JOURNAL OF APPLIED POLYMER SCIENCE
·
2018
·Vol. 136
·期 1
·46906
·
IF 1.901
Jinhui Liu,Jieting Geng,Kai Liu,Lingli Zou,Zhaobo Wang,Jing Hua
Molybdenum-based random 1,2-polybutadiene (1,2-PB) rubber, with its excellent wet skid resistance, low rolling resistance, and low heat buildup, can be used for green tread rubber, and it has significant benefits for the enhancement of the mechanical strength of 1,2-PB. In this study, we investigated in detail the effects of the electronegativity and steric hindrance of the cocatalyst on the stereoselectivity of the resulting polymers. In the case of cocatalysts with moderate electronegativities, the active centers were more stable; this resulted in a larger molecular weight and a higher conversion, whereas a cocatalyst with excessive electronegativity tended to initiate cationic polymerization. The high sterically hindered substituent restricted the coordination configuration of the monomer; this ultimately resulted in the increase in the 1,2 structure to 90%. Fourier transform infrared analysis showed that the content of trans -1,4 structure increased from 7 to 66%, and its crystallinity reached 59.2%, as calculated with differential scanning calorimetry when triethyl aluminum was used as the cocatalyst. Consequently, trans -1,4-polybutadiene crystals were introduced into the 1,2-PB elastomer in one step; this could be a promising facile route for strengthening 1,2-PB. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 46906.
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
Frontiers of Chemical Science and Engineering
·
2017
·Vol. 11
·期 2
·205-210
·
IF 1.712
Zhou Shenghui,You Kuiyi,Yi Zhengming,Liu Pingle,Luo He’an
Metal salts with highly electronegative cations have been used to effectively catalyze the liquid-phase nitration of benzene by NO 2 to nitrobenzene under solvent-free conditions. Several salts including FeCl 3 , ZrCl 4 , AlCl 3 , CuCl 2 , NiCl 2 , ZnCl 2 , MnCl 2 , Fe(NO 3 ) 3 ∙9H 2 O, Bi (NO 3 ) 3 ∙5H 2 O, Zr(NO 3 ) 4 ∙5H 2 O, Cu(NO 3 ) 2 ∙6H 2 O, Ni (NO 3 ) 2 ∙6H 2 O, Zn(NO 3 ) 2 ∙6H 2 O, Fe 2 (SO 4 ) 3 , and CuSO 4 were examined and anhydrous FeCl 3 exhibited the best catalytic performance under the optimal reaction conditions. The benzene conversion and selectivity to nitrobenzene were both over 99%. In addition, it was determined that the metal counterion and the presence of water hydrates in the salt affects the catalytic activity. This method is simple and efficient and may have potential industrial application prospects.
研究领域:
化学工程
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催化化学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2019
·Vol. 7
·期 39
·22463-22474
·
IF 10.733
Qian Lu,Xiaohong Zou,Ran Ran,Wei Zhou,Kaiming Liao,Zongping Shao
Lithium–sulfur (Li–S) batteries are of great interest due to their high theoretical energy density and potentially low cost. However, two of the key issues hindering their commercialization are the polysulfide shuttling and Li-dendrite growth, which result in severe capacity decay and serious safety hazards. Herein, liquid-phase delaminated birnessite (HxMnO2+x) nanosheets along with graphene and carbon nanotubes are utilized for the first time to create an “electronegative” coating layer for Li–S batteries to suppress the polysulfide shuttling and Li-dendrite growth. The as-prepared coating layer enables stable cycling of the Li–S battery with a low capacity decay rate of 0.04% per cycle over 1000 cycles at 1C. In addition, a Li-symmetrical cell with the coating layer shows suppressed dendrite growth even after being cycled over 1000 hours at 1 mA cm−2. This excellent performance is ascribed, in part, to the synergistic effect of the chemical and electrostatic interactions among polysulfides, Li ions, and [MnO2+x]x− ions, resulting in a homogeneous Li-ion flux distribution and a mitigated polysulfide shuttling. The proposed concept of an “electronegative” bifunctional coating layer illustrates a simple and effective way to develop highly stable and safe Li–S batteries.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL POLLUTION
