JOURNAL OF MATERIALS RESEARCH
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2024
·
IF 2.7
Shen Wenting,Du Jiaxin,Mei Xiangyu,Liu Su,Liu Fujian,Si Yinsong
Graphitic carbon nitride (g-C 3 N 4 ), owing to its unique structure, has emerged as a hotspot in the semiconductor photocatalytic hydrogen production. However, the intrinsic poor crystallinity of g-C 3 N 4 , which leads to poor hydrogen production efficiency, remains a significant drawback. This study introduces a novel approach for synthesizing highly crystallized g-C 3 N 4 by optimizing precursor mass and employing a fixed temperature polymerization technique. Our research focuses on the intermediate stage polymerization at 220 °C using varying masses of dicyandiamide (DCY) precursors. The results indicate that an increase in the mass of the DCY precursor leads to g-C 3 N 4 with a more regular microstructure and enhanced crystallinity. The photocatalytic hydrogen production rate of this g-C 3 N 4 reached up to 3779 μmol·h −1 ·g −1 , which is five times that of the original g-C 3 N 4 .This research holds significant implications for improving the photocatalytic hydrogen production performance of intrinsic g-C 3 N 4 . Graphical abstract
研究领域:
材料科学
·
能源化学
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产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Yahao Liu,Yuansheng Wang,Xue Yang,Wei Huang,Yu Zhang,Xiao Zhang,Xuan Wang
Stiffness variable polymers are an essential family of materials that have aroused considerable attention in soft actuators. Although lots of strategies have been proposed to achieve variable stiffness, it remains a formidable challenge to achieve a polymer with a wide stiffness range and fast stiffness change. Herein, a series of variable stiffness polymers with a fast stiffness change and wide stiffness range were successfully synthesized, and the formulas were optimized via Pearson correlation tests. The rigid/soft stiffness ratio of the designed polymer samples can reach up to 1376-folds. Impressively, owing to the phase-changing side chains, the narrow endothermic peak can be observed with full width at half-maximum within 5 °C. Moreover, the shape memory properties of the shape fixity (Rf) and shape recovery ratio (Rr) values of the shape memory properties could reach up to 99.3 and 99.2%, respectively. Then, the obtained polymer was introduced into a kind of designed 3D printing soft actuator. The soft actuator can achieve sharp heating–cooling cycle of 19 s under a 1.2 A current with 4 °C water as coolant and can lift a 200 g weight at the actuating state. Moreover, the stiffness of the soft actuator can reach up to 718 mN/mm. The soft actuator exhibits an outstanding actuate behavior and stiffness switchable capability. We expect our design strategy and obtained variable stiffness polymers to be potentially applied in soft actuators and other devices.
研究领域:
材料科学
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软体机器人学
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DOI
PubMed
高影响因子
JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES
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2018
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IF 2.441
Xingchen Zhai,Haitian Zhao,Min Zhang,Xin Yang,Jingming Sun,Yongxin She,Aijun Dong,Hua Zhang,Lei Yao,Jing Wang
A new 3‑aminophenylboronic acid-functionalized stationary phase based on silica for hydrophilic interaction liquid chromatography (HILIC) was developed and showed great HILIC characteristics on separation for chito‑oligosaccharides. The material was synthesized by grafting 3‑aminophenylboronic acid group to silica, and it was characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), elemental analysis and thermal gravimetric analysis (TGA). Nucleobases and nucleosides were used to evaluate the retention property and to investigate retention mechanism by the models designed for description of partitioning and surface adsorption through adjusting ratio of water in the mobile phase . Parameters affecting chromatography behavior such as ionic strength , buffer pH and column temperature were also investigated. Results have indicated that the retention mechanism was a combination of partitioning and surface adsorption, and the hydrogen bond seemed to be the main force for the retention behavior. Finally, the new 3‑aminophenylboronic acid-functionalized based on silica stationary phase was applied to separate chito-oligosaccharide samples with optimized mobile phase conditions and showed acceptable chromatograms.
研究领域:
分析化学
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生物化学
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DOI
PubMed
高影响因子
Cell Reports Physical Science
·
2024
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IF 7.9
Hong-Qin Wang,Bu-Yun Yu,Zi-Yang Huang,Fang-Zhou Wang,Lu Ju,Zhi-Da Xiao,Jun-Lin Zhan,Hao Chen,Zhen-Guo Liu,Wei-Bing Lu,Cheng-Hui Li
Radio-frequency (RF) devices are an indispensable component in wireless communication systems. Developing high-strength, cost-effective RF devices with good performance on irregular surfaces is very important but remains highly challenging. Here, we report a dynamic variable-stiffness polymer with high mechanical strength, shape-memory behavior, and recyclability by introducing multiple dynamic cross-linking interactions (coordination bonds, dipole-dipole interactions, and chain entanglements). Leveraging the unique characteristics of the polymer, we fabricate several shape-adaptive RF devices and a backscatter communication system through the ultra-low-cost planar manufacturing process. These RF components can be fitted to various irregular surfaces when heated and retain their shape with high mechanical strength after cooling. In addition to simultaneously offering mechanical robustness and conformal capability, these devices possess high electromagnetic performance as well as self-healing and recyclable properties. We believe that such shape-adaptive RF devices hold great potential in robots, intelligent aircraft, wearable electronic systems, and more.
