Once inevitably released into the aquatic environment,polystyrene nanoplastics(PS-NPs)will present complicated environmental behaviors,of which the aggregation is a key process determining their environmental fate and...Once inevitably released into the aquatic environment,polystyrene nanoplastics(PS-NPs)will present complicated environmental behaviors,of which the aggregation is a key process determining their environmental fate and impact.In this study,the aggregation kinetics of different sizes(30 nm and 100 nm)of PS-NPs with metal cations(Na^(+),K^(+),Ca^(2+),Mg^(2+)and Pb^(2+))at different solution pH(3,6 and 8)were investigated.The results showed that the aggregation of PS-NPs increased with cation concentration.Taking Pb^(2+)as an example,the adsorption behavior of cations onto PS-NPs was determined by transmission electron microscopy(TEM)and energy dispersive X-ray(EDX)spectroscopy,which demonstrated Pb^(2+)could be adhered onto the surface of PS-NPs with the effect of charge neutralization.The critical coagulation concentrations(CCC)of smaller PS-NPs were higher than that of larger PS-NPs for monovalent cations,whereas a different pattern is observed for divalent cations.It was suggested that there were other factors that DLVO theory does not consider affect the stability of NPs with different particle sizes.In addition,it should be noted that PS-NPs had the capacity of adsorbing large amounts of heavy metal cations and carried them transport to a long distance,and the corresponding ecological risks need to further elucidate.展开更多
The aggregation and fractal structure of mixed metal hydroxides ( MMH ) agglomerates with increasing ionic strength have been studied by dynamic light scattering ( DLS ) and SEM techniques. The experiments indicate th...The aggregation and fractal structure of mixed metal hydroxides ( MMH ) agglomerates with increasing ionic strength have been studied by dynamic light scattering ( DLS ) and SEM techniques. The experiments indicate that the MMH agglomerates have two different structures in RLA regime and DLA regime, and also give the proof that the transition region between RLA and DLA may occur.展开更多
The aggregation kinetics of basic yttrium carbonate pericles in aqueous solution havebeen studied using dynamic light-scattering techniques. In 1.00mol/l NaCl solution fast diffusionlimited aggregation behavior was ob...The aggregation kinetics of basic yttrium carbonate pericles in aqueous solution havebeen studied using dynamic light-scattering techniques. In 1.00mol/l NaCl solution fast diffusionlimited aggregation behavior was observed with an increase in aggregate size over time describedby a power law. The aggregates are characterized by a fractal dimension D=1.82. Smoluchowskiand fractal theories were used to characterize the aggregation mechanism and to obtain theaggregation rate constant.展开更多
Slot-die coating with halogen-free solvents is a promising scalable fabrication strategy for organic solar cells(OSCs).However,the complex interplay between long-time-scale solute diffusion and microstructural evoluti...Slot-die coating with halogen-free solvents is a promising scalable fabrication strategy for organic solar cells(OSCs).However,the complex interplay between long-time-scale solute diffusion and microstructural evolution during the coating process remains poorly understood,limiting further optimization of morphology and device performance.In this study,we elucidate the critical role of solution viscosity in regulating phase separation and aggregation kinetics.Specifically,lower solution viscosity enhances solute diffusion,accelerating molecular aggregation while suppressing liquid-liquid phase separation(LLPS).Notably,we observe that in three different systems with varying crystallinity and immiscibility(PM6:Y6,PTQ10:Y6,and D18:Y6),the optimal processing conditions for peak device efficiency consistently correspond to a nearly identical solution viscosity(∼0.8 mPa s),despite variations in optimal processing temperatures.In situ characterizations reveal that at this viscosity,all three systems exhibit constrained LLPS and rapid molecular aggregation,promoting the formation of finely structured,continuous nanoscale domains.These findings establish solution viscosity as a universal governing parameter for morphology control in printed active layers.By providing a fundamental framework for understanding viscosity-mediated phase separation,this work offers valuable insights for advancing high-throughput,environmentally friendly printing techniques for high-efficiency OSCs.展开更多
