Materials Chemistry Frontiers
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2019
·Vol. 3
·期 9
·1833-1839
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IF 0
Shuliang Wang,Zenghe Liu,Luzhi Zhang,Yifan Guo,Jianchun Song,Jiaming Lou,Qingbao Guan,Chuanglong He,Zhengwei You
As a group of environmentally friendly adhesives, polyurethane hot-melt adhesives (HMAs) are used widely. However, existing thermoplastic (TPU) and thermoset (PUR) polyurethane HMAs have certain shortcomings. The adhesion strength and solvent resistance of TPU-HMAs are relatively poor owing to their linear structure. PUR-HMAs are non-reworkable and unrecyclable with low initial adhesion strength. These features greatly limit their applications. Herein, we used reversible oxime–carbamate bonds to build a dynamically crosslinked polyurethane HMA (DPU-HMA), which combines the advantages of TPU-HMAs and PUR-HMAs. Lap shear tests of stainless steel showed that the DPU-HMA had initial (3.47 ± 0.93 MPa after 5 min curing) and ultimate (5.71 ± 0.72 MPa after 1 day curing) adhesion strengths that were much higher than those for the commercial adhesive 3M PUR-HMA (0.02 ± 0.01 MPa after 5 min curing; 4.07 ± 0.13 MPa after 14 days curing). The DPU-HMAs retained moderate lap shear strength in solvent (acetone), whereas TPU-HMAs were completely dissolved. The DPU-HMAs were effective in bonding multiple substrates including metal, plastic, wood, and composites. Furthermore, the DPU-HMAs possessed smart features, such as debonding on demand and self-healing owing to their dynamic network. We expect that this new type of adhesive will be useful for applications in electronics assembly, and the automotive, and aerospace fields. The molecular design strategy might also be applicable for other adhesive systems.
研究领域:
材料科学
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化学工程
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环境科学
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ChemistrySelect
·
2024
·Vol. 9
·期 40
·e202402625
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IF 1.9
Weixing Song,Zhenxiao Zhang,Meng Hao,Xingwei Hu,Jiaqi Chai,Bo Jiang,Ying Song
Graphical Electrochromic hydrogels exhibit rapid response speed, consistent color change, excellent reversibility. The dynamic reversible borate bond formed between borax and PVA molecular chains confers the hydrogel with robust self-repairing properties. Cracking caused by aging or repeated bending can severely affect the lifetime of electrochromic devices. In this work, a self-healing electrochromic hydrogel was developed with poly (vinyl alcohol) (PVA)-sodium carboxymethyl chitosan (SCC) semi-inter transfer network as the matrix, viologen bromide (HPV 2+ 2Br − ) as the electrochromic substance, and borax as the cross-linking agent. The self-healing properties of hydrogel stem from the dynamic and reversible borate bonds between borax and PVA molecular chains. As the voltage changes, the color of the device transitions from colorless to light purple and then to dark purple. The optical contrast at 600 nm reaches approximately 51 %. At room temperature, the disconnected hydrogel can fully restore its original state after 30 minutes of contact, effectively addressing issues related to cracks and damage in flexible electrochromic devices. This research holds significant implications for enhancing the reliability and stability of flexible electrochromic devices.
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
JOURNAL OF MATERIALS SCIENCE
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2022
·Vol. 57
·期 22
·10444-10456
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IF 4.682
Zhang Tong,Su Huixin,Shi Xiangrong,Li Chengpeng
The rapid development of flexible electronics brings forward more requirements for self-healing substrate materials. Siloxane elastomers as an ideal substrate is widely used in the flexible electronics. However, self-healing siloxane elastomers still need to be improved in terms of mechanical properties. Herein, methacrylate/epoxy groups terminated hyperbranched polysiloxanes (HPBSi) as core was prepared to improve the mechanical properties via providing hierarchical permanent chemical cross-linked networks. A series of room-temperature self-healing siloxane elastomers are constructed by HPBSi with a linear dual-epoxy siloxane monomer through an amino disulfide compound (AFD) with reversible dynamic bonds. Especially, the content of HPBSi and AFD is systematically researched and proved to play a key role in adjusting the mechanical and self-healing properties of the siloxane elastomers. For the P1-5 containing 5 wt% HPBSi, its tensile strength is as high as 0.87 MPa that is improved about 410% compared with an elastomer without HPBSi. P11-5 elastomer with more AFD can obtain the same healing efficiency at room temperature in a shorter time (12 h) compared with 48 h of P1-5 elastomer. Finally, the self-healing siloxane is used as a flexible substrate to fabricate a strain sensor for monitoring multiple human motions, demonstrating a promising potential use in the flexible electronics.
