Design of dual-functional protic porous ionic liquids for boosting selective extractive desulfurization

Porous ionic liquids have demonstrated excellent performance in the field of separation,attributed to their high specific surface area and efficient mass transfer.Herein,task-specific protic porous ionic liquids(PPILs)were prepared by employing a novel one-step coupling neutralization reaction strategy for extractive desulfurization.The single-extraction efficiency of PPILs reached 75.0%for dibenzothiophene.Moreover,adding aromatic hydrocarbon interferents resulted in a slight decrease in the extraction efficiency of PPILs(from 45.2%to 37.3%,37.9%,and 33.5%),indicating the excellent extraction selectivity of PPILs.The experimental measurements and density functional theory calculations reveal that the surface channels of porous structures can selectively capture dibenzothiophene by the stronger electrophilicity(Eint(HS surface channel/DBT)=-39.8 kcal mol^(-1)),and the multiple extraction sites of ion pairs can effectively enrich and transport dibenzothiophene from the oil phase into PPILs throughπ...π,C-H...πand hydrogen bonds interactions.Furthermore,this straightforward synthetic strategy can be employed in preparing porous liquids,offering new possibilities for synthesizing PPILs with tailored functionalities.

A highly concentrated vanadium protic ionic liquid electrolyte for the vanadium redox flow battery

A protic ionic liquid is designed and implemented for the first time as a solvent for a high energy density vanadium redox flow battery.Despite being less conductive than standa rd aqueous electrolytes,it is thermally stable on a 100 ℃ temperature window,chemically stable for at least 60 days,equally viscous and dense with typical aqueous solvents and most importantly able to solubilize to 6 mol L^(-1) vanadium sulfate,thus increasing the VRFB energy density by a factor of 2.5.Electrochemical measurements revealed quasi-reversible redox transitions for both catholyte and anolyte at 25 ℃ while a proof-of-concept redox flow cell with the proposed electrolyte was tested for a total of 150 cycles at 25 ℃,showing an open circuit potential of 1.39 V and energy and coulombic efficiencies of 65% and 93%,respectively.What’s more,the battery can be equally cycled at 45℃ showing good thermal stability.This study underlines a new route to improve the energy-to-volume ratio of energy storage system.

Furans-Maleimides Diels-Alder Reactions in Protic Ionic Liquid

The authors have studied the Diels-Alder reactions between furan derivatives and maleimide derivatives in an ionic liquid and have found that higher reactivity can be obtained in a protic ionic liquid [Mim]Tf2N than in the conventional organic solvent. Furthermore, in the Diels-Alder reactions of 2- and 2,5-alkylfurans with N-alkylma- leimide, the reactivity increases by extending the alkyl chain length of N-alkylmaleimide. In addition, it was demon- strated that endo-selectivity increases when 2,5-disubstituted furans are used. These results will be explained by comparing the stability of the Diels-Alder adduct with that of the products obtained from the reactions of 2-substituted furans and 2,5-disubstituted furans.

Corrosion inhibiting performance and mechanism of protic ionic liquids as green brass inhibitors in nitric acid

Four protic ionic liquids(ILs)were synthesized via a one-step method by using benzotriazole(BTA)and benzimidazole as cations,and benzenesulfonic acid and 2-naphthalenesulfonic acid(NSA)as anions.These ILs were used as green corrosion inhibitors for brass specimens in a nitric acid solution.The structure of the protic ILs was characterized by 1H-NMR,13C-NMR,and FT-IR spectroscopy.The effects of the IL structure,IL concentration,acid concentration,and corrosion time on the surface morphology of brass specimens and the inhibition efficiency(η%)of ILs were investigated by the weight loss method combined with SEM and EDS spectroscopy.Polarization curves and impedance spectroscopy were used to analyze the electrochemical corrosion inhibition mechanism of ILs.Results showed that IL synthesis was a proton transfer process,and the proton of the–SO3H group on NSA was deprived by BTA.IL[BTA][NSA],which had a high charge density and large conjugateπband,was the most effective inhibitor for brass corrosion.Theη%of[BTA][NSA]decreased with the increase in acid concentration and corrosion time,which showed an increment with the increase in[BTA][NSA]concentration.The higher theη%of[BTA][NSA]is,the smoother the surface of the brass specimens is,and the smaller the undistributed area of Cu element will be.Corrosion inhibiting mechanism from electrochemical analysis indicated that the addition of[BTA][NSA]increased the polarization resistance of the brass electrode significantly and suppressed both anodic and cathodic reactions.

