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1.
Enrique Alvarez‐Guerra Angel Irabien Sónia P. M. Ventura João A. P. Coutinho 《American Institute of Chemical Engineers》2014,60(10):3577-3586
Ionic liquid‐based three‐phase partitioning (ILTPP) is a promising technique to recover high‐added value proteins at the liquid–liquid interface. Its economic and environmental performance highly depends on the net ionic liquid consumption. Alternatives to maximize the fraction of ionic liquid that can be recycled are studied. It is demonstrated that the addition of extra salt, previously proposed in literature, has a very limited effect on ionic liquid recovery for relatively high protein concentrations in the feed stream, and that it may even lead to an increase of the ionic liquid losses under certain conditions. However, small additions of salt are shown to be effective and profitable from an economic point of view. Vacuum evaporation is shown to allow for the complete ionic liquid and salt recovery, reinforcing the sustainability and viability of ILTPP processes. © 2014 American Institute of Chemical Engineers AIChE J, 60: 3577–3586, 2014 相似文献
2.
Phase transformation and interface segregation behavior in Si3N4 ceramics sintered with La2O3–Lu2O3 mixed additive
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Ryosuke Urakami Yukio Sato Masayoshi Ogushi Takeshi Nishiyama Aoi Goto Kazuhiro Yamada Ryo Teranishi Kenji Kaneko Mikito Kitayama 《Journal of the American Ceramic Society》2017,100(3):1231-1240
Microstructure and mechanical property of silicon nitride (Si3N4) ceramic are strongly dependent on the selection of sintering additives. When rare‐earth (RE) oxide is used as the sintering additive, segregation of RE ions at interface between Si3N4 grain and intergranular glassy film (IGF) is believed to play a critical role. Although the ionic radius of RE ion is known to be an empirical parameter to modify the mechanical property, the correlation between the segregated ions and their ionic radii is still under controversy. In order to address this issue, (i) rate of α‐β phase transformation and (ii) segregation behavior at the interface were studied for Si3N4 ceramics sintered using mixture of La2O3 and Lu2O3 as additives in this study. Specimens of Lu content 30% and higher exhibited lower activation energies for the α‐β phase transformation as compared with those of Lu content 20% and lower. In terms of the segregation behavior, La was preferably segregated at one site and Lu at the other site along β‐Si3N4/IGF interface in the specimens of Lu content 30% and higher. It is understood from these results that Lu segregation site should be more closely related with grain growth. 相似文献
3.
《Journal of the European Ceramic Society》2021,41(13):6213-6222
The wetting of ZrB2 ceramic by molten pure Cu, Cu-(20, 30, 40, 50 at.%)Ti alloys were performed by the sessile drop method under vacuum of ∼4 × 10−4 Pa in the 1030−1070 °C temperature range. The wetting and interfacial behaviors of Cu-Ti/ZrB2 systems were analyzed and discussed. Furthermore, the work of adhesion and electronic properties of the Cu(1 1 1)/ZrB2(0 0 0 1) and Ti(0 0 0 1)/ZrB2(0 0 0 1) atomic interfaces were quantitatively evaluated by first-principles method. The wettability is significantly improved with the Ti concentration or wetting temperature increasing as a result of the formation of (Ti) solid solution at interface. The calculated results show that the B-terminated ZrB2 (0 0 0 1) surface is preferable to bond with Ti(0 0 0 1) surface, and the electronic structure reveals that the dominant interfacial bonding is the Ti-B ionic bond for the Ti/B-terminated ZrB2 interface. 相似文献
4.
