The high throughput prediction of the thermodynamic phase behavior of active pharmaceutical ingredients(APIs)with pharmaceutically relevant excipients remains a major scientific challenge in the screening of pharmaceu...The high throughput prediction of the thermodynamic phase behavior of active pharmaceutical ingredients(APIs)with pharmaceutically relevant excipients remains a major scientific challenge in the screening of pharmaceutical formulations.In this work,a developed machine-learning model efficiently predicts the solubility of APIs in polymers by learning the phase equilibrium principle and using a few molecular descriptors.Under the few-shot learning framework,thermodynamic theory(perturbed-chain statistical associating fluid theory)was used for data augmentation,and computational chemistry was applied for molecular descriptors'screening.The results showed that the developed machine-learning model can predict the API-polymer phase diagram accurately,broaden the solubility data of APIs in polymers,and reproduce the relationship between API solubility and the interaction mechanisms between API and polymer successfully,which provided efficient guidance for the development of pharmaceutical formulations.展开更多
A novel photo-catalytic system composed of N-doped biochars(NBCs),MnFe_(2)O_(4) and sulfite activation under ultraviolet(NBCs/MnFe_(2)O_(4)/sulfite/UV)was constructed to realize the efficient eliminate of tetracycline...A novel photo-catalytic system composed of N-doped biochars(NBCs),MnFe_(2)O_(4) and sulfite activation under ultraviolet(NBCs/MnFe_(2)O_(4)/sulfite/UV)was constructed to realize the efficient eliminate of tetracycline(TC).As the carrier of MnFe_(2)O_(4),NBCs were synthesized from alfalfa,which has large specific surface area,graphite like structure and hierarchical porous structure.The adsorption isotherm indicated that NBCs/MnFe_(2)O_(4)-2:1 had the best adsorption performance for TC(347.56 mg g^(-1)).Through synergistic adsorption and photocatalysis,the removal rate of TC reached 84%,which was significantly higher than that of MnFe_(2)O_(4).Electrochemical impedance spectroscopy(EIS)and Photoluminescence(PL)characterization results showed that the introduction of NBCs improved the separation efficiency of photogenerated electron and hole pairs and enhanced the photocatalytic performance.Moreover,the adsorption,degradation mechanism and degradation path of TC by the catalyst were systematically analyzed by coupling HPLC–MS measurement with the theoretical calculation.Considering the advantages of excellent degradation performance,low cost,easy separation and environmental friendliness of NBCs/MnFe_(2)O_(4),this work was expected to provide a new path for the practical application of biochar.展开更多
Biological solubility is one of the important basic parameters in the development process of poorly soluble drugs,but the current measurement methods are mainly based on a large number of experiments,which are time-co...Biological solubility is one of the important basic parameters in the development process of poorly soluble drugs,but the current measurement methods are mainly based on a large number of experiments,which are time-consuming and cost-intensive.There is still a lack of effective theoretical models to accurately describe and predict the biological solubility of drugs to reduce costs.Therefore,in this study,osaprazole and irbesartan were selected as model drugs,and their solubility in solutions containing surfactants and biorelevant media was measured experimentally.By calculating the parameters of each component using the perturbed-chain statistical associating fluid theory(PC-SAFT)model,combined with pH-dependent and micellar solubilization models,the thermodynamic phase behavior of the two drugs was successfully modeled,and the predicted results were in good agreement with the experimental values.These results demonstrate that the model combination used provides important basic parameters and theoretical guidance for the development and screening of poorly soluble drugs and related formulations.展开更多
As a technology of separation and purification,crystallization plays a vital role in diverse industries such as inorganic salt,pharmaceutical,and food industries,which has a huge impact on purity,crystal polymorph,cry...As a technology of separation and purification,crystallization plays a vital role in diverse industries such as inorganic salt,pharmaceutical,and food industries,which has a huge impact on purity,crystal polymorph,crystal morphology,and particle size distribution of final products.In the past few decades,with the rapid advancement of experimental approaches and molecular simulation methods,considerable advances in the interpretation of crystallization mechanisms have been obtained,promoting the investigation and understanding of crystallization theories greatly.In this review,the advances of pharmaceutical