OPTICAL MATERIALS
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2023
·
IF 3.9
Xiaoshuai Li,Meishan Zhang,Chi Zhang,Rui Niu,Hongmei Ma,Yubao Sun
Bistable liquid crystal devices, which require electricity only at the switching processes of the two states, have advantages in energy saving and safety compared with monostable liquid crystal devices. Due to electrohydrodynamic and dielectric effects, the ion-doped cholesteric liquid crystal can switch between a focal conic state and a planar state with different frequencies of the driving voltage. However, the cholesteric liquid crystal that self-assembles from the dynamic scattering state always has a poor focal conic state, resulting in a low contrast ratio. This paper presents a bistable polymer-stabilized ion-doped cholesteric liquid crystal device. The introduction of a small amount of polymer network can greatly enhance the light scattering capabilities of the focal conic state, endowing the device with excellent electro-optic performance. The electro-optical properties of the device are investigated with the various content of monomer and chiral dopant , and rotational viscosity of liquid crystal. Liquid crystal with a low rotational viscosity coefficient is beneficial to the formation of a good polymer network. The pitch induced by chiral dopant impacts the formation process of the polymer network, which subsequently affects the electro-optical properties. The bistable device has a low driving voltage and a high contrast ratio, making it ideal for use in smart windows.
研究领域:
材料科学
·
光学工程
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DOI
高影响因子
Polymers
·
2021
·Vol. 13
·期 11
·1679
·
IF 4.329
Yanning Zeng,Weiming Yang,Shuxin Liu,Xiahui Shi,Aoqian Xi,Faai Zhang
Thermoset polymers show favorable material properties, while bringing about environmental pollution due to non-reprocessing and unrecyclable. Diels–Alder (DA) chemistry or reversible exchange boronic ester bonds have been employed to fabricate recycled polymers with covalent adaptable networks (CANs). Herein, a novel type of CANs with multiple dynamic linkers (DA chemistry and boronic ester bonds) was firstly constructed based on a linear copolymer of styrene and furfuryl methacrylate and boronic ester crosslinker. Thermoplastic polyurethane is introduced into the CANs to give a semi Interpenetrating Polymer Networks (semi IPNs) to enhance the properties of the CANs. We describe the synthesis and dynamic properties of semi IPNs. Because of the DA reaction and transesterification of boronic ester bonds, the topologies of semi IPNs can be altered, contributing to the reprocessing, self-healing, welding, and shape memory behaviors of the produced polymer. Through a microinjection technique, the cut samples of the semi IPNs can be reshaped and mechanical properties of the recycled samples can be well-restored after being remolded at 190 °C for 5 min.Keywords:CANs;semi IPNs;self-healing
研究领域:
材料科学
·
高分子化学
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DOI
PubMed
高影响因子
Vietnam Journal of Chemistry
·
2024
·
IF 1.3
Nguyen Binh Duong,Quan Thi Thu Trang,Phan Thi Ngoc Bich,Pham Van Lam
In this article, new interpenetrating polymer network (IPN) hydrogel as an efficient adsorbent for ammonium was prepared by a two-step process. First, semi-IPN hydrogel of chitosan-g-poly(acrylic acid)/bentonite (CAB) and chitosan (CTS) was synthesized by grafting polymerization in the presence of exfoliated bentonite as both cross-linking agent and nanoscale inorganic filler. Second, cross-linking polymer network of chitosan-glutaraldehyde (CGA) was formed by reaction of CTS with glutaraldehyde (GA). The obtained IPN hydrogel (CAB/CGA) was characterized by Fourier-transform infrared spectroscopy, scanning electron microscopy and its swelling degree and PZC value were also measured. These results demonstrate that copolymerized graft reaction was occurred between CTS, AA and bentonite forming CAB, and CGA presented as a cross-linker in CAB/CGA polymer network. CAB/CGA has a moderate swelling degree of 7.8. CAB/CGA exhibits high adsorption capacity and fast adsorption rate for ammonium. Adsorption process reaches equilibrium in 30 min and fits well to Langmuir adsorption model with a fairly high maximum adsorption capacity of 41.06 mg g −1 . The material has a good regeneration ability. After five times of adsorption–desorption, there was almost no decrease in ammonium adsorption capacity. Moreover, the low swelling degree leads to an improvement in material strength and a reduction of equipment cost.
