The equilibrium and kinetics of methyl isobutyl ketone(MIBK) extraction resin for adsorption and separation of zirconium and hafnium were studied under the different conditions of acidity,initial total concentrations ...The equilibrium and kinetics of methyl isobutyl ketone(MIBK) extraction resin for adsorption and separation of zirconium and hafnium were studied under the different conditions of acidity,initial total concentrations of zirconium and hafnium and temperature.The equilibrium data of both zirconium and hafnium are found to follow the Freundlich adsorption isotherm,and the Freundlich isotherm constants(KF) are 3.53 and 0.64 mg/g,respectively.The equilibrium data of zirconium also fit the Langmuir adsorption isotherm,and the saturation adsorption capacity(Qmax) and the Langmuir isotherm constant(KL)are 75.93 mg/g and-0.012 7 L/g,respectively.The obtained kinetic data of both zirconium and hafnium are found to fit the HO pseudo-second-order kinetic model,and the rate constants of pseudo-second-order equation(k2) are-0.019 and 0.41 g/(mg·min),respectively.Column tests show that the MIBK extraction resin could be used as efficient adsorbent material for separating hafnium from zirconium.展开更多
Methyl isobutyl ketone(MIBK) is widely used as extraction agent in hydrometallurgy. As it has a definite solubility in water, so when using MIBK as extraction agent, there will be MIBK in stripping solutions inevitabl...Methyl isobutyl ketone(MIBK) is widely used as extraction agent in hydrometallurgy. As it has a definite solubility in water, so when using MIBK as extraction agent, there will be MIBK in stripping solutions inevitably, which not only pollutes working conditions, but also affects the quality of ultimate product. In order to remove MIBK from aqueous solutions, the means of flat vacuum membrane distillation(VMD) is studied in the paper. The area of the membrane used in the study is 0.02 m 2, the initial volume of feed is 2 L, each experiment was conducted over a time period of 60 120 min. The influences of the factors such as temperature(34.8 55.0 ℃); pressure in the permeate side(10.67 14.67 kPa) and feed flow rate(27.8 69.4 mL/s) were experimentally studied. Increasing the temperature or reducing the pressure in the permeate side results in a faster removal of MIBK; however there is a decrease in removal factor β , increasing the feed flow rate results in a faster removal of MIBK and an increase of removal factor β , especially in the range of lower flow rate. The study indicates that the aim of MIBK removal and recycle from dilute aqueous solutions can be achieved by VMD.展开更多
The one-pot synthesis of methyl isobutyl ketone（MIBK） from acetone using multifunctional catalysts is an important sustainable organic synthesis method with high atom and energy efficiency.Herein. we report a series...The one-pot synthesis of methyl isobutyl ketone（MIBK） from acetone using multifunctional catalysts is an important sustainable organic synthesis method with high atom and energy efficiency.Herein. we report a series of Pd supported on mixed metal oxide（MMO） catalysts with controllable acidic/basic/metallic sites on the surface. We study the relationship between the nature, synergy,and proximity of active sites and the catalytic performance of the multifunctional catalyst in the tandem reaction, in detail. In the existence of Lewis acid and base sites, the catalysts with medium-strength acidic/basic sites show preferred activity and/or MIBK selectivity. For multifunctional catalysts, the catalytic properties are more than just a collection of active sites, and the Pd/Mg_3Al-MMO catalyst possessing 0.1% Pd loading and ~0.4 acid/base molar ratio exhibits the optimal 42.1% acetone conversion and 37.2% MIBK yield, which is among the best reported so far for this tandem reaction under similar conditions. Moreover, the proximity test indicates that the intimate distance between acidic/basic/metallic sites can greatly shorten the diffusion time of the intermediate species from each active site, leading to an enhancement in the catalytic performance.展开更多