crystallization theories in recent years from the perspectives of nucleation and crystal growth are summarized and discussed.Two thermodynamic models that are helpful in the study of the crystallization mechanisms will be introduced.In this section,the perturbed-chain statistical associating fluid theory(PC-SAFT)and a chemical-potential-gradient model will be introduced,which have been successfully applied in pharmaceutical solubility prediction,the research of dissolution mechanism as well as dissolution kinetics analysis.These two models are expected to be applied to the study of pharmaceutical crystallization process and mechanism.Furthermore,molecular simulation based on the interaction between particles can provide structural information,thermodynamics,and dynamics properties of complex systems at the molecular level,like intermolecular interaction and surface adsorption energies.Application and some shortcomings of molecular simulation,especially molecular dynamics simulation,in the field of pharmaceutical crystallization will be expounded.展开更多
Current formulation development strongly relies on trial-and-error experiments in the laboratory by pharmaceutical scientists,which is time-consuming,high cost and waste materials.This research aims to integrate vario...Current formulation development strongly relies on trial-and-error experiments in the laboratory by pharmaceutical scientists,which is time-consuming,high cost and waste materials.This research aims to integrate various computational tools,including machine learning,molecular dynamic simulation and physiologically based absorption modeling(PBAM),to enhance andrographolide(AG)/cyclodextrins(CDs)formulation design.The light GBM prediction model we built before was utilized to predict AG/CDs inclusion's binding free energy.AG/γ-CD inclusion complexes showed the strongest binding affinity,which was experimentally validated by the phase solubility study.The molecular dynamic simulation was used to investigate the inclusion mechanism between AG andγ-CD,which was experimentally characterized by DSC,FTIR and NMR techniques.PBAM was applied to simulate the in vivo behavior of the formulations,which were validated by cell and animal experiments.Cell experiments revealed that the presence of D-α-Tocopherol polyethylene glycol succinate(TPGS)significantly increased the intracellular uptake of AG in MDCKMDR1 cells and the absorptive transport of AG in MDCK-MDR1 monolayers.The relative bioavailability of the AG-CD-TPGS ternary system in rats was increased to 2.6-fold and 1.59-fold compared with crude AG and commercial dropping pills,respectively.In conclusion,this is the first time to integrate various computational tools to develop a new AG-CD-TPGS ternary formulation with significant improvement of aqueous solubility,dissolution rate and bioavailability.The integrated computational tool is a novel and robust methodology to facilitate pharmaceutical formulation design.展开更多
To improve the stability of nanoparticles in aqueous solution,polymer or surfactant,etc.are often added in solutions during the preparation process of nanoparticles,which can induce new interfaces that influence the s...To improve the stability of nanoparticles in aqueous solution,polymer or surfactant,etc.are often added in solutions during the preparation process of nanoparticles,which can induce new interfaces that influence the solubility of nanoparticles.In this work,a novel interfacial thermodynamic model for describing the Gibbs energy of the nanoparticles coated by stabilizers was proposed to predict the solubility of nanoparticles.Within the developed model,the activity coefficient of nano metal system was determined by Davies model and that of nano drug system by Perturbed-Chain Statistical Associating Fluid Theory(PC-SAFT).The Gibbs energy of the interface was established as a function of molecular parameters via the application for nano metal system.Furthermore,the model was further used to predict the solubility of nano drugs itraconazole,fenofibrate,and griseofulvin.It was found that the Gibbs energy of the interface plays an important role especially when the radius of nano metal is less than 40 nm,and the developed model can predict the solubility of nano drug with high accuracy in comparison with the experimental data as well as predict the changing trend of solubility of nano drugs that increases as the particle size decreases.Meanwhile,the stabilization mechanism of stabilizers on nano drugs was studied which provided theoretical guidance for the selection of polymer or surfactant stabilizer.These findings showed that the developed model can provide a reliable prediction of the solubility of nanoparticles and help to comprehend the stabilization mechanism of the stabilizers on nano drugs with different particle sizes,which is expected to provide important information for the design of nano drugs formulations.展开更多