研究领域:
材料科学
·
环境科学
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DOI
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Ping Zhang,Weiyu Zhou,Yunfeng He,Ziyi Xu,Maochun Li,Wei Hong,Canhui Yang
Adhesives are ubiquitous, but the mutual exclusion between hyperelasticity and adhesiveness impedes their uses in emerging techniques such as flexible/stretchable electronics. Herein, we propose a strategy to synthesize hyperelastic adhesives (HEAs), by designating hyperelasticity and adhesiveness to the bulk and the surface of a polymer network, respectively. The bulk is hyperelastic but nonadhesive, and the surface is viscoelastic but adhesive, while the HEA is hyperelastic and adhesive. We exemplify the principle by synthesizing poly(butyl acrylate) as the bulk and poly(butyl acrylate-co-isobornyl acrylate) as the surface. The resulting HEA exhibits a low hysteresis of 4% at 100% strain and an adhesion energy of 270 J m–2. Moreover, the HEA is optically transparent, thermally stable, spontaneously adhesive to various materials, and mechanically stable against cyclic load, relaxation, and creep. We demonstrate two applications enabled by the unique combination of hyperelasticity and adhesiveness. The proposed strategy is generic, paving new avenues for stretchable yet resilient adhesives for diverse applications.
研究领域:
材料科学
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化学工程
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DOI
PubMed
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2024
·
IF 7.4
Jie Pan,Xueliang Chen,Yizhen Chen,Wendi Liu,Mingen Fei,Renhui Qiu
An adhesive serves as a vital tool in construction, repair, and rehabilitation projects. Typically crafted from polymer materials such as epoxies or polyurethane latex, it facilitates the creation of resilient bonds between a variety of surfaces, ranging from concrete-concrete and metal-concrete to concrete-composites. However, employing epoxy or polyurethane individually as adhesives often demonstrate insufficient performance and weak interfacial adhesion during service. In this study, an adhesive combining polyurethane and epoxy was synthesized, featuring an interpenetrating polymer network (IPN) structure. This innovative agent was created using polyols sourced from soybean oil and a commercial epoxy resin. By tuning the infusion of polyurethane content, the resultant resin exhibited favorable flowability in civil applications, simultaneously improved strength and toughness due to the IPN structure, and outstanding thermal stability. Notably, the incorporation of 20 wt% polyurethane yielded a polymer with a remarkable tensile strength of 35.9 MPa. Additionally, the bonding adhesion of the prepared resins on concrete specimens was investigated through splitting tensile test and shear strength test. The study explored the influences of polyurethane content, concrete strength, and adhesive layer thickness on interfacial bonding strength. The introduction of an IPN structure within the PU-20 agent proved advantageous for enhancing the bonding adhesion of the concrete, resulting in remarkable interfacial tensile and shear strengths of 4.56 MPa and 21.73 MPa, respectively.
研究领域:
材料科学
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土木工程
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高分子化学
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建筑材料
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产品关联
DOI
高影响因子
Small Structures
·
2025
·
IF 11.3
Wei Feng
Alignment of liquid crystals (LCs) is critical for actuation of LC polymer-based devices. A common strategy to induce surface deformation in LC polymer coatings involves engineering the polymers into multidomain configurations. The application of an electric field serves as an efficient means to achieve this goal. While LCs are partially ordered fluids characterized by intrinsic dynamic disorder and order fluctuations, these fluctuations can be suppressed by electric fields, a phenomenon known as electrical quenching. However, the impact of quenching LC order fluctuations on the molecular actuation behavior of LC polymers remains insufficiently understood. Herein, the translation of the electric quenching effect on LC order from the molecular scale to the macroscopic level, with a focus on regulating the topographical deformation of polymerized LC polymer coatings, is demonstrated. The findings reveal that the suppression of monomeric LC order fluctuations through electric quenching significantly reduces the topographical deformation of the polymerized network. This advancement offers new opportunities for fabricating tunable surfaces with complex patterns, broadening the potential applications of LC-based dynamic surfaces.
研究领域:
材料科学
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物理学
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DOI
高影响因子
GIANT
·
2024
·
IF 5.4
Jinghua Zhao,Ming Zhang,Yongxing Guo,Wei Liu,Yi Li,Yonggang Yang
Colorful cholesteric liquid crystal polymer network (CLCN) patterns can be applied for decoration and anti-counterfeiting. Herein, the CLC inks were prepared using an acrylate liquid crystal, chiral dopants and a photoinitiator. Full-color CLCN patterns were able to be printed out using only two CLC inks by changing their volume ratio. A structure with a gradient helical pitch was identified between different colors. For anti-counterfeiting, the color patterns composed of opposite-handed CLCNs were also printed. A helical-nonhelical-helical structure was identified at the interface. In addition, CLCN patterns with a grating structure were also prepared. The results shown here not only give us a better understanding the cholesteric structure, but also lay the foundations for the applications of CLCN patterns in the fields of decoration and anti-counterfeiting.
