International Journal of Coal Preparation and Utilization
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2019
·
IF 2.02
Zechen Liu,Yinfei Liao,Yongtian Wang,Maoyan An,Qingteng Lai
Low-rank coals are difficult to float using common hydrocarbon oily collectors, such as dodecane and diesel. In this investigation, a mixture of dodecane and n-valeric acid was used as a collector to enhance low-rank coal flotation. The changes in the induction time and surface functional groups of low-rank coal were measured before and after different collector’s adsorption to indicate its absorption mechanism. The surface free energy was calculated to identify the interaction mechanism quantitatively between coal and collectors. The results showed that the flotation performance using the mixture as a collector was much better than that using dodecane or n-valeric acid solely. The induction time of coal conditioned with the mixed collector was the shortest, which meant the better hydrophobicity and floatability. When used the mixture as collector, the polar group of the n-valeric acid interacting with the oxygenated functional group on the coal surface by hydrogen bond while dodecane primarily covers the hydrophobic sites on the coal surface. Additionally, the mixed collector can minimize the surface free energy of raw coal, the dodecane primarily reduces the nonpolar part of the coal surface free energy while the n-valeric acid reduces the polar part of the coal surface free energy.
研究领域:
矿物加工工程
·
化学工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Zhuoyang Li,Yang Zhang,Guishang Pei,Mengjiao Jiao,Xuewei Lv
MnV 2 O 6 and Mn 2 V 2 O 7 are essential compounds in the manganese salt roasting process for extracting vanadium and serve as excellent battery materials. Determining their thermodynamic properties is of significant theoretical and practical importance. In this study, MnV 2 O 6 and Mn 2 V 2 O 7 were synthesized through solid-state synthesis under a nitrogen atmosphere, and their crystal structures were analyzed using X-ray powder diffraction. The heat capacity of MnV 2 O 6 and Mn 2 V 2 O 7 were measured using relaxation calorimetry over the temperature range of 2–300 K. The entropy at 298.15 K, including magnetic contributions, was calculated as 178.99 ± 5.35 J K -1 ·mol -1 for MnV 2 O 6 and Mn 2 V 2 O 7 for 258.93 ± 6.47 J K -1 ·mol -1 . The standard molar enthalpies of formation were determined using high-temperature solution calorimetry in a molten lead borate solvent, yielding -1997.09 ± 23.97 for MnV 2 O 6 and -2427.71 ± 29.12 kJ mol -1 for Mn 2 V 2 O 7 from their element references. Based on these reliable experimental data, other thermodynamic properties, including enthalpy changes, entropy, and Gibbs free energy, were calculated. Finally, thermodynamic simulations were conducted to analyze phase evolution during the manganese salt roasting process and to evaluate the water solubility of MnV 2 O 6 and Mn 2 V 2 O 7 .
研究领域:
材料科学
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热力学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL PHYSICS
·
2023
·Vol. 158
·期 12
·
IF 4.4
Song Kun,Jin Xin,Lv Xiaodong,Xin Yuntao,Lv Xuewei
Lithium-ion batteries (LIBs) are widely used in electronic applications because of their high voltage, high specific energy, long lifespan, and other characteristics. Electrode materials have garnered interest as an indispensable component of LIBs. Na 7 [H 2 PV 14 O 42 ] is used as an electrode material because of its excellent properties. In this study, Na 7 [H 2 PV 14 O 42 ] was synthesized by the water bath method using NaVO 3 as the raw material, experimentally characterized, and its thermodynamic data were measured using the Neumann–Kopp rule from 298.15 to 843 K, a Physical Property Measurement System from 15 to 309 K, and the MHTC 96 line from 473 to 773 K. The data were fitted to the Debye–Einstein heat capacity equation at low temperatures and a polynomial function at higher temperatures. The heat capacity equation of Na 7 [H 2 PV 14 O 42 ] was obtained from the fitted curves. The corresponding enthalpy ( ▵ 298.15 T H m ), entropy ( ▵ 298.15 T S m ), and Gibbs energy ( ▵ 298.15 T G m ) (from 298.15 to 800 K) were calculated according to the heat capacity equation. The obtained heat capacity of Na 7 [H 2 PV 14 O 42 ], as a function of temperature, was modeled as Cp = 1502.30 + 0.27T − 2.44E7T −2 J mol −1 K −1 (473–773 K). This study can compensate for the thermodynamic deficiency of Na 7 [H 2 PV 14 O 42 ].
