MACROMOLECULES
·
2024
·
IF 5.1
Tianfeng Zhou,Haotian Duan,Zhenzhong Li,Yu Jin,Hai Liu,Yuxia Pang,Hongming Lou,Dongjie Yang,Xueqing Qiu
Steric repulsive force is the main dispersion force between cement particles. In order to improve the dispersibility of polycarboxylate superplasticizers (PCEs), we designed and synthesized a new Y-type macromonomer (YPEG) with a molecular weight of Mw = 4100 Da. A long side chain-branched polycarboxylate superplasticizer (YPCE) was successfully synthesized by employing YPEG. Several common comb PCEs having the same side chain density but different lengths, such as PCE2400 and PCE4000, are employed to compare with YPCE for evaluating the dispersion performance. The results show that YPCE has a more excellent dispersion performance than the common PCEs under different water–cement ratios. Additionally, YPCE shows stronger water reduction for concrete. Furthermore, a dynamic light scattering study elucidates that YPCE can increase the adsorbed layer thickness from 5.6 to 7.9 nm, thus forming stronger steric hindrance. Simulations using molecular dynamics are conducted to investigate the influence of the conformational transformation of PCEs from comb-type to Y-type on the adsorption configuration and radius of gyration (Rg) of PCEs on calcium silicate hydrate surface. It is observed that the side chain of YPCE remains in an extended state, and Rg fluctuates little during the fitting process. This study provides a new strategy to enhance the steric hindrance of PCEs.
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高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Jingjing Wang,Jinchuan Zhao,Zhihui Wen,Xinjie Wei,Junjie Liao,Liping Chang,Kechang Xie
CeY zeolite sorbent was reported to have a high adsorptive desulfurization selectivity for thiophene. However, only the cerium in the supercage, which is larger than the thiophene molecule, is effective for thiophene adsorption. In this case, regulating the cerium location to anchor it more in the surpercage of Y zeolite is an important issue. Herein, the glycine was used as a complexing agent with cerium to control its size, ensuring that the cerium precursor is in the supercage. G 0.1 CeY were prepared by ion exchange technique with glycine and cerium coordination from NaY. The adsorption capacity of sorbents was measured, and their physical and chemical properties were characterized by XRD, SEM, N 2 adsorption/desorption, NH 3 -TPD, and in situ FT − IR. The glycine complexation could effectively control the location of Ce, so that the G 0.1 CeY has the highest content of Ce located in the supercage. Moreover, in order to further explore the influence of zeolite type, HY was used as the raw material to prepared G 0.1 CeHY in the same way. G 0.1 CeHY has a higher desulfurization performance than that of G 0.1 CeY, whereas the Ce content in its supercage is lower. The NH 3 -TPD and Py-FT − IR results that the medium-strong Brønsted acid of the G 0.1 CeHY sorbent is also effectively for the improvement of desulfurization efficiency. The G 0.1 CeHY exhibits the hightest desulfurization effectiveness (51 %) and the highest breakthrough adsorption capacity of 5.42 mg/g.
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高影响因子
FUEL
·
2022
·
IF 8.035
Shijie Wang,Yihang Chen,Yu Jia,Chen Wang,Guizhuan Xu,Youzhou Jiao,Chao He,Chun Chang,Qianhui Guo
An effective catalytic strategy for the conversion of glucose to 5-ethoxymethylfurfural (EMF) catalyzed by ultrastable Y zeolite (USY) in a co-solvent system was developed. Effects of co-solvent and reaction conditions were first investigated. Tetrahydrofuran (THF) with low dipolarity/polarizability (π*) was screened as the appropriate co-solvent, and a higher EMF yield of 41.46% was obtained as the ratio of ethanol to THF was 7:3. The macroscopic reaction kinetic study indicated that THF can protect EMF from easy degradation to EL. Moreover, the reusability and the characterization of USY verified the feasibility of USY as an efficient solid acid catalyst. In this study, density functional theory (DFT) calculations for the catalytic mechanism and solvent effect at the molecular scale were performed for the first time. The extra-framework aluminum species (EFAL), in which Al 3+ played an essential role in the reaction as the preferred EFAL species, and THF can reduce the energy barrier of USY-catalyzed glucose isomerization . Meanwhile, the inhibitory effect of THF on EMF alcoholysis was explored via the frontier molecular orbital theory. The results showed that THF increased the LUMO energy of EMF compared with ethanol and γ-valerolactone, which decreased its susceptibility to nucleophilic attack and reduced the adverse alcoholysis of EMF and humins formation. This study provided an enlightening reference for the efficient synthesis of EMF from carbohydrates catalyzed by solid acid catalyst under solvent effect.