In this work,hollow manganese dioxide/gold nanoparticle(MnO2/GNPs)hybrid drug nanocarriers were prepared by coupling the gold nanoparticles(GNPs)with hollow structure manganese dioxide(MnO2).Among them,GNPs have been ...In this work,hollow manganese dioxide/gold nanoparticle(MnO2/GNPs)hybrid drug nanocarriers were prepared by coupling the gold nanoparticles(GNPs)with hollow structure manganese dioxide(MnO2).Among them,GNPs have been used as near-infrared(NIR)-responsive element for photothermal effect under NIR laser irradiation.The glutathione(GSH)-responsive and p H-responsive performances of drug release were derived from hollow MnO2.Particularly,Doxorubicin hydrochloride(DOX)can be loaded into hollow MnO2/GNPs with the drug loading efficiency up to 82.0%.Moreover,the photothermal effect and GSH-/pH-responsive properties of hollow MnO2/GNPs were investigated.The hollow MnO2/GNPs possessed satisfactory drug release efficiency(ca.87.4%of loaded drug released in 12 h)and have high photothermal conversion efficiency,multiresponsive properties,and degradability.Finally,the kinetics of drug release was discussed in detail.Thus,our finding highlights that the multiresponsive nanocarriers are of great potential in the field of drug controlled release.展开更多
Struvite(MAP)crystallization technology is widely used to treat ammonia nitrogen in waste effluents of its simple operation and good removal efficiency.However,the presence of heavy metal ions in the waste effluents c...Struvite(MAP)crystallization technology is widely used to treat ammonia nitrogen in waste effluents of its simple operation and good removal efficiency.However,the presence of heavy metal ions in the waste effluents causes problems such as slow crystallization rate and small crystal size,limiting the recovery rate and economic value of the MAP.The present study was conducted to investigate the effects of concentrations of three heavy metal ions(Cu^(2+),Zn^(2+),and Pb^(2+))on the crystal morphology,crystal size,average growth rate,and crystallization kinetics of MAP.A relationship was established between the kinetic rate constant Ktcalculated by the chemical gradient model and the concentrations of heavy metal ions.The results showed that low concentrations of heavy metal ions in the solution created pits on the MAP surface,and high level of heavy metal ions generated flocs on the MAP surface,which were composed of metal hydroxides,thus inhibiting crystal growth.The crystal size,average growth rate,MAP crystallization rate,and kinetic rate constant Ktdecreased with the increase in heavy metal ion concentration.Moreover,the Ktdemonstrated a linear relationship with the heavy metal concentration ln(C/C~*),which provided a reference for the optimization of the MAP crystallization process in the presence of heavy metal ions.展开更多
“Thermodynamics is the only physical theory of universal content concerning which I am convinced that,within the framework of the applicability of its basic concepts,it will never be overthrown.”—Albert Einstein Ch...“Thermodynamics is the only physical theory of universal content concerning which I am convinced that,within the framework of the applicability of its basic concepts,it will never be overthrown.”—Albert Einstein Chemical Engineering plays an essential role in modern society.It has been used to produce a wide variety of important materials,for example,the plastic drinking-water bottles,the jet fuels for transoceanic flights,and raw materials for assembling CPUs.Chemical Engineering is also on the frontline to manufacture massive masks,gloves,testing kits,and vaccines to fight against COVID-19 globally.展开更多
Utilizing ionic liquid(IL)-water mixtures as selective extraction solvents for raw materials from natural sources represents an efficacious approach;however,elucidating the underlying mechanisms inherent in various ty...Utilizing ionic liquid(IL)-water mixtures as selective extraction solvents for raw materials from natural sources represents an efficacious approach;however,elucidating the underlying mechanisms inherent in various types of IL-aqueous solutions continues to pose a significant challenge.In this study,molecular dynamics simulations and density functional theory calculations are employed to illuminate the influence of the functional anion within ILs and the water content on the solvation mechanism and phase separation phenomena observed during the extraction of camptothecin(CPT)using aqueous IL solutions.The simulation results show that the anions in ILs preferentially dissolve CPT through hydrogen bonding at low water concentrations.As the water concentration increases,the hydrophobic IL binds more tightly to CPT,enabling the water to self-aggregate.The anions in hydrophilic IL form hydrogen bonds with water instead,further enhancing the dissolution of CPT.This work reveals the mechanism of phase separation and solvation of different types of IL aqueous solutions,which is helpful in developing new drug extraction and purification technologies.展开更多