To study the characteristic of liquid-liquid extraction equilibrium of lithium from brine sources, the complexes formed from tributyl phosphate （TBP） and methyl isobutyl ketone （MIBK） with lithium were investi- ga...To study the characteristic of liquid-liquid extraction equilibrium of lithium from brine sources, the complexes formed from tributyl phosphate （TBP） and methyl isobutyl ketone （MIBK） with lithium were investi- gated using FeCl3 as coextracting agent. Liquid-liquid extraction reaction mechanisms were proposed and the stoichiometry of tetrachloroferrate（III） complex with lithium was obtained by regressing the experimental data. It is found that the stoichiometry of tetrachloroferrate（III） to lithium in the complex is 1 ： 1 with either TBP or MIBK as extractant in kerosene. The stoichiometry of the complex of TBP with Li was 1 ： 1 and that of MIBK with Li was 2 ： 1. The formed complexes of TBP and MIBK with lithium are determined to be LiFeCla-TBP and LiFeC14.2MIBK, respectively, according to the rule of neutralization.展开更多
A sensitive solvent extraction method for the determination of nonamolar concentrations of silicate in natural waters is developed. According to the traditional aqueous silicate method, silicomolybdenum blue formed by...A sensitive solvent extraction method for the determination of nonamolar concentrations of silicate in natural waters is developed. According to the traditional aqueous silicate method, silicomolybdenum blue formed by the reaction between silicate and ammoni- um molydate and reduced by metol-sulfite reagent is extracted by methyl isobutyl ketone. The absorbance can be enhanced substantially up to 10-folds. The detection limit of silicate is 8 nmol/dm^3 , which is one tenth smaller than the traditional method, with the precision of 4.0% at a silicate level of 50 nmol/dm^3 and 3.2% at a silicate level of 6 μmol/dm^3. Comparing the calibration curves in the distilled water and seawater, it can be seen that the salt effect also exists in the extraction method. However, the salt effect is a linear function of the salinity and can be corrected by simple calibration. The proposed method is successfully applied to the determination of silicate in natural waters. Natural concentrations of arsenate, arsenite and phosphate cause negligible interference.展开更多
Effectiveness of pulsed power plasma for the degradation of two toxic volatile organic compounds(VOCs),toluene and methyl isobutyl ketone(MIBK),in aqueous solution was evaluated.The plasma degradation of MIBK has been...Effectiveness of pulsed power plasma for the degradation of two toxic volatile organic compounds(VOCs),toluene and methyl isobutyl ketone(MIBK),in aqueous solution was evaluated.The plasma degradation of MIBK has been studied for the first time.The influence of initial concentration of target compound,solution pH and scavengers on percentage degradation was evaluated.100%removal of 200 mg/L of toluene and MIBK was achieved both in liquid and gaseous phases after 12 and 16 min of plasma treatment,respectively.The first order rate constant of toluene and MIBK degradation(for 200 mg/L each)was 0.421 and 0.319 min~(-1)respectively when they were treated individually,and these values decreased slightly during degradation of their mixture.MIBK degradation was slower than toluene and it might be due to semi volatile and hydrophilic nature of MIBK.The effect of initial concentration of toluene and MIBK showed different degradation patterns.Highest degradation of both the compounds was obtained in neutral pH and in absence of scavengers.·OH radical was the major reactive species involved in their degradation.Their degradation in real environmental matrices showed that removal reduced significantly in secondary effluent due to scavenging of reactive species by various ions and organic matter.The total number of degradation intermediates identified in case of toluene and MIBK was 11 and 14 respectively and formate was the one recalcitrant byproduct generated.The degradation pathway of toluene and MIBK involving reactions of reactive oxygen and nitrogen species and reductive species is proposed.展开更多