·
2021
·
IF 8.071
Qiushi Zhang,Xing Cao,Shichang Sun,Weichen Yang,Lin Fang,Rui Ma,Chenghua Lin,Haowen Li
Lead-zinc slag (LZS) is a solid waste product that is rich in silicon and aluminum and has enormous resource potential for functional environmental functional geopolymer materials. Unfortunately, the solidification mechanism of heavy metals in geopolymers is still unclear, which is detrimental to the heavy metal solidification of LZS. In this study, we comprehensively studied and demonstrated the solidification mechanisms of Pb and Zn in geopolymers, based on the preparation of high-performance LZS-based geopolymers (compressive strength up to 89.3 MPa, and Pb and Zn solidification efficiency up to 93.1% and 90.0%, respectively). Thereafter, the solidification mechanism differences between Pb and Zn were explained by electronegativity and ion potential. Due to the ionic potential order of Zn 2+ > Pb 2+ > Na + , both Zn 2+ and Pb 2+ could exchange with Na + in the geopolymer. In addition, due to the electronegativity order of Pb > Si > Zn, Pb could attack the [SiO 4 ] structure and form covalent bonds in the Pb–O structure, while Zn did not (shown by Raman spectroscopy). As a result, Pb simultaneously solidified in the geopolymer through covalent bonding and ion exchange, while Zn was solidified mainly by ion exchange. Thus, this work provides new perspectives and ideas for the solidification mechanisms of heavy metals in geopolymers.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MATERIALS LETTERS
·
2021
·
IF 3.423
Hong Wang,Zhongying Liu,Yihai Zhou,Renchun Yang
In this paper, P O was grafted on the surface of rutile TiO 2 by one-step hydrothermal method . Due to the presence of the highly electronegative oxygen element, the surface of TiO 2 often presented an electron-deficient state, which limited its application in reduction reactions. Herein, the low electronegativity element P from the phosphate was grafted on the surface of TiO 2 to form a P O structure, which changes the electronic equilibrium state of the TiO 2 and provide a new channel for electron migration. The surface of TiO 2 presented an electron-enrich structure, which promoted the best hydrogen production performance around 28 mmol·g −1 ·h −1 on TiO 2 -P-0.01.
研究领域:
材料科学
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纳米技术
·
光催化
✓ 已验证
DOI
高影响因子
Advanced Fiber Materials
·
2025
·
IF 21.3
Pei Yanchun,Wu Xueyan,Ren Zhichao,Lv Yan,Xue Rui,Guo Jixi,Jia Dianzeng
Electrospun fiber membranes enable oil–water emulsion separation via tunable morphology and chemistry, yet most face an efficiency–permeability trade-off where enhancing one compromises the other. Herein, optimized membranes (C-NFO@GDY) are synthesized with a uniform honeycomb nanostructure of graphdiyne (GDY) on flexible coal-based preoxidized fibers (C-NFO) through the Glaser‒Hay coupling reaction. The honeycomb nanostructure of GDY effectively disperses external stress on the C-NFO fibers, increasing the tensile strength from 2.8 to 3.2 MPa. In addition, the nanostructure enhances hydration layer formation