Synthesis and characterization on a novel series of protic pyrrolidinium surfactants

A novel series of protic tertiary pyrrolidinium surfactants were prepared and characterized by different techniques.These compounds show good conductivity and efficient ability to reduce surface tension.Thermogravimetric analysis proves their high thermal stability at decomposition temperatures over 250℃.Their lyotropic and thermotropic liquid crystalline properties are also discussed.

The effect of protic ionic liquids incorporation on CO_(2) separation performance of Pebax-based membranes

The separation of carbon dioxide(CO_(2))is of great importance for environment protection and gas resource purification.The ionic liquids(ILs)-based gas separation membrane provides a new chance for efficient CO_(2)separation,while high permeability and selectivity of membranes is a great challenge.In this study,the influence of two protic ILs with different anion([TMGH][Im]and[TMGH][PhO])on the CO_(2)separation performance of the prepared ILs/Pebax blended membranes were systematically investigated at different temperature.The results showed the CO_(2)permeability exhibits the rising trend for ILs/Pebax blended membranes with the increment of IL content.Especially,the[TMGH][Im]with low viscosity and high CO_(2)absorption capacity leads to the blended membranes showing better CO_(2)permeability and ideal CO_(2)selectivity than that of membranes with[TMGH][PhO]at high IL content.Besides,with operating temperature increasing,the gas permeability of 20%(mass)[TMGH][Im]/Pebax blended membrane increases due to the decreasing viscosity of IL and the rising chain mobility of polymer.Inversely,the gas selectivity shows decreasing trend because CO_(2)absorption capacity obviously decreased at higher temperature.

STUDY ON THE INTRAMOLECULAR CVCLIZATION THROUGH OPENING OF EPOXIDE II RING CLOSURE OF N-METHYL-N-BENZOYLMETHYLENE-β-PHENYL-α,β-EPOXYPROPIONAMIDE IN PROTIC SOLVENT

When the title compound was treated in protic solvent with alkali catalyses,γ-lacatam was almost the sole product.The ratio of ketone 1 to ketone 2 depended upon the reaction condition.

Theoretical insights into NH3 absorption mechanisms with imidazolium-based protic ionic liquids

Ionic liquids(ILs)provide a promising way for efficient absorption and separation of ammonia(NH_(3))due to their extremely low vapor pressures and adjustable structures.However,the understanding of absorption mechanisms especially in terms of theoretical insights is still not very clear,which is crucial for designing targeted ILs.In this work,a universal method that integrates density functional theory and molecular dynamic simulations was proposed to study the mechanisms of NH_(3) absorption by protic ionic liquids(PILs).The results showed that the NH_(3) absorption performance of the imidazolium-based PILs([BIm][X],X=Tf_(2)N,SCN and NO_(3))is determined by not only the hydrogen bonding between the N atom in NH_(3) and the protic site(H–N_(3))on the cation but also the cation–anion interaction.With the increase in NH_(3) absorption capacity,the hydrogen bonding between[BIm][Tf_(2)N]and NH_(3) changed from orbital dominated to electrostatic dominated,so 3.0 mol NH_(3) per mol IL at 313.15 K and 0.10 MPa was further proved as a threshold for NH_(3) capacity of[BIm][Tf_(2)N]by the Gibbs free energy results,which agrees well with the experimental results.Furthermore,the anions of[BIm][X]could also compete with NH_(3) for interaction with H-N_(3) of the cation,which weakens the interaction between the cation and NH_(3) and then decreases the NH_(3) absorption ability of PILs.This study provides further understanding on NH_(3) absorption mechanisms with ILs,which will guide the design of novel functionalized ILs for NH_(3) separation and recovery.