Extracellular polymeric substances(EPS)in activated sludge from wastewater treatment plants(WWTPs)could affect interactions between nanoparticles and alter their migration behavior.The influence mechanisms of silver n...Extracellular polymeric substances(EPS)in activated sludge from wastewater treatment plants(WWTPs)could affect interactions between nanoparticles and alter their migration behavior.The influence mechanisms of silver nanoparticles(Ag NPs)and silver sulfide nanoparticles(Ag_(2)S NPs)aggregated by active EPS sludge were studied in monovalent or divalent cation solutions.The aggregation behaviors of the NPs without EPS followed the Derjaguin-Landau-Verwey-Overbeek(DLVO)theory.The counterions aggravated the aggregation of both NPs,and the divalent cation had a strong neutralizing effect due to the decrease in electrostatic repulsive force.Through extended DLVO(EDLVO)model analysis,in NaNO3 and low-concentration Ca(NO_(3))_(2)(<10 mmol/L)solutions,EPS could alleviate the aggregation behaviors of Cit-Ag NPs and Ag_(2)S NPs due to the enhancement of steric repulsive forces.At high concentrations of Ca(NO_(3))_(2)(10‒100 mmol/L),exopolysaccharide macromolecules could promote the aggregation of Cit-Ag NPs and Ag_(2)S NPs by interparticle bridging.As the final transformation form of Ag NPs in water environments,Ag_(2)S NPs had better stability,possibly due to their small van der Waals forces and their strong steric repulsive forces.It is essential to elucidate the surface mechanisms between EPS and NPs to understand the different fates of metal-based and metal-sulfide NPs in WWTP systems.展开更多
The structure of aggregation state and isothermal crystallization behavior of Nylon-1010 have been studied by WAXD, DSE, Variance-Range Function and density measurement. The results show that crystallization of Nylon-...The structure of aggregation state and isothermal crystallization behavior of Nylon-1010 have been studied by WAXD, DSE, Variance-Range Function and density measurement. The results show that crystallization of Nylon-1010 has the most suitable annealing temperature, the crystals of the Nxlon-1010 are two-dimension heterogeneous nucleation. Both low treatment temperature and high crystallization te, temperature are disadvantageous for Nylon-1010 crystal growth.展开更多
Blood cell aggregation and adhesion to endothelial cells under shear flow are crucial to many biological processes such as thrombi formation, inflammatory cascade, and tumor metastasis, in which these cellular interac...Blood cell aggregation and adhesion to endothelial cells under shear flow are crucial to many biological processes such as thrombi formation, inflammatory cascade, and tumor metastasis, in which these cellular interactions are mainly mediated by the underlying receptor-ligand bindings. While theoretical modeling of aggregation dynamics and adhesion kinetics of interacting cells have been well studied separately, how to couple these two processes remains unclear. Here we develop a combined model that couples cellular aggregation dynamics and adhesion kinetics under shear flow. The impacts of shear rate （or shear stress） and molecular binding affinity were elucidated. This study provides a unified model where the action of a fluid flow drives cell aggregation and adhesion under the modulations of the mechanical shear flow and receptor-ligand interaction kinetics. It offers an insight into understanding the relevant biological processes and functions.展开更多
We propose a kinetic aggregation model where species A aggregates evolve by the catalysis-coagulation and the catalysis-fragmentation, while the catalyst aggregates of the same species B or C perform self-coagulation ...We propose a kinetic aggregation model where species A aggregates evolve by the catalysis-coagulation and the catalysis-fragmentation, while the catalyst aggregates of the same species B or C perform self-coagulation processes. By means of the generalized Smoluchowski rate equation based on the mean-field assumption, we study the kinetic behaviours of the system with the catalysis-coagulation rate kernel K（i,j;l） l^v and the catalysis-fragmentation rate kernel F（i,j; l） l^μ, where l is the size of the catalyst aggregate, and v and μ are two parameters reflecting the dependence of the catalysis