driving fields. Here, we report a giant barocaloric effect in inorganic NH 4 I with reversible entropy changes of \(\Delta {S}_{{P}_{0}\to P}^{{{\max }}}\) ∼ 71 J K −1 kg −1 around room temperature, associated with a structural phase transition. The phase transition temperature, T t , varies dramatically with pressure at a rate of d T t /d P ∼ 0.79 K MPa −1 , which leads to a very small saturation driving pressure of Δ P ∼ 40 MPa, an extremely large barocaloric strength of \(\left|\Delta {S}_{{P}_{0}\to P}^{{{\max }}}/\Delta P\right|\) ∼ 1.78 J K −1 kg −1 MPa −1 , as well as a broad temperature span of ∼ 41 K under 80 MPa. Comprehensive characterizations of the crystal structures and atomic dynamics by neutron scattering reveal that a strong reorientation-vibration coupling is responsible for the large pressure sensitivity of T t . This work is expected to advance the practical application of barocaloric refrigeration.
研究领域:
材料科学
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热力学
·
制冷工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials Today Physics
·
2022
·
IF 11.021
Wan Ting Dai,Zhen Hua Xie,Yu Bin Ke,Yang You,Min Zhi Rong,Ming Qiu Zhang,Chun Yong He,Han Qiu Jiang,Hua Yang
To understand the molecular origin of the significantly improved mechanical properties of the newly emerged reversibly interlocked polymer networks (ILNs), which are composed of two dynamically crosslinked polymers regardless of their miscibility, the present work employs small angle neutron scattering (SANS) technique to study the microstructural evolution of the materials during stretching. Accordingly, polyacrylate networks containing reversible Diels-Alder (DA) bonds and polyether networks containing reversible Schiff base bonds are synthesized and then interlocked together through topological rearrangement of the two single networks. By using deuterated acrylate monomers , furthermore, the single networks with DA bonds are labeled, providing the model ILNs with necessary contrast for the SANS measurements. The strain-dependent SANS profiles and 2D SANS patterns of the ILNs reveal that the latter maintain the homogeneity after extension. It means that the two parent single networks are simultaneously deformed because the interlocking sites act as movable crosslinkages, so that the chains conformation can be modulated and the applied stress can be effectively transferred. When relative movement of the neighboring molecular chains occurs, a great number of molecular chains in the interlocked polymer networks are able to be tightened at the same time, and more mechanical energy can be dissipated by internal friction in the process. The findings reveal that the mechanical enhancement results from the unique interlocked structure, and provide guidance for the rational design of high-performance multi-component polymer materials.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
MACROMOLECULES
·
2025
·
IF 5.2
Wan Ting Dai,Zhen Hua Xie,Yu Bin Ke,Yang You,Ze Ping Zhang,Min Zhi Rong,Ming Qiu Zhang
Reversibly interlocked polymer networks (RILNs) have emerged as a versatile platform technology for the development of advanced functional materials. This is achieved by integrating two chemically independent subnetworks through supposition and cooperation principles. However, their physical image and the structure–property relationships remain unclear due to the undisclosed distribution of the subnetworks. In this study, a specially designed RILN system is synthesized, where the two component subnetworks exhibit distinct microstructures in their single network states. Moreover, one subnetwork is labeled with deuterons. The microstructures of the subnetworks in the interlocked state are examined using small-angle neutron scattering experiments based on the contrast-matching method. The deuterated subnetwork, which is homogeneous prior to interlocking, displays a heterogeneous microstructure in the RILNs like the nondeuterated subnetwork. Conversely, the nondeuterated subnetwork, which exhibits segmental aggregation before joining the RILNs, becomes homogenized in the interlocked state. These findings demonstrate the convergence of microstructures of the subnetworks, contributing to a better understanding of the physical image of the RILNs and enhancing our comprehension of their structure–property relationships.
