ACTA MATERIALIA
·
2023
·
IF 9.4
Yifei Peng,Guohu Luo,Yongxiang Hu,Ding-Bang Xiong
The plastic deformation of metals is usually sensitive to loading rates, and such rate-dependent behaviors are influenced by various factors, among which inclusions especially nanoinclusions such as graphene and carbon nanotubes were found to have dramatic influence on the deformation mechanisms of metallic materials. However, relative studies are basically focused in quasi-static regimes. Here, the full spectrum of deformation behaviors of graphene/copper (Gr/Cu) submicro-laminated composites at wide-range strain rates (from 10 −4 /s to ≥10 8 /s) and various temperatures (room temperature and -70 °C) are provided, and relevant mechanisms, especially when deformed at high strain rates and low temperatures, are studied elaborately. Unlike conventional copper materials whose strain rate sensitivity drops dramatically (∼50%) with decreasing temperature, Gr/Cu submicro-laminates has an enhanced strain rate sensitivity that decreases limitedly (∼10%) with temperature. Microstructural analysis revealed that a graphene-assisted deformation mechanism dominated the dynamic compression of Gr/Cu composites, where graphene inclusions act as lubricants that enhanced the deformation ability of the submicro-laminates. Further analysis on copper matrix revealed that dislocation dominated deformation switch to twinning dominated deformation from high to extreme strain rates loading, and extreme loading conditions as well as graphene inclusions are prerequisites for high-density deformation twins in Gr/Cu submicro-laminates.
研究领域:
材料科学
·
力学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2021
·
IF 4.311
Guanqiu Wang,Chunying Zhu,Taotao Fu,Youguang Ma
In many applications of microdroplets, the high monodispersity of the product is usually an essential requirement, the appearance of undesired satellite droplets needs to be avoided. In this study, the deformation of droplets and the formation of tail satellite droplets in microchannel were investigated experimentally, and the process mechanism was also explored. Three flow regimes of moving droplets were observed: (1) droplet with convex cap; (2) droplet with tip; (3) droplet with satellite. It was found that the rear cap of the droplet was more prone to deformation. The shearing force on the droplet becomes strengthened with the increase of the superficial velocity of the droplet, the flow rate ratio of two phases or the viscosity of the continuous phase, which facilitates the formation of tail satellite droplets. The critical criterion for formation of tail satellite droplets was proposed, which is at good agreement with the experiment result.
研究领域:
微流体学
·
流体力学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
·
2021
·
IF 5.234
Cheng Zhang,Jilai Xue,Xuan Liu,Haipeng Li,Zengjie Wang,Xiang Li,Ying Liu
The deformation and structure stability of graphite cathodes are of importance for its service lifetime. The time dependence and coupling of deformation, elastoplastic property change and microstructure evolution of graphite cathodes were investigated under constant pressure at 940 °C. The deformations from early expansion transiting to the rapid and latter steady creep were found with increased hardness and modulus, in parallel with decreasing interplanar spacing of graphite (002) planes ( d 002 ) and increasing crystallite size along c -axis of graphite lattice ( L c ). The inner fracture among (002) planes may be related to the kink bands structure in graphite. It is clarified that no Na–C intercalation compounds get involved in change of graphite lattice. The crystallite size along a -axis ( L a ) can play an important role in structure stability with deformation-hardening effect on elastoplastic property and pinning effect on creep resistance. The deformation mechanism and the influencing factors on long-term structure stability of graphite cathode are also discussed in detail.
研究领域:
材料科学
·
固体力学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Zilong Han,Peng Wang,Guoyong Mao,Tenghao Yin,Danming Zhong,Burebi Yiming,Xiaocheng Hu,Zheng Jia,Guodong Nian,Shaoxing Qu,Wei Yang
As one of the most promising drug delivery carriers, hydrogels have received considerable attention in recent years. Many previous efforts have focused on diffusion-controlled release, which allows hydrogels to load and release drugs in vitro and/or in vivo. However, it hardly applies to lipophilic drug delivery due to their poor compatibility with hydrogels. Herein, we propose a novel method for lipophilic drug release based on a dual pH-responsive hydrogel actuator. Specifically, the drug is encapsulated and can be released by a dual pH-controlled capsule switch. Inspired by the deformation mechanism of Drosera leaves, we fabricate the capsule switch with a double-layer structure that is made of two kinds of pH-responsive hydrogels. Two layers are covalently bonded together through silane coupling agents. They can bend collaboratively in a basic or acidic environment to achieve the “turn on” motion of the capsule switch. By incorporating an array of parallel elastomer stripes on one side of the hydrogel bilayer, various motions (e.g., bending, twisting, and rolling) of the hydrogel bilayer actuator were achieved. We conducted an in vitro lipophilic drug release test. The feasibility of this new drug release method is verified. We believe this dual pH-responsive actuator-controlled drug release method may shed light on the possibilities of various drug delivery systems.
