Non-aqueous emulsions have a wide range of applications in cosmetics,drug-controlled release,and the preparation of functional nanoparticles.However,due to the weaker polarity of non-aqueous solvents,these emulsions o...Non-aqueous emulsions have a wide range of applications in cosmetics,drug-controlled release,and the preparation of functional nanoparticles.However,due to the weaker polarity of non-aqueous solvents,these emulsions often exhibit inferior stability compared to their aqueous counterparts.In this experiment,the properties of quaternary ammonium surfactants in glycerol were investigated through surface tension measurements,to further enhance the stability of n-decane/glycerol emulsions,hydrophilic nanoparticles SiO_(2) were modified in situ using double tailed quaternary ammonium surfactants Di-C_(12)DAB and Di-C_(16)DAB.Stable n-decane/glycerol Pickering emulsions were successfully prepared.These emulsions were stable at 45℃for over six months,and no significant changes in droplet size occurred.The minimum droplet size of the emulsion was only 2-3μm.Contact angle measurements showed that the wettability of the silica surface was tremendously affected by the concentration and the alkyl chain length of the double-tailed surfactants.In the presence of Di-C_(12)DAB,the contact angle of glycerol on the silica surface increased monotonically with the surfactant concentration.This explains the phenomenon that the Pickering emulsions containing Di-C_(12)DAB and silica particles were stable within the contact angle range of 80°-120°.Comparatively,the contact angle of the glycerol on the silica surface in the presence of Di-C_(16)DAB first increased with surfactant concentrations and then decreased,reaching a maximum at 0.6 mmol/L.It can be concluded that Di-C_(12)DAB formed monolayers at the surface of silica particles within all investigated concentrations.On the contrary,Di-C_(16)DAB formed monolayers at concentrations below 0.6 mmol/L and formed double layers at concentrations above 0.6 mmol/L,leading to a non-monotonic change in the contact angle with respect to concentration.Using these stable non-aqueous Pickering emulsions as templates,polymer microspheres with a particle size of 2-3μm were successfully prepared with high yield.This work is helpful to expand the potential applications of non-aqueous emulsions in the encapsulation of drug,controlled release,material preparation,and cosmetic formulations.展开更多
The energy production system must be completely transformed to reach net zero emissions by 2050,and advanced battery technologies will play a pivotal role in helping downstream sectors transition to sustainable energy...The energy production system must be completely transformed to reach net zero emissions by 2050,and advanced battery technologies will play a pivotal role in helping downstream sectors transition to sustainable energy sources.Li-air batteries(LABs)provide a fascinating“beyond Li-ion”option because of their ultrahigh theoretical energy density,which far surpasses conventional lithium-ion batteries.However,LABs face significant hurdles in practical implementation,including electrolyte instability,irreversible electrodes,poor cycling performance,and low-rate capability.This review provides a detailed analysis of recent progress in LAB systems,highlighting innovative approaches such as electrolyte stabilization,electrode modification,and interfacial engineering to address these challenges.It evaluates current strategies for overcoming these problems and outlines targeted research directions aimed at resolving the remaining obstacles in LAB technology.The progress made so far indicates a way to realize practical LABs with a specific energy density potentially comparable to gasoline,which could revolutionize electric transportation.展开更多
Nanoqueous phase liquid(NAPL) simulator is a powerful and popular mathematical model for modeling the flow and transport of non-aqueous phase liquids in subsurface,but the testing of its feasibility under water table ...Nanoqueous phase liquid(NAPL) simulator is a powerful and popular mathematical model for modeling the flow and transport of non-aqueous phase liquids in subsurface,but the testing of its feasibility under water table fluctuation has received insufficient attention.The feature in a column test was tested through two cycles of water table fluctuation.The sandy medium in the column was initially saturated,and each cycle of water table fluctuation consisted of one water table falling and one rising,resulting in a drainage and an imbibition of the medium,respectively.It was found that the difference between the simulated and measured results in the first drainage of the column test was minor.However,with the propagation of the water table fluctuations,the simulation errors increased,and the simulation accuracy was not acceptable except for the first drainage in the two fluctuation cycles.The main reason was proved to be the estimation method of residual saturation used in this simulator.Also,based on the column tests,it was assumed that the resulting residual saturation from an incomplete imbibition process was a constant,with a value equal to that of the residual value resulting from the main imbibition process.The results obtained after modifying NAPL simulator with this assumption were found to be more accurate in the first cycle of water table fluctuation,but this accuracy decreased rapidly in the second one.It is concluded that NAPL simulator is not adequate in the case of LNAPL migration under water table fluctuation in sandy medium,unless a feasible assumption to estimate residual saturation is put forward.展开更多
BTEX contaminants in groundwater seriously impact the ecological environment and human health that has become one of the urgent problems needed to be solved.Due to its low density,low solubility and strong volatility,...BTEX contaminants in groundwater seriously impact the ecological environment and human health that has become one of the urgent problems needed to be solved.Due to its low density,low solubility and strong volatility,BTEX in groundwater usually form non-aqueous phase liquid(NAPL) contaminants and exist in three phases:gas,aqueous and oil phase.Air sparging(AS) is an in situ treatment technology展开更多