reaction on the size of the catalyst aggregate. The relation between the values of parameters v and μ reflects the competing roles between the two catalysis processes in the kinetic evolution of species A. It is found that the competing roles of the catalysis-coagulation and catalysis-fragmentation in the kinetic aggregation behaviours are not determined simply by the relation between the two parameters v and μ, but also depend on the values of these two parameters. When v 〉 μ and v ≥0, the kinetic evolution of species A is dominated by the catalysis-coagulation and its aggregate size distribution αk（t） obeys the conventional or generalized scaling law; when v 〈 μ and v ≥ 0 or v 〈 0 but μ≥ 0, the catalysis-fragmentation process may play a dominating role and ak（t） approaches the scale-free form; and in other cases, a balance is established between the two competing processes at large times and ακ（t） obeys a modified scaling law.展开更多
Dispersion and aggregation of nanoparticles in aqueous solutions are important factors for safe application of nanoparticles. In this study, dispersion and aggregation of nano-TiO2 in aqueous solutions containing vari...Dispersion and aggregation of nanoparticles in aqueous solutions are important factors for safe application of nanoparticles. In this study, dispersion and aggregation of nano-TiO2 in aqueous solutions containing various anions were investigated. The influences of anion concentration and valence on the aggregation size, zeta potential and aggregation kinetics were individually investigated. Results showed that the zeta potential decreased from 19.8 to-41.4 mV when PO4^（3-） concentration was increased from 0 to 50 mg/L, while the corresponding average size of nano-TiO2 particles decreased from 613.2 to 540.3 nm. Both SO4^（2-） and NO3^-enhanced aggregation of nano-TiO2in solution. As SO4^（2-） concentration was increased from 0 to 500 mg/L, the zeta potential decreased from 19.8 to 1.4 mV, and aggregate sizes increased from 613.2 to 961.3 nm.The trend for NO3^- fluctuation was similar to that for SO4^（2-） although the range of variation for NO3^- was relatively narrow. SO4^（2-） and NO3^-accelerated the aggregation rapidly, while PO4^（3-） did so slowly. These findings facilitate the understanding of aggregation and dispersion mechanisms of nano-TiO2 in aqueous solutions in the presence of anions of interest.展开更多
The aggregation of common manganese diox- ide （MnO2） colloids has great impact on their surface reactivity and therefore on their fates as well as associated natural and synthetic contaminants in engineered （e.g. w...The aggregation of common manganese diox- ide （MnO2） colloids has great impact on their surface reactivity and therefore on their fates as well as associated natural and synthetic contaminants in engineered （e.g. water treatment） and natural aquatic environments. Nevertheless, little is known about the aggregation kinetics of MnO2 colloids and the effect of humic acid （HA） and surfactants on these. In this study, the early stage aggregation kinetics of MnO2 nanoparticles in NaNO3 and Ca（NO3）2 solutions in the presence of HA and surfactants （i.e., sodium dodecyl sulfate （SDS）, and polyvinylpyrrolidone （PVP）） were modeled through time-resolved dynamic light scattering. In the presence of HA, MnO2 colloids were significantly stabilized with a critical coagulation concentration （CCC） of-300mmol · L-1 NaNO3 and 4 mmol.L-1 Ca（NO3）2. Electrophoretic mobility （EPM） measurements confirmed that steric hindrance may be primarily responsible for increasing colloidal stability in the presence of HA. Moreover, the molecular and/or chemical properties of HA might impact its stabilizing efficiency. In the case of PVP, only a slight increase of aggregation kinetics was observed, due to steric reactions originating from adsorbed layers of PVP on the MnO2 surface. Consequently, higher CCC values were obtained in the presence of PVP. However, there was a negligible reduction in MnO2 colloidal stability in the presence of 20 mg·L-1SDS.展开更多