研究领域:
材料科学
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无线通信
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电子工程
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产品关联
DOI
高影响因子
Polymer Chemistry
·
2019
·Vol. 10
·期 16
·2073-2082
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IF 4.76
Yujie Zhu,Yang Xue,Xiaohua Li,Jianhua Zhang,Ruiwei Guo
Regioselective addition of nonsymmetrical monomers in radical polymerization is a basic issue for control of the kinetics and structure of the resulting products. In RAFT polymerization, head addition generates primary alkyl adducts trapped by RAFT agents. Due to the low leaving ability of primary alkyl radicals, this kind of adduct in RAFT polymerization will become non-active macro-RAFT agents, i.e., dead dormant species (DDS). The contents of non-active macro-RAFT agents in RAFT polymerization of three acrylates (ethyl, butyl, and 2-ethylhexanyl acrylate), two methacrylates (ethyl and butyl methacrylate) and styrene were determined by a combination technology of RAFT block polymerization derivation and gradient polymer elution chromatography. The head addition incidences of these monomers were estimated according to our previously proposed formula between the DDS content and head addition incidence. The results showed that the number or type of side chains both had significant influence on head addition incidence, with incidence of methacrylates and styrene about one order of magnitude smaller than that of acrylates due to steric repulsion effects. The results also showed that DDS contents would accumulate with increased degree of polymerization. Therefore, head addition played an important role in acrylate RAFT polymerization when product composition was considered, especially for polymers of high molecular weight.
研究领域:
高分子化学
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材料科学
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DOI
高影响因子
MACROMOLECULAR CHEMISTRY AND PHYSICS
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2020
·Vol. 221
·期 18
·2000148
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IF 2.335
Mengyuan Zhang,Yang Xue,Shixian Zhang,Jianhua Zhang,Ruiwei Guo
Regioselective addition of nonsymmetrical monomers in radical polymerization is a basic issue for control of the reaction kinetics and structure of the resulting products. In reversible addition-fragmentation chain transfer (RAFT) polymerization, head addition generates primary alkyl adducts when trapped by RAFT agents. Due to the low leaving ability of primary alkyl radicals, this kind of adduct in RAFT polymerization will become nonactive macro-RAFT agents, that is, dead dormant species (DDS). Based on the previously-developed equation for the correlation of DDS content (α) with head-addition incidence (ρ 1 ) in RAFT polymerization and the quantitative determination method of DDS content by coupling a block-polymerization derivatization with gradient polymer elution chromatography analysis, the ρ 1 values of methyl acrylate (MA) at different temperatures are determined with benzyl N -carbazolecarbodithioate (BCBD) as RAFT agent and 2-methyloxyethyl acrylate as the second monomer for block-polymerization derivatization. The results show that the ρ 1 values of MA at 60, 70, 80, and 90 °C are 2.04 × 10 −3 , 2.37 × 10 −3 , 2.72 × 10 −3 , and 3.28 × 10 −3 , respectively, and the activation energy for ρ 1 is 15.8 kJ mol −1 . The DDS in BCBD-mediated RAFT polymerization of MA is separated by column chromatography and characterized by 1 H-NMR and MALDI-TOF MS.
研究领域:
高分子化学
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材料科学
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DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
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2023
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IF 7.4
Guoqiang Sun,Ting Ma,Mingjun Hu,Xiaolong Sun,Zhilong Cao,Ruiqi Zhao
Due to the excellent shear deformation resistance of high-viscosity polymer-modified bitumen (HVPMB), the traditional methods based on time sweep and linear amplitude sweep (LAS) had problems with insufficient damage accumulation and inability to disrupt the integrity of HVPMB, making it difficult to accurately evaluate its fatigue and healing characteristics. To solve this problem, this study developed an effective evaluation proposal called continuous multiple LAS (MLAS) test and MLAS-based healing (MLASH) test. One base bitumen and three HVPMBs were selected for related experiments. MLAS test results confirmed that the percentage of strain energy attenuation ( PSEA ) can be used to evaluate the fatigue damage degree of HVPMBs. The lower the PSEA , the lesser damage. Combined with the fluorescence microscope and direct photography observation, the fatigue hairline cracks during MLAS test gradually expanded from the sample periphery to center until completely destroyed. Further, the MLASH test was developed to evaluate the healing performance of HVPMB by introducing intermittent duration into MLAS test. The variation of PSEA after tenth LAS loading (i.e. Δ PSEA ) was proposed to evaluate the healing performance of HVPMB. The larger the Δ PSEA , the better the healing performance of HVPMB. All HVPMBs showed satisfactory healing performance once there was sufficient healing intermittent time (e.g. 180 s), and the healing performance was negatively correlated with the damage degree. Notably, the polymer structures had a dual effect on the healing performance of HVPMB, that is, they promoted the elastic healing recovery of HVPMB at lower temperature, while hindering the flow healing recovery at higher temperatures. Moreover, different temperatures caused a shift in the ranking of healing performance of various HVPMBs, thus the healing result at only single temperature cannot comprehensively represent the healing performance of HVPMB. Overall, the newly developed evaluation proposal can help to select HVPMB with excellent fatigue resistance and healing properties and provide a certain basis for accurately predicting HVPMB pavement life.
