Small
·
2024
·
IF 13
Bo Zhu,Di Tan,Kangjian Xiao,Zhekun Shi,Gang Li,Yifeng Lei,Daobing Chen,Sheng Liu,Longjian Xue
The gradient modulus in beetle setae plays a critical role in allowing it to stand and walk on natural surfaces. Mimicking beetle setae to create a modulus gradient in microscale, especially in the direction of setae radius, can achieve reliable contact and thus strong adhesion. However, it remains highly challenging to achieve modulus gradient along radial directions in setae-like structures. Here, polydimethylsiloxane (PDMS) micropillar with radial gradient modulus, (termed GM), is successfully constructed by making use of the polymerization inhibitor in the photosensitive resin template. GM gains adhesion up to 84 kPa, which is 2.3 and 4.7 times of soft homogeneous micropillars (SH) and hard homogeneous micropillars (HH), respectively. The radial gradient modulus facilitates contact formation on various surfaces and shifts stress concentration from contact perimeter to the center, resulting in adhesion enhancement. Meanwhile, GM achieves strong friction of 8.1 mN, which is 1.2 and 2.6 times of SH and HH, respectively. Moreover, GM possesses high robustness, maintaining strong adhesion and friction after 400 cycles of tests. The work here not only provides a robust structure for strong adhesion and friction, but also establishes a strategy to create modulus gradient at micron-scale.
研究领域:
材料科学
·
仿生学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
GIANT
·
2024
·
IF 5.4
Jin Huang,Hangsheng Zhou,Li Zhang,Hao Zha,Wei Shi,Tianyi Zhao,Mingjie Liu
Traditional impact-resistance materials relying on the combination of supporting materials and energy-dissipation elastomers can effectively reduce shock load, yet the sharp interface between two types of materials causes discontinuous stress transfer and cracking. Here, inspired by the squid beak, we report a type of high impact-resistance gradient elastomers with large-scale modulus gradient with about three orders of magnitude (modulus range of 7 × 10 3 ∼ 7 × 10 6 Pa) and high energy dissipation (loss factor > 0.6) over a wide temperature range by diffusively introducing stiff polymers in a highly damping elastomer with controlled mechanical properties. Under the action of an external force, our gradient elastomers exhibit soft-while-stiff attributes, combining cushioning and support. In drop hammer impact tests, our gradient materials can reduce impact strength by 80 %, significantly better than commercial protective gear. It is worth mentioning that the modulus of the bottom layer matches that of the tissues for better protection.
研究领域:
材料科学
·
生物力学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2025
·
IF 4.5
Qingguang Bao,Jiangang Liu,Qingfeng Sun,Ning Wang,Shan Cheng,Jingyao Feng,Nan Li,Xigao Jian
Aiming at the problems of low bonding strength and large modulus difference at the interface between carbon fibers (CFs) and resin matrix, this research achieved in-situ growth of an adhesive "metal-phenolic" complex network (TA@Fe 3+ ) on CFs surfaces. Additionally, a modulus gradient transition layer featuring alternating "rigid-flexible" interlayer structures ((TA@Fe 3+ -GO) 2 ) was further constructed. The flexible TA@Fe 3+ complex network boosts chemical bonding at the fiber-resin interface, whereas the rigid GO enhances load transfer and dispersion. Through the synergistic effect of "interfacial adsorption-physical reinforcement", the interfacial strength is improved. The alternating “rigid-flexible” interfacial layer reduces the modulus mismatch between CFs and the resin by expanding the interfacial phase thickness and slowing the modulus decline rate, thereby minimizing interfacial stress concentration. Compared with UCF/PPESK composites, the modified composites exhibit a 40.4% increase in flexural strength and a 70% increase in interlaminar shear strength (ILSS). This study offers novel perspectives on the design of multi-level gradient modulus interlayer structures and the fabrication of strong-interfacial carbon fiber-reinforced polymer matrix composites (CFRPs).
研究领域:
材料科学
·
聚合物复合材料
·
表面工程
·
机械工程
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2022
·
IF 4.432
Bo Zhang,Songyue Liu,Lijie Yin,Ming Tian,Nanying Ning,Liqun Zhang,Wencai Wang
The reaction mechanism and the interfacial modulus gradient of the interfacial transition layer between the environmentally friendly dipping system (PAL) and the rubber have not been fully studied. In order to better understand the chemical structures and nano-mechanical properties of the interface between the dip layer and the rubber, we used advanced atomic force microscope (AFM) and nanoscale Fourier transform infrared spectroscopy (nano-FTIR) to perform detailed analysis in this article. The characterization of interfacial nano-mechanical properties and chemical structures is very significant for the illustration of interfacial adhesion mechanism. AFM can effectively characterize the detailed interfacial modulus gradient and the thickness of interface, while nano-FTIR can comprehensively measure the interfacial chemical structures and the distribution of chemical bonds. The results suggest that the thickness of the interface between the PAL dip layer and the rubber matrix is 175 nm, and the crosslinking density of the interfacial layer is high, which explains that the failure location of fiber/rubber composites after pull-out tests occurs on the side of the rubber matrix. Similarly, the microstructure of resorcinol-formaldehyde-latex (RFL) system was also characterized, and the preparation of RFL usually requires carcinogenic and toxic substances such as formaldehyde and resorcinol .
研究领域:
材料科学
·
复合材料
·
纳米技术
·
高分子科学
✓ 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）