Graphical Abstract
研究领域:
材料科学
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柔性电子学
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高分子化学
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DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2024
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IF 4.9
Shengping Dai,Longhua Zeng,Shuyong Xie,Jiayi Hu,Hao Yan,Wei Huang,Huixian Ye,Ningyi Yuan
Thin film actuator has the advantages of simple construction and repaid responses. However, once damaged, it makes them face great challenges in terms of performance stability. Here, a self-healing thermal actuator was developed by combining a self-healing silicone elastomer with a polyimide film. The silicone elastomer with excellent self-healing and high mechanical properties was designed by triple dynamic reversible bond of hydrogen bond, oxime bond, and metal coordination bond. Polyurea groups provided a large number of cross-linking points for supramolecular hydrogen bonding, and nitrogen atoms on the oxime group form complexes with various metal ions (such as Cu 2+ , Zn 2+ , Fe 3+ ), which can significantly improve its mechanical strength (up to 4818 kPa). Silicone elastomer exhibited fast and efficient self-healing properties (99.9% within 10 h at room temperature) based on a triple dynamic reversible bond. In addition, the actuator can be thermally driven and achieve a maximum bend of 59.9° at 100 °C. The actuator shows excellent cyclic stability in the range of 100 cycles, and can still achieve the original bending angle after healing. The realization of self-healing performance on flexible actuators provides the experimental basis for the further development of artificial muscles.
研究领域:
材料科学
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柔性电子学
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DOI
高影响因子
ACS Applied Materials & Interfaces
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2021
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IF 9.229
Yi Meng,Fuyu Song,Hang Chen,Yi Cheng,Jie Lu,Haisong Wang
As a nature ultralight, well-aligned porous and anisotropy feedstock, cornstalk pith (CSP) has not been exploited for material design. Herein, we use CSP as substrate to prepare multifunctional elastic composite gels. First, CSP is pretreated by ferric chloride then immersed in an unsaturated monomer solution, following by a polymerization to form enhanced networks. The ferric ions act as junction sites for the combination between the polymer chains and the CSP matrix, therefore, dynamically reversible bonds are constructed. The bonds dissipate the compression force by breaking the dynamic bonds and reconstruct when the loading is removed. The reconstructed dynamic bonds endow an antifatigue performance of the prepared gels, in the cyclic compression test conducting 100 times with a 50% strain, and the gel holds a 94% elastic recovery. Furtherly, oil/water separation, cushioning system and biobased sensor are developed on the basis of what the matrix endows and what the reversible bonds exhibit. The preparation method in this study enriches a simply and high value-added method to utilize biobased material.
研究领域:
材料科学
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环境科学
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生物工程
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DOI
高影响因子
MICROCHIMICA ACTA
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2025
·Vol. 193
·期 1
·16
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IF 5.3
Qiao Yu,Tan Liju,Zhao Jiayin,Wang Jiangtao,Liu Hui
Conventional hydrogen-bonded molecularly imprinted polymers (MIPs) suffered from significantly compromised adsorption performance in aqueous environments due to competitive interference from water molecules. To overcome this limitation, this study developed a novel imprinting strategy based on reversible Schiff base bonding. Schiff base covalent imprinting utilizes aldehyde groups and amino groups to form reversible covalent bonds (C = N), achieving specific recognition between template molecules and functional monomers. Schiff base has strong affinity and selectivity, which can effectively reduce the competitive interference of water molecules in aqueous environments. The amino groups of the functional monomer (4-vinyl aniline, 4-VAn) and the aldehyde groups of vanillin (Vnl) formed a precursor via Schiff base reaction, which was then copolymerized with the crosslinker divinylbenzene (DVB) to fabricate molecularly imprinted polymer microspheres (S-MIPs). The adsorption of Vnl by S-MIPs follows a chemisorption mechanism dominated by covalent recognition, which is significantly influenced by the pH of the aqueous solution. S-MIPs demonstrated excellent specificity and reusability, with an adsorption capacity of 163.95 mg·g -1 , an imprinting factor of 3.27, and the recoveries of Vnl ranged from 91.76% to 96.02% in milk tea samples. This strategy effectively enhances the aqueous-phase adsorption performance of molecularly imprinted polymers by constructing stable covalent recognition sites, providing a new approach for the development of high-performance aqueous-phase recognition materials. Graphical
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PubMed
高影响因子
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
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2019
·Vol. 57
·期 22
·2228-2234
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IF 2.591
Changhong Lin,Dekun Sheng,Xiangdong Liu,Shaobin Xu,Fance Ji,Li Dong,Yan Zhou,Yuming Yang