Franciele L. Bernard Leonardo M. dos Santos Marina B. Schwab Barbara B. Polesso Jailton F. do Nascimento Sandra Einloft 《应用聚合物科学杂志》2019,136(20):47536
Carbon dioxide separation from CH4 is important to the environment and natural gas processing. Poly (ionic liquid)s (PILs) based on polyurethane structures are considered as potential materials for CO2 capture. Thus, a series of anionic PILs based on polyurethane were synthesized. The effects of polyol chemical structure and counter-cations (imidazolium, phosphonium, ammonium, and pyridinium) in CO2 sorption capacity and CO2/CH4 separation performance were evaluated. The synthesized PILs were characterized by NMR, DSC, TGA, dinamical mechanical thermo analysis (DMTA), SEM, and AFM. CO2 sorption, reusability, and CO2/CH4 selectivity were assessed by the pressure-decay technique. The counter-cation and polyol chemical structure play an important role in CO2 sorption and CO2/CH4 selectivity. PILs exhibited competitive thermal mechanical properties. Results showed that PILPC-TBP was the best poly (ionic liquid) for CO2/CH4 separation. Moreover, poly (liquid ionic) base polyol (polycarbonate) with phosphonium (PILPC-TBP) demonstrated higher CO2 sorption capacity (21.4 mgCO2/g at 303.15 K and 0.08 MPa) as compared to other reported poly (ionic liquids). © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47536. 相似文献
5.
Piao Cao Yuan Yuan Chizhou Huang Weizhen Sun Ling Zhao 《American Institute of Chemical Engineers》2020,66(8):e16979
Seven typical quaternary ammonium ionic liquids, amino acid ionic liquids, and imidazolium ionic liquids were synthesized, characterized, and investigated as co-catalyst for the sulfuric acid catalyzed isobutane alkylation. The results show that the introduction of [OPSIm][HSO4] or [Pr3NPS][HSO4] both leads to a better catalytic performance and higher quality of alkylate products. The molecular dynamic simulation indicates that the [OPSIm][HSO4] can promote the dissolution of isobutane molecules at interface, further improving the ratio of isobutane to olefin from 1.02 to 1.18. Differently, the [Pr3NPS][HSO4] can significantly increase the interface width from 0.66 to 0.97 nm and reduce the interface tension from 28.49 to 14.62 mN/m, thereby enhancing the reaction area and improving the ion transfer. The [Pro][HSO4] and [Gly][HSO4] result in a worse quality of alkylate products due to no positive effect on the interfacial properties such as interfacial solubility of isobutane. 相似文献
6.
《Journal of the European Ceramic Society》2002,22(13):2181-2186
Pure alumina (99.9% grade compositions) was brazed to 4J33-Kovar alloy based on PTLP technique with nickel and titanium foils interlayer. The solder formed a sandwich microstructure: an α-Ti solid solution belt at mid part and Ti2Ni intermetallics belts at two sides. This structure accounts for the good property of the joint. Microanalysis identified a reaction product at the alumina-braze interface as Ni2Ti4O phase. The special properties and structural compatibility of Ni2Ti4O contributed to the firm joint. The effects of brazing conditions on the joint properties were investigated. The joint shear strength showed the highest value of about 65MPa and did not monotonously increase with the brazing temperature ascending. It was shown that extending of brazing time gave thicker reaction layer and higher joint strength. 相似文献
7.
The adsorption of an anionic-type polyelectrolyte (polyacrylamide) onto zirconium dioxide from aqueous dispersion has been studied as a function of pH. Polymer adsorption takes place in the acid region, obeying a Langmuir-type isotherm. Adsorption decreases with increasing pH. The zero-point of charge (zpc) at the ZrO2–H2O interface and the nature of the ionic charge on the polymer molecules were investigated. The behavior of polymer attachment is discussed on the grounds of a nonionic bonding mechanism including H bonding and of electrostatic interaction. It has been found that the zpc of ZrO2 is at pH ~3.5 and that the ionic properties of the polymer molecules depend, to a noticeable extent, upon the pH of the medium. 相似文献
8.