Supported nickel-based catalysts were prepared by the incipient wetness impregnation method for the selective hydrogenation of methyl isobutyl ketone to methyl isobutyl carbinol in a fixed-bed reactor. The effects of ...Supported nickel-based catalysts were prepared by the incipient wetness impregnation method for the selective hydrogenation of methyl isobutyl ketone to methyl isobutyl carbinol in a fixed-bed reactor. The effects of the nickel source,Ni loading, calcination time, and calcination temperature on the hydrogenation performance were studied. The experimental results showed that the Ni/γ-Al_2O_3 catalyst demonstrated the highest catalytic performance under the preparation conditions by using nickel nitrate as the nickel source with a NiO loading of 20%, followed by calcination at 440°C for 5h. In addition,this catalyst showed the largest specific surface area, best crystal structure, highest active component content, smallest particle size, and uniform distribution of NiO on the surface of the carrier. The nickel-based catalyst prepared using the optimized conditions exhibited a 96.1% conversion of methyl isobutyl ketone, with a methyl isobutyl carbinol selectivity of 99.6%. The described procedure is very effective for the preparation of methyl isobutyl carbinol using methyl isobutyl ketone as the feedstock.展开更多
A method for the determination of iodine based upon compound H2HgI4, formed between I- and Hg1＋ in nitric acid and extracted in methyl isobutyl ketone（MIBK）, was developed via atomic fluorescence spectrometry（AFS...A method for the determination of iodine based upon compound H2HgI4, formed between I- and Hg1＋ in nitric acid and extracted in methyl isobutyl ketone（MIBK）, was developed via atomic fluorescence spectrometry（AFS）. After the compound is reduced with potassium borohydrid（KBH4）, the resultant mercury vapor was injected into the instrument and iodine was, therefore, indirectly determined. Experimental parameters such as the conditions of extraction reagents, aqueous phase acidity, elemental mercury diffusion temperature in a vial and other factors were investigated and optimized. Under the optimum experimental conditions, this method shows a detection limit of 0.038μg/L iodine and a linear relationship between 0.04-20 p.g/L. The method was applied to determining the iodine content in marine duck eggs, kelps, laver and Ganoderma lucidum spirulina, showing a relative standard deviation（RSD） of 2.15% and the recoveries in the range of 98.1%-102.5%.展开更多
The effects of NaCl, KCl and Na_2SO_4 on the liquid–liquid equilibrium(LLE) data for the ternary system, water+ phenol + methyl isobutyl ketone, were determined at 0.101 MPa and 333.15 K and 343.15 K.The nonrandom tw...The effects of NaCl, KCl and Na_2SO_4 on the liquid–liquid equilibrium(LLE) data for the ternary system, water+ phenol + methyl isobutyl ketone, were determined at 0.101 MPa and 333.15 K and 343.15 K.The nonrandom two-liquid(NRTL) model was used to correlate the experimental data and to yield corresponding binary interaction parameters for these salt containing systems.The Hand and Othmer–Tobias equations were used to confirm the dependability of the determined LLE data in this work.Distribution coefficient and selectivity were used to evaluate the extraction performance of methyl isobutyl ketone with the existence of salt.The magnitude of salt effect on the water + phenol + methyl isobutyl ketone(MIBK) system is in the following order: Na_2SO_4>NaCl>KCl.展开更多
The reduction of diaryldiselenides by Cp2TiCl2/BuiMgBr/THF led to arylselenium complex of titanocene [Cp2TiSeAr]. This species reacted smoothly with electrophilic substrates such as acylhalides, α-bromocarbonyl compo...The reduction of diaryldiselenides by Cp2TiCl2/BuiMgBr/THF led to arylselenium complex of titanocene [Cp2TiSeAr]. This species reacted smoothly with electrophilic substrates such as acylhalides, α-bromocarbonyl compounds, diaryliodonium salts, α,β-unsaturated carbonyl compounds to afford the corresponding organic selenides in high yields.展开更多
