MACROMOLECULAR RAPID COMMUNICATIONS
·
2023
·
IF 4.6
Chunyan Cao,Tao Huang,Yunming Li
Conductive polymer hydrogels are vital instrain sensors, yet achieving high resilience and toughness is a challenge. This study employs a prestretch method to engineer a tough conductive polymer hydrogel with sufficient resilience. Initially, a blend film of polyvinylalcohol (PVA) and ethylene-vinyl alcohol copolymer (EVOH) is prepared through solution casting, followed by a swelling process to form a PVA-EVOH hydrogel. This hydrogel, with PVA crystallites as crosslinking points, exhibits high toughness. The hydrogel is then immersed in pyrrole and ferric chloride solutions for in-situ polymerization of polypyrrole (PPy), creating a conductive PPy/PVA-EVOH hydrogel. Finally, a 200% prestretch is applied, breaking short chains within the network, eliminating energy dissipation at low strains. This results in a hydrogel with a 100% elastic deformation range, while maintaining high fracture toughness (1700 J m -2 ). The prestretched PPy/PVA-EVOH hydrogel functions as a strain sensor with low hysteresis, providing consistent strain measurements during loading and unloading. This outperforms the non-prestretched sample, which shows inconsistent responses between stretching and releasing.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER
·
2022
·
IF 4.432
Yu-Ting Huang,Yu Zhou,Wei-Wei Yu,Shuangquan Liao,Ming-Chao Luo
The design of double-network (DN) improves the properties of matrix effectively, which has attracted wide attention. The recently reported construction of DN structure usually involves the prestretching process (swelling process). However, such complicated multistep swelling processes become more difficult in high molecular weight matrix, which are not suitable for constructing DN structure in the universal elastomers (for example, natural rubber and polyisoprene rubber). To expand the application fields of DN, this work designs the dense crosslinking domain and the sparse crosslinking domain to construct nonprestretching DN structure through physical interaction-induced aggregation. We find that physical interaction induced-aggregation form the dense crosslinking domain and the sparse crosslinking domain, which builds the two contrasting DN structures. Double-quantum nuclear magnetic resonance, dynamic mechanical analyzer, and mechanical property characterization demonstrate that the dense crosslinking domain as the brittle first network is preferentially ruptured upon deformation, leading to a large energy dissipation. This design concept represents a general approach to develop the nonprestretching DN structure, which expands the application fields of DN structure in the elastomer matrix.
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
ACS Applied Polymer Materials
·
2022
·
IF 4.855
Yu Zhao,Qi-Yao Feng,Ya-Kun Xie,Zi-Li Zhang,Li-Juan Yin,Zhi-Min Dang
Dielectric elastomers (DEs) are widely studied as artificial muscles due to their large actuation strain and fast electromechanical response. Currently, the commonly used acrylate DEs require high prestretching and are subjected to a high actuation electric field to achieve excellent actuation performance. In this work, we prepared DEs with very simple prescriptions by UV curing method. The prepared DEs have very low mechanical losses (<4%) and high dielectric constants (≥5.67) and obtain a large actuation strain (30.2%) under a relatively low electric field (31.6 kV/mm) with non-prestretching. This is because the soft butyl acrylate (BA) can guarantee the DEs with low Young‘s modulus and increase the dielectric constant by its polar functional group (-COO-), besides controlling the content of the cross-linker urethane acrylate (TR-U201XS) to regulate the cross-link density of the DEs and further influence its electromechanical properties, which are positive for improving the DEs’ actuation performance. And the DEs can be used to fabricate a fishtail-type device, which obtains a large swing range of about 90° in air and can overcome the resistance of water to work in water.