研究领域:
化学工程
·
催化化学
·
计算化学
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DOI
高影响因子
Catalysts
·
2025
·Vol. 15
·期 11
·1005
·
IF 4
Kuo Zhou,Jialin Xu,Shengrong Guo,Hongjun Wu
The catalytic synthesis of 1,2-pentanediol from biomass-derived feedstocks is of remarkable significance for addressing current environmental challenges and energy crises. In this paper, a series of Pt-based catalysts were prepared and evaluated in the hydrogenolysis of furfuryl alcohol. The 5Pt0.5Y/MgO provided a 1,2-pentanediol yield of 68.9% and a tetrahydrofurfuryl alcohol yield of 19.8% with 98.1% conversion of furfuryl alcohol, at 200 °C and 2 MPa H2for 10 h. The promotional effect of yttrium on the catalytic performance was investigated through catalytic reaction and comprehensive characterization. It was found that the reducibility of Pt species was suppressed by the introduction of Y species, resulting in reduced activity compared to the 5Pt/MgO catalyst. However, the addition of Y notably shifted the reaction pathway towards 1,2-pentanediol formation at the expense of tetrahydrofurfuryl alcohol selectivity. This increase in 1,2-pentanediol selectivity was attributed to a higher concentration of medium-strength basic sites on the Y-modified Pt catalyst. Furthermore, the strong interaction between Y2O3, Pt particles, and the MgO support led to high Pt dispersion and stability on the MgO surface, consequently yielding satisfactory recyclability.
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高影响因子
Journal of Materials Chemistry B
·
2021
·Vol. 10
·期 2
·262-270
·
IF 6.331
Wei Sun,Jingrui Liu,Qing Hao,Kunyan Lu,Zhaoqiang Wu,Hong Chen
The simultaneous introduction of two new functionalities into the same polymeric substrate under mild reaction conditions is an interesting and important topic. Herein, dual-functional polydimethylsiloxane (PDMS) surfaces with antibacterial and antifouling properties were conveniently developed via a novel Y-shaped asymmetric dual-functional photoiniferter (Y-iniferter). The Y-iniferter was initially immobilized onto the PDMS surface by radical coupling under visible light irradiation. Afterwards, poly(2-hydroxyethyl methacrylate) (PHEMA) brushes and antibacterial ionic liquid (IL) fragments were simultaneously immobilized on the Y-iniferter-modified PDMS surfaces by combining the sulfur(VI)-fluoride exchange (SuFEx) click reaction and UV-photoinitiated polymerization. Experiments using E. coli as a model bacterium demonstrated that the modified PDMS surfaces had both the expected antibacterial properties of the IL fragments and the excellent antifouling properties of PHEMA brushes. Furthermore, the cytotoxicity of the modified PDMS surfaces to L929 cells was examined in vitro with a CCK-8 assay, which showed that the modified surfaces maintained excellent cytocompatibility. Briefly, this strategy of constructing an antibacterial and antifouling PDMS surface has the advantages of simplicity and convenience and might inspire the construction of diverse dual-functional surfaces by utilizing PDMS more effectively.
研究领域:
材料科学
·
高分子化学
·
生物材料
·
表面工程
·
生物医学工程
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DOI
PubMed
高影响因子
JOURNAL OF SOLID STATE ELECTROCHEMISTRY
·
2023
·Vol. 27
·期 3
·763-772
·
IF 2.5
Jiang Tongzhou,Wu Fei,Ren Yurong,Qiu Jianhua,Chen Zhihui
High-entropy pyrochlore oxide (Y,Dy,Ce,Nd,La) 2 Sn 2 O 7 has been synthesized by the co-precipitation method. EDS and XPS analysis demonstrated the high-entropy structure in M 2 Sn 2 O 7 (M = Y, Dy, Ce, Nd, La) ultrafine powders, which is developed as the active material in lithium anode. The effects of different binders on the cycling performance and rate capability were discussed. Benefiting from the synergistic effects of high-entropy system and the strong intermolecular force provided by the sodium carboxymethyl cellulose (CMC) system, the optimized M 2 Sn 2 O 7 /CMC (M = Y, Dy, Ce, Nd, La) delivers a high initial discharge capacity of about 766 mAh g −1 and exhibits excellent cycle stability. A reversible capacity of 396 mAh g −1 and superior delivering retention of ~ 100% can be obtained at 100 mA g −1 after 100 cycles. Meanwhile, the capacity retention rate of 54.5% can still be reached after the cycling at various current densities from 0.05 to 1 A g −1 , demonstrating potential application prospect of the M 2 Sn 2 O 7 /CMC.
