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1.
The development of novel materials for carbon dioxide (CO2) capture is of great importance in resource utilization and environmental preservation. In this study, imidazolium‐based ionic liquids (ILs) with symmetrical ester and hydroxyl groups were prepared, and their corresponding polymer were synthesized by melt condensation polymerization. The structure and properties of the poly(ionic liquid)s (PILs) were characterized by proton nuclear magnetic resonance, gel permeation chromatograph, differential scanning calorimetry, X‐ray diffraction, and scanning electron microscopy. In addition, the CO2 sorption behavior of the IL monomers and PILs were studied at a low pressure (648.4 mmHg CO2) and under a temperature of 25°C using a thermogravimetric analyzer. The CO2 sorption capacity of 1,3‐bis(2‐hydroxyl ethyl)‐imidazolium hexafluorophosphate ([HHIm]PF6, 10 mol%) was the highest among all the IL monomers and PILs studied. This capacity is also much higher than those reflected of previously reported ILs. Moreover, the sorption equilibrium of [HHIm]PF6 was achieved within a short time. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

2.
In this work, using divinylbenzene (D), 1‐vinylimidazole (V) and 1‐vinyl‐3‐butylimidazolium bromide ([VBIM][Br]) as monomers, the binary‐monomer poly (ionic liquids) (PILs) and ternary‐monomer PILs were successfully synthesized, via hydrothermal polymerization and anion exchange, sequentially. Compared with each other, the ternary polymeric acidic IL catalyst has a clear spongy porous structure, while having a more stable macroporous structure, a larger specific surface area, more acidic groups and more active sites. Catalytic performance of catalyst was investigated through the alkylation of o‐xylene and styrene. The effect of the amount of IL added and the length of the cation chain on the ternary polymerization of acidic IL was systematically investigated. Under optimal reaction conditions (molar ratio of monomers was D:V:[VBIM][Br] = 2:1:1, the most suitable cation chain length was C4), the synthesized MPD‐[C4V]‐[VBIM][SO3CF3] has a larger specific surface area (89.47 m2/g), large pore volume (0.29 cm3/g), and abundant mesopores and macropores, which help to improve the contact between the active site and reactants. Moreover, the catalyst could maintain a relatively high conversion of styrene (99.0%), 1,2‐diphenylethane yield (98.7%) and high thermostability under reaction and be easily be divided from the solution, which is critical for heterogeneous solid catalysts.  相似文献   

3.
Ionic liquids, which are extensively known as low-melting-point salts, have received significant attention as the promising solvent for CO2 capture. This work presents the synthesis, thermophysical properties and the CO2 absorption of a series of ammonium cations coupled with carboxylate anions producing ammonium-based protic ionic liquids (PILs), namely 2-ethylhexylammonium pentanoate ([EHA][C5]), 2-ethylhexylammonium hexanoate ([EHA][C6]), 2-ethylhexylammonium heptanoate ([EHA][C7]), bis-(2-ethylhexyl)ammonium pentanoate ([BEHA][C5]), bis-(2-ethylhexyl)ammonium hexanoate ([BEHA][C6]) and bis-(2-ethylhexyl)ammonium heptanoate ([BEHA][C7]). The chemical structures of the PILs were confirmed by using Nuclear Magnetic Resonance (NMR) spectroscopy while the density (ρ) and the dynamic viscosity (η) of the PILs were determined and analyzed in a range from 293.15K up to 363.15K. The refractive index (nD) was also measured at T = (293.15 to 333.15) K. Thermal analyses conducted via a thermogravimetric analyzer (TGA) and differential scanning calorimeter (DSC) indicated that all PILs have the thermal decomposition temperature, Td of greater than 416K and the presence of glass transition, Tg was detected in each PIL. The CO2 absorption of the PILs was studied up to 29 bar at 298.15 K and the experimental results showed that [BEHA][C7] had the highest CO2 absorption with 0.78 mol at 29 bar. The CO2 absorption values increase in the order of [C5] < [C6] < [C7] anion regardless of the nature of the cation.  相似文献   