Additives have been proven to be useful in improving electrospinnability and controlling fiber morphology through the modification of solution properties, including the conductivity, viscosity, and surface tension. In this study, the effects of adding small amounts of four different types of ionic liquids [i.e., 1‐butyl‐3‐methylimidazolium chloride (C4MIMCl), 1‐dodecyl‐3‐methylimidazolium chloride (C12MIMCl), 1‐ethyl‐3‐methylimidazolium bromide (C2MIMBr), and 1‐ethyl‐3‐methylimidazolium phosphate (C2MIM)3PO4] on the solution properties, electrospinning process, and characteristics of polyacrylonitrile (PAN) were investigated. The results show that the solution conductivities significantly increased with the addition of different ionic liquids with concentrations varying from 0.1 to 1.0 wt %, and the tendency depended on the structures of the ionic liquids. (C2MIM)3PO4 showed the highest conductivity value; this was followed by C2MIMBr, C4MIMCl, and C12MIMCl. The ionic liquids formed visible crystals; this made the fiber surfaces rough, and some fiber segments underwent partial aggregation. A regular varying tendency between the minimum mean diameter of the PAN/ionic liquid fibers and the structure of the ionic liquid was found. The PAN/N,N‐dimethylformamide (DMF)/(C2MIM)3PO4 solution showed the highest conductivity among the four systems with different ionic liquids added, and the thinnest minimum diameter of the PAN/(C2MIM)3PO4 fibers appeared with a relatively low ionic liquid concentration of 0.25 wt %, whereas the PAN/DMF/C12MIMCl solution had the lowest conductivity, and the minimum mean diameter of PAN/C12MIMCl fibers appeared at a relatively high ionic liquid concentration of 0.8 wt %. Although the conductivity of the PAN/DMF/C2MIMBr solution was higher than that of the PAN/DMF/C4MIMCl solution, the minimum mean diameters of the PAN/C2MIMBr and PAN/C4MIMCl fibers appeared at the same ionic liquid concentration of 0.5 wt % because of the similar ionic activities of C2MIMBr and C4MIMCl. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2359–2368, 2013 相似文献
9.
Electrochemical intercalation/deintercalation behavior of lithium into/from electrodes of lithium ion batteries was comparatively investigated in 1 mol/L LiClO4 ethylene carbonate-diethyl carbonate (EC-DEC) electrolyte and a quaternary ammonium-based ionic liquid electrolyte. The natural graphite anode exhibited satisfactory electrochemical performance in the ionic liquid electrolyte containing 20 vol.% chloroethylenene carbonate (Cl-EC). This is attributed to the mild reduction of solvated Cl-EC molecules at the graphite/ionic electrolyte interface resulting in the formation of a thin and homogenous SEI on the graphite surface. However, rate capability of the graphite anode is poor due to the higher interfacial resistance than that obtained in 1 mol/L LiClO4/EC-DEC organic electrolyte. Spinel LiMn2O4 cathode was also electrochemically cycled in the ionic electrolyte showing satisfactory capacity and reversibility. The ionic electrolyte system is thus promising for 4 V lithium ion batteries based on the concept of “greenness and safety”. 相似文献
10.
《Electrochimica acta》1985,30(2):191-197
The adsorption behaviour of H2PO−4 anions on mercury has previously been analysed from capacitance-potential relations at the interface of mercury with KH2PO4.It is not possible to determine unambiguously the adsorption characteristics of H2PO−4 ions from single salt solution experiments because of the possible existence of a layer of water molecules between the electrode and the adsorbed ions. In this work, the adsorption behaviour of H2PO−4 ions on mercury is analysed from experimental measurements of the capacitance as a function of potential at the interface of mercury with constant ionic strength solutions of compositions x M KH2PO4 + (1 − x) M KF. It is shown that the calculated amounts of adsorbed ions do not depend on the position of these ions relative to the solvent molecules. The double layer parameters were calculated taking into account the variations of activity coefficients of KH2PO4 and KF with solution composition. In constant ionic strength solutions, the plot of adsorbed charge vs electrode charge exhibits a maximum due to competition between the adsorbed H2PO−4 anions with the solvent or other ionic species. This result is shown to be important in determining the properties of the double layer characteristics in the presence of adsorbed H2PO−4 ions. 相似文献
11.