研究领域:
材料科学
·
热力学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Catalysis Science & Technology
·
2021
·Vol. 11
·期 16
·5579-5589
·
IF 6.119
Qixiao Gai,Shoutian Ren,Xiaochun Zheng,Wenjun Liu,Quanli Dong
Transition metal co-catalysts exhibit considerable potential in the photocatalytic water splitting process, but their limited activity and poor stability inhibit their extensive application, and therefore effective schemes are required to further enhance their co-catalytic performance. In this article, 2D/2D C3N4/CdS heterogeneous photocatalysts are first synthesized, and then CoNi alloyed NPs are selectively loaded on their CdS nanosheets by a convenient photodeposition method. The CoNi loading amount and Co/Ni ratio are adjusted by the photodeposition time and precursor Co2+/Ni2+ ratio, respectively. Meanwhile, Co–S bonds are formed between CdS and CoNi NPs. Their optimal hydrogen evolution rate can reach up to 2936.65 μmol g−1 h−1, which is higher than that of C3N4/CdS with Co, Ni or Pt as co-catalysts (i.e. 844.59, 2385.96 and 2486.66 μmol g−1 h−1), respectively. The enhanced photocatalytic performance should be due to the following three points: (1) the formation of the 2D/2D C3N4/CdS heterojunction; (2) the optimized Gibbs free energy of the CoNi co-catalysts; (3) the formation of Co–S bonds between CoNi and CdS. Our work provides a cost-effective scheme to exploit stable and efficient photocatalysts.
研究领域:
材料科学
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能源化学
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DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
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2019
·
IF 4.561
Xiangrong Li,Chenglin Jiang,Jianguo Liu,Ye Qin,Zhongyu Zhang,Zaibo Liu,Jiazhen Yang,Chuanwei Yan
In this paper, a model for viscosity of high-concentrated additive (methanesulfonic acid) in vanadium electrolyte is reported. Methanesulfonic acid was evaluated as a possible stabilizing agent for the thermal precipitation of supersaturated V(V) solutions at elevated temperatures. Viscosity ( η ) of the ternary solution CH 3 SO 3 H + VOSO 4 + H 2 O was measured between the temperatures 283.15 K and 318.15 K under atmospheric pressure. Based on the viscosity, viscosity B -coefficient, activation energy (Δ μ 0 ≠ 0 ) and Gibbs free energy of activation (Δ G ≠ ) were further calculated. With the help of these paraments, a semi-empirical predicting function is established to estimate the viscosity of high-concentrated additive, i.e. methanesulfonic acid in vanadium electrolyte. AARD of this semi-empirical method is 0.22%, which demonstrates that viscosity estimation for high-concentrated ternary solution CH 3 SO 3 H + VOSO 4 + H 2 O can be achieved.