Due to the shortage of fossil energy,biomass has a potential to be a very promising alternative source.Unfortunately,a large part of biomass resources worldwide causes serious environmental pollution,low value-added u...Due to the shortage of fossil energy,biomass has a potential to be a very promising alternative source.Unfortunately,a large part of biomass resources worldwide causes serious environmental pollution,low value-added utilization and energy waste due to unsustainable utilization of biomass.Simulation and optimization of the thermochemical utilization of biomass resources is a hot issue in the industry and academia,which can provide the relationship between the utilizations of biomass with sustainable objective and compositions of biomass,operational parameters,etc.This review focused on the theoretical research progress of sustainable utilization of biomass resources from three aspects:basic thermochemical data estimation,process simulation and system optimization of pyrolysis and gasification.And the application of artificial intelligence as a tool in the field of above three aspects was also introduced.Advantages and limitations of current methods,as well as future opportunities and challenges were also discussed.展开更多
In this paper,the research framework for specific structure crystallization modeling has been proposed in which four steps are required in order to investigate the rigorous crystallization modeling by thermodynamics.T...In this paper,the research framework for specific structure crystallization modeling has been proposed in which four steps are required in order to investigate the rigorous crystallization modeling by thermodynamics.The first is the activity coefficient model of the solution,the second is Solid-Liquid equilibrium,the third and fourth are the dissolution and crystallization kinetics modeling,respectively.Our investigations show that the mechanisms of complex structure formation and microphase transition can be analyzed by combining the dissolution and crystallization kinetics modeling.Moreover,the formation mechanism of the porous KCl has been analyzed,which may provide a reference for the porous structure formation in the advanced material synthesis.展开更多
In this work,the influence of the initial chemical potential gradient,stirring speed,and polymer type on sulfamethoxazole(SMX)crystal growth kinetics was systematically investigated through density functional theory(D...In this work,the influence of the initial chemical potential gradient,stirring speed,and polymer type on sulfamethoxazole(SMX)crystal growth kinetics was systematically investigated through density functional theory(DFT)calculations,experimental measurements and the two-step chemical potential gradient model.To investigate the influence of different conditions on the thermodynamic driving force of SMX crystal growth,SMX solubilities in different polymer solutions were studied.Four model polymers effectively improved SMX solubility.It was further found that polyvinylpyrrolidone(PVP)and hydroxypropyl methyl cellulose(HPMC)played a crucial role in inhibiting SMX crystal growth.However,polyethylene glycol(PEG)promoted SMX crystal growth.The effect of the polymer on the crystal growth mechanisms of SMX was further analyzed by the two-step chemical potential gradient model.In the system containing PEG 6000,crystal growth is dominated by the surface reaction.However,in the system containing PEG 20000,crystal growth is dominated by both the surface reaction and diffusion.In addition,DFT calculations results showed that HPMC and PVP could form strong and stable binding energies with SMX,indicating that PVP and HPMC had the potential ability to inhibit SMX crystal growth.展开更多
基金the financial support from the National Natural Science Foundation of China(22278070,21978047,21776046)。
文摘The high throughput prediction of the thermodynamic phase behavior of active pharmaceutical ingredients(APIs)with pharmaceutically relevant excipients remains a major scientific challenge in the screening of pharmaceutical formulations.In this work,a developed machine-learning model efficiently predicts the solubility of APIs in polymers by learning the phase equilibrium principle and using a few molecular descriptors.Under the few-shot learning framework,thermodynamic theory(perturbed-chain statistical associating fluid theory)was used for data augmentation,and computational chemistry was applied for molecular descriptors'screening.The results showed that the developed machine-learning model can predict the API-polymer phase diagram accurately,broaden the solubility data of APIs in polymers,and reproduce the relationship between API solubility and the interaction mechanisms between API and polymer successfully,which provided efficient guidance for the development of pharmaceutical formulations.