4.
The combination of zeolitic imidazolate framework-8 (ZIF-8) and ionic liquids (ILs) to create porous ionic liquids (PILs) is highly significant for efficient carbon dioxide (CO2) capture and the advancement of carbon capture, utilization, and storage (CCUS) technologies. To further investigate the CO2 capture characteristics of different PILs, two different-sized ZIF-8 structures and two functionalized ILs were prepared. Additionally, the enhancement factor of the reaction process was calculated using the dual-film theory and mass transfer coefficient. The results demonstrated that the original [PMIm]Cl had low CO2 absorption capacity at ambient temperature and pressure, whereas the functionalized ILs had a maximum CO2 capture capacity of approximately .31 mol/mol, with the 20 wt% concentration of tetraethylene pentamine-2-methylimidazole ([TEP][MIm]) exhibiting the highest CO2 capture capacity of around 1.93 mol/mol. The synthesized PILs demonstrated a maximum CO2 capture capacity of approximately 2.22 and 2.16 mol/mol at 20 and 10 wt% ionic concentrations, respectively, with a porous ionic liquid addition of 1.0/100 g. The corresponding enhancement factors were 1.53 and 1.59, respectively. These findings have significant implications for CCUS technology.  相似文献   

5.
We synthesized one quaternary ammonium polymeric ionic liquids(PILs)P[VBTHEA]Cl and three imidazolium PILs of P[VEIm]Br, P[VEIm]BF_4, P[VEIm]PF_6 by free-radical polymerization in solution. These PILs were characterized by FT-IR,~1 H-NMR,~(13)C-NMR, TGA, XRD and SEM. Their CO_2 adsorption capacities were measured under different pressures and temperatures by constant-volume technique. It was observed that quaternary ammonium PILs of P[VBTHEA]Cl have higher adsorption capacity for CO_2 than those imidazolium PILs, following P[VBTHEA]Cl P[VEIm]PF_6 P[VEIm]BF_4 P[VEIm]Br, which may be ascribed to higher positive charge density on ammonium cation than that on imidazolium cation and thus stronger interaction with CO_2, consistent with the results from dual-mode adsorption model that ammonium PILs have much higher CO_2 bulk absorption than imidazolium PILs. CO_2 adsorption capacity of P[VBTHEA]Cl is 9.02 mg/g under 295 K and 1 bar, which is comparable to that of some other PILs, and is much higher than that of the corresponding ILs monomer. These PILs have good adsorption selectivity for CO_2 over N_2 and regeneration efficiency.  相似文献   

6.
A series of novel polymerized ionic liquids (PILs) contained imidazolium, poly (2,5‐bis{[6‐(1‐butyl‐3′‐imidazolium)hexyl] oxy carbonyl}styrene salts) (denoted as P1? X?, X??Br?, BF4?, PF6? and TFSI?) were successfully synthesized via radical polymerization. The chemical structures of the monomers and their corresponding PILs were confirmed by 1H NMR, 13C NMR, and Fourier transform infrared spectroscopy. Thermogravimetric analysis results showed that these PILs had excellent thermal stability. The phase transitions and liquid‐crystalline (LC) behaviors of these polymers were investigated by differential scanning calorimetry, polarized light microscopy (PLM), and wide‐angle X‐ray diffraction. The combined experimental results showed that all the PILs could form hexagonal columnar (?H) LC ordered structures because of the strong interaction between the anions and cations in the side groups except for P1? TFSI?. The conductivities of monomers and PILs were sketchily investigated, and monomers had higher conductivities than those of conprespoding PILs. For comparison, we have synthesized a polymer without counter‐anion, but similar to the chemical structure of P1? X?, poly (2, 5‐bis{[6‐(4‐butoxy‐4′‐oxy phenyl) hexyl] oxycarbonyl} styrene) (denoted as P2). In this case, phenyl took place of imidazolium of side chain, and LC ordered structure did not form. The comparison between P1? X? and P2 suggested that ion played an important role in the constructing of LC ordered structure. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013  相似文献   

