MATERIALS AND STRUCTURES
·
2024
·Vol. 57
·期 5
·1-12
·
IF 3.4
Zhang Wan,Wu Zhihong,Huang Wang,Liu Jiayuan,Zhou Huafeng,Qiu Junlong
It is insufficient to enhance the strength of shotcrete by simply relying on the early strength component aluminum sulfate in the liquid accelerator. The introduction of organic additives can effectively compensate for this deficiency. In this study, three different structures of organic ethers, 18-crown-6 (ECS), tetraethylene glycol monomethyl ether (Tg), and ethylene glycol monomethyl ether (Eg), were added to an aluminum sulfate alkali-free liquid accelerator, and their effects were comprehensively investigated. The results revealed that these organic ethers were capable of bolstering the strength of the mortar after 28 d. The efficiency of these ether organics on the strength of cement mixed with the accelerator followed the order: ECS > Tg > Eg. Specifically, when the ECS content reached 0.3%, the compressive strength of the mortar at 1 d was measured at 8.07 MPa. In addition, changes in the phase composition and micromorphology were scrutinized through X-ray diffraction and scanning electron microscopy, culminating in the establishment of a mechanistic model elucidating the hydration process of organic ether accelerator cement.
研究领域:
建筑材料学
·
化学工程
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产品关联
DOI
高影响因子
MATERIALS LETTERS
·
2022
·
IF 3.574
Shuimiao Xia,Zhicheng Shi,Liang Sun,Shengbiao Sun,Davoud Dastan,Runhua Fan
High dielectric materials are widely used in electronic devices, but their applications are severely hindered by the high loss and low breakdown strength. Herein, a layered structure is designed to effectively suppress the loss and enhance the breakdown strength of high dielectric materials. In the design, the high dielectric films are stacked with linear dielectric films, which can not only form breakdown barriers between adjacent layers but also reduce the leakage conduction loss. As a result, an obvious suppression of loss from 0.13 to 0.05 at 100 Hz, along with a significant increase of breakdown strength from 138 kV/mm to 413 kV/mm, are successfully achieved.
研究领域:
材料科学
·
电子工程
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产品关联
DOI
高影响因子
Additive Manufacturing
·
2024
·
IF 10.3
Lijing Shao,Zhaolong liu,Qi Liu,Haochuan Wang,Chong Wang,Wei Wang,Jinxiang Hong,Changwen Miao,Pan Feng
Printability is a crucial attribute for 3D-printed cement-based materials, as it not only governs the material's printability but also directly impacts the quality of the final structure. A good printability indicates that the printed materials are flowable for transport and extrusion, followed by a rapid increase in strength to establish a stable structure. In this paper, a novel strategy is proposed to enhance the 3D printability of cementitious materials by leveraging the rapid strength enhancement of fresh mortar during in-situ polymerization of acrylamide (AM) in the matrix within 30–60 min of contact with water. Prior to extrusion, AM monomers are absorbed onto cement particles to enhance the flowability of mortar to approximately 185 mm, thereby improving pumpability and extrudability of printed materials. Shortly after extrusion, in-situ polymerization of AM monomers within the mortar takes place, resulting in a sudden albeit modest strength increases in the fresh mortar, enhancing the buildability of the printed mortar. Moreover, the flexural strength of 3D printed filaments with 5 % AM are increased by 52.4 % at 28d, respectively. Meanwhile, the interactions between the AM in-situ polymerization and cement hydration are comprehensively discussed. This innovative approach to enhance 3D printability is expected to drive the advancement of 3D-printed materials with enhanced adaptability and superior properties.
研究领域:
土木工程
·
材料科学
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS
·
2022
·
IF 4.804
Kai Li,Dongyang He,Hailang Liu,Zhuangzhi Wu,Dezhi Wang
Incoherent interphases and oxygen segregation at the grain boundaries (GBs) significantly deteriorate the strength of Mo-based alloys. In this study, a new additive, LaB 6 , was proposed to enhance the mechanical properties . It was found that LaB 6 reacted with the matrix to generate coherent La 2 O 3 , volatile B 2 O 3 and tiny MoB in situ during sintering. The addition of LaB 6 does not increase strength by itself, but can limit grain growth and construct a coherent interface between the as-obtained La 2 O 3 and Mo matrix. More importantly, the oxygen impurity is removed by B in the form of B 2 O 3 , which purifies the GBs. As a result, the as-sintered Mo-La-B billets present an extremely high ultimate tensile strength of 965 MPa, which is among the best recorded values for all sintered Mo-based alloys. The enhanced strength can be attributed to the refined grain size, coherent phase interface , and purified GBs.