研究领域:
材料科学
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光学
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产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2020
·Vol. 44
·期 37
·16045-16053
·
IF 3.288
Yang Ma,Mingming Li,Keren Shi,Zhifeng Chen,Baozhong Yang,Deyu Rao,Xiawei Li,Wei Ma,Shaozhang Hou,Guojing Gou,Huiqin Yao
Based on semi-interpenetrating polymer network (semi-IPN) hydrogel films, a multiple stimuli-responsive film system composed of poly(acrylic acid) (PAA) and N,N-diethyl acrylamide (DEA), designated as PAA–PDEA semi-IPN films, was realized on a glassy carbon (GC) electrode surface with a one-step polymerization method. Rutin (RT), an electroactive probe, displayed invertible pH-, thermo- and SO42− concentration–sensitive cyclic voltammogram (CV) behaviors in the film system. This multiply sensitive electrocatalysis of RT at the PAA–PDEA films was employed to further investigate the multiple stimuli-responsive ON–OFF behaviors of RT. The scanning electron microscopy (SEM) images and control experiments showed pH-sensitive ON–OFF properties of RT, which could be ascribed to the protonated/deprotonated carboxylic (–COOH) groups of the PAA component in different pH buffers and the properties of RT itself. However, the confirmation change or phase transition of the PDEA hydrogel film between the coil and globular states led to thermo- and SO42− concentration–sensitive ON–OFF properties. According to these results, a 3-input/3-output logic gate and a 2-to-1 encoder were constructed successfully. This present system was fabricated for the first time, which may offer numerous possibilities for the design of new electrochemical drug sensors, drug-mimicking release processes and other medical applications. Furthermore, it also can contribute to the development of biomolecular or molecular computing.
研究领域:
材料科学
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生物医学工程
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电化学
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Handong Shi,Shijiao Li,Kai Han,Chuanhao Xu,Lei Gao,Fan Liao,Yanpeng Lv,Yurong Zhang,Chongwei An
This study presents a strategy for developing CL-20 (Hexanitrohexaazaisowurtzita-ne)-based energetic composites with enhanced mechanical properties and intrinsic safety through the synergistic design of PVA (polyvinyl alcohol) /PAA (polyacrylic acid) interpenetrating polymer networks (IPNs) and direct ink writing (DIW) technology. Based on the “hydrogen bond-covalent bond-plasticization” synergistic reinforcement strategy, an IPNs gel system with tunable mechanical properties was developed. After optimizing the polymer ratio (4:3), Crosslinking agent (1 %), and glycerol content (17.5 %), a balance between toughness, ductility, and strength was attained. The DIW-printed structure exhibited excellent molding accuracy and interfacial adhesion (0.924 MPa to aluminum). System characterization demonstrated that the IPN structure achieved uniform CL-20 distribution and controlled porosity, significantly enhancing its mechanical properties, safety, and detonation performance. Its elastic modulus is close to that of engineering plastics(4.504 GPa), the hardness is between soft rubber and hard plastics (0.107 GPa), and the compressive strength is higher than that of typical PBX explosives (15.64 MPa). By using PVA/PAA IPNs, a “topological entanglement-passivation defect” mechanism was established to suppress mechanical sensitivity. Compared to submicron ε-CL-20, the molded sample reduced impact sensitivity by 33.3 % and friction sensitivity by 128.6 %. Additionally, detonation propagation was achieved in a 1.2 × 1.2 mm charge slot within a 90°-160° corner range, with the critical detonation transmission size reaching 0.3 × 0.3 mm and the detonation velocity maintained at 7362 m/s (82.4 % theoretical detonation velocity). This study offers a scalable manufacturing framework for developing energetic devices that combine mechanical properties, intrinsic safety, and adaptability to complex structures.