Hydrogen bond producers in powerful protic ionic liquids for enhancing dissolution of natural cellulose

The manipulation of hydrogen bonding within protic ionic liquids is conducive to conquering the robust hydrogen bonding interactions in cellulose for its effective dissolution,but it is a great challenge to establish the delicate bal-ance of hydrogen bonding network between solvent and cellulose.Herein,we proposed the concept of“hydrogen bond producers”for urea molecules in 1,1,3,3-tetramethylguanidinium methoxyacetate acid([TMGH][MAA])to enhance the dissolution of cellulose.The optimization of physicochemical properties for[TMGH][MAA]solvent as a function of urea concentration revealed a remark-able increase in cellulose solubility from 13%to 17%(w/w)by adding only 0.25 wt%urea,highlighting the efficiency of[TMGH][MAA]as a power-ful solvent for the dissolution of cellulose.The experimental and simulation results verified that the significant improvement on dissolution of cellulose was attributed to the hydrogen bonding interaction of urea molecules with ion pairs and part of free ions,reducing the interference with the active ions bonded to cellulose.Furthermore,the considerable enhancement on compre-hensive properties of regenerated cellulose films demonstrated the effectiveness of[TMGH][MAA]/urea solvent.The concept of“hydrogen bond producers”presented here opens a new avenue for significantly enhancing the dissolu-tion of natural cellulose,promoting the sustainable development in large-scale processing of cellulose.

Synthesis of highly selective and stable mesoporous Ni-Ce/SAPO-34 nanocatalyst for methanol-to-olefin reaction:Role of polar aprotic N,N-dimethylformamide solvent

A series of mesoporous nanocrystalline silicoaluminophosphate (SAPO)zeolites (SAPO-34)were synthesized via an ultrasonic and microwave-assisted hydrothermal method in the presence of [3- (trimethoxysilyl)propyl]octadecyldimethylammonium chloride and cetyltrimethylammonium bromide surfactants as soft templates.Nickel and cerium were then doped on SAPO-34using incorporation and impregnation methods,and all the catalysts were applied to the methanol-to-olefin (MTO)reaction. The catalysts were characterized using X-ray diffraction,field-emission scanning electron microcopy, inductively coupled plasma-atomic emission spectroscopy,transmission electron microscopy,Fourier- transform infrared spectroscopy,Brunauer-Emmett-Teller analysis,NH3temperature-programmed desorption analysis,and thermogravimetric analysis.For the impregnation method,the effect of using protic or aprotic solvents as impregnation media on the physico-chemical properties of the metal-based SAPO-34was investigated.Water and N,N-dimethylformamide (DMF)were employed as the protic and aprotic solvents,respectively.The catalyst prepared using the aprotic DMF solvent exhibited higher dispersion and lower aggregation of metal species compared with that prepared using the protic water solvent.Furthermore,the sample synthesized using the incorporation method exhibited good catalytic performance;however,the Ni-Ce[SAPO-34 sample prepared using the impregnation method and aprotic DMF solvent exhibited superior catalytic performance in the MTO reaction.

Protic ionic liquid-promoted synthesis of dimethyl carbonate from ethylene carbonate and methanol

In this work,the protic ionic liquid[DBUH][Im](1,8-diazabicyclo[5.4.0]-7-undeceniumimidazolide)was developed as an efficient catalyst for the transesterification of ethylene carbonate with methanol to produce dimethyl carbonate.At 70℃,up to 97%conversion of ethylene carbonate and 91%yield of dimethyl ca rbonate were obtained with 1 mol%[DBUH][Im](relative to ethylene carbonate)as catalyst in 2 h.Even at room temperature,the conversion of ethylene carbonate can reach 94%and the yield of dimethyl carbonate can approach 81%for 6 h.Catalytic mechanism investigation showed the high catalytic efficiency of this ionic liquid results from the synergistic activation effect,wherein the cation can activate ethylene carbonate and the anion can activate methanol through hydrogen bond formatio n.Although the reusability of the ionic liquid need to be further improved,high efficiency and comme rcial availability of[DBUH][Im]render it a promising catalyst for the preparation of dimethyl carbonate.