《Electrochimica acta》1987,32(2):325-330
The adsorption of N-tosylglycine (CH3-Ø-SO2-NH-CH2COOH) has been studied at the mercury/aqueous solution interface (0.1 M NaClO4 as base electrolyte) with the aim of comparing the interfacial properties of the molecular forms of the amino acid present in solution at different pH values. The analysis of the interfacial behaviour was performed by tensammetric measurements using an ac phase selective polarographic method of pH = 4, 6 and 12.It has been shown that the adsorption isotherm. (Frumkin type) is congruent with respect to the potential, with a slight attractive interaction factor at pH = 4, but higher and repulsive at pH = 6 and 12. At pH = 4 the species adsorbed seems to be the neutral one, white at pH = 6 and 12 the monoanionic species seems to be involved in the electrode interaction. Moreover, there is evidence that the molecule, in its neutral or ionic form, is always adsorbed with the tosyl group flat on the surface and the glycine moiety turned toward the solution. 相似文献
12.
A work was carried out on a solid polymeric electrolyte system comprising blends of poly (vinyl chloride) and liquid 50% epoxidized natural rubber (LENR50) as a polymer host with LiClO4 as a salt and prepared by solution casting technique. In this paper, the main study was the effect of LiClO4 salt concentration on the electrolyte properties. The effect of the salt on the electrolyte properties was characterized and analyzed with impedance spectroscopy (EIS), X‐ray diffraction (XRD), differential scanning calorimeter (DSC), and scanning electron microscopy (SEM). The EIS result showed that highest ionic conductivity was obtained at 30 wt % salt with a value of 2.3 × 10?8 S cm?1. The XRD results revealed that the LiClO4 salt was fully complexed within the polymer host as no sharp peaks were observed. However, above 30 wt % of salt, some sharp peaks were observed. This phenomenon was caused by the association of ions. Meanwhile, DSC analysis showed that Tg increased as the salt content increased. This implied that LiClO4 salt had interaction with polymer host by forming coordination bond. The morphologies' studies showed that good homogeneity and compatibility of the electrolyte were achieved. Upon the addition of the salt, formation of micropores occurred. It was noted that micropores which aid in mobility of ions in the electrolyte system has increased the ionic conductivity. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献
13.
Understanding interfacial behaviors of isobutane alkylation with C4 olefin catalyzed by sulfuric acid or ionic liquids
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Weizhong Zheng Huanying Wang Wenxiu Xie Ling Zhao Weizhen Sun 《American Institute of Chemical Engineers》2018,64(3):950-960
The interfacial properties between the hydrocarbon phase including isobutane and 2‐butene and the catalyst phase including H2SO4 or ionic liquids (ILs) with various alkyl chain length on their imidazolium cations have been investigated using molecular dynamics (MD) simulations. Compared to H2SO4, ILs can obviously improve the interfacial width, solubility and diffusion of reactants at the interface. The ILs with longer chains on cations exhibit a significant density enrichment of alkyl chains at the interface and tend to orient themselves with alkyl chains perpendicular to the interface and protruding into the reactant phase, which is in good agreement with the van der Waals energy between the reactants and cations of the ILs. The ILs with longer chains can improve the interfacial width and facilitate the dissolution of isobutane in catalyst phase, and thus exhibit a better catalytic performance, which agrees well with alkylation experiments in this work. © 2017 American Institute of Chemical Engineers AIChE J, 64: 950–960, 2018 相似文献
14.
Han Zhang Jie Lu Lirong Luo Xiaofeng Zhao Fangwei Guo Ping Xiao 《Journal of the European Ceramic Society》2021,41(3):1995-2001
The chemical compatibility of a series of rare earth apatite (RE-apatite), with Y2O3-stabilized ZrO2 (YSZ) has been investigated. Three types of RE-apatite powders with different ionic radius (RE = Gd, Nd and La) were prepared, and bulks prepared from the powder mixtures of RE-apatite and YSZ were heat-treated at 1300 °C up to 100 h in this study. It was found that Gd-apatite reacted with YSZ and formed a reaction layer (Gd2Si2O7) at the Gd-apatite/YSZ interface. Meanwhile, the intense Gd3+ diffusion resulted in the formation of Gd solid solutions in YSZ and much YSZ phase transformation. In contrary, as for Nd- or La-apatite/YSZ composite, which has larger ionic radius, no reaction product was observed at interface and there was less RE diffusion into YSZ as well as YSZ transformation. These results clearly indicated that large ionic radius of RE3+ could enhance the chemical compatibility of RE-apatite with YSZ. 相似文献
15.
