Polymers
·
2019
·Vol. 11
·期 6
·950
·
IF 3.164
Hongtao Cao,Beijun Liu,Yiwen Ye,Yunfang Liu,Peng Li
Bisphenol A dicyanate (BADCy) resin microparticles were prepared by precipitation polymerization synthesis and were homogeneously dispersed in a BADCy prepolymer matrix to prepare a BADCy self-reinforced composites. The active functional groups of the BADCy resin microparticles were characterized by Fourier transform infrared (FT-IR) spectroscopy. The results of an FT-IR curve showed that the BADCy resin microparticles had a triazine ring functional group and also had an active reactive group -OCN, which can initiate a reaction with the matrix. The structure of the BADCy resin microparticles was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). From the TEM results, the BADCy resin microparticles dispersed in the solvent were nano-sized and distributed at 40–60 nm. However, from the SEM results, agglomeration occurred after drying, the BADCy resin particels were micron-sized and distributed between 0.3 μm and 0.6 μm. The BADCy resin prepolymer was synthesized in our laboratory. A BADCy self-reinforced composite was prepared by using BADCy resin microparticles as a reinforcement phase. This corresponds to a composite in which the matrix and reinforcement phase are made from different morphologies of the same monomer. The DSC curve showed that the heat flow of the microparticles is different from the matrix during the curing reaction, this means the cured materials should be a microscopic two-phase structure. The added BADCy resin microparticles as reaction sites induced the formation of a more complete and regular cured polymer structure, optimizing the cross-linked network as well as increasing the interplay between the BADCy resin microparticles and prepolymer matrix. Relative to the neat BADCy resin material, the tensile strength, flexural strength, compressive strength and impact strength increased by 98.1%, 40.2%, 27.4%, and 85.4%, respectively. A particle toughening mechanism can be used to explain the improvement of toughness. The reduction in the dielectric constant showed that the cross-linked network of the self-reinforced composite was more symmetrical and less polar than the neat resin material, which supports the enhanced mechanical properties of the self-reinforced composite. In addition, the thermal behavior of the self-reinforced composite was characterized by thermogravimetric analysis (TGA) and dynamic mechanical thermal analysis (DMTA). The results of DMTA also establishes a basis for enhancing mechanical properties of the self-reinforced composite.Keywords:cyanate ester;self-reinforced composite;cross-linked network;mechanical property
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
Polymers
·
2019
·Vol. 11
·期 9
·1403
·
IF 3.164
Lifen Tong,Xiting Lei,Guangyao Yang,Xiaobo Liu
A novel poly(arylene ether nitrile) terminated with hydroxyl groups (PEN–OH) was synthesized successfully. The effects of heat-treatment temperature on the thermal properties, mechanical properties, and dielectric properties of the PEN–OH films were studied in detail. Due to the cross-linking reaction occurring, at high temperature, among the nitrile groups on the side of the PEN–OH main chain to form a structurally stable triazine ring, the structure of materials changes from a linear structure to a bulk structure. Thus, the thermal properties and mechanical properties were improved. In addition, the occurrence of cross-linking reactions can reduce the polar groups in the material, leading to the decrease of dielectric constant. As the heat-treatment temperature increased, the glass-transition temperature increased from 180.6 °C to 203.6 °C, and the dielectric constant decreased from 3.4 to 2.8 at 1 MHz. Proper temperature heat-treatment could improve the tensile strength, as well as the elongation, at the break of the PEN–OH films. Moreover, because of the excellent adhesive property of PEN–OH to copper foil, a double-layer flexible copper clad laminate (FCCL) without any adhesives based on PEN–OH was prepared by a simple hot-press method, which possessed high peel strength with 1.01 N/mm. Therefore, the PEN–OH has potential applications in the electronic field.Keywords:low dielectric constant;poly(arylene ether nitrile);thermal properties;self-toughening;self-enhancement
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2021
·
IF 5.161
Yangyang Duan,You Wu,Ru Yan,Meng Lin,Shengjun Sun,Houyi Ma
A polyelectrolytes coating with self-healing and self-strengthening dual-function was fabricated on the titanium sheet for anticorrosion studies in fluorine-containing artificial saliva. The coating contains a polydopamine bottom film and 2-hydroxypropyltrimethyl ammonium chloride chitosan and sodium alginate multilayers. The incorporated polydopamine bottom film was modified to assure the adhesion of the polyelectrolytes coating on the titanium sheet. Based on the scratch assay, there are two stages for the scratched coating immersed in fluorine-containing artificial saliva: healing and strengthening. Results exhibited that the coating possesses a remarkable self-healing property in the early-stage immersion due to the swollen polyelectrolytes migrating to the scratched region and the calcium cations of the corrosive medium as an ionic crosslinker intercalated in the swollen polyelectrolytes forming calcium alginate and filling the micro-scale scratch. During the later-stage immersion, the self-healing coating showed excellent self-strengthening performance originating from the formation of the more and more compact film with calcium cations intercalated. This research provides an effective strategy to prolong the service life and improve corrosion performance for the implants in the human body environments.