研究领域:
材料科学
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爆炸化学
·
先进制造
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产品关联
DOI
高影响因子
CHEMISTRY-A EUROPEAN JOURNAL
·
2022
·Vol. 28
·期 72
·e202202717
·
IF 5.02
Yaduo Song,Yanxin Jiang,Longjiang Deng,Guang Yang
Graphical Self-healing quasi-solid polymer electrolyte (SIPH-x-y%) with good flexibility was prepared by polyaddition method. SIPH-x-y% could show high room temperature ionic conductivity, high lithium ion transference number, and good interfacial stability with electrode. The Li/LFP battery assembled with SIPH-20-40% showed high specific capacity and excellent cycle performance. Developing high-performance functional polymer-based electrolytes is important for realizing next generation safe lithium metal batteries. In this study, a new type of quasi-solid polymer network electrolyte (SIPH-x-y%) was prepared by combining synthesized polymer network (SIPH) containing urethane bond linked ionic liquids (ILs), polyethylene glycol (PEG), and disulfide bond moieties, lithium bis(trifluoromethanesulfonyl)imide salt (LiTFSI), and glyme type additive. It was found that SIPH-20-40% was mechanically flexible, self-healable, and showed high ionic conductivity of 2.67×10 −4 S cm −1 . Also, SIPH-20-40% possesses a high lithium ion transference number of 0.43 and good electrochemical stability. These properties enabled the SIPH-20-40% electrolyte membrane to support Li/Li symmetrical cell to cycle stably during long term Li plating and stripping. The Li/SIPH-20-40%/LFP showed high delivered specific capacity and good stability (166.1 mAh g −1 after 106 cycles at 0.2 C). Such glyme doped polymer network electrolyte provides new experimental findings for developing polymer-based electrolyte with excellent mechanical integrity and battery related properties.
研究领域:
材料科学
·
电化学
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DOI
PubMed
高影响因子
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
·
2021
·
IF 5.471
Jincheng Lei,Ziqian Li,Shuai Xu,Zishun Liu
Fracture is a highly nonlinear problem, especially under a large deformation in cross-linked elastomers. Existing constitutive theories and fracture models fail to predict the fracture behavior of cross-linked elastomers because of the absence of the random polymer network structure. Meanwhile, few numerical methods can present the realistic fracture process of a polymer network. In this study, we propose a mesoscopic network mechanics method to present the entire large deformation and fracture process of the polymer network in cross-linked elastomers. The microstructure of a cross-linked elastomer is abstracted as a polymer network model where nodes are referred to as crosslinkers and connections between nodes are referred to as polymer chains. A hybrid total energy form of the network model is proposed including the free energy of polymer chains and volumetric deformation energy. In addition, using a proposed stretch criterion of polymer chains to realize chain scission, this mesoscopic network mechanics method is numerically implemented by coding. Two-dimensional network models with uniform and randomly distributed chain lengths, as well as models with different types of pre-cracks, are constructed and simulated under uniaxial tension tests using our method. Our method reproduces the entire hyper-elastic large deformation and fracture process of polymer network models. The random network models show a lower Young's modulus and a less significant strain-hardening stage, indicating that the structural randomness is the primary cause of accuracy degradation for existing hyperelastic constitutive models under large deformations. The results also reveal that the structural randomness of the polymer network is a primary reason for the ductile fracture and the low notch sensitivity of cross-linked elastomers.
研究领域:
材料科学
·
力学
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DOI
高影响因子
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
·
2023
·
IF 5.3
Xingjian Sun,Ping Rao,Xitao He,Canhui Yang,Wei Hong
Do materials prepared from identical compositions of constituting ingredients always exhibit similar mechanical properties? The answer is negative for most structural materials, as has been demonstrated by extensive studies on various factors such as the effects of processing and microstructures. However, the same question has seldom been addressed in the case of polymeric gels. In this work, by using a simple chemically crosslinked hydrogel as a model system, the mechanical properties, including elastic stiffness , fracture toughness , and fatigue threshold, of gels with identical chemical compositions are systematically investigated. The distinct material properties are then rationalized and quantitatively correlated to synthesis conditions and manufacture processes through scaling laws derived from basic physics. Different scaling laws are identified between samples prepared from swelling and deswelling. Extreme mechanical properties, such as the remarkable fracture energy of hydrogels prepared by deswelling from highly swollen samples, are observed and attributed to the structural characteristics of the polymer network , and further correlated to the synthesis processes. This study provides insights into the synthesis-property correlations of polymeric gels, which may have profound influences on the design of new polymeric materials and their applications in various fields.
研究领域:
材料科学
·
物理学
✓ 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）