Tribological behavior of ammonium-based protic ionic liquid as lubricant additive

In this study, the tribological behavior of an ammonium-based protic ionic liquid(PIL) as an additive in a base mineral oil(MO) is investigated on a steel–steel contact at room temperature and 100℃. Tri-[bis(2-hydroxyethylammonium)] citrate(DCi) was synthesized in a simple and low-cost way, and the ionic structure of DCi was confirmed by proton nuclear magnetic resonance(^(1)H NMR). The stability measurement of 1 wt% DCi to a MO was investigated, and the lubricating ability and anti-wear properties of DCi as an additive in MO were also examined using a custom-designed reciprocating ball-on-flat tribometer. Optical microscope and profilometry were used to obtain the worn morphology of the steel disks. Scanning electron microscopy(SEM) and energy dispersive X-ray spectroscopy(EDS) were carried out to investigate the wear mechanism and to analyze the surface interactions between the rubbing components. When 1 wt% DCi is added into the base MO, frictional performance is improved at both temperatures studied with a friction reduction of 29.0% and 35.5%, respectively. Moreover, the addition of 1 wt% DCi to MO reduced the wear volume 59.4% compared to the use of MO. An oxygen-richened tribolayer is confirmed by EDS on the disk surface when DCi was used as additive under 100℃.

Synthesis, Crystal Structure of Protic Pyrazolium Ionic Liquid and Its Catalytic Properties for CO2 Cycloaddition

Two protic pyrazolium ionic liquids(ILs)are synthesized and characterized by mass spectra(MS),1H NMR,13C NMR,and single-crystal X-ray diffraction.Then,their catalytic activity for the cycloaddition of PO and CO2 is investigated.Two protic pyrazolium ILs are the orthorhombic and triclinic systems of space groups Cmca and C2/c for HTMPzBr and HDMPzBr,respectively.They could catalyze the cycloaddition reaction of carbon dioxide(CO2)with epoxides(PO)to produce cyclic carbonate(PC)without any solvent and co-catalyst and show strong catalytic activity when the reaction temperature is over 110℃.

Stable Metal–Halide Perovskite Colloids in Protic Ionic Liquid

Obtaining long-term stable and robust perovskite colloids solution remains an important scientific challenge due to the limited interaction between solvent and perovskite solutes.Here,we unveil the formation mechanism of chemically robust perovskite precursor solutions under ambient conditions using methylammonium acetate(CH3NH3•CH3COO,MAAc)protic ionic liquid(PIL)solvent.Tens of nanometers colloids are assembled on the molecular level via regular oriented gel-like lamellae with a mean thickness of 34.69 nm,width of 56.81 nm,and distance of 91.05 nm.

棉浆纤维素/质子型离子液体溶液的流变行为

为实现棉浆纤维素的绿色、高效溶解,促进其高值化利用,以质子型离子液体([DBNH][Lev])为溶剂,制备了5种不同质量分数的纤维素/[DBNH][Lev]溶液;借助核磁共振技术研究了纤维素在离子液体中的溶解机制,测定了纤维素溶液在不同条件下的稳态和动态流变行为,讨论了纤维素含量、温度和剪切速率等对均相聚合物溶液黏度的影响规律。结果表明:纤维素/[DBNH][Lev]溶液为典型的假塑性流体,对温度具有敏感性,且黏度随温度升高而降低;此外,该溶液在高频率下出现凝胶点,存在黏性流动为主的类液态向弹性形变为主的类固态转变,且温度越高转变点越向低频区移动,这为纤维素在离子液体中的流变响应提供理论基础,并对后续的纤维素加工工艺(如涂层、纺丝)提供技术指导。