基金gratefully acknowledge the financial support for this research from the National Natural Science Foundation of China(Grant No.:21978047,21776046)the Six Talent Climax Foundation of Jiangsu(Grant No.:XCL-079).
文摘A novel photo-catalytic system composed of N-doped biochars(NBCs),MnFe_(2)O_(4) and sulfite activation under ultraviolet(NBCs/MnFe_(2)O_(4)/sulfite/UV)was constructed to realize the efficient eliminate of tetracycline(TC).As the carrier of MnFe_(2)O_(4),NBCs were synthesized from alfalfa,which has large specific surface area,graphite like structure and hierarchical porous structure.The adsorption isotherm indicated that NBCs/MnFe_(2)O_(4)-2:1 had the best adsorption performance for TC(347.56 mg g^(-1)).Through synergistic adsorption and photocatalysis,the removal rate of TC reached 84%,which was significantly higher than that of MnFe_(2)O_(4).Electrochemical impedance spectroscopy(EIS)and Photoluminescence(PL)characterization results showed that the introduction of NBCs improved the separation efficiency of photogenerated electron and hole pairs and enhanced the photocatalytic performance.Moreover,the adsorption,degradation mechanism and degradation path of TC by the catalyst were systematically analyzed by coupling HPLC–MS measurement with the theoretical calculation.Considering the advantages of excellent degradation performance,low cost,easy separation and environmental friendliness of NBCs/MnFe_(2)O_(4),this work was expected to provide a new path for the practical application of biochar.
基金the financial support from the National Natural Science Foundation of China(22278070,21978047,21776046)。
文摘Biological solubility is one of the important basic parameters in the development process of poorly soluble drugs,but the current measurement methods are mainly based on a large number of experiments,which are time-consuming and cost-intensive.There is still a lack of effective theoretical models to accurately describe and predict the biological solubility of drugs to reduce costs.Therefore,in this study,osaprazole and irbesartan were selected as model drugs,and their solubility in solutions containing surfactants and biorelevant media was measured experimentally.By calculating the parameters of each component using the perturbed-chain statistical associating fluid theory(PC-SAFT)model,combined with pH-dependent and micellar solubilization models,the thermodynamic phase behavior of the two drugs was successfully modeled,and the predicted results were in good agreement with the experimental values.These results demonstrate that the model combination used provides important basic parameters and theoretical guidance for the development and screening of poorly soluble drugs and related formulations.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.21776046 and 21606043)the Six Talent Peaks Project in Jiangsu Province(Grant No.XCL-079)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.2242019K40145)the Recruitment Program for Young Professionals(the Thousand Youth Talents Plan)。
文摘As a technology of separation and purification,crystallization plays a vital role in diverse industries such as inorganic salt,pharmaceutical,and food industries,which has a huge impact on purity,crystal polymorph,crystal morphology,and particle size distribution of final products.In the past few decades,with the rapid advancement of experimental approaches and molecular simulation methods,considerable advances in the interpretation of crystallization mechanisms have been obtained,promoting the investigation and understanding of crystallization theories greatly.In this review,the advances of pharmaceutical crystallization theories in recent years from the perspectives of nucleation and crystal growth are summarized and discussed.Two thermodynamic models that are helpful in the study of the crystallization mechanisms will be introduced.In this section,the perturbed-chain statistical associating fluid theory(PC-SAFT)and a chemical-potential-gradient model will be introduced,which have been successfully applied in pharmaceutical solubility prediction,the research of dissolution mechanism as well as dissolution kinetics analysis.These two models are expected to be applied to the study of pharmaceutical crystallization process and mechanism.Furthermore,molecular simulation based on the interaction between particles can provide structural information,thermodynamics,and dynamics properties of complex systems at the molecular level,like intermolecular interaction and surface adsorption energies.Application and some shortcomings of molecular simulation,especially molecular dynamics simulation,in the field of pharmaceutical crystallization will be expounded.