《分离科学与技术》2012,47(12):2849-2858
Abstract An aqueous two‐phase system (ATPS) was presented with hydrophilic ionic liquid 1‐butyl‐3‐methylimidazolium chloride ([Bmim]Cl) and NaH2PO4 aqueous solution in this paper. The partitioning behavior of penicillin G in the ATPS was investigated. Concentrations of NaH2PO4, penicillin G, and [Bmim]Cl were evaluated to determine their effects on the partition coefficient and extraction yield of penicillin G. It was found that both of partition coefficient and extraction yield strongly depended on the concentration of [Bmim]Cl, penicillin and NaH2PO4. A high extraction yield of 93% was achieved with the following parameters: NaH2PO4 · 2H2O 40% (wt%), penicillin 45000~50000 u/ml, [Bmim]Cl 20~21% (wt%). The [Bmim]Cl/NaH2PO4 system was also applied in a real filtration of penicillin G fermentation broth and the extraction yield was averaged at 91.5%. It is worthy noting that the working pH value of ATPS was at the range of 5~6, no emulsification and protein denaturation could be observed. 相似文献
16.
Ping Cheng Ruihao Chen Junfei Wang Jianong Yu Tian Lan Wanjun Wang Haijun Yang Haixia Wu Changsheng Deng 《Nanoscale research letters》2010,5(8):1313-1319
We reported a composite electrolyte prepared by incorporating layered α-titanium phosphate (α-TiP) into an iodide-based electrolyte
using 1-ethyl-3-methylimidazolium tetrafluoroborate(EmimBF4) ionic liquid as solvent. The obtained composite electrolyte exhibited excellent electrochemical and photovoltaic properties
compared to pure ionic liquid electrolyte. Both the diffusion coefficient of triiodide (I3
−) in the electrolyte and the charge-transfer reaction at the electrode/electrolyte interface were improved markedly. The mechanism
for the enhanced electrochemical properties of the composite electrolyte was discussed. The highest conversion efficiency
of dye-sensitized solar cell (DSSC) was obtained for the composite electrolyte containing 1wt% α-TiP, with an improvement
of 58% in the conversion efficiency than the blank one, which offered a broad prospect for the fabrication of stable DSSCs
with a high conversion efficiency. 相似文献
17.
Preparation and performance analysis of barium titanate incorporated in corn starch‐based polymer electrolytes for electric double layer capacitor application
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Polymer electrolyte membranes composing of corn starch as host polymer, lithium perchlorate (LiClO4) as salt, and barium titanate (BaTiO3) as composite filler are prepared using solution casting technique. Ionic conductivity is enhanced on addition of BaTiO3 by reducing the crystallinity and increasing the amorphous phase content of the polymer electrolyte. The highest ionic conductivity of 1.28 × 10?2 S cm?1 is obtained for 10 wt % BaTiO3 filler in corn starch‐LiClO4 polymer electrolytes at 75°C. Glass transition temperature (Tg) of polymer electrolytes decreases as the amount of BaTiO3 filler is increased, as observed in differential scanning calorimetry analysis. Scanning electron microscopy and thermogravimetric analysis are employed to characterize surface morphological and thermal properties of BaTiO3‐based composite polymer electrolytes. The electrochemical properties of the electric double‐layer capacitor fabricating using the highest ionic conductivity polymer electrolytes is investigated using cyclic voltammetry and charge‐discharge analysis. The discharge capacitance obtained is 16.22 F g?1. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43275. 相似文献
18.