Low molecular weight organic acids(LMWOAs),as active components in the rhizosphere carbon cycling,may influence the environmental behaviors of biochar colloids.This study selected the pine-wood and wheat-straw biochar...Low molecular weight organic acids(LMWOAs),as active components in the rhizosphere carbon cycling,may influence the environmental behaviors of biochar colloids.This study selected the pine-wood and wheat-straw biochars(PB and WB)as two typical biochars.The effects of typical LMWOAs(oxalic acid,citric acid,and malic acid)on aggregation kinetics of PB and WB colloids were investigated under pH 4 and 6 conditions.Critical coagulation concentrations(CCCs)of both PB and WB colloids were decreased with the LMWOAs regardless of the types of biochar and the solution pH,and the most significant effect occurred in pH 4 due to more LMWOAs sorption on the biochar colloids.The different types of LMWOAs caused various CCCs changes.For example,the CCC values of PB colloids decreased from 75 mM to 56,52,and 47 mM in the pH 4 NaCl solutions when 1 mM oxalic acid,citric acid,and malic acid were present in the suspensions,respectively.The chemical structure(functional groups)and molecular weight of LMWOAs,solution pH,and the electrophoretic mobility(EPM)of biochar co-influence the interactions between biochar colloids and LMWOAs,thus affecting the stability of biochar colloids in the presence of LMWOAs.The presence of LMWOAs accelerated the aggregation of colloidal biochar by increasing the interaction of surface bridging bonds(hydrogen bonding)and decreasing the repulsive force between colloidal biochar particles.This study showed that LMWOAs could accelerate the aggregation of biochar colloids in acidic or neutral environments and reduce the mobility of biochar colloids in soil rhizosphere.展开更多
Chirality and luminescence are important for both chemistry and biology,which are highly influenced by aggregation.In this work,a pair of metalated tetraphenylethylene(TPE)-based organic cage enantiomers are reported,w...Chirality and luminescence are important for both chemistry and biology,which are highly influenced by aggregation.In this work,a pair of metalated tetraphenylethylene(TPE)-based organic cage enantiomers are reported,which fea-ture a quadrangular prismatic cage structure.These homochiral cages exhibit concentration-dependent chiral behaviors alongside a propensity for thermodynamic aggregation.Aggregation caused quench effect is found for these cages accom-panying the increasing of the concentrations.When a poor solvent is added to produce a kinetical aggregation,the aggregation-annihilation circular dichroism and aggregation-induced emission behaviors are observed for these enantiomeric cages.By comparing these observations with the photophysical behaviors of a pair of structurally similar organic molecular enantiomers,the unique photophysical proper-ties observed are intricately linked to the metal-integrated TPE-functionalized cage structures.展开更多
基金supported by Scientific Research Project of Guangzhou University(No.YK2020017)the Program Foundation of Institute for Scientific Research of Karst Area of NSFC-GZGOV(No.U1612442)+2 种基金Research Grants Council of the Hong Kong Special Administrative Region,China(No.UGC/IDS(R)16/19)IndustryUniversity Cooperation and Collaborative Education Project of the Ministry of Education of the People's Republic of China(No.202101134012)Innovative training program for College Students of Guangzhou University(No.S202111078039).
文摘Once inevitably released into the aquatic environment,polystyrene nanoplastics(PS-NPs)will present complicated environmental behaviors,of which the aggregation is a key process determining their environmental fate and impact.In this study,the aggregation kinetics of different sizes(30 nm and 100 nm)of PS-NPs with metal cations(Na^(+),K^(+),Ca^(2+),Mg^(2+)and Pb^(2+))at different solution pH(3,6 and 8)were investigated.The results showed that the aggregation of PS-NPs increased with cation concentration.Taking Pb^(2+)as an example,the adsorption behavior of cations onto PS-NPs was determined by transmission electron microscopy(TEM)and energy dispersive X-ray(EDX)spectroscopy,which demonstrated Pb^(2+)could be adhered onto the surface of PS-NPs with the effect of charge neutralization.The critical coagulation concentrations(CCC)of smaller PS-NPs were higher than that of larger PS-NPs for monovalent cations,whereas a different pattern is observed for divalent cations.It was suggested that there were other factors that DLVO theory does not consider affect the stability of NPs with different particle sizes.In addition,it should be noted that PS-NPs had the capacity of adsorbing large amounts of heavy metal cations and carried them transport to a long distance,and the corresponding ecological risks need to further elucidate.