研究领域:
材料科学
·
智能材料
✓ 已验证
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2025
·
IF 19
Wei Yu,Wenle Zheng,Shuaichuang Hua,Qinghai Zhang,Ziqi Zhang,Jianghua Zhao,Wenjing Yuan,Guoxian Li,Chuizhou Meng,Huichan Zhao,Shijie Guo
Dielectric elastomer actuators with high energy and power output, combined without pre-stretching treatment to simplify device fabrication, are highly desirable for soft robotics. Here, different from most studies that focus on modifying elastomers such as polyacrylates and silicones, the study designs a prestretch-free dielectric elastomer based on hydrogenated carboxylated nitrile butadiene rubber to reach a record-high energy density (564 J kg −1 ) and power density (5641 W kg −1 ), ≈15 times greater than natural muscle and three times greater than the state-of-the-art dielectric elastomers. This excellent performance arises from the synergistic polarization enhancement and strain stiffening overcoming the inherent trade-offs between electrical and mechanical properties, simultaneously endowing the elastomer with an extremely high dielectric constant ( ɛ r = 17, 100 Hz), ultralow mechanical loss (tan δ m = 0.04@1 Hz), and large electrical breakdown strength (105 V µm −1 ). The assembled 40-µm-thick actuator lifts a 200-g load with over 20% strain and maintains a stable power density of 4780 W kg −1 for 50 000 cycles. Furthermore, the actuators demonstrate diverse applications, including serving as biceps artificial muscles to achieve a 90° rotation angle at a speed of 360°/s and actuating a soft robot carrying a load 20 times its weight. These findings provide a different approach for developing high-performance dielectric elastomers to broaden their application in soft robotics.
研究领域:
软体机器人
·
材料科学
·
智能材料
✓ 已验证
产品关联
DOI
高影响因子
Energy Technology
·
2023
·Vol. 11
·期 6
·2201358
·
IF 3.8
Ganghong Zhang,Xiaotian Wu,Tianlong Du,Yu Wang,Zhengying Liu,Wei Yang,Mingbo Yang
The challenge to prepare conductive hydrogel electrodes for stretchable supercapacitors with high areal capacitance and excellent stability during stretching has attracted tremendous attention from researchers. Herein, a method to enhance the performance of a conductive hydrogel electrode is reported. The in situ oxidative polymerization of aniline monomer is performed in the prestretched polyacrylamide (PAAm) hydrogel. After releasing the hydrogel, the polyaniline (PANI) nanoparticles can shrink with the PAAm substrate to form a dense and continuous conductive network. Due to the enhanced conductive networks, the prestretched PAAm-PANI conductive hydrogel with prestrain of 500% (PPCH 5 ) electrode shows high areal capacitance of 509.9 mF cm −2 at 0.5 mA cm −2 . The symmetrical stretchable supercapacitor based on PPCH 5 electrodes exhibits a high areal capacitance of 219.7 mF cm −2 . The device shows high capacitance retention of 68.5% even when stretched to 200% strain and noncapacitance decays after 2000 stretching cycles at 100% strain. This strategy can be expanded to the carbon nanotubes (CNT)-filled hydrogel systems. The PAAm-PANI-CNT conductive hydrogel with prestrain of 500%-based supercapacitor shows specific capacitance of 1429.87 mF cm −2 . The results demonstrate that prestretching is a highly effective method to enhance capacitance and stretching stability of PANI hydrogel electrode for stretchable supercapacitors.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2023
·
IF 11.2
Jianhua Huang,Gong Chen,Tianhang Han,Chenxin Yi,Yujia Zhang,Lang Ding,Tianshu Sun,Ting Jin,Shuai Zhou
Customizable structures and patterns are becoming powerful tools for biomimetic design and application of soft materials. The construction of long-range ordered self-wrinkled structures on multi-dimensional and complex-shaped surfaces with facile, fast and efficient strategies still faces serious challenges. During the stretch-recovery process, the carboxyl groups in the polyacrylamide/sodium alginate dual network gel form robust coordination with Fe 3+ to achieve a hard shell layer, resulting in a modulus mismatch between the inner soft layer and the outer hard layer, thereby forming a wrinkled surface. This flexible strategy allows simultaneous construction of complex topologies from 1D to 3D wits well-organized microstructure and controllable dimensions. The mechanism of the influence of ion treating time and pre-stretching ratio on wrinkle wavelength was explored in detail. The finite element simulations matched well with the experimental results. Due to the unique surface and dual crosslinking network, the self-wrinkled hydrogel maintains a high sensitivity of up to 67.47 kPa −1 in 1000 compression cycles. As a high-sensitivity pressure sensor integrated into the detection system, it can be efficiently applied to the contact dynamic tactile perception and monitoring of various movement behaviors of the human body.