研究领域:
材料科学
·
力学性能研究
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DOI
高影响因子
RSC Advances
·
2013
·Vol. 3
·期 46
·24586-24592
·
IF 2.562
Junlong Song,Aijian He,Yongcan Jin,Qiang Cheng
A facile procedure to synthesize an amphoteric cellulose (AC) derivative in one pot using NaOH–urea solution as solvent was developed to avoid the time-consuming separation and purification between steps in conventional methods. Microcrystalline cellulose (MCC) was initially dissolved in 7 wt% NaOH–12 wt% urea aqueous solution at cold temperature and followed by reaction of 3-chloro-2-hydroxyl-propyltrimethyl ammonium chloride and 3-chloro-2-hydroxypropanesulfonic acid sodium salt sequentially or simultaneously at a designed temperature in one container. The degree of substitution (DS) values for positively and negatively charged groups were found to be a function of reaction temperature, dosages of cationic and anionic reagents, reaction time and the addition order of the two reagents. The total DS values of obtained ACs ranged between 0.046 and 0.76, all AC samples except AC-1 were soluble in water. The paper strength performance of ACs was tested and the results indicate that the strength improvement of AC products strongly relates to the DS of ACs. The product with DS of 0.69 can improve the tensile, tear and burst strength index of a paper sheet by about 20% compared with the control at a dosage of 1%.
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
Journal of Physical Chemistry C
·
2017
·
IF 4.536
Yiru Zhu,Shuwen Zhao,Bin Zhou,Hao Zhu,Youfa Wang
In this work, we report a phenomenon that upconversion emission intensity of Er3+ was enhanced by cadmium. Cd2+ was taken with 0, 3, 10, 20, 30, and 40 mol % as a new dopant to codope LiY0.78Yb0.20Er0.02F4, meanwhile the doping effects on the crystal structure, morphology, and upconversion fluorescence emission are investigated by XRD, Rietveld refinement, TEM, and upconversion spectroscopy analysis methods in detail. The green upconversion emission intensity was enhanced, and the maximum emission intensities were enhanced to twice when 10 mol % Cd2+ was codoped into tetragonal LiYF4, while its decay lifetime was reduced. Additionally, we further designed the synthesis of the homogeneous LiYF4:20%Yb,2%Er,10%Cd@LiYF4 of which the emission intensity is 11 times higher than that of the Cd2+-free nanocrystals, meanwhile an intriguing morphology of core–shell nanocrystals was obtained. This investigation may be useful for the design and improvement of upconversion materials for fulfilling the prerequisite of the practical application.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2024
·Vol. 17
·期 4
·854
·
IF 3.1
Peixuan Lin,Song Ye,Ling Pan,Ruihao Huang,Haoran Zhang,Deping Wang
In this research, upconversion nanocrystals incorporated with MOR zeolite composites were synthesized using the desilicated MOR zeolite as a host for the in situ growth of NaREF4(RE = Y, Gd) Yb/Er nanocrystals. The structure and morphology of the composites were studied with XRD, XPS, and TEM measurements, and the spectral studies indicated that the subsequent thermal treatment can effectively improve the upconversion emission intensity of Er3+. By using the NaYF4:Yb/[email protected]composite that holds the strongest upconversion emission, a probe of UCNC@DSiMOR/BPEI was constructed with the modification of branched poly ethylenimine for the detection of Cu2+. It was indicated that the integrated emission intensity of Er3+shows a linear dependence with the logarithm value of the Cu2+concentration ranging from 0.1 to 10 μM. This study offered a feasible method for the construction of UCNC@zeolite composites with enhanced upconversion emission, which may have a potential application as fluorescent probes for the detection of various metal ions by adjusting the doping luminescent center.
研究领域:
材料科学
·
分析化学
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产品关联
DOI
PubMed
高影响因子
Soft Matter
·
2013
·Vol. 9
·期 24
·5807-5814
·
IF 3.909
Xiuqin Cai,Ying Wu,Liya Wang,Ni Yan,Jing Liu,Xiaohua Fang,Yu Fang
Two novel cholesteryl derivatives of calix[4]arene with L- or D-phenylalanine residues in the linkers (1 and 2, respectively) were designed and synthesized. The gelation behaviors of the compounds in 30 organic solvents were tested. It was demonstrated that 1 gels n-butanol and n-pentanol at room temperature, but 2 gels isopropanol only under the treatment of heating–cooling cycling or energy supplementing via sonication, vortex or agitation at room temperature. AFM and SEM measurements revealed that the structures of the gel networks are greatly affected by the spatial configurations of the linkers contained in the calix[4]arene derivatives. Furthermore, mechanical treatment not only promotes the gelation of the system of 2–isopropanol, but also enhances the strength of the gel. Specifically, 18 min of agitation at room temperature makes the storage modulus and the yield stress of the gel (3.5%, w/v) exceed 1 × 106 Pa and 6 × 103 Pa, respectively, which are second only to the mechanically strongest low molecular mass gelator-based molecular gel reported until now. XRD analysis revealed the hexagonal packing structure of 1 in its n-pentanol gel.