基金financially supported by the FDCT Project 0029/2018/A1the University of Macao Research Grants(MYRG2019-00041-ICMS)performed in part at the High-Performance Computing Cluster(HPCC)which is supported by Information and Communication Technology Office(ICTO)of the University of Macao。
文摘Current formulation development strongly relies on trial-and-error experiments in the laboratory by pharmaceutical scientists,which is time-consuming,high cost and waste materials.This research aims to integrate various computational tools,including machine learning,molecular dynamic simulation and physiologically based absorption modeling(PBAM),to enhance andrographolide(AG)/cyclodextrins(CDs)formulation design.The light GBM prediction model we built before was utilized to predict AG/CDs inclusion's binding free energy.AG/γ-CD inclusion complexes showed the strongest binding affinity,which was experimentally validated by the phase solubility study.The molecular dynamic simulation was used to investigate the inclusion mechanism between AG andγ-CD,which was experimentally characterized by DSC,FTIR and NMR techniques.PBAM was applied to simulate the in vivo behavior of the formulations,which were validated by cell and animal experiments.Cell experiments revealed that the presence of D-α-Tocopherol polyethylene glycol succinate(TPGS)significantly increased the intracellular uptake of AG in MDCKMDR1 cells and the absorptive transport of AG in MDCK-MDR1 monolayers.The relative bioavailability of the AG-CD-TPGS ternary system in rats was increased to 2.6-fold and 1.59-fold compared with crude AG and commercial dropping pills,respectively.In conclusion,this is the first time to integrate various computational tools to develop a new AG-CD-TPGS ternary formulation with significant improvement of aqueous solubility,dissolution rate and bioavailability.The integrated computational tool is a novel and robust methodology to facilitate pharmaceutical formulation design.
基金funding from the National Natural Science Foundation of China(21776046,21978047)the Fundamental Research Funds for the Central Universities(2242020K40033)the Six Talent Peaks Project in Jiangsu Province(XCL-079)。
文摘To improve the stability of nanoparticles in aqueous solution,polymer or surfactant,etc.are often added in solutions during the preparation process of nanoparticles,which can induce new interfaces that influence the solubility of nanoparticles.In this work,a novel interfacial thermodynamic model for describing the Gibbs energy of the nanoparticles coated by stabilizers was proposed to predict the solubility of nanoparticles.Within the developed model,the activity coefficient of nano metal system was determined by Davies model and that of nano drug system by Perturbed-Chain Statistical Associating Fluid Theory(PC-SAFT).The Gibbs energy of the interface was established as a function of molecular parameters via the application for nano metal system.Furthermore,the model was further used to predict the solubility of nano drugs itraconazole,fenofibrate,and griseofulvin.It was found that the Gibbs energy of the interface plays an important role especially when the radius of nano metal is less than 40 nm,and the developed model can predict the solubility of nano drug with high accuracy in comparison with the experimental data as well as predict the changing trend of solubility of nano drugs that increases as the particle size decreases.Meanwhile,the stabilization mechanism of stabilizers on nano drugs was studied which provided theoretical guidance for the selection of polymer or surfactant stabilizer.These findings showed that the developed model can provide a reliable prediction of the solubility of nanoparticles and help to comprehend the stabilization mechanism of the stabilizers on nano drugs with different particle sizes,which is expected to provide important information for the design of nano drugs formulations.