kinetics, achieving superhydrophilicity (0°) and underwater superoleophobicity (> 150°) of the membrane. When tested against three surfactant-stabilized emulsions (cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS), and polyoxyethylene sorbitan monooleate (Tween 80)), the membranes demonstrated separation fluxes of 2936 L/(m 2 h), 2149 L/(m 2 h), and 1855 L/(m 2 h), and the corresponding separation efficiencies were 99.6%, 96.6%, and 93.1%. For CTAB-stabilized emulsions, the C-NFO@GDY membrane (zeta potential: − 65.2 mV) exhibits strong electrostatic attraction with cationic surfactants, achieving a high flux of 2936 L/(m 2 h) and a separation efficiency of 99.6%, surpassing those of recently reported MXene and PANI composites under identical conditions. Overall, the synergy between honeycomb nanostructure and electronegativity of GDY overcomes the flux–efficiency trade-off, offering new ideas for the preparation of oil–water separation membranes. Graphical
研究领域:
材料科学
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环境工程
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2013
·Vol. 4
·期 6
·3082-3089
·
IF 2.562
Weitong Cai,Hui Wang,Dalin Sun,Qingan Zhang,Xiangdong Yao,Min Zhu
Destabilization by the alkali metal hydroxides LiOH, NaOH, and KOH in the solid-state dehydrogenation of LiBH4 is reported. 6.5 wt% of hydrogen was liberated within 10 minutes at 250 °C. Destabilization originated from the interaction between H+ in [OH]− and H− in [BH4]−. A larger Pauling's electronegativity of the alkali metal (Li > Na > K) led to a greater acidity of the proton donor [OH]− site, and thus enhanced destabilization. The temperature of the predominant dehydrogenation was reduced to 207, 221, and 230 °C, for ball milled LiBH4–LiOH, 2LiBH4–NaOH, and 2LiBH4–KOH, respectively. The LiBH4: LiOH stoichiometry greatly affected the destabilization, by providing differing reaction pathways in LiBH4-xLiOH (x = 1, 1.36, 4). The incremental increase in the LiOH content of LiBH4-xLiOH increased the dehydrogenation rate, but the temperature increased from 207 °C (x = 1) to 250 °C (x = 4). 4.1 and 6.5 wt% of hydrogen was liberated within 10 minutes by LiBH4–LiOH and LiBH4–4LiOH, respectively. The incremental increase in dehydrogenation temperature was attributed to differing [BH4]−⋯[OH]− interactions, formed by the differing stoichiometric ratios.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2023
·Vol. 16
·期 6
·2214
·
IF 3.4
Junzhan Zhang,Shangyi Liu,Zhifeng Tian,Ying Zhang,Zongmo Shi
High entropy perovskite oxides (HEPOs) were a class of advanced ceramic materials, which had attracted much scientific attention in recent years. However, the effect of factors affecting the phase stability of high entropy perovskite oxides was still controversial. Herein, 17 kinds of A-site HEPOs were synthesized by solid-state methods, and several criteria for the formation of HEPOs and phase stability were investigated. Single-phase solid solutions were synthesized in 12 kinds of subsystems. The results show that the phase stability of a single-phase solid solution was affected by the size disorder and configurational entropy. The electronegativity difference was the key parameter to predict the evolution of the cubic/tetragonal phase, rather than the tolerance factor. Cubic HEPOs were easily formed when the electronegativity difference was <0.4, while the tetragonal HEPOs were easily formed when the electronegativity difference was ≥0.4. This study can further broaden the family of HEPOs and is expected to design the phase stability of HEPOs through electronegativity difference.