Objective To reduce the risk of surgical resection of giant arteriovenous malformation (AVM) (>6.0 cm) and prevent normal perfusion pressure breakthrough (NPPB) for lowering the postoperative mortality. Methods ...Objective To reduce the risk of surgical resection of giant arteriovenous malformation (AVM) (>6.0 cm) and prevent normal perfusion pressure breakthrough (NPPB) for lowering the postoperative mortality. Methods During the operation under barbiturate anesthesia, the proximal end of the feeding arteries were ligated at first, and 0.5 ml isobutyl 12 cyanoacrylate (IBCA) with 0.5 ml 5% glucose was injected into the vessels towards the AVM, then the malformed vessels were resected totally. Postoperative digital subtraction angiography of the four vessels was performed in all patients. Results 50 patients with giant AVM survived after operation, only 6 (12.0%) had transient neurological dysfunction and 44 (88.0%) recovered after a follow up of 6-36 months. No patient suffered from normal perfusion pressure breakthrough (NPPB). Conclusions The embolization could block the arteriovenous shunts sufficiently to decrease the blood flow away from the normal areas of the brain so as to prevent the incidence of intra and postoperative rebleeding, especially in NPPB. Therefore, the combination of intraoperative embolization with surgical resection is an effective strategy in the treatment of giant cerebral AVMs, which make it operable for those used to be regarded as inoperable cases.展开更多
Biodiesel was used to prepare epoxidized fatty acid isobutyl esters(Ep-FABEs)as a biobased plasticizer in this work.Transesterification of biodiesel with isobutanol catalyzed by tetrabutyl titanate was carried out in ...Biodiesel was used to prepare epoxidized fatty acid isobutyl esters(Ep-FABEs)as a biobased plasticizer in this work.Transesterification of biodiesel with isobutanol catalyzed by tetrabutyl titanate was carried out in a gas-liquid tower reactor.The conversion achieved nearly 100%within 5 h under the reaction temperature,the mass ratio of catalyst to fatty acid methyl esters(FAMEs),and isobutanol to FAMEs total molar ratio of 180℃,0.4%(mass),and 5.4:1,respectively.In addition,kinetic model of the transesterification reaction was developed at 150–190℃.The calculated activation energy was 48.93 kJ·mol^(-1).Then,the epoxidation of obtained fatty acid isobutyl esters(FABEs)was conducted in the presence of formic acid and hydrogen peroxide.The Ep-FABEs was further analyzed for its plasticizing effectiveness to replace dioctyl phthalate(DOP)and compared with conventional epoxy plasticizer epoxidized fatty acid methyl esters(Ep-FAMEs).The results indicated that the thermal stability and mechanical properties of PVC films with Ep-FABEs plasticizer were significantly improved compared with those plasticized with DOP.In addition,the extraction resistance and migration stability of Ep-FABEs were better than those of EpFAMEs.Overall,the prepared Ep-FABEs via structural modification of biodiesel proved to be a promising biobased plasticizer.展开更多
As an important organic,isobutyl acetate(IbAc)has been widely used in industries because of its good biodegradability,low surface tension,and other properties.The industrial production of IbAc is usually catalyzed by ...As an important organic,isobutyl acetate(IbAc)has been widely used in industries because of its good biodegradability,low surface tension,and other properties.The industrial production of IbAc is usually catalyzed by sulfuric acid.However,the use of sulfuric acid has the drawbacks of causing considerable corrosion to equipment and being difficult to be separated.In this work,n-sulfopropyl-3-methylpyridinium trifluoromethanesulfonate([HSO_(3)-PMPY][CF_(3)SO_(3)])Bronsted acidic ionic liquid(BAIL)was used as the catalyst and the catalytic activity,solubility,and corrosiveness were evaluated for the esterification of acetic acid with isobutanol.The reaction kinetics and chemical equilibrium were systemically studied.Compared to conventional acid catalysts,[HSO_(3)-PMPY][CF_(3)SO_(3)]showed higher catalytic activity,more excellent reusability,more favorable phase separation,and non-corrosiveness.Three kinetic equations based on ideal homogeneous(IH),non-ideal homogeneous(NIH),and modified nonideal homogeneous(NIH-M)models were established and correlated with the experimental data to determine the parameters and errors.The NIH-M model exhibited the best agreement with the experimental data,owing to its prediction considering the non-ideality and the self-catalysis