SYNTHESIS-STUTTGART
·
2015
·Vol. 48
·期 02
·231-237
·
IF 2.689
Yongbo Zhou,Zhongwen Li,Xiao Yang,Xiulin Chen,Mei Li,Tieqiao Chen,Shuang-Feng Yin
A simple and environmentally benign method was developed for the synthesis of chalcones in high to excellent yields by a phosphorous acid promoted alkyne–aldehyde hydration–condensation in an oil/water two-phase system. The method is the first efficient protocol for the preparation of chalcones that is mediated by a simple Brønsted acid in a two-phase system.
研究领域:
有机化学
·
绿色化学
✓ 已验证
DOI
高影响因子
CHEMISTRY OF MATERIALS
·
2024
·
IF 7.2
Lingfeng Hu,Jinge Li,Xiaoniu Yang,Mingbo Ruan
Polyurethane (PU) has been used in clinical practice for artificial meniscus to alleviate the distress of patients with meniscus injury, but the high friction of PU in synovial fluid can lead to the deterioration of knee joints. In this work, PUs with sulfobetaine zwitterions modified by hydrophobic chains in bulk (PU-hSBs) are synthesized to solve the above-mentioned challenge, and the lubrication behavior and mechanism of PU-hSBs in the aqueous solution of representative synovial components that mimic the in vivo environment of synovial fluid to some extent are studied. Among the above materials, PU-hSB70 can meet the low friction of an artificial meniscus and also has appropriate tensile modulus and low cytotoxicity. Moreover, PU-hSB70 can maintain excellent tribological and mechanical properties after prolonged immersion and compressive fatigue tests, which support its long-term application in vivo. Additionally, the lubrication role of synovial components is identified by contrasting the lubrication behavior of PU-hSBs in deionized water after excluding the effect of the lubricant viscosity. A formed hydration layer of noncrystal water is improved by the hydration of the complexes of phosphatidylcholine-hyaluronic acid adsorbed onto PU-hSB70 via hydrophobic and electrostatic interactions. However, the presence of serum protein on PU-hSB70, which interacts hydrophobically, has a diminishing effect on the thickness of the layer. Our results show the potential of PU-hSB70 can be used as an artificial meniscus. Furthermore, the lubrication chemistry and mechanism of representative synovial components are deeply proven through hydration.
研究领域:
生物医学工程
·
材料科学
·
骨科
·
生物材料
·
摩擦学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF WUHAN UNIVERSITY OF TECHNOLOGY-MATERIALS SCIENCE EDITION
·
2019
·Vol. 34
·期 3
·604-613
·
IF 0.605
Ma Baoguo,Mei Junpeng,Tan Hongbo,Li Hainan,Liu Xiaohai,Jiang Wenbin,Zhang Ting
The influences of nano silica (NS) on the hydration and microstructure development of steam cured cement high volume fly ash (40 wt%, CHVFA) system were investigated. The compressive strength of mortars was tested with different NS dosage from 0 to 4%. Results show that the compressive strength is dramatically improved with the increase of NS content up to 3%, and decreases with further increase of NS content ( e g , at 4%). Then X-ray diffraction (XRD), differential scanning calorimetry-thermogravimetry (DSCTG), scanning electron microscope (SEM), energy disperse spectroscopy (EDS), mercury intrusion porosimeter (MIP) and nuclear magnetic resonance (NMR) were used to analyze the mechanism. The results reveal that the addition of NS accelerates the hydration of cement and fly ash, decreases the porosity and the content of calcium hydroxide (CH) and increases the polymerization degree of C-S-H thus enhancing the compressive strength of mortars. The interfacial transition zone (ITZ) of CHVFA mortars is also significantly improved by the addition of NS, embodying in the decrease of Ca/Si ratio and CH enrichment of ITZ.
研究领域:
材料科学
·
土木工程
✓ 已验证
DOI
高影响因子
ChemCatChem
·
2016
·Vol. 8
·期 4
·812-817
·
IF 4.724
Zhifeng Dai,Qi Sun,Fang Chen,Shuxiang Pan,Liang Wang,Xiangju Meng,Jixue Li,Feng-Shou Xiao
Graphical Rational design : A porous organic polymer with a very high salen concentration is rationally synthesized from the self-polymerization of a salen-based monomer. After the loading of Co 3+ , the heterogeneous catalyst shows even better properties than the homogeneous version in the catalytic hydration of epoxides because of the enrichment of activated reactants. The rational design of catalytic materials from the reaction characteristics is expected to be a useful strategy to create highly efficient catalysts. Herein, according to a well-established reaction pathway of epoxide hydration catalyzed a dual-molecular system of Co 3+ /salen in which a high concentration of active sites is favorable to enhance the activity, we provide an alternative way to prepare a highly efficient heterogeneous catalyst with a high concentration of Co 3+ /salen from the polymerization of vinyl-functionalized salen monomers followed by the loading of Co 3+ species (Co 3+ /POL-salen). Co 3+ /POL-salen has a hierarchical porosity and an extraordinary hydrothermal stability. Importantly, catalytic tests in epoxide hydration demonstrate that Co 3+ /POL-salen affords excellent high activities, which are even better than those of the homogeneous version. This phenomenon is related to the very high concentration of Co 3+ /salen in the catalyst. In addition, this catalyst can be recycled readily because of its excellent hydrothermal stability.