基金supported by the National Natural Science Foundation of China(Grant Nos.:21776046,21606043)the Six Talent Peaks Project in Jiangsu Province(Grant No.:XCL-079)+2 种基金the Fundamental Research Funds for the Central Universities(Grant No.:2242019K40145)the Cooperative Research Project between Southeast University and China Pharmaceutical Universitythe Recruitment Program for Young Professionals(the Thousand Youth Talents Plan)。
文摘In this work,hollow manganese dioxide/gold nanoparticle(MnO2/GNPs)hybrid drug nanocarriers were prepared by coupling the gold nanoparticles(GNPs)with hollow structure manganese dioxide(MnO2).Among them,GNPs have been used as near-infrared(NIR)-responsive element for photothermal effect under NIR laser irradiation.The glutathione(GSH)-responsive and p H-responsive performances of drug release were derived from hollow MnO2.Particularly,Doxorubicin hydrochloride(DOX)can be loaded into hollow MnO2/GNPs with the drug loading efficiency up to 82.0%.Moreover,the photothermal effect and GSH-/pH-responsive properties of hollow MnO2/GNPs were investigated.The hollow MnO2/GNPs possessed satisfactory drug release efficiency(ca.87.4%of loaded drug released in 12 h)and have high photothermal conversion efficiency,multiresponsive properties,and degradability.Finally,the kinetics of drug release was discussed in detail.Thus,our finding highlights that the multiresponsive nanocarriers are of great potential in the field of drug controlled release.
基金financial support from the National Natural Science Foundation of China (21838004)Priority Academic Program Development of Jiangsu Higher Education Institutions (PPZY2015A044)Top-notch Academic Programs Project of Jiangsu Higher Education Institution (TAPP)。
文摘Struvite(MAP)crystallization technology is widely used to treat ammonia nitrogen in waste effluents of its simple operation and good removal efficiency.However,the presence of heavy metal ions in the waste effluents causes problems such as slow crystallization rate and small crystal size,limiting the recovery rate and economic value of the MAP.The present study was conducted to investigate the effects of concentrations of three heavy metal ions(Cu^(2+),Zn^(2+),and Pb^(2+))on the crystal morphology,crystal size,average growth rate,and crystallization kinetics of MAP.A relationship was established between the kinetic rate constant Ktcalculated by the chemical gradient model and the concentrations of heavy metal ions.The results showed that low concentrations of heavy metal ions in the solution created pits on the MAP surface,and high level of heavy metal ions generated flocs on the MAP surface,which were composed of metal hydroxides,thus inhibiting crystal growth.The crystal size,average growth rate,MAP crystallization rate,and kinetic rate constant Ktdecreased with the increase in heavy metal ion concentration.Moreover,the Ktdemonstrated a linear relationship with the heavy metal concentration ln(C/C~*),which provided a reference for the optimization of the MAP crystallization process in the presence of heavy metal ions.
文摘“Thermodynamics is the only physical theory of universal content concerning which I am convinced that,within the framework of the applicability of its basic concepts,it will never be overthrown.”—Albert Einstein Chemical Engineering plays an essential role in modern society.It has been used to produce a wide variety of important materials,for example,the plastic drinking-water bottles,the jet fuels for transoceanic flights,and raw materials for assembling CPUs.Chemical Engineering is also on the frontline to manufacture massive masks,gloves,testing kits,and vaccines to fight against COVID-19 globally.