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials Horizons
·
2025
·
IF 10.7
Weijun Yang,Yu Zhang,Bing Li,Xiang Zhang,Debora Puglia,Deyu Niu,Pengwu Xu,Piming Ma
This work focuses on a simple approach for designing the polyurethane elastomers with ultra-robust properties. Initially, polyurethane/lignin elastomers were synthesized using polytetramethylene ether glycol (PTMG) as soft segment, hexamethylene diisocyanate (HDI) along with 4,4'-dihydroxydiphenyl ether (DO) as hard segments, and lignin nanoparticles (LNP) as the biomacromolecule crosslinker. Subsequently, the resulting elastomer were pre-stretched at certain ratios (λ), and surprisingly, the pre-stretched polyurethane/lignin elastomer (λ=14) displayed significant improvement in mechanical properties, while the tensile strength and toughness were sharply enhanced from 32.4 MPa and 298.7 MJ/m3 to 120.2 MPa and 501.3 MJ/m3, respectively. The improvement can be attributed to the denser cross-linked networks combined with the multiscale structure orientation and stress-induced crystallization (SIC) effects induced by pre-stretching. The interphase distance (d_p) decreased from 15.708 to 14.612 nm, while the interplanar crystal distance (d_c) increased from 4.387 Å to 4.398 Å, and the Herman orientation factor (f) increased from -0.0066 to 0.0518. This work presents a novel strategy for preparing polyurethane elastomers with exceptional mechanical performance.
研究领域:
材料科学
·
高分子科学
·
机械工程
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2025
·
IF 5.1
Gui-Xiang Liu,Yu-Ting Huang,Shuangquan Liao,Yan-Chan Wei
Rubber materials are frequently degraded by environmental factors such as light, heat and oxygen during service. Conventional protective approaches, however, often involve adding antioxidants during processing, which not only causes significant environmental pollution but also limits the applicability of rubber products in the biomedical field. Therefore, developing robust aging mitigation strategies constitutes a critical imperative to ensure material longevity. This study proposes a feasible and effective strategy: inducing network rearrangement in rubber through pre-stretching to achieve a more stable crosslinked structure, thereby enhancing its thermo-oxidative stability. During vulcanization, polysulfide and disulfide bonds are formed in the crosslinking network of rubber. Pre-stretching preferentially broke weaker bonds, inducing the conversion of polysulfide bonds to disulfide bonds during the stretching process. This strain-induced network rearrangement enhanced the rigidity and stability of rubber. At elevated temperatures, this mechanism became more pronounced. Pre-stretching triggered rapid conversion of polysulfide to disulfide bonds during the initial stages of thermo-oxidative aging. Given the higher bond energy and stability of disulfide bonds under thermal-oxidative conditions, the aging resistance of rubber is significantly improved. Both atomic force microscopy tests and mechanical tests demonstrated that stretching induced dynamic transformation of sulfur bonds in the crosslinking network, leading to significant changes in spatial heterogeneity under thermo-oxidative conditions. As a result, the thermo-oxidative resistance of natural rubber was enhanced, with the retention of tensile strength increasing from 58.6 % to 81.1 % after 24 h of thermo-oxidative aging. This study not only provided important guidance for the general design of thermo-oxidation-resistant elastomers but also advanced the understanding of rubber network evolution mechanisms under thermo-mechanical coupling conditions.