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Laser & Photonics Reviews
·
2022
·Vol. 17
·期 1
·2200166
·
IF 10.947
Fengwen Kang,Yongping Du,Ze Yang,Philippe Boutinaud,Martijn Wubs,Jie Xu,Haiyan Ou,Dongzhe Li,Kaibo Zheng,Abebe T. Tarekegne,Guohuan Sun,Xuhui Xu,Sanshui Xiao
Herein, the grown-into-glass (GIG) CsPbBr 3 :Ln 3+ (Ln = La, Lu) nanocrystals (NCs) are designed and fabricated using an in situ nanocrystallization method. It is shown that a substitution of Pb 2+ sites with Ln 3+ ions leads to a blueshift of emission position induced by an increase of the bandgap of CsPbBr 3 . Additionally, the GIG-samples are found to feature excellent photoluminescent (PL) properties after being immersed respectively in water for 300 days at room temperature, boiling water for 12 h, and corrosive environments for 24 h, as well as recoverable PL intensity either after several cycles of heat-cooling experiments or after being continuously exposed to a 405 nm laser irradiation. Besides, a spontaneous enhancement of 20-25% of emission intensity during the 1-2.5 hours' stage of a 405 nm laser irradiation, attributed to the radiative recombination of charge carriers that can be de-trapped from trapping levels upon the laser light irradiation and that then spontaneously reinforces the emission intensity, is observed in the GIG-CsPbBr 3 :Ln 3+ NCs. Finally, a white light-emitting prototype, with a CIE chromaticity coordinate at (0.4110, 0.3706), a color rendering index of 89 and a correlated color temperature of 3363 K is realized by combining the GIG-CsPbBr 3 NCs, YAG:Ce and CaWO 4 :Eu phosphors.
研究领域:
材料科学
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光学
·
化学
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产品关联
DOI
高影响因子
SENSORS
·
2024
·Vol. 24
·期 2
·474
·
IF 3.4
Wenkai Zhao,Runxiang Tan,Yanping Yang,Haoyong Yang,Jianing Wang,Xiaodong Yin,Daheng Wu,Tao Zhang
Surface-enhanced Raman scattering (SERS) spectroscopy is a powerful technology in trace analysis. However, the wide applications of SERS in practice are limited by the expensive substrate materials and the complicated preparation processes. Here we report a simple and economical galvanic-replacement-assisted synthesis route to prepare Ag nanoparticles on Cu(0) foil (nanoAg@Cu), which can be directly used as SERS substrate. The fabrication process is fast (ca. 10 min) and easily scaled up to centimeters or even larger. In addition, the morphology of the nanoAg@Cu (with Ag particles size from 30 nm to 160 nm) can be adjusted by various additives (e.g., amino-containing ligands). Finally, we show that the as-prepared nanoAg@Cu can be used for SERS characterization of two-dimensional polymers, and ca. 298 times relative enhancement of Raman intensity is achieved. This work offers a simple and economical strategy for the scalable fabrication of silver-based SERS substrate in thin film analysis.
研究领域:
材料科学
·
分析化学
·
纳米技术
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2023
·
IF 8.2
Shaomin Kang,Zhenghong Wu,Yena Liu,Peipei Wang,Xinyu Zhang,Mehraj Ahmad,Mohammad Rizwan Khan,Wenyuan Zhu,Jiaqi Guo,Yongcan Jin,Huining Xiao,Junlong Song
Cationic starch is the most widely used paper strength additive for papermaking wet end applications. However, it remains unclear how differently quaternized amylose (QAM) and amylopectin (QAP) are adsorbed on the fiber surface and their relative contribution to the inter-fiber bonding of papers. Herein, separated amylose and amylopectin were quaternized with different degrees of substitution (DS). After that, the adsorption behaviors of QAM and QAP on the fiber surface, the viscoelastic properties of the adlayers and their strength enhancement to fiber networks were comparatively characterized. Based on the results, the morphology visualizations of the starch structure displayed a strong impact on the adsorbed structural distributions of QAM and QAP. QAM adlayer with a helical linear or slightly branched structure was thin and rigid, while the QAP adlayer with a highly branched structure was thick and soft. In addition, the DS, pH and ionic strength had some impacts on the adsorption layer as well. Regarding the paper strength enhancement, the DS of QAM correlated positively to the paper strength, whereas the DS of QAP correlated inversely. The results provide a deep understanding of the impacts of starch morphology on performance and offer us some practical guidelines in starch selection.
研究领域:
造纸科学
·
材料科学
·
化学工程
✓ 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）