研究领域:
材料科学
·
生物医学工程
·
腐蚀与防护
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POLYMER SCIENCE
·
2024
·Vol. 62
·期 15
·3346-3359
·
IF 3.9
Xiaohui Wang,Yarui Hou,Yiyuan Fan,Zeqi Liu,Ran Li,Xiaojun Li,Bin Yang,Qingye Liu
Soft tissues, such as muscle could autonomously grow through re-alignment and/or -combination of collagen nanofibrils upon the mechanical training. This adaptive capability is highly expected in artificial materials, particularly in hydrogel actuator. In order to avoid the failure for devices by suffering from the accumulated mechanical loading, in this work, a double layered thermo-responsive hydrogel actuator capable of self-strengthening was successfully prepared. In the bilayer, PVA nanocrystals with different particle sizes were uniformly distributed in each monolayer matrix, giving rise to the asymmetric structure and the resultant differentiated de-swelling behaviors. Thus, the obtained hydrogel actuator with the semi-interpenetrating network of P(NIPAM-co-NMA) can display diverse programmable transformations by varying the temperatures. The existence of PVA nanocrystals in both layers not only can enhance the mechanical strength, dramatically minimizing the collapse of hydrogel actuator in service due to the imbalance of the mechanical properties for bilayer structure, but also was greatly involved in the self-reinforcing behavior. After repetitive tensile training with 80% strain, the tensile strength and fracture strain increased from 29.6 to 45.8 kPa and 95% to 104%, respectively. The experimental results indicated that the anisotropic orientation and strain-induced-crystallization for PVA crystalline domains readily occurred along the tensile direction, finally leading to the synchronous enhancement in mechanical strength for both layers. This work provides a new strategy for designing smart and robust biomimetic hydrogel systems that can be further used as the intelligent soft robotics in various fields. Graphical
研究领域:
材料科学
·
生物仿生学
·
软体机器人
✓ 已验证
产品关联
DOI
高影响因子
ACS Nano
·
2022
·
IF 18.027
Jing-Jie Ye,Wuyang Yu,Bo-Ru Xie,Ke Li,Miao-Deng Liu,Xue Dong,Zhao-Xia Chen,Jun Feng,Xian-Zheng Zhang
Conventional cancer targeting methodology needs to be reformed to overcome the intrinsic barriers responsible for poor targeting efficiency. This study describes a concept of self-reinforced cancer targeting (SRCT) by correlating targeting with therapy in a reciprocally enhancing manner. SRCT is achieved on the basis of two prerequisites: (1) target molecules have to be expressed on cancer cell membranes but not on normal cells, and (2) notably, their expression on cancer cells must be actively upregulated in response to cellular attack by cancer treatments. As a proof-of-concept, a GRP78-targeting nanovehicle for chemotherapy was designed. Resultant data showed that chemotherapeutic drugs could effectively elevate GRP78 expression on the plasma membranes of cancer cells while having minimal influence on normal cells. DOX pretreatment of cancer cells and tumor tissues can greatly increase the targeting efficacy and therapeutic performance of the prepared GRP78-targeting nanomedicine while somewhat disfavoring the nontargeting counterpart. In vivo and in vitro results demonstrated that this GRP78-targeting nanomedicine could accurately target cancer cells to not only implement chemotherapy but also induce GRP78 upregulation on cancer cells, eventually benefiting continuous cancer-cell-targeted attack by the nanomedicines remaining in the blood circulation or administered in the next dose. The GRP78-targeting nanomedicine displays much better antitumor performance compared with the nontargeting counterpart. SRCT is expected to advance cancer-targeted therapy based on the positive dependency between targeting and therapeutic modalities.