Yanlei Wang Cheng Qian Feng Huo Baohua Xu Hongyan He Suojiang Zhang 《American Institute of Chemical Engineers》2021,67(3):e17060
The transport behavior of CO2 at the ionic liquids (ILs)-electrode interface was revealed from the thermodynamic view via molecular dynamics simulations. The hopping and self-diffusive mechanisms were identified in the interfacial and bulk region, and thereafter a hopping-diffusion model was developed to evaluate the transport resistance of CO2 from bulk to the interface. Meanwhile, the vibrational spectrum and entropy change of CO2 at the interface were calculated using the thermodynamic analysis method. For ILs with the same cation ([Emim]+), both transport resistance and entropy decrease follow the order: [BF4]− < [AC]− < [NO3]−, indicating [BF4]− possesses the faster CO2 transport efficiency across the electrical double layer. Furthermore, the methyl substitution effect on transport and thermodynamic properties was clarified, indicating the coupling relation between the transport process and thermodynamic advantage. These findings can lay the ground for the molecule design of ILs-electrode interface in the applications in the chemical engineering field. 相似文献
19.
The potential of poly(ethylene oxide) (PEO) and 49% poly(methyl methacrylate) grafted natural rubber (MG49) as a polymer host in solid polymer electrolytes (SPE) was explored for electrochemical applications. PEO–MG49 SPEs with various weight percentages of lithium perchlorate salt (LiClO4) was prepared with the solution casting technique. Characterization by scanning electron microscopy, Fourier transform infrared spectroscopy, and impedance spectroscopy was done to investigate the effect of LiClO4 on the morphological properties, chemical interaction, and ionic conductivity behavior of PEO–MG49. Scanning electron microscopy analysis showed that the surface morphology of the sample underwent a change from rough to smooth with the addition of lithium salts. Infrared analysis showed that the interaction occurred in the polymer host between the oxygen atom from the ether group (C? O? C) and the Li+ cation from doping salts. The ionic conductivity value increased with the addition of salts because of the increase in charge carrier up to the optimum value. The highest ionic conductivity obtained was 8.0 × 10?6 S/cm at 15 wt % LiClO4. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献
20.
Preparation of oligochitosan via In situ enzymatic hydrolysis of chitosan by amylase in [Gly]BF4 ionic liquid/water homogeneous system
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The preparation of oligochitosan with excellent performance via in situ enzymatic hydrolysis of chitosan by amylase in ionic liquid system is reported. It has been found that [Gly]BF4 ionic liquid leads to the good solubility and assistant degradation for chitosan, as well as good biocompatibility for amylase. In the homogeneous system that contained 1.0 g chitosan (degree of deacetylation = 88.5%) and 99.0 g 2 wt % [Gly]BF4 aqueous solution, oligochitosan with 2200 viscosity‐average molecular weight has been obtained after 0.12 g amylase being used for 3 h at 50°C and pH 5.0. This result is superior to that conducted in acetic acid system. Moreover, [Gly]BF4 can be easily separated from the product and reused with only slight performance loss (oligochitosan product with 2700 viscosity‐average molecular weight has been obtained after [Gly]BF4 being reused for five times). In addition, the mechanism for enzymatic hydrolysis of chitosan in [Gly]BF4 ionic liquid has been described. The research on the moisture‐absorption, ‐retention, and antibacterial activity of oligochitosan product shows that the smaller molecular weight would bring the better moisture‐absorption and antibacterial properties. The oligochitosan product with 2200 viscosity‐average molecular weight exhibits preferable antibacterial properties to S. aureus and E. coli. At the same time, the moisture‐absorption and ‐retention capacity of the above product can reach 32% (relative humidity (RH) = 43%), 62% (RH = 81%), and 150% (RH = 43%), 35% (dry silica gel) respectively. The enzymatic preparation of oligochitosan through [Gly]BF4 ionic liquid/water homogeneous system can be an efficient and environment‐friendly method for academics and industry. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41152. 相似文献