研究领域:
材料科学
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高分子化学
✓ 已验证
产品关联
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2017
·
IF 3.531
Dong Liu,Xueyu Li,Hongtao Song,Pucheng Wang,Jie Chen,Qiang Tian,Liangwei Sun,Liang Chen,Bo Chen,Jian Gong,Guangai Sun
Combining neutron and X-ray scattering (SANS, SAXS, and WAXD) as the contrast matching probes, the hierarchical structures of the multi-wall carbon nanotubes/high density polyethylene (MWCNTs/HDPE) composites (0.1–2.0 wt%) have been studied. SANS measurement avoided the correlation peak associated to the semicrystalline nature of HDPE from SAXS, and the passible scattering from the stretch induced voids. Benefitting from SANS data, the power law ( α ) taking the flexible cylinder suggested that whole MWCNTs in the unstretched composites follow a self-avoiding random walk ( α ≈ 1.67). SANS data suggest a hollow flexible cylinder structure with outer and inner diameters (core-shell-like cross section) of the scatterers as ca. 12.6 nm and 4.1 nm, while the Kuhn length is about 43.0 nm. Tensile test displayed improved mechanical properties. Interestingly, the Hermans orientation parameter ( f ) of HDPE crystals ( f c ) in the stretched composites are around a plateau ca. 0.96 initially, while decreased remarkably to 0.776 when the fraction is further increased to 2.0 wt%. f obtained by SANS showed a similar tendency (decreased from 0.756 to 0.572). Combining all the results along with differential scanning calorimetry (DSC) measurement, a mechanism of adhered crystals on the surface of MWCNTs and a reinforcement model are proposed.
研究领域:
高分子材料科学
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纳米复合材料
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结构表征
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中子散射技术
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X射线散射技术
✓ 已验证
DOI
高影响因子
The Innovation
·
2025
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IF 25.7
Jieming Sheng,Le Wang,Wenrui Jiang,Han Ge,Nan Zhao,Tiantian Li,Maiko Kofu,Dehong Yu,Wei Zhu,Jia-Wei Mei,Zhentao Wang,Liusuo Wu
Spin excitation continua observed in neutron scattering studies are often considered to be strong evidence of quantum spin liquid formation. In a disorder-free magnetic compound with a quantum spin liquid ground state, the elementary excitation is no longer the conventional spin waves (magnons). Instead, the magnons fractionalize into spinons, producing a characteristic two-spinon continuum. However, it remained uncertain whether a clean, ordered antiferromagnet could exhibit a continuous spectrum similar to that of a quantum spin liquid. This paper presents evidence of a spin excitation continuum in the magnetically ordered state of Na 2 BaCo(PO 4 ) 2 , where free spinons are absent. This challenges the interpretation of such a continuum as a definitive signature of a quantum spin liquid in new material studies.
研究领域:
凝聚态物理
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量子磁性
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中子散射谱学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Physical Chemistry Letters
·
2023
·
IF 5.7
Zhuanfang Jing,Yongquan Zhou,Toshio Yamaguchi,Koji Yoshida,Kazutaka Ikeda,Koji Ohara,Guangguo Wang
Ion hydration in aqueous solutions plays a paramount role in many fields. Despite many studies on ion hydration, the nature of ion hydration is not consistently understood at the molecular level. Combining neutron scattering (NS), wide-angle X-ray scattering (WAXS), and molecular dynamics (MD), we quantify the ionic hydration degree (hydration ability) systematically for a series of alkali metal and halide ions based on static and dynamic hydration numbers. The former is based on the orientational correlation of water molecules bound to an ion derived from the positional information from NS and WAXS. The latter is defined as the mean number of water molecules remaining in the first coordination shell of an ion over a residence time of bound water molecules around the ion from MD. The static and dynamic hydration numbers distinguish hydration from coordination and quantify the ionic hydration degree, which provides a valuable reference for understanding various phenomena in nature.
研究领域:
物理化学
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化学物理
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溶液化学
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分子模拟
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材料科学
✓ 已验证
DOI
高影响因子
POLYMER
·
2022
·
IF 4.432
Xiaoxue Wu,Tiantian Song,Zizhen Wei,Lei Shen,Hanqiu Jiang,Yubin Ke,Chunyong He,Hua Yang,Weichao Shi
Studies on phase behavior of polymer blends with lithium salts can provide a theoretical basis for developing solid polymer electrolytes in lithium-ion battery. In this paper, the liquid-liquid phase separation of PEO/PS/LiTFSI system is characterized by small angle neutron scattering (SANS) and small angle laser light scattering (SALLS). A combination of the Debye-Bueche equation and Ornstein-Zernike scattering function is employed to fit the SANS data in the homogeneous state. The thermodynamic parameters , including the forward scattering intensity I 0 , correlation length ξ , spinodal temperature T s , effective interaction parameter χ eff and cloud point boundaries, are obtained. The cloud point temperatures increase with LiTFSI concentration, especially at the low PEO fractions. We conclude that even a small amount of lithium salt enhances the liquid-liquid phase separation of PEO/PS blends significantly, and the effect of electrostatic interaction increases with temperature.