研究领域:
肿瘤学
·
药理学
·
分子生物学
✓ 已验证
DOI
PubMed
高影响因子
Polymer Chemistry
·
2022
·Vol. 13
·期 37
·5368-5379
·
IF 5.364
Chenru Tian,Haoran Feng,Yuchen Qiu,Ganggang Zhang,Tianwei Tan,Liqun Zhang
Covalent crosslinking and reinforcement are two critical issues in elastomer science and engineering. It remains challenging to achieve green crosslinked and mechanically robust elastomer materials through a facile and efficient strategy. In the present work, a facile and novel strategy for multi-crosslinking network design is proposed to prepare high-performance elastomers based on the amidoxime modification of commercial nitrile–butadiene rubber (NBR). For the first time, we found that amidoxime-functionalized NBR (AO-NBR) shows unique self-crosslinking and self-reinforcing abilities. The hydrogen bonds and metal–ligand coordination bonds arising from amidoxime groups can be formed between the AO-NBR chains. Moreover, AO-NBR could be chemically self-crosslinked based on the reaction between amidoxime groups and nitrile groups without additional additives at elevated temperature, generating the 1,2,4-oxadiazole groups. Based on the inherent properties of AO-NBR, the multi-crosslinking network structures including covalent crosslinking bonds, physical hydrogen bonds, and metal–ligand coordination bonds could be constructed by a simple hot-pressing process and the introduction of zinc ions. What's more, the hydrogen bonds and Zn-based coordination bonds as sacrificial motifs can break prior to covalent bonds with large energy dissipation and undergo reversible breaking and reforming under an external force, which endows the AO-NBR with self-reinforcing ability. Hence, the obtained elastomers show excellent mechanical properties, and their tensile strength, modulus, and toughness are improved simultaneously. Overall, we envisage that this work may open up new avenues to design high-performance elastomers based on a facile self-crosslinking and self-reinforcing strategy.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Nature Communications
·
2024
·Vol. 15
·期 1
·1-11
·
IF 14.7
Zhu Ruixin,Zhu Dandan,Zheng Zhen,Wang Xinling
Most tough hydrogels are reinforced by introducing energy dissipation mechanisms, but simultaneously realizing a high toughness and low hysteresis is challenging because the energy dissipation structure cannot recover rapidly. In this work, high mechanical performance highly entangled double network hydrogels without energy dissipation structure are fabricated, in which physical entanglements act as the primary effective crosslinking in the first network. This sliding entanglement structure allows the hydrogel network to form a highly uniform oriented structure during stretching, resulting in a high tensile strength of ~3 MPa, a fracture energy of 8340 J m −2 and a strain-stiffening capability of 47.5 in 90% water content. Moreover, almost 100% reversibility is obtained in this hydrogel via energy storage based on entropy loss. The highly entangled double network structure not only overcomes the typical trade-off between the high toughness and low hysteresis of hydrogels, but more importantly, it provides an insight into the application of entanglement structures in high-performance hydrogels.
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
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2020
·
IF 16.683
Lijun Yang,Hui Li,Yang Yu,Yang Wu,Lei Zhang
A binder-free electrode with metallic Co embedded in N-doped carbon nanotube array (Co@N-CNT) was fabricated via an electrodeposition , stereoscopic assembly and self-boosting catalytic pyrolysis . Specifically, directed-eletrodeposition vertical growth of Co(OH) 2 -nanosheet serves as the structure inducer to offer abundant sites for ZIF-67 growth, and melamine is selected as an initiator for orientated growth of N-CNTs. As an integrative non-noble electrocatalyst for water splitting, it requires only 1.58 V to achieve 30 mA cm −2 in an alkali-electrolyzer. The remarkable electrochemical performance is mainly attributed to the unique 3D hierarchical tubular structure and the synergistic effect of each chemical compositions, which provide amount of accessible active sites, accelerate the diffusion of electron/electrolyte, and improve the electrical conductivity, hydrophilicity and structural stability. The electro-catalytic splitting water mechanism was further explored by density functional theory. This universal method can be extensively applied to fabricate well-defined monometal or bimetal encapsulated into N-CNTs for various electrochemical applications.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Science China-Chemistry
·
2024
·Vol. 67
·期 10
·3458-3467
·
IF 10.4
Zuo Han,Zhang Luzhi,Xuan Huixia,Gu Shijia,Xu Xinxin,Neisiany Rasoul Esmaeely,Wu Qilin,You Zhengwei
Polymeric materials have penetrated all aspects of society and play an irreplaceable role. However, there is an inherent contradiction between their mechanical properties and processing behavior. Here, inspired by cement, a crucial construction material renowned for its excellent fabricating behavior and self-strengthening properties, we have developed dynamic cross-linked poly(oxime-urethane) (CPOU). The synthesized CPOU showed good self-healing ability and 3D printability owing to the dynamic dissociation and re-association of oxime-carbamate bonds. Simple objects printed through the fused deposition modeling technique were able to be readily assembled into complex architectures through intrinsic self-healing. Furthermore, the self-strengthening of CPOU was successfully realized through multiple-step tandem reactions. The dissociation of dynamic oxime-carbamate bonds produced–NCO groups, which reacted with the surrounding water to form polar urea bonds in the polymer network, leading to an increase in the tensile strength of CPOU from 11.95 to 19.37 MPa. This work not only develops the polymers with combined self-healing, facile fabricating, and self-strengthening properties but also provides a new molecular strategy to modulate the properties of polymers, which could be potentially applied in diverse areas.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
·
2020
·
IF 7.094
Xidong Suo,Zhuo Cao,Yuxiu Yu,Yaodong Liu
In this study, the self-stiffening under cyclic dynamic strain has been observed in polymeric blends containing polyacrylonitrile (PAN) and various contents of thermoplastic polyurethanes (TPU). The increase of the stiffness depends on the phase diagram of the blend, and it was found that the efficiency of self-stiffening decreases when phase separation occurs. Also, TPU containing alternative hard and soft blocks. When the hard block content in TPU increases, the self-stiffening becomes more effective. The interactions between PAN and TPU were investigated by different characterization methods. The soft and hard blocks of TPU plays different roles on the self-stiffening of the PAN/TPU blends, and the interface in between hard blocks and PAN matrix is crucial for the mechanical enhancement. These results indicate that the interface in between polymer chains with significant property difference could possibly lead to unique behaviors. Here, we observe that the fatigue life of PAN films under cyclic strains increases to more than 28 times, as well as the cyclization peak shifts to lower temperature and becomes broader with the addition of 0.5 wt % TPU. These interfaces induced unique behaviors, such as self-stiffening and longer fatigue life, would be valuable for the future developments of adaptable structural materials.