研究领域:
材料科学
·
陶瓷材料
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DOI
PubMed
高影响因子
JOURNAL OF CATALYSIS
·
2023
·
IF 7.3
Fan Wu,Zhankai Liu,Jian Sheng,Lihan Zhu,Wen-Duo Lu,Bin Qiu,Dongqi Wang,An-Hui Lu
Boron-based catalysts are active and selective in the oxidative dehydrogenation reaction of propane (ODHP) to propylene. Herein, the binary boron-based compounds (boron nitride, boron phosphide, boron carbide, and silicon boride) composed of boron elements and one type of other non-boron elements, and the elemental boron were systematically compared to elucidate how the non-boron elements of binary borides influence their catalytic activity in ODHP. By combined experimental and computational studies, we demonstrated that the non-boron elements can modulate the performance of catalysts by altering the ability of the B-OH site to activate dioxygen and the subsequent activation of propane. In particular, the turnover frequency (TOF) of the catalyst exhibited a high negative linear correlation with the electronegativity of the non-boron element, except for the boron phosphide. This study highlights the importance of the chemical environment around the active boron sites and provides insight into the design of efficient ODHP catalysts.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
SOLID STATE SCIENCES
·
2024
·
IF 3.4
Meng-Jie Cui,Imran Muhammad,Jian Feng,Tie-Zhen Ren
The crystal and particle size distribution of α-alumina (α-Al 2 O 3 ) nanoparticles is increasingly important for their potential application. However, it is difficult to produce α-Al 2 O 3 nanoparticles due to the high activation energy barrier making it difficult to obtain a pure α-Al₂O₃. In this paper, α-Al 2 O 3 nanoparticles with an average size of 60 nm in width and about 100–300 nm in length were prepared using isopropanol through thermal treatment at 1200 °C, accompanied by a minor fraction of the θ phase. Addressing the challenge of achieving pure phase α-Al 2 O 3 , Density Functional Theory (DFT) calculation was conducted to explore the energy landscape similarity between the θ and α crystal phases. The results provided valuable insights into obstacles associated with obtaining pure α-Al 2 O 3 , enlightening the relationship between surface electronegativity and crystal phases. Furthermore, X-ray Photoelectron Spectroscopy and electrochemical tests were employed to demonstrate that the α phase could enhance the surface electronegativity of Al 2 O 3 . This comprehensive study not only encompasses the synthesis of Al 2 O 3 nanoparticles but also elucidates the distinctions between α and θ phases. These results offer valuable insights into methods optimizing for the synthesis of pure phase α-Al₂O₃.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Materials
·
2024
·Vol. 17
·期 12
·2868
·
IF 3.1
Panpan Li,Yongbin Yao,Shanshan Chai,Zhijian Li,Fan Xue,Xi Wang
The robust electronegativity of the [BO3]3−structure enables the extraction of electrons from adjacent metals, offering a strategy for modulating oxygen activation in propane oxidative dehydrogenation. Metals (Ni 1.91, Al 1.5, and Ca 1.0) with varying electronegativities were employed to engineer borate catalysts. Metals in borate lacked intrinsic catalytic activity for propane conversion; instead, they modulated [BO3]3−group reactivity through adjustments in electron density. Moderate metal electronegativity favored propane oxidative dehydrogenation to propylene, whereas excessively low electronegativity led to propane overoxidation to carbon dioxide. Aluminum, with moderate electronegativity, demonstrated optimal performance. Catalyst AlBOx-1000 achieved a propane conversion of 47.5%, with the highest propylene yield of 30.89% at 550 °C, and a total olefin yield of 51.51% with a 58.92% propane conversion at 575 °C. Furthermore, the stable borate structure prevents boron element loss in harsh conditions and holds promise for industrial-scale catalysis.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2025
·
IF 5.2
Dan Su,Jingyi Huang,Ge Zhang,Jing Gao,Zhipan Wen,Yingru Wang
In this study, the magnetic modification of rectorite was conducted to enhance its regenerability and surface electronegativity. When using the raw rectorite, the removal rate of ciprofloxacin was 78 % and the recovery rate was only 26 % after six regeneration cycles. However, with magnetized modified rectorite (M-REC), the removal rate of ciprofloxacin was 97 % and the recovery rate exceeded 75 %. The magnetic properties, easy magnetic separation and enhanced surface electronegativity of M-REC were confirmed through SEM, TEM, VSM, XRD, BET and XPS characterization. After six regeneration recycles, the basic skeleton structure of M-REC remained largely unchanged, indicating that has excellent stability. Additionally, the adsorption kinetics and thermodynamics of M-REC were investigated, and the Langmuir model accurately described the adsorption isotherm. The adsorption kinetics data fit the pseudo-second order models. The adsorption rate was determined by the number of available adsorption sites on the M-REC surface, and the removal process was primarily driven by chemisorption. Therefore, M-REC is an environmentally friendly adsorption material with potential applications in environmental remediation.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）