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 27
·16688-16702
·
IF 3.108
Li Zhao,Xinli Guo,Yuanyuan Liu,Chuang Ge,Liping Guo,Xin Shu,Jiaping Liu
In this paper, the graphene oxide (GO) modified by polycarboxylate superplasticizer (PC) (PC@GO) was decorated by silica nanoparticles (SiO2 NPs) to form a hybrid structure of SiO2 NPs/PC@GO. The as-prepared SiO2 NPs/PC@GO hybrid was incorporated in cement matrix for further reinforcement. The results show that SiO2 NPs are uniformly distributed on the surface of GO nanosheets. The addition of SiO2 NPs/PC@GO hybrid (1.5% SiO2 and 0.02% GO by weight of cement) can increase the compressive strength by factors of 38.31%, 44.47% and 38.89% at 3, 7, 28 days, respectively, which are much higher than those of cement composites reinforced by a single-promoter (either PC@GO or SiO2 NPs). Moreover, our results demonstrate that SiO2 NPs/PC@GO hybrid can accelerate the cement hydration, improve the degree of pozzolanic reaction and refine the microstructure of hydration products. The excellent reinforcement is attributed to the synergistic effects of SiO2 NPs/PC@GO hybrid including better dispersion property, higher degree of pozzolanic reaction and cross-linking structure of [SiO2–GO–CSH]. This work provides a very effective way to reinforce cement composites by SiO2 NPs/PC@GO hybrid.
研究领域:
材料科学
·
土木工程
✓ 已验证
产品关联
DOI
高影响因子
SOLAR ENERGY
·
2022
·
IF 7.188
J. Yan,B.W. Yang,C.Y. Zhao
Thermochemical energy storage (TCES) is a promising energy storage method because of its high energy storage density and long-term storage ability. The reactor is the most critical part of the TCES system, and the fluidized bed reactor (FBR) is a novel reactor, which is not restricted by the low effective thermal conductivity of energy storage materials. However, there is little theoretical guidance about the design and operation of the FBR for a TCES system. In this study, we investigated the performance of an FBR using MgO/Mg(OH) 2 as reaction materials by establishing a numerical model followed by experimental validation. The influence of operating parameters on the bed temperature was discussed based on numerical results. According to the sensitivity analysis, the reactor inner diameter, material mass, and inlet gas velocity were the main factors affecting the bed temperature. The optimal boundary surface temperature was analyzed, which influences the proportion of TCES in the total heat storage.
研究领域:
能源工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2022
·
IF 7.693
Xiaotao Zhang,Shun Zhou,Han Zhou,Dongxu Li
In this study, the effect of the incorporation of GO and KH550 modified GO(MGO) on the microstructure, mechanical properties and hydration process of the cement-based composites has been discussed. It is observed that the MGO surface is grafted with the functional groups, which reduce the interlayer force, thus, the dispersibility in the cement paste is improved. In addition, compared with GO, the addition of MGO can further promote the hydration of cement, and optimize the content of the various hydration products owing to no impact on the types of the hydration products, thus, make the microstructure of the cement more uniform. At the same time, the incorporation of MGO can refine the CH crystal size, reduce the total porosity of the cement material, and promote the conversion of harmful pores to harmless pores, thus, making the cement-based materials more compact and effectively improving the mechanical properties.
研究领域:
材料科学
·
土木工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Building Engineering
·
2022
·
IF 7.144
Yimu Wang,Jinqing Jia,Qi Cao,Xing Gao
The replacement of Portland cement (PC) by fly ash (FA) or slag will cause low early age strength development of concrete. However, the addition of chemical additives can eliminate the well-known drawbacks above. The effect of calcium formate (CF) on the compressive strength development of ternary cement (containing FA and slag) was studied based on simplex centroid design in this paper. Results show that CF can be safely used to increase the strength of ternary cement composite . In addition, the influence of CF on the hydration process and microstructural features of PC and PC-FA/slag blends was investigated using isothermal calorimetry, X-ray diffraction, thermal analysis, and scanning electron microscopy. These results show that the addition of CF can enhance the strength of PC and PC-FA/slag blends at early curing ages, which is mainly because of a kind of calcium aluminate silicate hydrate called gismondine (CaAl 2 Si 2 O 8 ·4H 2 O) and more formation of ettringite (AFt). Furthermore, at later ages of hydration, CF can promote the silicate reaction of PC and PC-FA/slag blends and accelerate the pozzolanic reaction of FA in order to improve the strength.