effect of acetic acid in this system.Besides,the error of NIH-M model fitting was mainly caused by the difference in solubility between[HSO_(3)-PMPY][CF_(3)SO_(3)]with reactants and products in the reaction system.Furthermore,the applicability of the NIH-M model was investigated by simulating the esterification of acetic acid with three short-chain alcohols(ethanol,n-butanol,and isobutanol)catalyzed by BAILs.The NIH-M model displayed an acceptable simulation for this type of acetic acid esterification reaction catalyzed by BAILs at different ranges of the BAILs concentration and temperature.This study confirmed the industrial prospects of[HSO_(3)-PMPY][CF_(3)SO_(3)]in isobutyl acetate production and the applicability of the NIH-M kinetic model in the esterif展开更多
文摘The equilibrium and kinetics of methyl isobutyl ketone(MIBK) extraction resin for adsorption and separation of zirconium and hafnium were studied under the different conditions of acidity,initial total concentrations of zirconium and hafnium and temperature.The equilibrium data of both zirconium and hafnium are found to follow the Freundlich adsorption isotherm,and the Freundlich isotherm constants(KF) are 3.53 and 0.64 mg/g,respectively.The equilibrium data of zirconium also fit the Langmuir adsorption isotherm,and the saturation adsorption capacity(Qmax) and the Langmuir isotherm constant(KL)are 75.93 mg/g and-0.012 7 L/g,respectively.The obtained kinetic data of both zirconium and hafnium are found to fit the HO pseudo-second-order kinetic model,and the rate constants of pseudo-second-order equation(k2) are-0.019 and 0.41 g/(mg·min),respectively.Column tests show that the MIBK extraction resin could be used as efficient adsorbent material for separating hafnium from zirconium.
文摘Methyl isobutyl ketone(MIBK) is widely used as extraction agent in hydrometallurgy. As it has a definite solubility in water, so when using MIBK as extraction agent, there will be MIBK in stripping solutions inevitably, which not only pollutes working conditions, but also affects the quality of ultimate product. In order to remove MIBK from aqueous solutions, the means of flat vacuum membrane distillation(VMD) is studied in the paper. The area of the membrane used in the study is 0.02 m 2, the initial volume of feed is 2 L, each experiment was conducted over a time period of 60 120 min. The influences of the factors such as temperature(34.8 55.0 ℃); pressure in the permeate side(10.67 14.67 kPa) and feed flow rate(27.8 69.4 mL/s) were experimentally studied. Increasing the temperature or reducing the pressure in the permeate side results in a faster removal of MIBK; however there is a decrease in removal factor β , increasing the feed flow rate results in a faster removal of MIBK and an increase of removal factor β , especially in the range of lower flow rate. The study indicates that the aim of MIBK removal and recycle from dilute aqueous solutions can be achieved by VMD.
文摘The one-pot synthesis of methyl isobutyl ketone（MIBK） from acetone using multifunctional catalysts is an important sustainable organic synthesis method with high atom and energy efficiency.Herein. we report a series of Pd supported on mixed metal oxide（MMO） catalysts with controllable acidic/basic/metallic sites on the surface. We study the relationship between the nature, synergy,and proximity of active sites and the catalytic performance of the multifunctional catalyst in the tandem reaction, in detail. In the existence of Lewis acid and base sites, the catalysts with medium-strength acidic/basic sites show preferred activity and/or MIBK selectivity. For multifunctional catalysts, the catalytic properties are more than just a collection of active sites, and the Pd/Mg_3Al-MMO catalyst possessing 0.1% Pd loading and ~0.4 acid/base molar ratio exhibits the optimal 42.1% acetone conversion and 37.2% MIBK yield, which is among the best reported so far for this tandem reaction under similar conditions. Moreover, the proximity test indicates that the intimate distance between acidic/basic/metallic sites can greatly shorten the diffusion time of the intermediate species from each active site, leading to an enhancement in the catalytic performance.