质子型离子液体N,N-二甲基乙醇胺丙酸盐的密度、粘度及电导率(英文)

在283.15 333.15 K温度范围内,测量了质子型离子液体N,N-二甲基乙醇胺丙酸盐(DMEOAP)的密度、粘度及电导率.讨论了温度对密度、粘度和电导率等物理化学参数的影响.通过经验和半经验方程得到了该离子液体的热膨胀系数、分子体积、标准摩尔熵及晶格能等热力学性质参数.由电导率和密度计算出了该离子液体的摩尔电导率.利用Vogel-Fulcher-Tamman(VFT)方程,将测量的动力粘度和电导率对温度拟合,得到了动力粘度和电导率随温度变化方程式.并通过Walden规则,建立了粘度与摩尔电导率之间的联系.

加酶益生素对哺乳及断奶仔猪生产性能和腹泻频率的影响

采用单因子饲养试验的方法 ,探讨益生素对哺乳仔猪进行早期接种 ,以及哺乳仔猪料和断奶仔猪料中添加加酶益生素后对生产性能和腹泻率的影响。试验结果表明 :试验组哺乳仔猪日增重比对照组提高15 .94% (P <0 .0 1) ,试验组断奶仔猪日增重比对照组提高 8.75 % (P >0 .0 5 ) ;哺乳仔猪腹泻频率低于对照组 (P<0 .0 5 ) ,断奶仔猪腹泻频率比对照组低 46 .5 6 % (P <0 .0 1)。哺乳仔猪 0～ 7d涂抹益生素接种 ,哺乳断奶全程使用加酶益生素可有效提高哺乳仔猪日增重 。

DMFC用质子型离子液体复合隔膜的制备及性能表征

由酸碱中和法制得质子型离子液体α-甲基吡啶三氟乙酸盐,再经相转化将质子型离子液体与PVDF-HFP复合成(PIL)/PVDF-HFP膜.交流阻抗测试表明,复合膜电导率随温度增加而递增,室温电导率:8×10-3S/cm,30℃电导率:1×10-2S/cm,80℃电导率:3×10-2S/cm.用计时电流法研究复合前后膜的甲醇渗透性能,结果显示,该离子液体复合前、后膜的阻醇性能无明显变化,但复合膜阻醇性能略优.

不同介质中间硝基苯磺酸钠的电化学行为

研究了铜电极上间硝基苯磺酸钠在含有四丁基高氯酸铵(TBAP)电解质的质子惰性介质(DMF)、质子介质(H_2O)及混合介质(DMF/H_2O)中的电化学行为。结果表明:在质子惰性介质中,间硝基苯磺酸钠分步连续地被还原为ArNO_2·和[ArNO_2]^(2-)·阴离子自由基;其中ArNO_2/ArNO_2^-·为扩散控制的单电子转移可逆氧化还原反应。在水溶液中,间硝基苯磺酸钠经历了ArNO_2/ArNO和ArNO/ArNHOH反应。而在混合溶剂中,由于DMF的存在阻碍了硝基的质子化进程,间硝基苯磺酸钠经历了ArNO_2/ArNO_2^-·和ArNO_2·/ArNHOH反应。通过量化计算进一步证实了上述实验结果。

新型氟离子红外识别受体的合成及研究

将配体N-(2-吡啶基)-N'-苯基脲与中间体三氨基三羰基铬反应,合成了一种新型的氟离子识别受体N-(2-吡啶基)-N'-苯基脲三羰基铬,通过元素分析、IR、1HNMR、13CNMR以及EI-MS对其结构进行了表征。采用傅里叶红外光谱(FT-IR)研究了受体分子对氟离子的识别传感性能,实验结果表明,质子型介质乙醇当中,随着氟离子的加入受体分子金属羰基特征吸收峰向低波数的方向偏移,产生较好的红外识别响应。受体分子对于氟离子的红外识别检测下限可达1.0×10-5 mol/L。