A dual crosslinked self-healing polyurethane was prepared with robust mechanical properties through the dynamic reversible pyridine-Fe 3+ coordination bonds and Diels–Alder (DA) covalent bonds dual crosslinking strategy. Moreover, the mechanical properties and self-healing ability of polyurethane can be tuned readily by different ratio of the coordination bonds and DA bonds. Under external load, the coordination bonds serve as sacrificial bonds are broken to dissipate energy, the DA bonds can keep the shape of sample. With the coordination bonds participation, the damaged samples can be healed under moderate heating treatment or with the aid of FeCl 3 solution. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 2228–2234
研究领域:
高分子化学
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材料科学
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自修复材料
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功能高分子
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智能材料
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DOI
高影响因子
MACROMOLECULES
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2025
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IF 5.2
Aofei Zhang,Xiaoyu Du,Jianglong Li,Jianlong Wen,Lang Shuai,Yongqiang Ming,Yijing Nie
How to effectively improve the strength and toughness of polymer elastomers is important for the expansion of their application fields. Construction of two distinct types of dynamic reversible bonds within elastomers represents an effective strategy for enhancing their mechanical properties. However, the interplay mechanisms between different dynamic reversible bonds have not been fully studied. Herein, we constructed both a hydrogen bond network and a metal coordination network in polyurethane (PU) elastomers. The introduction of both weak hydrogen bonds and strong metal coordination bonds can endow the elastomers with high tensile strength without the sacrifice of stretchability. This special phenomenon can be attributed to the dynamic synergistic mechanisms between the hydrogen bond network and coordination bond network. In short, the presence of strong coordination bonds can promote the orientation of local segments, while the recombination of weak hydrogen bonds can cause the relaxation of locally oriented segments.
研究领域:
高分子科学
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材料工程
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物理化学
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机械工程
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DOI
高影响因子
Polymer-Plastics Technology and Materials
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2024
·
IF 2.6
Shuai Qi,Shiwei Xie,Bo Li,Chang Liu,Sai Gong,Xiao Zhang,Shenzhen Li
Traditional epoxy resins are of technological significance for structural adhesives and composite materials, as well as many others. However, brittleness limits its further development, and achieving a combination of toughness and rigidity in epoxy networks remains a great challenge. In this work, we designed and synthesized low-temperature curable, tough and repairable epoxy networks via hindered urea bond (HUB) crosslinking strategies. Mechanical testing revealed that the material exhibited simultaneously improved toughness and stiffness, and specifically, tensile strength, elongation at break, and toughness were able to reach 78.2 MPa, 8.61%, and 4.63 MJ · m−3, respectively. More importantly, the dynamic exchange of HUB dispersed between polymer chains enables HUB crosslinked epoxy with thermal-triggered reparability and recyclability. In addition, thermal properties, chemical stability and water resistance of toughened epoxy samples were also characterized. This work provides a practical guidance for the exploration of high-performance epoxy with the potential to be extended to other polymers.
研究领域:
材料科学
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聚合物化学
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复合材料
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粘合剂
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DOI
高影响因子
TALANTA
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2024
·
IF 5.6
Wenyan Zeng,Qingyuan Jiang,Chaofan Ruan,Wang Ni,Changchang Zhu,Xueling Zeng,Xuan Shi,Rongke You,Ning Ma,Fang-Chang Tsai
The emergence of stimuli-responsive fluorescence anti-counterfeiting technology has garnered increasing attention in the era of intelligent internet. Smart fluorescent hydrogels combine the characteristics of luminous materials with the unique structure of hydrogels, offering the potential for dynamic reversible erasing and multi-tiered data encryption. In this work, a fluorescent hydrogel was constructed by zeolitic imidazolate framework-8 loaded with fluorescein and then mixed with polyvinyl alcohol hydrogel, sodium carboxymethyl cellulose and borax, which could be used for image hiding in visible light. The reversible bonds cross-linked fluorescent hydrogel was stretchable and self-healing with a three-dimensional network structure. The hydrogel presented bright green fluorescence under 365 nm UV light, which was quenched by adding copper ions. Meanwhile, the imprint of the hydrogel could be cleared by L-Cysteine and repeatedly recorded information many times. The alkali-induced shape memory capability was further utilized to achieve multi-tiered data encryption by deforming it to a 3D-specific shape through folding. The rewritable and multi-dimensional encrypted hydrogel is expected to improve data security and reduce resource consumption.
研究领域:
材料科学
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化学
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纳米技术
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信息安全
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DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）