研究领域:
材料科学
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土木工程
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DOI
高影响因子
RSC Advances
·
2021
·Vol. 11
·期 60
·37744-37751
·
IF 3.361
Yi He,Jiayu Guo,Xiazhen Yang,Bing Guo,Hangyan Shen
Ambient humidity plays an important role in the fields of industrial and agricultural production, food and drug storage, climate monitoring, and maintenance of precision instruments. To sense and control humidity, humidity-responsive actuators that mimick humidity responsive behavior existing in nature, have attracted intense attention. The most common and important class of humidity actuators is active bilayer structures. However, such bilayer structures generally show weak interfacial adhesion, tending to delaminate during frequent bending and restoration cycles. In this work, to address this problem, a novel monolayer humidity-driven actuator with no adhesive issue is developed by integrating the swellable metal–organic frameworks (MIL-88A) into thermoplastic polyurethane films. The proposed actuators display excellent humidity response that under the conditions of relative humidity simulated with saturated salt solution, the MIL-88A/polyurethane composite films show good self-folding response and stability for recycling use. In addition, a deep insight into the self-folding of the composite films is also provided and a new response mechanism is proposed. In this case, the results show that both the preparation method and response properties of the humidity actuators are improved. Therefore, it suggests a new promising way to develop and design flexible humidity actuators.
研究领域:
材料科学
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机械工程
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化学工程
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环境科学
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DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
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2020
·
IF 8.758
Cuicui Su,Yiqi Hu,Qing Song,Yumin Ye,Lingling Gao,Peng Li,Ting Ye
We report initiated chemical vapor deposition of model-graded polymer coatings enabling antibacterial, antifouling, and biocompatible surfaces. The graded coating was constructed by a bottom layer consisting of bactericidal poly(dimethyl amino methyl styrene) and a surface layer consisting of both dimethyl amino methyl styrene (DMAMS) and hydrophilic vinyl pyrrolidone (VP) moieties. Fourier transform infrared spectra showed existence of both DMAMS and VP in the coating with DMAMS as the major component, while X-ray photoelectron spectroscopy analysis and water contact angle measurement revealed a VP-enriched coating surface. The resultant coating exhibited more than 99.9% killing rate against both Gram-negative Escherichia coli and Gram-positive Bacillus subtilis despite the incorporation of VP on the surface. We believe that such bactericidal capability resulted because of its high surface zeta potential, which could be originated from the DMAMS units distributed both on the top surface and underneath. The graded coating achieved more than 85% bacterial fouling resistance than the pristine substrate, as well as improved biocompatibility, owing to the abundant surface lactam groups from the VP moiety. Furthermore, the graded coating maintained good bactericidal capability after multicycle challenges of bacterial solutions and was durable against continuous rigorous washing, suggesting potential applications in biomedical devices.
研究领域:
材料科学
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生物医学工程
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表面化学
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聚合物科学
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DOI
PubMed
高影响因子
Small Methods
·
2024
·
IF 10.7
Jiongfeng Sun,Rui Wang,Guangjie Xue,Guofu Qiao
Concrete, in particular application scenarios, such as crack repair, disaster rescue and relief, and 3D printing, needs to be cured quickly. In this work, a novel synthesis strategy, UV-initiated frontal polymerization (FP), for fast preparation of high-strength polymer concrete at room temperature is proposed, and the whole fabrication progress within several minutes, in which coarse aggregates and a small amount of short carbon fibers (CF) are used to enhance mechanical properties and heat conduction and reduce the amounts of chemical adhesives. SEM, DSC, MIP, Ultra depth of field microscope, and Rheometer are employed to characterize the properties of chemical adhesives, polymer concrete, and polymerization process. In addition, the finite element method is used to investigate the internal temperature field status of the FP process. The results indicate that the compressive and flexural strengths of the polymer concrete with 1.0 wt%-1 mm-CF-50 vol.%-quartz sand exceeded 70 and 20 MPa, respectively, in which the average self-propagation velocity reached 58 mm min −1 . The investigation provides a promising approach for the rapid construction of structural facilities, emergency repair after disasters, 3D printing concrete, etc.
研究领域:
材料科学
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土木工程
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聚合物化学
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建筑技术
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灾害管理
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3D打印
✓ 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）