研究领域:
化学工程
·
能源科学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Danni Zeng,Tingzhe Shen,Yadong Hu,Fengjiao Liu,Ze Liu,Jun Song,Rongfeng Guan,Changjian Zhou
Photothermal synergistic catalysis is a novel technology that converts energy. In this study, ZnIn 2 S 4 with S-vacancy (ZIS-Vs) is combined with Nickel, Nickle Oxide and Carbon Nanofiber aggregates (Ni-NiO@CNFs) to create a multi-interface coupled photocatalyst with double Schottky barrier, double channel and mixed photothermal conversion effect. Theoretical calculation confirms that the Gibbs free energy (ΔG *H ) of the S-scheme heterojunction in the composite material is −0.07 eV, which is close to 0. This promotes the adsorption of H* and accelerates the formation of H 2 . Internal photothermal catalysis is achieved by visible-near infrared (Vis-NIR, RT) irradiation. The internal photothermal catalytic hydrogen production rate of the best sample (0.9Ni-NiO@CNFs/ZIS-Vs) is as high as 17.24 mmol·g −1 ·h −1 , and its photothermal conversion efficiency (η) is as high as 61.42 %. Its hydrogen production efficiency is 20.52 times that of ZIS-Vs (0.84 mmol·g −1 ·h −1 ) under visible light (Vis, RT) conditions. When the Vis-NIR light source is combined with external heating (75 ℃), the hydrogen production efficiency is further improved, and the hydrogen production efficiency (29.16 mmol·g −1 ·h −1 ) is 26.75 times that of ZIS-Vs (1.09 mmol·g −1 ·h −1 , Vis-NIR, RT). Further analysis shows that the increase in hydrogen production resulted from the apparent activation energy (Ea) of the catalyst decreasing from 16.7 kJ·mol −1 to 9.28 kJ·mol −1 . This study provides a valuable prototype for the design of an efficient photothermal synergistic catalytic system.
研究领域:
材料科学
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催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF FOOD SCIENCES AND NUTRITION
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2020
·
IF 3.483
Nan Chen,Hao-Xiang Gao,Qiang He,Zhi-Long Yu,Wei-Cai Zeng
The interaction and action mechanism of starch with different phenolic compounds were investigated. By using scanning electron microscope, nuclear magnetic resonance, Fourier transform infra-red spectroscopy and thermogravimetric analysis, phenolic compounds exhibited the significant effects on the morphology, intensity of hydrogen bond, crystalline structure and thermal stability of starch, respectively. Furthermore, according to the analysis of molecular dynamics simulation by using short-chain glucose (SGS) as model, phenolic compounds could change the spatial configuration of starch, and had the obvious effects on the formation of hydrogen bonds (including intra- and intermolecular hydrogen bonds) and the strength of binding free energy. Meanwhile, epigallocatechin gallate possessed the strongest capacity to change the spatial configuration of starch with the consistent hydrogen bond occupancy and the lowest binding free energy. All present results suggested that phenolic compounds might be potentially utilised for improving the quality of starch in food industry.
研究领域:
食品科学
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分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Polymers
·
2017
·Vol. 9
·期 6
·233
·
IF 3.364
Fei Wang,Leishan Shao,Qiyao Bai,Xinyuan Che,Bin Liu,Yinghan Wang
Vertical alignment of liquid crystal (LC) was achieved in an easy and effective way: in situ photopolymerization of dodecyl acrylate (DA) monomers initiated by polyimide based on 3,3′,4,4′-benzophenonetetracarboxylic dianhydride and 3,3′-dimethyl-4,4′-diaminodiphenyl methane (BTDA-DMMDA PI). The alignment behavior and alignment stabilities were characterized by a polarizing optical microscope (POM), which showed a stable vertical alignment after 12 h of thermal treatment. The chemical structures, morphology, and water contact angles of alignment films peeled from LC cells with and without DA monomers were analyzed by means of a Fourier transform infrared spectrometer (FTIR), a scanning electron microscope (SEM), and a contact angle tester, separately. The results confirmed that the DA monomers underwent self-polymerization and grafting polymerization initiated by the BTDA-DMMDA PI under ultraviolet irradiation, which aggregated on the surfaces of PI films. The water contact angles of the alignment films were about 15° higher, indicating a relative lower surface energy. In conclusion, the vertical alignment of LC was introduced by the low surface free energy of PI films grafted with DA polymer and intermolecular interactions between LC and DA polymers.Keywords:vertical alignment;photopolymerization;alignment stability;surface free energy
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2023
·
IF 6.1
Zilu Li,Xingyu Zhang,Yue Wang,Zirui Zheng,Chenhui Zhang,Tianyue Wu,Yanling Wu,Yuxia Gao,Fengpei Du
Glyphosate, one of the most widely used herbicides, plays an important role in controlling weeds and ensuring crop production. While using glyphosate, adjuvants are commonly added to improve its deposition on weeds and control efficacy. However, changes in weed leaf surface characteristics may reduce glyphosate penetration and contribute to evolved glyphosate resistance. Therefore, it is significant to introduce an improved method for regularizing leaf surface characterization and guide adjuvant selection to improve glyphosate efficacy. In this work, surface characteristics of typical weed leaves have been systematically investigated by 3D surface analysis and scanning electron microscopy, finally quantified by apparent surface free energy (ASFE) due to its comprehensive and quantitative evaluation of leaf surfaces. Moreover, the relationship between the weed leaf surface characteristics and the retention of glyphosate on weeds was established, further related to the control efficacy against weeds. To maximize the utilization rate of glyphosate, the types and concentrations of adjuvants should be regulated according to the ASFE of weeds. Our findings not only regularize the surface properties of weed leaves but also reveal their influencing mechanism on the deposition and biological activity of glyphosate, which provide effective guidance for the use of glyphosate.