基金supported by the National Natural Science Foundation of China(No.20273041)the Ministry of the Education.
文摘The aggregation and fractal structure of mixed metal hydroxides ( MMH ) agglomerates with increasing ionic strength have been studied by dynamic light scattering ( DLS ) and SEM techniques. The experiments indicate that the MMH agglomerates have two different structures in RLA regime and DLA regime, and also give the proof that the transition region between RLA and DLA may occur.
文摘The aggregation kinetics of basic yttrium carbonate pericles in aqueous solution havebeen studied using dynamic light-scattering techniques. In 1.00mol/l NaCl solution fast diffusionlimited aggregation behavior was observed with an increase in aggregate size over time describedby a power law. The aggregates are characterized by a fractal dimension D=1.82. Smoluchowskiand fractal theories were used to characterize the aggregation mechanism and to obtain theaggregation rate constant.
基金the National Natural Science Foundation of China(W2411049,52303247,and 52173023)the Fundamental Research Funds for the Central Universities(xzy012023169)+2 种基金the Postdoctoral Research Project of Shaanxi Province(2023BSHEDZZ24)the 111 Project 2.0(BP0618008)the China Postdoctoral Science Foundation(2023TQ0273)。
文摘Slot-die coating with halogen-free solvents is a promising scalable fabrication strategy for organic solar cells(OSCs).However,the complex interplay between long-time-scale solute diffusion and microstructural evolution during the coating process remains poorly understood,limiting further optimization of morphology and device performance.In this study,we elucidate the critical role of solution viscosity in regulating phase separation and aggregation kinetics.Specifically,lower solution viscosity enhances solute diffusion,accelerating molecular aggregation while suppressing liquid-liquid phase separation(LLPS).Notably,we observe that in three different systems with varying crystallinity and immiscibility(PM6:Y6,PTQ10:Y6,and D18:Y6),the optimal processing conditions for peak device efficiency consistently correspond to a nearly identical solution viscosity(∼0.8 mPa s),despite variations in optimal processing temperatures.In situ characterizations reveal that at this viscosity,all three systems exhibit constrained LLPS and rapid molecular aggregation,promoting the formation of finely structured,continuous nanoscale domains.These findings establish solution viscosity as a universal governing parameter for morphology control in printed active layers.By providing a fundamental framework for understanding viscosity-mediated phase separation,this work offers valuable insights for advancing high-throughput,environmentally friendly printing techniques for high-efficiency OSCs.
基金We sincerely thank the National Natural Science Foundation of China(No.51878092 and No.52070029)for their support.
文摘Extracellular polymeric substances(EPS)in activated sludge from wastewater treatment plants(WWTPs)could affect interactions between nanoparticles and alter their migration behavior.The influence mechanisms of silver nanoparticles(Ag NPs)and silver sulfide nanoparticles(Ag_(2)S NPs)aggregated by active EPS sludge were studied in monovalent or divalent cation solutions.The aggregation behaviors of the NPs without EPS followed the Derjaguin-Landau-Verwey-Overbeek(DLVO)theory.The counterions aggravated the aggregation of both NPs,and the divalent cation had a strong neutralizing effect due to the decrease in electrostatic repulsive force.Through extended DLVO(EDLVO)model analysis,in NaNO3 and low-concentration Ca(NO_(3))_(2)(<10 mmol/L)solutions,EPS could alleviate the aggregation behaviors of Cit-Ag NPs and Ag_(2)S NPs due to the enhancement of steric repulsive forces.At high concentrations of Ca(NO_(3))_(2)(10‒100 mmol/L),exopolysaccharide macromolecules could promote the aggregation of Cit-Ag NPs and Ag_(2)S NPs by interparticle bridging.As the final transformation form of Ag NPs in water environments,Ag_(2)S NPs had better stability,possibly due to their small van der Waals forces and their strong steric repulsive forces.It is essential to elucidate the surface mechanisms between EPS and NPs to understand the different fates of metal-based and metal-sulfide NPs in WWTP systems.