7.
Protic ionic liquids (PILs) in solution especially in water have attracted more and more attention due to their unique properties. The solvation of PILs in water is important to their properties and applications. To explore the solvation of bio-based PILs in water, acidity of 49 [AA]X amino acid ionic liquids (AAILs) consisting of 7 different cations and 7 different anions was studied as a favorable probe. The pKa values for [AA]X PILs containing same cations were obtained and discussed. The acidity strength of the [AA]X PILs varies with both cation and anion which does not follow the conventional assumption that the acidity for PILs is independent of anions. The acidic discrepancy of [AA]X PILs aqueous solution is probably mediated by the formation of ion pairs according to a revised solvation model of PILs. Quantum-chemistry calculation was employed to unpuzzle anion's different effects on the acid balance of cations where cation-anion hydrogen bonds play an important role. Such difference in acidity allows us to understand the formation of solvated ion pairs. This work provides an insight into the fundamental solvation of PILs from acid perspective and their influence on acidity properties for the first time.  相似文献   

8.
Polymerized ionic liquids (PILs) are a platform for fundamental studies of structure‐property relationships in single ion conductors, with potential applications in energy storage and conversion. The synthesis, thermal properties, and ionic conductivities of homologous, narrow dispersity styrenic PILs are described. Hydrophilic poly(4‐vinylbenzyl alkylimidazolium chloride) (PVBn(alkyl)ImCl) homopolymers with constant average degrees of polymerization were synthesized by post‐synthetic functionalization of a poly(4‐vinylbenzyl chloride) (Mn = 15.9 kg/mol, Mw/Mn = 1.34) master batch with N‐alkylimidazoles (alkyl = ? CH3 (Me), ? C4H9 (Bu), and ? C6H13 (Hex)). The chloride counterions of PVBnHexImCl were exhaustively metathesized with BF, PF, and bis(trifluoromethanesulfonyl)imide (TFSI?) to yield a series of hydrophobic PILs. Thermogravimetric analyses indicate that PVBn(alkyl)ImCl homopolymers are unstable above 220 °C, whereas the hydrophobic PILs remain stable up to 290 °C. The glass transition temperatures (Tg) decrease with both increasing alkyl side‐chain length and increasing counterion size, exemplified by Tg = 9 °C for PVBnHexImTFSI. Hydrophilic PILs exhibit high ionic conductivities (as high as ~0.10 S cm?1) that depend on the relative humidity, water uptake, and the PIL side chain length. The hydrophobic PILs exhibit lower conductivities (up to ~5 × 10?4 S cm?1) that depend predominantly on the polymer Tg, however, counterion size and symmetry also contribute. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 49: 1287–1296, 2011  相似文献   

9.
A set of eight functional 4‐vinyl‐1,2,3‐triazolium monomers were synthesized using copper catalyzed azide‐alkyne 2 + 3 Hüisgen cycloaddition. These vinyl‐trizolium monomers readily polymerized via free radical polymerization. The physical properties of the vinyl‐triazolium based poly(ionic liquid)s (PILs) are strongly dependent on the pendant functional groups. These polymers were characterized for glass transition temperature (Tg), solubility, and the thermal decomposition. The vinyl‐triazolium based PILs offer an efficient route to highly functional PILs with the advantage of facile synthesis and the ability to incorporate many desirable functional moieties. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 417–423  相似文献   