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
ADVANCED FUNCTIONAL MATERIALS
·
2019
·Vol. 29
·期 32
·1902533
·
IF 15.621
Lingling Li,Ziyi Zhang,Ying Chen,Qin Xu,Jian-Rong Zhang,Zixuan Chen,Yun Chen,Jun-Jie Zhu
Lead halide perovskite quantum dots (QDs) are promising electrochemiluminescence (ECL) nanoemitters due to their fascinating photophysical properties. However, due to their poor structural stability against the external environment, the trade-off between their colloidal stability and carrier injection/transport efficiency is a major challenge in the advancement of perovskite-based ECL technology. In this work, intense and stable ECL from CsPbBr 3 (CPB) QDs is achieved by simultaneously encapsulating CPB QDs and coreactant (CoR) into in situ generated SiO 2 matrix via hydrolysis of tetramethyl orthosilicate. The well-designed architecture of the as-obtained CPB-CoR@SiO 2 nanocomposites (NCs) guarantees not only greatly improved stability thanks to the peripheral SiO 2 protecting matrix, but also efficient self-enhanced ECL between CPB and the intra-coreactants. Consequently, by elaborately selecting the CoR molecules with different tertiary/secondary amines and functional groups, multifold higher (up to 10.2 times) ECL efficiencies are obtained for the CPB-CoR@SiO 2 NCs alone in reference to the standard Ru(bpy) 3 2+ /tri- n -propylamine system. This work provides an efficient design strategy for obtaining stable and highly efficient ECL from perovskite QDs, and offers a new perspective for the development and application of perovskite-based ECL system.
研究领域:
材料科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2021
·Vol. 56
·期 18
·11174-11185
·
IF 4.22
Cong Xin,Ren Jiannan,Xiang Chunhui,Gai Xuzhao,Wang Guibin,Yang Yanchao,Wang Shengdao,Zhang Jiacheng,Luan Jiashuang,Yu Zhenxiang
It remains a challenge to prepare special engineering paper with excellent mechanical properties, high temperature resistance and chemical resistance. The emergence of high-performance fiber provides support for the technical progress of special engineering paper. Herein, a novel method to obtain a novel self-reinforced poly (ether ether ketone) (PEEK) composite paper (SR-DI-PEEK/paper) by vacuum filtration, impregnation and hot pressing. Specially, PEEK fibers were used as the skeleton fiber and a small amount of aramid pulp was added as the decanted fiber. By optimizing the process of SR-DI-PEEK/paper preparation, the best mechanical properties of SR-DI-PEEK/paper was presented. Compared with the composite paper prepared with Phenolic solution (PF-PEEK/paper) and Polyimide solution (PI-PEEK/paper), the mechanical properties of SR-DI-PEEK/paper was significantly improved. In particular, when the concentration of impregnation was 3 wt%, the tensile index of SR-DI-PEEK/paper reached 51.10 N m g −1 (tensile strength 47.16 kN m −1 ), which is 16.48 times than that of the un-impregnated PEEK/paper (2.86 kN m −1 ). SR-DI-PEEK/paper also exhibited excellent chemical resistance among acid, alkali, and polar solvents, while the tensile index maintained 96.3% after 40 wt% H 2 SO 4 treatment. Besides, SR-DI-PEEK/paper showed superior thermal performance, while the temperatures corresponding to the weight loss of 5% were 574 °C. Graphical abstract
研究领域:
材料科学
·
工程学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）