POLYMER
·
2015
·
IF 3.562
Xue Jiang,Chun Feng,Guolin Lu,Xiaoyu Huang
A homopolymer strategy was developed to synthesize temperature and pH/CO 2 stimulus-responsive homopolymers. A new class of acrylamide monomers bearing oligo(ethylene glycol) unit and N,N -diethylaminoethyl group were designed and prepared through Aza-Michael addition reaction followed by amidation with acryloyl chloride using amino group as a linkage to connect oligo(ethylene glycol), N,N -diethylaminoethyl, and polymerizable double bond groups together. Subsequently, the corresponding homopolymers containing oligo(ethylene glycol) unit and N,N -diethylaminoethyl group in each repeated unit were prepared via RAFT polymerization with controlled molecular weights and relatively narrow molecular weight distributions . The lower critical solution temperature (LCST) of homopolymer was examined to be influenced by molecular weight, salt concentration, and pH value of aqueous solution. The LCSTs of homopolymers could be tuned in a wide temperature window by changing pH value of aqueous solution and it increased with the decrease of pH value. Particularly, CO 2 gas as a unique pH stimulus can also reversibly adjust the solubility of homopolymer without the addition of acids or bases.
研究领域:
高分子化学
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智能材料
·
药物递送
·
生物医用材料
·
刺激响应材料
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Haoyu Gu,Tong Lv,Qiankun Zhang,Dequan Chi,Yang Zhang,Zhongjun Cheng,Zhimin Xie,Yongjun Xu,Dongjie Zhang,Yuyan Liu
Smart reconfigurable metamaterials can better adapt to changing electromagnetic environments and broaden the range of applications. However, constructing electromagnetic reconfigurable metamaterials, especially those with large areas or applied to complex surfaces via a universal approach, is still a challenge. Here, we introduce a smart reconfigurable metamaterial consisting of a thermadapt shape memory polymer ethylene vinyl acetate copolymer (EVA) matrix and a flowable liquid–metal resonant unit. Based on the excellent self-healing properties of EVA, large-area metamaterials can be constructed by thermal assembly of metamaterial units. In addition, the original shape of the metamaterial can be reprogrammed to apply to complex three-dimensional surfaces with the reprocessing properties of EVA. Moreover, by utilizing the shape memory performance of the EVA, the temporary resonant frequency of the metamaterial can be set by programming and the resonant frequency tuning of the metamaterial can be controlled under external temperature stimulation, achieving noncontact tuning. In the future, this concept can be broadly applied in fields such as complex structure stealth layers and multifunction filters.
研究领域:
材料科学
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电磁学
·
高分子化学
·
智能材料
·
功能材料
✓ 已验证
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2023
·
IF 8.4
Likai Hou,Zhongjun Liang,Xu Fan,Jian Yu,Fubing Bao
Many soft coiled actuators are mimic the desirable structures of plant tendril. Here, we present a facile microfluidic spinning method to fabricate self-coiling Janus microfiber actuator with tunable morphology, spontaneous coiling performance and reversible traction property. By adjusting the component of hydrogel Janus fiber in a microfluidic spinning device with theta-shaped channels, tens of hundreds of homogeneous coils can be spontaneously and rapidly generated due to asymmetric contraction upon dehydration process, and three different forms of coiled fibers with various screw diameters are presented. Furthermore, the coiled Janus microfiber with hygroscopic properties possesses a reversible coiling/uncoiling performance under humidity gradients, which can serve as a micro-actuator to lift a certain weight with enough tensile strain and long-range tractive displacement. In addition, local reversible coiling/uncoiling morphing is achieved under water contact and near infrared light optothermal stimulations. As a verification of this coiled microfiber actuator, a smart switch is designed to control different colored LED lights for sensing an ambient moisture content.
研究领域:
生物医学工程
·
软体机器人
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功能高分子材料
·
微纳制造
·
生物传感器
·
刺激响应材料
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2016
·
IF 4.836
Man Zhang,Rui Wang,Zhenqiang Shi,Xuelian Huang,Weifeng Zhao,Changsheng Zhao
A novel family of multi-responsive, tough, and reversible hydrogels were prepared by the combination of dipole-dipole interaction, hydrogen bonding interaction and slightly chemical cross-linking, using monomers of acrylonitrile, sodium allylsulfonate and itaconic acid. Reversible gel-sol transition was achieved by the flexible conversion of the dipole-dipole interactions between acrylonitrile-acrylonitrile and acrylonitrile-sodium thiocyanate, and the hydrogels could freely form desired shapes. The dipole-dipole and hydrogen bonding interactions improved the mechanical strength of the hydrogels with a compressive stress of 2.38 MPa. Meanwhile, the hydrogels sustained cyclic compressive tests with 60% strain, and exhibited excellent elastic property. The hydrogels were sensitive to pH and ionic strength, and could keep their perfect spherical structures without any obvious cracks even after immersing in strong ionic strength (or pH) solution for several reversible cycles. Furthermore, the hydrogels were recycled for environmental pollution remediation, and showed great potential to be applied in water treatments and other related fields.
研究领域:
高分子材料科学
·
生物医学工程
·
环境修复
·
功能水凝胶
·
智能响应材料
✓ 已验证
DOI
高影响因子
MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2019
·Vol. 220
·期 18
·1900299
·
IF 2.622
Huidong Yang,Hong Wang,Jingang Feng,Yumin Ye,Wenna Liu
Asymmetric divinyl monomers are attractive candidates for constructing functional polymer thin films owing to their ability to undergo further reactions after polymerization. Here, the first solventless synthesis of poly(allyl methacrylate) (PAMA) film with retention of abundant allyl groups using initiated chemical vapor deposition (iCVD) is reported. It is demonstrated that lower substrate and filament temperatures lead to better allyl retention, while higher temperatures lead to intramolecular cyclization. The retained allyl groups can be further crosslinked under UV light, and the crosslinking degree can be easily tuned by adjusting the exposure time. Patterning of iCVD PAMA films with 20 µm resolution using a TEM grid as photomask is also demonstrated. The reported synthesis method suggests possible solventless incorporation of AMA in thin films as a latent crosslinker or anchoring sites for further functionalization. The solventless patterning can also extend patterning technique to solvent-sensitive and non-planar substrates.
研究领域:
高分子材料科学
·
表面化学
·
功能薄膜
·
光响应材料
·
生物医学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）