10.
The CO2 capture materials and technology have received much attention in recent years due to the environmental deterioration caused by the greenhouse gas emissions. Several imidazolium polymeric ionic liquids (PILs) were synthesized and immobilized on mesoporous γ-Al2O3 (MA) using ultrasonic immersion method. The prepared adsorbents were characterized by FT-IR, 1H NMR, EA, TGA, SEM, XRD, BET and TEM, indicating the successful synthesis of the desired PILs/MA. The CO2 adsorption capacity was investigated under different loading ratios, temperatures, pressures and CO2 flow rates, whose optimal adsorption conditions were 1/1, 313 K, 5 bar and 10 mL/min, respectively. Moreover, the adsorption curves for P[VCIm]Cl/MA were coincident with pseudo-second order model, and the CO2 adsorption kinetics model was calculated and obtained. Compared with P[VRIm]Cl and P[VEIm]Cl, P[VCIm]Cl/MA demonstrated an outstanding adsorption amount of 0.562 mmol/g under the suitable conditions, and its regeneration efficiency could achieve 94.8% after 5 times cycle.  相似文献   

11.
《Arabian Journal of Chemistry》2020,13(11):8003-8011
A series of micro-mesoporous polymeric ionic liquids (PILs) have been successfully synthesized by the method of anion and cation copolymerization. Then use FT-IR, N2 adsorption–desorption isotherms, SEM, and TG to characterize them. Furthermore, the catalytic performance of the synthesized PILs was investigated for the Prins reaction of propylene with 1, 3, 5-trioxane. Among the four PILs synthesized, VIMBs-DVB-SSA has better catalytic activities for the Prins reaction. Under the optimal conditions, 100 °C, 8 wt%, 4 h and n (propylene)/n (1, 3, 5-trioxane) = 4:1, the conversion of formaldehyde (99.8%) and selectivity (81.7%) for 4-methyl-1, 3-dioxane. In addition, the effects of reaction time, catalyst dosage, and reaction temperature and mole ratio of reaction substrates on the reaction were also investigated. The prepared catalyst had good thermal stability and can be reused easily.  相似文献   

12.
Complex [Na(phen)3][Cu(NPh2)2] ( 2 ), containing a linear bis(N‐phenylanilide)copper(I) anion and a distorted octahedral tris(1,10‐phenanthroline)sodium counter cation, has been isolated from the catalytic C? N cross‐coupling reaction with the CuI/phen/tBuONa (phen=1,10‐phenanthroline) catalytic system. Complex 2 can react with 4‐iodotoluene to produce 4‐methyl‐N,N‐diphenylaniline ( 3 a ) with 70.6 % yield. In addition, 2 can work as an effective catalyst for C? N coupling under the same reaction conditions, thus indicating that 2 is the intermediate of the catalytic system. Both [Cu(NPh2)2]? and [Cu(NPh2)I]? have been observed by in situ electron ionization mass spectrometry (ESI‐MS) under catalytic reaction conditions, thus confirming that they are intermediates in the reaction. A catalytic cycle has been proposed based on these observations. The molecular structure of 2 has been determined by single‐crystal X‐ray diffraction analysis.  相似文献   

13.
The first study of pseudo‐bimolecular cycloaddition reaction dynamics in the gas phase is presented. We used femtosecond time‐resolved photoelectron spectroscopy (TRPES) to study the [2+2] photocycloaddition in the model system pseudo‐gem‐divinyl[2.2]paracyclophane. From X‐ray crystal diffraction measurements we found that the ground‐state molecule can exist in two conformers; a reactive one in which the vinyl groups are immediately situated for [2+2] cycloaddition and a nonreactive conformer in which they point in opposite directions. From the measured S1 lifetimes we assigned a clear relation between the conformation and the excited‐state reactivity; the reactive conformer has a lifetime of 13 ps, populating the ground state through a conical intersection leading to [2+2] cycloaddition, whereas the nonreactive conformer has a lifetime of 400 ps. Ab initio calculations were performed to locate the relevant conical intersection (CI) and calculate an excited‐state [2+2] cycloaddition reaction path. The interpretation of the results is supported by experimental results on the similar but nonreactive pseudo‐para‐divinyl[2.2]paracyclophane, which has a lifetime of more than 500 ps in the S1 state.  相似文献   