研究领域:
材料科学
·
高分子科学
·
机械工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
MECHANICS OF ADVANCED MATERIALS AND STRUCTURES
·
2025
·
IF 0
Jiayu Tian,Chenzhe Li,Ying Zhao
Three-dimensional (3D) soft actuators capable of 3D-to-3D shape morphing have garnered significant research interest. However, realizing multifunctional capabilities remains challenging, as most existing designs are limited to transformations between geometrically similar 3D shapes. To address this limitation, this article presents the design and fabrication of a 3D soft actuator capable of morphing between geometrically dissimilar 3D shapes. The actuator features a bilayer structure fabricated by bonding a liquid crystal elastomer (LCE) layer onto a pre-stretched elastomer substrate. Independent control over the substrate’s pre-stretch direction and the LCE’s alignment direction enables programmable 3D-to-3D shape transformations between dissimilar modes, such as bending-to-twisting or twisting-to-bending. The practical utility of morphing between dissimilar shapes is demonstrated via two applications: a multifunctional 3D gripper performing both grasping and winding, and a soft actuator facilitating directional object manipulation. This work overcomes the restriction of similar deformation modes inherent in many existing actuators, offering enhanced design flexibility for tailoring initial and actuated configurations to specific application requirements.
研究领域:
软体机器人
·
智能材料
·
执行器技术
·
形状变形
·
材料科学
✓ 已验证
DOI
SOFT MATERIALS
·
2022
·
IF 1.619
Kai Chen,Tian Zong,Qin Chen,Siyu Liu,Linmin Xu,Dekun Zhang
In order to control complex motion behavior in organisms, most biological tissues have highly oriented structures and anisotropic mechanical properties, such as articular cartilage, muscle, skin and blood vessel. In this study, inspired by the directional structure and excellent mechanical properties of biological soft tissues, polyvinyl alcohol/carboxymethyl cellulose hydrogels with different contents of sodium alginate were prepared by combining freeze-thaw and prestretching methods. Compared with SEM images without pre-stretch hydrogels, there are obvious ordered pore structures in the pre-stretch samples along the tensile direction, and the network structure becomes denser. XRD and FTI R results indicate that the introduction of SA and CMC increases the number of internal hydrogen bond and forms new covalent bonds. The tensile strength of the hydrogel without annealing and stretching treatments is only 0.41MPa. After annealing and stretching treatments, the tensile strength of the hydrogel is increased to 0.93MPa. Furthermore, the creep deformation of hydrogel was reduced from 1.08 mm to 0.27 mm by annealing and stretching treatments. To sum up, these results suggested that PVA/SA/CMC composite hydrogels with oriented structure might have potential applications in soft tissue repair and other biomaterials.
研究领域:
材料科学
·
生物医学工程
·
生物材料
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2023
·
IF 8.2
Li Zhong,Yuhui Zhang,Fei Liu,Luzhen Wang,Qian Feng,Chuchu Chen,Zhaoyang Xu
Conductive hydrogels are considered one of the most promising materials for preparing flexible sensors due to their flexible and extensible properties. However, conventional hydrogels' weak mechanical and isotropic properties are greatly limited in practical applications. Here, the internal structure of the hydrogel was regulated by pre-stretching synergistic ion crosslinking to construct a carboxymethyl cellulose-based double network-oriented hydrogel similar to muscle. The introduction of pre-stretching increased the tensile strength of the double-network hydrogel from 1.45 MPa to 4.32 MPa, and its light transmittance increased from 67.3 % to 84.5 %. In addition, the hydrogel's thermal stability and electrical conductivity were improved to a certain extent. Its good mechanical properties and conductive properties can be converted into stable electrical signal output during deformation. The carboxymethyl cellulose-based double network oriented hydrogels were further assembled as flexible substrates into flexible sensor devices. The hydrogel sensors can monitor simple joint movements as well as complex spatial movements, which makes them have potential application value in the research field of intelligent response electronic devices such as flexible wearables, intelligent strain sensing, and soft robots.
研究领域:
材料科学
·
纳米技术
·
生物医学工程
·
电子学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）