研究领域:
材料科学
·
电化学
·
能源存储
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DOI
高影响因子
Coatings
·
2026
·Vol. 16
·期 1
·135
·
IF 2.8
Chanxi Yan,Gaoping Liu,Qing Zhu,Yashi Zhou,Yuan Yuan
Ice accumulation on power transmission lines poses serious threats to operational safety and can lead to substantial social and economic impacts. While various anti-icing coatings have been investigated, their performance is often limited by the effectiveness and durability of anti-icing. Slippery lubricant-infused porous surfaces (SLIPSs) have shown remarkable anti-icing properties and durability, aided by their lubricant-infused and self-healing capability. In this study, SLIPSs were successfully fabricated on aluminum substrates using a two-step anodization process. The effects of the anodizing parameter of the current density on pore diameter and depth at each stage were systematically investigated. Compared to untreated aluminum and superhydrophobic coatings (SHCs), SLIPSs presented good anti-icing properties. First, at −6 °C, droplets slid off the surface completely within 4340.5 ms without pinning, indicating sustained droplet-shedding capability. It also significantly delayed ice formation, extending the freezing time to 80 min—eight times longer than that of the untreated surface. Moreover, the SLIPSs also exhibited ultra-low ice adhesion, with an initial strength of only 6.93 kPa. Meanwhile, after 100 frosting–defrosting cycles, SLIPSs could still maintain low ice adhesion strength (<20 kPa). The prepared SLIPS with a Y-shaped pore structure demonstrates good potential for anti-icing.
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高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2020
·
IF 4.551
Yaorui Li,Adede Ochieng Simon,Caishan Jiao,Meng Zhang,Wenfu Yan,Heng Rao,Jiancong Liu,Jianan Zhang
In this study, a new and efficient sorbent material was developed by the surface modification of zeolite Y with surfactant of cetyltrimethyl ammonium bromide (CTAB) and amino acid of l -aspartic acid (Asp) for rapid removal of Sr 2+ , Cs + and UO 2 2+ in solution. The as-synthesized and modified zeolite Y were characterized by powder X-ray diffraction (XRD), scanning electron microscope (SEM), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR) and nitrogen adsorption-desorption analysis. The results showed that after first grafting the cations of CTAB on the external surface of zeolite Y crystals, negatively charged Asp was then successfully introduced onto zeolite to form the CTAB + Asp dually modified zeolite Y sorbent . The fraction of CTAB and Asp in dually modified zeolite Y is 9.6 wt % and 16.3 wt %, respectively. The sorption isotherm of UO 2 2+ , Sr 2+ and Cs + by such sorbent was better fitted by Langmuir model. The CTAB + Asp dually modified zeolite Y took 20 min to reach the maximum sorption amount, while the unmodified zeolite Y took 240 min. This encouraging result provides a new concept to design sorbent materials for rapid removal of radionuclides from contaminated water system in an emergency.
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高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2018
·
IF 13.325
Li Jing,Yin Ruiming
In this study, self-reinforced Y-α-SiAlON was prepared by two-step phase transformation using single or dual rare-earth oxide addition. The process was implemented by a two-step sintering technique. The mechanism of two-step phase transformation and microstructure evolution of Y-α-SiAlON with or without Ce 2 O 3 addition were investigated in detail. The predominant phase of the sample after the first step (i.e., pressureless sintering at low temperature) comprised elongated β-SiAlON grains. By contrast, the majority phase of sample after the second step (i.e., gas pressure sintering at high temperature) included coarse, elongated α-SiAlON grains. The driving force for β-to-α SiAlON phase transformation and liquid viscosity decreased, whereas the amount of liquid phase increased because of Ce 2 O 3 addition, which contributed to anisotropic growth and resulted in more elongated α-SiAlON grains. The sample co-doped with Y and Ce exhibited the best mechanical properties with fracture toughness of 7.8 MPa m 1/2 and Vickers hardness of 19.81 GPa.