14.
A novel polyelectrolyte‐grafted multiwalled carbon nanotubes (MWCNTs‐g‐PILs) which possesses a hard backbone of MWCNTs and a soft shell of brush‐like poly (ionic liquids) (PILs) has been synthesized via the surface atom transfer radical polymerization (ATRP). Chemical structure and the grafted PILs quantities of MWCNTs‐g‐PILs were determined by FTIR, TGA, and XPS. TEM and FE‐SEM observations indicate that the nanotubes were coated with a PILs layer, exhibiting core‐shell nanostructures with the PILs chains as the brush‐like or hairy shell and the MWCNTs as the hard backbone. Furthermore, the effect of counter‐anions on the solubility of MWCNTs‐g‐PILs was investigated. The results indicate that relative solubility of MWCNTs‐g‐PILs in various solvents could be switched by anion exchange. This tunable solubility results in the formation of the cycle of reversible phase‐transition. Tribological property of MWCNTs‐g‐PILs as additives in base lubricant 1‐methyl‐3‐butylimidaaolium hexafluorophosphate (LP104) was evaluated using an Optimol SRV oscillating friction and wear tester, confirming that MWCNTs‐g‐PILs are the excellent antiwear and friction‐reducing additives, which can amend the tribological properties of base lubricant significantly. This is attributed to the good dispersibility and core‐shell structure of MWCNTs‐g‐PILs. These results reported in this work may open primarily toward constructing a bridge among carbon nanotues (CNTs), ILs, and lubricant additives and secondarily to prove that CNTs (modified CNTs) as lubricant additives are promising candidates. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7225–7237, 2008  相似文献   

15.
The reaction of biphenylene ( 1 ) with Et2SiH2 in the presence of [Ni(PPhMe2)4] results in the formation of a mixture of 2‐diethylhydrosilylbiphenyl [ 2 (Et2HSi)] and 9,9,‐diethyl‐9‐silafluorene ( 3 ). Silafluorene 3 was isolated in 37.5 % and 2 (Et2HSi) in 36.9 % yield. The underlying reaction mechanism was elucidated by DFT calculations. 4‐Methyl‐9,9‐diethyl‐9‐silafluorene ( 7 ) was obtained selectively from the [Ni(PPhMe2)4]‐catalyzed reaction of Et2SiH2 and 1‐methylbiphenylene. By contrast, no selectivity could be found in the Ni‐catalyzed reaction between Et2SiH2 and the biphenylene derivative that bears tBu substituents in the 2‐ and 7‐positions. Therefore, two pairs of isomers of tBu‐substituted silafluorenes and of the related diethylhydrosilylbiphenyls were formed in this reaction. However, a subsequent dehydrogenation of the diethylhydrosilylbiphenyls with Wilkinson’s catalyst yielded a mixture of 2,7‐di‐tert‐butyl‐9,9‐diethyl‐9‐silafluorene ( 8 ) and 3,6‐di‐tert‐butyl‐9,9‐diethyl‐9‐silafluorene ( 9 ). Silafluorenes 8 and 9 were separated by column chromatography.  相似文献   

16.
A copper(I)‐catalyzed tandem reaction of 2‐iodoanilines with isothiocyanates was achieved in hydrophobic [bmim][PF6] ionic liquid under mild conditions, generating a variety of 2‐aminobenzothiazoles in good to excellent yields. The tandem reaction that was carried out in [bmim][PF6] has some obvious advantages such as accelerated reaction rate and increased yield as compared with the reaction run in volatile solvents such as toluene. Furthermore, the CuI/1,10‐phenanthroline catalytic system can be reused up to eight times without loss of activity and efficiency. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