研究领域:
材料科学
·
药学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Minhao Shen,Renli Fu,Yunan Liu,Yunjia Hu,Yanlin Jiang,Zhe Zhao,Ming Liu
Inspired by the double-helix structure of biological DNA, low-volume fraction and high-strength Al 2 O 3 twisted honeycomb structures with characteristics similar to those of helical structures in the z -axis were prepared by digital light processing 3D printing technology. As the twist angle increased, the compressive strength of the fabricated Al 2 O 3 structure decreased, and the deformation mechanism of the Al 2 O 3 structures gradually changed from stretching-dominated to bending-dominated, which can be predicted by the Gibson–Ashby model. The relationship between the effective elastic modulus and the volume fraction that can be modified by varying the wall thickness was described by the Pabst–Gregorova exponential relationship. The compressive strength of the Al 2 O 3 structure with a twist angle of 0° can reach 62.4 MPa at a volume fraction of 13.3%, providing guidance to optimize lightweight structures of ceramics.
研究领域:
材料科学
·
机械工程
✓ 已验证
产品关联
DOI
高影响因子
Science Advances
·
2025
·Vol. 11
·期 27
·
IF 12.5
Shenghong Ren,Heyang Chen,Huangliu Fu,Haoran Huang,Tian-Ran Wei,Xun Shi,Xiuyan Li
Ductile polycrystals are usually metals with high-symmetry structures that provide multiple slip systems to coordinate the synergetic deformation of adjacent grains. However, while exceptional plasticity was recently discovered in a series of low-symmetry semiconductors, their deformation mechanism remains mysterious. Here, taking monoclinic Ag 4 SSe as a case study, we show that the inherent high-symmetry anion sublattice with a quasi–body-centered cubic (bcc) structure is embedded in the monoclinic matrix. This, coupled with the highly diffuse cations, results in multiple slip systems and is responsible for the superior plasticity as normally unexpected in low-symmetry structures. We observe typical slip systems conforming with those of the bcc structure by experiment. This finding clarifies the deformation mechanism of Ag 2 S-based low-symmetry semiconductors and sheds light on future exploration of ductile inorganic semiconductors.
研究领域:
材料科学
·
固体物理
·
半导体物理
·
晶体学
·
材料力学性能
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
·
2025
·Vol. 43
·期 9
·1671-1680
·
IF 4
Wu Zi-Shuo,Deng Jia-Ying,Chen Wei
The deformation mechanism of glycerol plasticized poly(vinyl alcohol) (PVA) with different hydrolyses (88%, 92%, 98%) at elevated temperatures (60–100 °C) was elucidated by in situ synchrotron radiation X-ray scattering. The vinyl acetate (VAc) in PVA acts as a non-crystalline chain defect, which significantly influences the plastic deformation and stretching-induced crystallization behavior of PVA. The key microstructural parameters of PVA during deformation, such as crystallinity ( χ c ), lateral crystallite size ( L ), and long period ( l ), in combination with the stress-strain curves, were obtained. The experimental results show that the deformation process of the plasticized PVA film present a three-stage evolution: (i) a plastic deformation zone. The plastic deformation of the crystallite occurs as evidenced by the apparent decrease in crystallinity and lamellar reorientation induced by stretching; (ii) the stress softening zone. The decreasing trend of crystallinity becomes slow, and the long period becomes smaller, which indicates that PVA crystallization is induced by stretching; and (iii) the strain-hardening zone. There is a synergistic effect between the crystallite destruction and formation. Further research reveals that a high temperature and low degree of alcoholysis favor the stretching-induced crystallization of PVA, while the system with a high degree of alcoholysis shows significant characteristics of preferred crystal growth.
研究领域:
高分子材料科学
·
软物质物理
·
生物医用材料
·
结构表征
·
力学性能
✓ 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）