基金Supported by the National High Technology Research and Development Program of China (2008AA06Z111)the Qinghai Key Technology R&D Program (2011-J-154)
文摘To study the characteristic of liquid-liquid extraction equilibrium of lithium from brine sources, the complexes formed from tributyl phosphate （TBP） and methyl isobutyl ketone （MIBK） with lithium were investi- gated using FeCl3 as coextracting agent. Liquid-liquid extraction reaction mechanisms were proposed and the stoichiometry of tetrachloroferrate（III） complex with lithium was obtained by regressing the experimental data. It is found that the stoichiometry of tetrachloroferrate（III） to lithium in the complex is 1 ： 1 with either TBP or MIBK as extractant in kerosene. The stoichiometry of the complex of TBP with Li was 1 ： 1 and that of MIBK with Li was 2 ： 1. The formed complexes of TBP and MIBK with lithium are determined to be LiFeCla-TBP and LiFeC14.2MIBK, respectively, according to the rule of neutralization.
基金The National Science Foundation of China under contract No.40606028the Special Fund from the National Key Basic Research Program of China under contract No.2006CB400601.
文摘A sensitive solvent extraction method for the determination of nonamolar concentrations of silicate in natural waters is developed. According to the traditional aqueous silicate method, silicomolybdenum blue formed by the reaction between silicate and ammoni- um molydate and reduced by metol-sulfite reagent is extracted by methyl isobutyl ketone. The absorbance can be enhanced substantially up to 10-folds. The detection limit of silicate is 8 nmol/dm^3 , which is one tenth smaller than the traditional method, with the precision of 4.0% at a silicate level of 50 nmol/dm^3 and 3.2% at a silicate level of 6 μmol/dm^3. Comparing the calibration curves in the distilled water and seawater, it can be seen that the salt effect also exists in the extraction method. However, the salt effect is a linear function of the salinity and can be corrected by simple calibration. The proposed method is successfully applied to the determination of silicate in natural waters. Natural concentrations of arsenate, arsenite and phosphate cause negligible interference.
基金the financial support received from Department of Science and Technology(DST),Government of India(Nos.DST/TM/WTI/WIC/2K17/82(G)and DST/CCP/Co E/141/2018(G))for this study。
文摘Effectiveness of pulsed power plasma for the degradation of two toxic volatile organic compounds(VOCs),toluene and methyl isobutyl ketone(MIBK),in aqueous solution was evaluated.The plasma degradation of MIBK has been studied for the first time.The influence of initial concentration of target compound,solution pH and scavengers on percentage degradation was evaluated.100%removal of 200 mg/L of toluene and MIBK was achieved both in liquid and gaseous phases after 12 and 16 min of plasma treatment,respectively.The first order rate constant of toluene and MIBK degradation(for 200 mg/L each)was 0.421 and 0.319 min~(-1)respectively when they were treated individually,and these values decreased slightly during degradation of their mixture.MIBK degradation was slower than toluene and it might be due to semi volatile and hydrophilic nature of MIBK.The effect of initial concentration of toluene and MIBK showed different degradation patterns.Highest degradation of both the compounds was obtained in neutral pH and in absence of scavengers.·OH radical was the major reactive species involved in their degradation.Their degradation in real environmental matrices showed that removal reduced significantly in secondary effluent due to scavenging of reactive species by various ions and organic matter.The total number of degradation intermediates identified in case of toluene and MIBK was 11 and 14 respectively and formate was the one recalcitrant byproduct generated.The degradation pathway of toluene and MIBK involving reactions of reactive oxygen and nitrogen species and reductive species is proposed.