17.
The manganese(II)‐palladium(II)‐sulfide complex [MnCl23‐S)2Pd2(dppp)2] ( 2 ) was prepared from the reaction of [PdCl2(dppp)] with [Li(N,N'‐tmeda)]2[Mn(SSiMe3)4] ( 2 ) in a 2:1 ratio under mild conditions. The new trimethylsilylthiolate complex [Pd(dppp)(SSiMe3)2] ( 3 ) was synthesized from the reaction of [Pd(dppp)(OAc)2] with two equivalents of Li[SSiMe3]; this was then used in a reaction with [Mn(CH3CN)2(OTf)2] to form the manganese(II)‐palladium(II)‐sulfide cluster [Mn(OTf)(thf)23‐S)2Pd2(dppp)2]OTf ( 4 ).  相似文献   

18.
A novel and efficient method for the preparation of 1,3‐dihydro‐3‐oxo‐2‐benzofuran‐1‐carboxylates 4 under mild conditions has been developed. Thus, the reaction of [2‐(dimethoxymethyl)phenyl]lithiums, generated easily from 1‐bromo‐2‐(dimethoxymethyl)benzenes 1 , with α‐keto esters gives the corresponding 2‐[2‐(dimethoxymethyl)phenyl]‐2‐hydroxyalkanoates 2 . The TsOH‐catalyzed cyclization of these hydroxy acetals is followed by the oxidation of the resulting cyclic acetals 3 with PCC to give the desired products in satisfactory yields. The reaction of [2‐(dimethoxymethyl)‐4,5‐dimethoxyphenyl]lithium with (MeOC?O)2, followed by treatment with NaBH4 or organolithiums, affords 2‐[2‐(dimethoxymethyl)‐4,5‐dimethoxyphenyl]‐2‐hydroxyalkanoates 6 , which can similarly be transformed into the corresponding 1,3‐dihydro‐3‐oxo‐2‐benzofuran‐1‐carboxylates 7 in reasonable yields.  相似文献   

19.
Vapor pressure data were measured for nine binary systems containing water, ethanol, or methanol with one of three protonic ionic liquids (PILs), viz. mono-, di- and tri-ethanolammonium tetrafluoroborate ([HMEA][BF4], [HDEA][BF4], and [HTEA][BF4]), at varying temperatures and PIL-contents using a quasi-static ebulliometer. The vapor pressure data were correlated by NRTL model with an overall average absolute relative deviation (AARD) of 0.0175. It is showed that the effect of PILs on the vapor pressure lowering of solvents follows the order of [HMEA][BF4] > [HDEA][BF4] > [HTEA][BF4], and the vapor pressure lowering degree follows the order of water > methanol > ethanol. Besides, the activity coefficients of solvent for binary system {solvent + PIL} at fixed PIL mole fraction of 0.10 were calculated using the regressed NRTL parameters. The results indicate that three PILs can give rise to a negative deviation from the Raoult's law for water and methanol and a positive deviation for ethanol to a varying degree, leading to the variation of relative volatility of a solvent.  相似文献   

20.
To extensively explore the influence of anion structure on the physical properties of poly(ionic liquid)s (PILs) a series of PILs having main‐chain 1,2,3‐triazolium cations was synthesized via copper(I)‐catalyzed azide‐alkyne 1,3‐dipolar cycloaddition (CuAAC) followed by N‐alkylation with iodomethane and anion metathesis with different metal salts, that is, Li(CF3SO2)2N, Li(CF3CF2SO2)2N, K(FSO2)2N, K(CF3SO2)N(CN), Ag(CN)2N, and sodium 4,5‐dicyano‐1,2,3‐triazolate. To isolate the effect of anion on physical properties of PILs, a common iodide precursor was used to maintain constant the average degree of polymerization (DPn) and chain dispersity. Detailed structure/properties relationship analyses demonstrated a lack of correlation between anion chemical structure, ionic conductivity, and glass transition temperatures. Among synthesized series, the PIL derivative having bis(trifluoromethylsulfonyl)imide counter anion showed the best compromise in performance: low glass transition temperature (Tg = ?68 °C), high thermal stability (Tonset = 340 °C) and superior ionic conductivity (σDC = 8.5 × 10? 6 S/cm at 30 °C), which makes it an interesting candidate for various key modern electrochemical applications. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 2191–2199  相似文献   

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