基金supported by the National Natural Science Foundation of China(Grant Nos.:22278070,21978047)
文摘Utilizing ionic liquid(IL)-water mixtures as selective extraction solvents for raw materials from natural sources represents an efficacious approach;however,elucidating the underlying mechanisms inherent in various types of IL-aqueous solutions continues to pose a significant challenge.In this study,molecular dynamics simulations and density functional theory calculations are employed to illuminate the influence of the functional anion within ILs and the water content on the solvation mechanism and phase separation phenomena observed during the extraction of camptothecin(CPT)using aqueous IL solutions.The simulation results show that the anions in ILs preferentially dissolve CPT through hydrogen bonding at low water concentrations.As the water concentration increases,the hydrophobic IL binds more tightly to CPT,enabling the water to self-aggregate.The anions in hydrophilic IL form hydrogen bonds with water instead,further enhancing the dissolution of CPT.This work reveals the mechanism of phase separation and solvation of different types of IL aqueous solutions,which is helpful in developing new drug extraction and purification technologies.
基金support from the National Natural Science Foundation of China(Grant No.:21776046,21878337,21676291)the Fundamental Research Funds for the Central Universities(Grant No.2242020K40033).
文摘Due to the shortage of fossil energy,biomass has a potential to be a very promising alternative source.Unfortunately,a large part of biomass resources worldwide causes serious environmental pollution,low value-added utilization and energy waste due to unsustainable utilization of biomass.Simulation and optimization of the thermochemical utilization of biomass resources is a hot issue in the industry and academia,which can provide the relationship between the utilizations of biomass with sustainable objective and compositions of biomass,operational parameters,etc.This review focused on the theoretical research progress of sustainable utilization of biomass resources from three aspects:basic thermochemical data estimation,process simulation and system optimization of pyrolysis and gasification.And the application of artificial intelligence as a tool in the field of above three aspects was also introduced.Advantages and limitations of current methods,as well as future opportunities and challenges were also discussed.
基金supported by the Chinese National Key Technology Research and Development Program(Grant Nos.2006BAB09B02,2006AA03Z455,and 2006BAE03B7-2)the Chinese National Science Foundation for Outstanding Young Scholars(No.20428606)+4 种基金the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(08KJB530003)the National Natural Science Foundation of China(Grant Nos.20676062,20731160614,20736002,B061101,B060105,20706029,and 20706028)NSFC-RGC(No.20731160614)the Key Science Foundation of Jiangsu Province,China(BK 2004215)Program for Changjiang Scholars and Innovative Research Team in University(No.IRT0732).
文摘In this paper,the research framework for specific structure crystallization modeling has been proposed in which four steps are required in order to investigate the rigorous crystallization modeling by thermodynamics.The first is the activity coefficient model of the solution,the second is Solid-Liquid equilibrium,the third and fourth are the dissolution and crystallization kinetics modeling,respectively.Our investigations show that the mechanisms of complex structure formation and microphase transition can be analyzed by combining the dissolution and crystallization kinetics modeling.Moreover,the formation mechanism of the porous KCl has been analyzed,which may provide a reference for the porous structure formation in the advanced material synthesis.
基金This research received funding from the National Natural Science Foundation of China(Grant Nos.22278070,21978047,and 21776046).
文摘In this work,the influence of the initial chemical potential gradient,stirring speed,and polymer type on sulfamethoxazole(SMX)crystal growth kinetics was systematically investigated through density functional theory(DFT)calculations,experimental measurements and the two-step chemical potential gradient model.To investigate the influence of different conditions on the thermodynamic driving force of SMX crystal growth,SMX solubilities in different polymer solutions were studied.Four model polymers effectively improved SMX solubility.It was further found that polyvinylpyrrolidone(PVP)and hydroxypropyl methyl cellulose(HPMC)played a crucial role in inhibiting SMX crystal growth.However,polyethylene glycol(PEG)promoted SMX crystal growth.The effect of the polymer on the crystal growth mechanisms of SMX was further analyzed by the two-step chemical potential gradient model.In the system containing PEG 6000,crystal growth is dominated by the surface reaction.However,in the system containing PEG 20000,crystal growth is dominated by both the surface reaction and diffusion.In addition,DFT calculations results showed that HPMC and PVP could form strong and stable binding energies with SMX,indicating that PVP and HPMC had the potential ability to inhibit SMX crystal growth.