研究领域:
植物学
·
农学
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2020
·
IF 5.065
Xiaojie Liu,Chunying Zhu,Taotao Fu,Youguang Ma
The densities and viscosities of ternary solution of piperazine (PZ) + 2-Amino-2-methyl-1-propanol (AMP) + H 2 O were measured at P = 101 kPa and T = (303.15–343.15) K. The effects of temperature and concentration on the density and viscosity of ternary solution were investigated. The apparent molar volume ( V φ ), the limiting partial molar volume ( V φ 0 ), viscosity B -coefficient, Helper's constant and the free energies of activation per mole of solvent ( Δμ 1 0≠ ) and solute ( Δμ 2 0≠ ) were calculated from the density and viscosity, respectively. The solute-solute and solvent-solute interactions were analyzed from the volumetric and viscometric properties. The results show that the PZ has a destructive effect on the structure of mixed solvent.
研究领域:
物理化学
·
溶液化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2018
·Vol. 6
·期 31
·15057-15063
·
IF 9.931
Yunlu Pan,Suichu Huang,Feiran Li,Xuezeng Zhao,Weijie Wang
The coexistence of superhydrophilicity and superoleophobicity was considered abnormal since a superoleophobic surface would also be superhydrophobic based on the classic surface free energy (SFE) theory. However, several studies have succeeded in preparing uperhydrophilic/superoleophobic surfaces, although the theoretical explanations were still not convincing due to the lack of experimental evidence. In this study, a theory for the coexistence of superhydrophilicity and superoleophobicity was developed with a series of experimental proofs. Four different superhydrophilic/superoleophobic surfaces were prepared as examples and it can be inferred that much more different surfaces with such wettability can be prepared for different specific applications based on the developed theory, and oil/water separations were conducted by using one kind of these prepared surfaces.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
SURFACE & COATINGS TECHNOLOGY
·
2021
·
IF 4.158
Huanhuan Zhang,Tao Liang,Yuzhi Liu,R.D.K. Misra,Ying Zhao
Low surface free energy coating can effectively suppress the initial adhesion of fouling organism. However, continuous attack of corrosive medium will inevitably weaken the coating barrier effect. Herein, a novel self-healing coating based on fluorine‑silicon copolymer (FSiAC) and 0.1 wt% graphene oxide (GO) was prepared by free radical copolymerization . The formed GO/FSiAC coating with the surface free energy of 22.6 mJ/m 2 effectively suppressed the adhesion of chlorella, and the inhibition rate was 97%. EIS results showed that the impedance of GO/FSiAC coating increased and the coating porosity decreased with immersion time, indicating that the coating had self-healing property. DSC and FTIR measurements revealed that during the immersion process, the coating cross-linking degree increased due to the formation of net-like Si-O-Si structure. The barrier performance of GO and the self-healing capacity contributed to the superior corrosion resistance of the coating. The outstanding antifouling property is dependent on the low surface free energy of the coating and the antibacterial effect of GO. Novel GO/FSiAC coating with excellent antifouling and good self-healing anticorrosion performance has a potential application in marine engineering fields.
研究领域:
材料科学
·
海洋工程
·
生物学
✓ 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）