文摘Non-aqueous emulsions have a wide range of applications in cosmetics,drug-controlled release,and the preparation of functional nanoparticles.However,due to the weaker polarity of non-aqueous solvents,these emulsions often exhibit inferior stability compared to their aqueous counterparts.In this experiment,the properties of quaternary ammonium surfactants in glycerol were investigated through surface tension measurements,to further enhance the stability of n-decane/glycerol emulsions,hydrophilic nanoparticles SiO_(2) were modified in situ using double tailed quaternary ammonium surfactants Di-C_(12)DAB and Di-C_(16)DAB.Stable n-decane/glycerol Pickering emulsions were successfully prepared.These emulsions were stable at 45℃for over six months,and no significant changes in droplet size occurred.The minimum droplet size of the emulsion was only 2-3μm.Contact angle measurements showed that the wettability of the silica surface was tremendously affected by the concentration and the alkyl chain length of the double-tailed surfactants.In the presence of Di-C_(12)DAB,the contact angle of glycerol on the silica surface increased monotonically with the surfactant concentration.This explains the phenomenon that the Pickering emulsions containing Di-C_(12)DAB and silica particles were stable within the contact angle range of 80°-120°.Comparatively,the contact angle of the glycerol on the silica surface in the presence of Di-C_(16)DAB first increased with surfactant concentrations and then decreased,reaching a maximum at 0.6 mmol/L.It can be concluded that Di-C_(12)DAB formed monolayers at the surface of silica particles within all investigated concentrations.On the contrary,Di-C_(16)DAB formed monolayers at concentrations below 0.6 mmol/L and formed double layers at concentrations above 0.6 mmol/L,leading to a non-monotonic change in the contact angle with respect to concentration.Using these stable non-aqueous Pickering emulsions as templates,polymer microspheres with a particle size of 2-3μm were successfully prepared with high yield.This work is helpful to expand the potential applications of non-aqueous emulsions in the encapsulation of drug,controlled release,material preparation,and cosmetic formulations.
文摘The energy production system must be completely transformed to reach net zero emissions by 2050,and advanced battery technologies will play a pivotal role in helping downstream sectors transition to sustainable energy sources.Li-air batteries(LABs)provide a fascinating“beyond Li-ion”option because of their ultrahigh theoretical energy density,which far surpasses conventional lithium-ion batteries.However,LABs face significant hurdles in practical implementation,including electrolyte instability,irreversible electrodes,poor cycling performance,and low-rate capability.This review provides a detailed analysis of recent progress in LAB systems,highlighting innovative approaches such as electrolyte stabilization,electrode modification,and interfacial engineering to address these challenges.It evaluates current strategies for overcoming these problems and outlines targeted research directions aimed at resolving the remaining obstacles in LAB technology.The progress made so far indicates a way to realize practical LABs with a specific energy density potentially comparable to gasoline,which could revolutionize electric transportation.
基金Project(41072182)supported by the National Natural Science Foundation of ChinaProject(2010Z1-E101)supported by Science and Technology Program of Guangzhou City,China+1 种基金Project(20100103)supported by Science and Technology Program of Daya Bay,Huizhou City,ChinaProject(2012A030700008)supported by the Science and Technology Planning Program of Guangdong Province,China
文摘Nanoqueous phase liquid(NAPL) simulator is a powerful and popular mathematical model for modeling the flow and transport of non-aqueous phase liquids in subsurface,but the testing of its feasibility under water table fluctuation has received insufficient attention.The feature in a column test was tested through two cycles of water table fluctuation.The sandy medium in the column was initially saturated,and each cycle of water table fluctuation consisted of one water table falling and one rising,resulting in a drainage and an imbibition of the medium,respectively.It was found that the difference between the simulated and measured results in the first drainage of the column test was minor.However,with the propagation of the water table fluctuations,the simulation errors increased,and the simulation accuracy was not acceptable except for the first drainage in the two fluctuation cycles.The main reason was proved to be the estimation method of residual saturation used in this simulator.Also,based on the column tests,it was assumed that the resulting residual saturation from an incomplete imbibition process was a constant,with a value equal to that of the residual value resulting from the main imbibition process.The results obtained after modifying NAPL simulator with this assumption were found to be more accurate in the first cycle of water table fluctuation,but this accuracy decreased rapidly in the second one.It is concluded that NAPL simulator is not adequate in the case of LNAPL migration under water table fluctuation in sandy medium,unless a feasible assumption to estimate residual saturation is put forward.
文摘BTEX contaminants in groundwater seriously impact the ecological environment and human health that has become one of the urgent problems needed to be solved.Due to its low density,low solubility and strong volatility,BTEX in groundwater usually form non-aqueous phase liquid(NAPL) contaminants and exist in three phases:gas,aqueous and oil phase.Air sparging(AS) is an in situ treatment technology