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高影响因子
CERAMICS INTERNATIONAL
·
2022
·Vol. 48
·期 6
·8773-8778
·
IF 5.532
Xin Kang,Xiaohui Li,Xiaoyi Chen,Bo Gao,Pengjun Zhao,Zhaoyang Chen,Wenwen Kong,Aimin Chang
In this study, a series of novel negative temperature coefficient thermistor materials based on A 2 Ti 2 O 7 ( A = Sm, Eu, Y) titanate ceramics have been developed for high-temperature applications. The A 2 Ti 2 O 7 ( A = Sm, Eu, Y) ceramics showed cubic pyrochlore structures with dense morphology in X-ray diffraction and scanning electron microscopic analyses. These ceramics showed typical NTC characteristics in a wide temperature range of 673–1473 K, accompanied by resistance drift rates of 2.71%, 1.63%, and 4.95% for 400 h of ageing at 1173 K. The proposed ceramics have high resistivity and thermal constants B that ensure their better sensitivity at high temperatures and also show unique oxygen insensitivity. These properties outperform those of traditional high-temperature NTC materials composed of perovskite-type or scheelite-type ceramics, making A 2 Ti 2 O 7 ( A = Sm, Eu, Y) ceramics promising candidates for fabricating high-temperature NTC thermistors.
研究领域:
材料科学
·
陶瓷
·
电子材料
·
热电材料
·
固态物理
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·Vol. 47
·期 4
·4831-4837
·
IF 3.83
Yu Wang,Ying Tang,Jie Li,Weishuang Fang,Shiyao Shen,Feihu Li,Lian Duan,Ming Qin,Liang Fang
The Ca 3 M 2 Si 3 O 12 (M = Yb, Y) ceramics with orthorhombic silico-carnotite structure were fabricated via high-energy ball milling and solid-state reaction route. Dense Ca 3 Yb 2 Si 3 O 12 and Ca 3 Y 2 Si 3 O 12 ceramics sintered at 1260 °C and 1240 °C revealed promising microwave dielectric properties with ε r = 9.2 and 8.7, Q×f = 56,400 GHz and 29,094 GHz, τ f = −77.5 ppm/°C and −76.8 ppm/°C, respectively. The connection between crystal structure and Q×f values of Ca 3 M 2 Si 3 O 12 (M = Yb, Y) ceramics was discussed with respect to the packing fraction, and their intrinsic microwave dielectric properties were examined using the infrared reflectivity spectra analysis. The thermal stability of Ca 3 Yb 2 Si 3 O 12 was improved successfully by forming 0.91Ca 3 Yb 2 Si 3 O 12 ‐0.09CaTiO 3 composite ceramics with τ f = +2.9 ppm/°C, ε r = 12.93 and Q×f = 26,729 GHz.
研究领域:
材料科学
·
陶瓷
·
微波材料
·
固态化学
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DOI
高影响因子
Journal of Materials Chemistry A
·
2024
·Vol. 12
·期 21
·12599-12608
·
IF 10.7
Yiming Yang,Jiachen Lu,Xinyu Zhang,Yanuo Shi,Peng Du,Xiao Ling,Nan Yang,Qianli Chen
Y-doped Ba(Zr,Ce)O3 (BZCY) proton conducting ceramics have attracted extensive attention because of their promising applications as electrolytes for intermediate-temperature proton ceramic electrochemical cells. The proton conductivity of BZCY is governed by their lattice volume and crystal symmetry; however, systematic studies of the competition between these two factors are lacking, hindering further improvement of their proton conductivity at low and intermediate temperatures. In this work, the crystal symmetry of BZCY epitaxial films deposited on NdGaO3 (110) is compared to that of polycrystalline bulk BZCY based on Raman spectra. The Raman signal of BZCY epitaxial films is amplified using surface-enhanced Raman spectroscopy and subsequently extracted utilizing the nonnegative matrix factorization method. The relative Raman intensity ratio of the BO6 octahedra motion to the Ba-BO6 relative motion in the ABO3 structure indicates that as the Ce content increases, the crystal symmetry of polycrystalline bulk BZCY decreases, whereas that of the epitaxial films on NdGaO3 remains consistently lower compared to bulk BZCY. The relationship between the activation energy and relative Raman intensity of epitaxial films and bulk BZCY indicates quantitatively that higher activation energy is observed in the crystal structure with lower symmetry. This work suggests that crystal symmetry has a predominant effect on the activation energy of BZCY. The results provide a deeper insight for developing proton conducting electrolyte membranes with high proton conductivity and low activation energy.
研究领域:
材料科学
·
固体离子学
·
光谱学
·
能源材料
·
陶瓷电解质
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DOI
高影响因子
危险品化学品经营许可证（带存储）