基金financially supported by the National Natural Science Foundation of China (91634101)the Project on Construction of Innovative Teams and Teacher Career Development for Universities and Colleges under Beijing Municipality (IDHT20180508)
文摘Supported nickel-based catalysts were prepared by the incipient wetness impregnation method for the selective hydrogenation of methyl isobutyl ketone to methyl isobutyl carbinol in a fixed-bed reactor. The effects of the nickel source,Ni loading, calcination time, and calcination temperature on the hydrogenation performance were studied. The experimental results showed that the Ni/γ-Al_2O_3 catalyst demonstrated the highest catalytic performance under the preparation conditions by using nickel nitrate as the nickel source with a NiO loading of 20%, followed by calcination at 440°C for 5h. In addition,this catalyst showed the largest specific surface area, best crystal structure, highest active component content, smallest particle size, and uniform distribution of NiO on the surface of the carrier. The nickel-based catalyst prepared using the optimized conditions exhibited a 96.1% conversion of methyl isobutyl ketone, with a methyl isobutyl carbinol selectivity of 99.6%. The described procedure is very effective for the preparation of methyl isobutyl carbinol using methyl isobutyl ketone as the feedstock.
文摘A method for the determination of iodine based upon compound H2HgI4, formed between I- and Hg1＋ in nitric acid and extracted in methyl isobutyl ketone（MIBK）, was developed via atomic fluorescence spectrometry（AFS）. After the compound is reduced with potassium borohydrid（KBH4）, the resultant mercury vapor was injected into the instrument and iodine was, therefore, indirectly determined. Experimental parameters such as the conditions of extraction reagents, aqueous phase acidity, elemental mercury diffusion temperature in a vial and other factors were investigated and optimized. Under the optimum experimental conditions, this method shows a detection limit of 0.038μg/L iodine and a linear relationship between 0.04-20 p.g/L. The method was applied to determining the iodine content in marine duck eggs, kelps, laver and Ganoderma lucidum spirulina, showing a relative standard deviation（RSD） of 2.15% and the recoveries in the range of 98.1%-102.5%.
基金Supported by the National Natural Science Foundation of China(21506066)State Key Laboratory of Pulp and Paper Engineering(201708)+2 种基金the Guangdong Natural Science Foundation(2014A030310260)the Fundamental Research Funds for the Central Universities SCUT(2017ZD069)the Guangzhou Technology Project(201804010219)
文摘The effects of NaCl, KCl and Na_2SO_4 on the liquid–liquid equilibrium(LLE) data for the ternary system, water+ phenol + methyl isobutyl ketone, were determined at 0.101 MPa and 333.15 K and 343.15 K.The nonrandom two-liquid(NRTL) model was used to correlate the experimental data and to yield corresponding binary interaction parameters for these salt containing systems.The Hand and Othmer–Tobias equations were used to confirm the dependability of the determined LLE data in this work.Distribution coefficient and selectivity were used to evaluate the extraction performance of methyl isobutyl ketone with the existence of salt.The magnitude of salt effect on the water + phenol + methyl isobutyl ketone(MIBK) system is in the following order: Na_2SO_4>NaCl>KCl.
文摘The reduction of diaryldiselenides by Cp2TiCl2/BuiMgBr/THF led to arylselenium complex of titanocene [Cp2TiSeAr]. This species reacted smoothly with electrophilic substrates such as acylhalides, α-bromocarbonyl compounds, diaryliodonium salts, α,β-unsaturated carbonyl compounds to afford the corresponding organic selenides in high yields.
文摘Objective To reduce the risk of surgical resection of giant arteriovenous malformation (AVM) (>6.0 cm) and prevent normal perfusion pressure breakthrough (NPPB) for lowering the postoperative mortality. Methods During the operation under barbiturate anesthesia, the proximal end of the feeding arteries were ligated at first, and 0.5 ml isobutyl 12 cyanoacrylate (IBCA) with 0.5 ml 5% glucose was injected into the vessels towards the AVM, then the malformed vessels were resected totally. Postoperative digital subtraction angiography of the four vessels was performed in all patients. Results 50 patients with giant AVM survived after operation, only 6 (12.0%) had transient neurological dysfunction and 44 (88.0%) recovered after a follow up of 6-36 months. No patient suffered from normal perfusion pressure breakthrough (NPPB). Conclusions The embolization could block the arteriovenous shunts sufficiently to decrease the blood flow away from the normal areas of the brain so as to prevent the incidence of intra and postoperative rebleeding, especially in NPPB. Therefore, the combination of intraoperative embolization with surgical resection is an effective strategy in the treatment of giant cerebral AVMs, which make it operable for those used to be regarded as inoperable cases.