研究领域:
土木工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Micromachines
·
2023
·Vol. 14
·期 8
·1497
·
IF 3.4
Mingpeng Yang,Nan Sun,Xiaochen Lai,Yanjie Li,Xingqiang Zhao,Jiamin Wu,Wangping Zhou
Human sweat is intricately linked to human health, and unraveling its secrets necessitates a substantial volume of experimental data. However, conventional sensors fabricated via complex processes such as photolithography offer high detection precision at the expense of prohibitive costs. In this study, we presented a cost-effective and high-performance wearable flexible sweat sensor for real-time monitoring of K+and Na+concentrations in human sweat, fabricated using screen printing technology. Initially, we evaluated the electrical and electrochemical stability of the screen-printed substrate electrodes, which demonstrated good consistency with a variation within 10% of the relative standard deviation (RSD), meeting the requirements for reliable detection of K+and Na+in human sweat. Subsequently, we employed an “ion-electron” transduction layer and an ion-selective membrane to construct the sensors for detecting K+and Na+. Comprehensive tests were conducted to assess the sensors’ sensitivity, linearity, repeatability, resistance to interference, and mechanical deformation capabilities. Furthermore, we evaluated their long-term stability during continuous monitoring and storage. The test results confirmed that the sensor’s performance indicators, as mentioned above, met the requirements for analyzing human sweat. In a 10-day continuous and regular monitoring experiment involving volunteers wearing the sensors, a wealth of data revealed a close relationship between K+and Na+concentrations in human sweat and hydration status. Notably, we observed that consistent and regular physical exercise effectively enhanced the body’s resistance to dehydration. These findings provided a solid foundation for conducting extensive experiments and further exploring the intricate relationship between human sweat and overall health. Our research paved a practical and feasible path for future studies in this domain.Keywords:wearable sweat sensor;screen-printing technology;hydration status;potassium ion detection;sodium ion detection
研究领域:
生物医学工程
·
材料科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2023
·
IF 4.7
Ke-Feng Yan,Jian-Yu Zhao,Hao Chen,Xiao-Sen Li,Chun-Gang Xu,Zhao-Yang Chen,Yu Zhang,Yi Wang,Jing-Chun Feng,Yi-Song Yu
A fundamental understanding of the hydration mechanism of salt ions on the methane hydrate formation would be beneficial for the interpretation of the reservoir formation mechanism and the development and utilization of natural gas hydrate . In this work, the hydration of salt ions (Na + and Cl - ) on the methane hydrate formation is investigated using experiments, quantum mechanics (QM) calculations and molecular dynamics (MD) simulations. The results show the salts ions firstly influence the orientation of the H 2 O molecules and then influence the OH symmetrical stretching vibrations by impacting the tetrahedral arrangement of H 2 O molecules after attaching the hydration-shell layers. The coupling process of the hydration and the mass transfer of salt ions influence the methane hydrate formation.
研究领域:
化学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2023
·
IF 7.3
Yuexia Wang,Qibin Yao,Bowen Xu,Kehang Lin,Mengshan Deng,Xinqing Lu,Rui Ma,Yanghe Fu,Weidong Zhu
Although the oxidative hydration of ethylene with hydrogen peroxide (H 2 O 2 ) to ethylene glycol (EG) over Ti-MWW zeolites take advantages of step-saving and facile operation, both H 2 O 2 utilization efficiency and EG yield are relatively low, because some extra-framework octahedral Ti species are usually formed in the Ti-MWW zeolites synthesized by prevailing methods, which are detrimental to selective oxidation . In the present work, an acid-modulated isomorphous substitution method, i.e. , layered borosilicate MWW-type zeolite (ERB-1) treated with HNO 3 aqueous solution containing tetrabutyl orthotitanate (TBOT), is developed to synthesize a Ti-MWW zeolite without extra-framework octahedral Ti species under the optimized synthesis conditions. In combination with the results from extensive characterizations for the synthesized zeolites, it is found that in the zeolite prepared by the currently developed synthesis method there are more open Ti(OSi) 3 OH sites formed, resulting in the stronger Lewis acidity that is very helpful to EG production from the oxidative hydration of ethylene with H 2 O 2 , compared to the one synthesized by the prevailing method. Moreover, the developed catalyst is recyclable after the regeneration of the deactivated zeolite by calcination at high temperatures. Therefore, it is anticipated that the currently developed Ti-MWW might be industrially applicable in the one-pot synthesis of EG from ethylene with H 2 O 2 .
研究领域:
化学工程
·
催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2018
·
IF 0
Xia Chen,Xu Ye,Wen-Yu Liang,Qing Zhou,Giang Vo-Thanh,Ye Liu
The unique amphiphilic Zwitterionic P,O-hybrid ligand ( L1 ) containing phosphino-fragment and −SO 3 − group was synthesized and firstly applied in Au-catalyzed hydration of alkynes. Without the aid of any auxiliary additive such as acid or silver salt, L1 -based Au-catalyst exhibited excellent activity towards hydration of alkynes to yield ketones with 100% selectivity according to Markovnikov’s rule. On the other hand, L1 -based Au-catalyst could be recycled for 4 runs in room temperature ionic liquid of [Bmim]PF 6 without obvious activity loss, and also exhibited wide generality to the hydration of different alkynes.
研究领域:
有机化学
·
催化化学
✓ 已验证
DOI
危险品化学品经营许可证（带存储）