研究领域:
材料科学
·
电化学
·
聚合物科学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2023
·
IF 9.9
Binghui Xue,Yuyan Lai,Yuan Liu,Mu Li,Xinpei Li,Panchao Yin
Nano-ions can complex with polyelectrolytes for coacervates with hierarchical structures; however, the rational design of functional coacervations is still rare due to the poor understanding of their structure–property relationship from their complex interaction. Herein, 1 nm anionic metal oxide clusters, PW 12 O 40 3- , with well-defined, mono-disperse structures are applied to complex with cationic polyelectrolyte and the system shows tunable coacervation via the alternation of counterions (H + and Na + ) of PW 12 O 40 3- . Suggested from Fourier transform infrared spectroscopy (FT-IR) and isothermal titration studies, the interaction between PW 12 O 40 3- and cationic polyelectrolytes can be modulated by the bridging effect of counterions via hydrogen bonding or ion–dipole interaction to carbonyl groups of polyelectrolytes. The condensed structures of the complexed coacervates are explored by small angle X-ray and neutron scattering techniques, respectively. The coacervate with H + as counterions shows both crystallized and discrete PW 12 O 40 3- clusters, with a loose polymer-cluster network in comparison to the system of Na + which shows a dense packing structure with aggregated nano-ions filling the meshes of polyelectrolyte networks. The bridging effect of counterions helps understand the super-chaotropic effect observed in nano-ion system and provides avenues for the design of metal oxide cluster-based functional coacervates.
研究领域:
材料科学
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化学
·
胶体科学
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纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nature Communications
·
2024
·Vol. 15
·期 1
·1-11
·
IF 14.7
Zhu Jinfeng,Ren Qingyong,Chen Chen,Wang Chen,Shu Mingfang,He Miao,Zhang Cuiping,Le Manh Duc,Torri Shuki,Wang Chin-Wei,Wang Jianli,Cheng Zhenxiang,Li Lisi,Wang Guohua,Jiang Yuxuan,Wu Mingzai,Qu Zhe,Tong Xin,Chen Yue,Zhang Qian,Ma Jie
While phonon anharmonicity affects lattice thermal conductivity intrinsically and is difficult to be modified, controllable lattice defects routinely function only by scattering phonons extrinsically. Here, through a comprehensive study of crystal structure and lattice dynamics of Zintl-type Sr(Cu,Ag,Zn)Sb thermoelectric compounds using neutron scattering techniques and theoretical simulations, we show that the role of vacancies in suppressing lattice thermal conductivity could extend beyond defect scattering. The vacancies in Sr 2 ZnSb 2 significantly enhance lattice anharmonicity, causing a giant softening and broadening of the entire phonon spectrum and, together with defect scattering, leading to a ~ 86% decrease in the maximum lattice thermal conductivity compared to SrCuSb. We show that this huge lattice change arises from charge density reconstruction, which undermines both interlayer and intralayer atomic bonding strength in the hierarchical structure. These microscopic insights demonstrate a promise of artificially tailoring phonon anharmonicity through lattice defect engineering to manipulate lattice thermal conductivity in the design of energy conversion materials.
研究领域:
材料科学
·
热电材料
·
凝聚态物理
✓ 已验证
DOI
高影响因子
POLYMER TESTING
·
2017
·
IF 2.464
Dong Liu,Chengsha Wei,Guanyun Yan,Guangai Sun
A series of well-defined double hydrophilic block copolymers Poly ( N -isopropylacrylamide)- b -poly (2-vinylpyridine) (PNIPAM 38 - b -P2VP 43 ) were synthesized. The ‘schizophrenic’ behavior and the aggregation process of PNIPAM- b -P2VP in response to temperature and pH in dilute aqueous solution were tested via transmittance measurements, dynamic light scattering (DLS), and small-angle neutron scattering (SANS). The results revealed that: i) both PNIPAM-core and P2VP-core micelles can be induced from an intermediate unimers state via the adjustment of temperature and pH; ii) The lower critical solution temperature (LCST) of PNIPAM homopolymers is narrowly in the range of 31–34 °C, while PNIPAM- b -P2VP diblock copolymers at pH = 7 and 2 have broad LCSTs of 25–40 °C and 41-50 °C, respectively; iii) SANS results show that only the PNIPAM- b -P2VP solution at pH = 7 and 50 °C (both blocks are hydrophobic) has a sphere form factor with diameter of about 110 nm.
研究领域:
高分子化学
·
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）