基金Financial support provided by the National High-tech Research and Development Program of China(2014AA022103)。
文摘Biodiesel was used to prepare epoxidized fatty acid isobutyl esters(Ep-FABEs)as a biobased plasticizer in this work.Transesterification of biodiesel with isobutanol catalyzed by tetrabutyl titanate was carried out in a gas-liquid tower reactor.The conversion achieved nearly 100%within 5 h under the reaction temperature,the mass ratio of catalyst to fatty acid methyl esters(FAMEs),and isobutanol to FAMEs total molar ratio of 180℃,0.4%(mass),and 5.4:1,respectively.In addition,kinetic model of the transesterification reaction was developed at 150–190℃.The calculated activation energy was 48.93 kJ·mol^(-1).Then,the epoxidation of obtained fatty acid isobutyl esters(FABEs)was conducted in the presence of formic acid and hydrogen peroxide.The Ep-FABEs was further analyzed for its plasticizing effectiveness to replace dioctyl phthalate(DOP)and compared with conventional epoxy plasticizer epoxidized fatty acid methyl esters(Ep-FAMEs).The results indicated that the thermal stability and mechanical properties of PVC films with Ep-FABEs plasticizer were significantly improved compared with those plasticized with DOP.In addition,the extraction resistance and migration stability of Ep-FABEs were better than those of EpFAMEs.Overall,the prepared Ep-FABEs via structural modification of biodiesel proved to be a promising biobased plasticizer.
基金supported by the National Natural Science Foundation of China(22168004)the Natural Science Foundation of Guangxi Province(2017GXNSFDA198047)the Dean Project of Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology(2019Z010,2021Z013)。
文摘As an important organic,isobutyl acetate(IbAc)has been widely used in industries because of its good biodegradability,low surface tension,and other properties.The industrial production of IbAc is usually catalyzed by sulfuric acid.However,the use of sulfuric acid has the drawbacks of causing considerable corrosion to equipment and being difficult to be separated.In this work,n-sulfopropyl-3-methylpyridinium trifluoromethanesulfonate([HSO_(3)-PMPY][CF_(3)SO_(3)])Bronsted acidic ionic liquid(BAIL)was used as the catalyst and the catalytic activity,solubility,and corrosiveness were evaluated for the esterification of acetic acid with isobutanol.The reaction kinetics and chemical equilibrium were systemically studied.Compared to conventional acid catalysts,[HSO_(3)-PMPY][CF_(3)SO_(3)]showed higher catalytic activity,more excellent reusability,more favorable phase separation,and non-corrosiveness.Three kinetic equations based on ideal homogeneous(IH),non-ideal homogeneous(NIH),and modified nonideal homogeneous(NIH-M)models were established and correlated with the experimental data to determine the parameters and errors.The NIH-M model exhibited the best agreement with the experimental data,owing to its prediction considering the non-ideality and the self-catalysis effect of acetic acid in this system.Besides,the error of NIH-M model fitting was mainly caused by the difference in solubility between[HSO_(3)-PMPY][CF_(3)SO_(3)]with reactants and products in the reaction system.Furthermore,the applicability of the NIH-M model was investigated by simulating the esterification of acetic acid with three short-chain alcohols(ethanol,n-butanol,and isobutanol)catalyzed by BAILs.The NIH-M model displayed an acceptable simulation for this type of acetic acid esterification reaction catalyzed by BAILs at different ranges of the BAILs concentration and temperature.This study confirmed the industrial prospects of[HSO_(3)-PMPY][CF_(3)SO_(3)]in isobutyl acetate production and the applicability of the NIH-M kinetic model in the esterif