文摘The structure of aggregation state and isothermal crystallization behavior of Nylon-1010 have been studied by WAXD, DSE, Variance-Range Function and density measurement. The results show that crystallization of Nylon-1010 has the most suitable annealing temperature, the crystals of the Nxlon-1010 are two-dimension heterogeneous nucleation. Both low treatment temperature and high crystallization te, temperature are disadvantageous for Nylon-1010 crystal growth.
基金supported by National Natural Science Foundation of China (grants 31230027, 31110103918 and 11172207)National Key Basic Research Foundation of China (grant 2011CB710904)Strategic Priority Research Program (grants XDA01030102 and XDA04020219)
文摘Blood cell aggregation and adhesion to endothelial cells under shear flow are crucial to many biological processes such as thrombi formation, inflammatory cascade, and tumor metastasis, in which these cellular interactions are mainly mediated by the underlying receptor-ligand bindings. While theoretical modeling of aggregation dynamics and adhesion kinetics of interacting cells have been well studied separately, how to couple these two processes remains unclear. Here we develop a combined model that couples cellular aggregation dynamics and adhesion kinetics under shear flow. The impacts of shear rate （or shear stress） and molecular binding affinity were elucidated. This study provides a unified model where the action of a fluid flow drives cell aggregation and adhesion under the modulations of the mechanical shear flow and receptor-ligand interaction kinetics. It offers an insight into understanding the relevant biological processes and functions.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 10875086 and 10775104)
文摘We propose a kinetic aggregation model where species A aggregates evolve by the catalysis-coagulation and the catalysis-fragmentation, while the catalyst aggregates of the same species B or C perform self-coagulation processes. By means of the generalized Smoluchowski rate equation based on the mean-field assumption, we study the kinetic behaviours of the system with the catalysis-coagulation rate kernel K（i,j;l） l^v and the catalysis-fragmentation rate kernel F（i,j; l） l^μ, where l is the size of the catalyst aggregate, and v and μ are two parameters reflecting the dependence of the catalysis reaction on the size of the catalyst aggregate. The relation between the values of parameters v and μ reflects the competing roles between the two catalysis processes in the kinetic evolution of species A. It is found that the competing roles of the catalysis-coagulation and catalysis-fragmentation in the kinetic aggregation behaviours are not determined simply by the relation between the two parameters v and μ, but also depend on the values of these two parameters. When v 〉 μ and v ≥0, the kinetic evolution of species A is dominated by the catalysis-coagulation and its aggregate size distribution αk（t） obeys the conventional or generalized scaling law; when v 〈 μ and v ≥ 0 or v 〈 0 but μ≥ 0, the catalysis-fragmentation process may play a dominating role and ak（t） approaches the scale-free form; and in other cases, a balance is established between the two competing processes at large times and ακ（t） obeys a modified scaling law.
基金supported by the International S&T Cooperation Program of China(No.2015DFG92750)the National Natural Science Foundation of China(No.51478172)the Department of Science and Technology of Hunan Province(No.2014GK1012)
文摘Dispersion and aggregation of nanoparticles in aqueous solutions are important factors for safe application of nanoparticles. In this study, dispersion and aggregation of nano-TiO2 in aqueous solutions containing various anions were investigated. The influences of anion concentration and valence on the aggregation size, zeta potential and aggregation kinetics were individually investigated. Results showed that the zeta potential decreased from 19.8 to-41.4 mV when PO4^（3-） concentration was increased from 0 to 50 mg/L, while the corresponding average size of nano-TiO2 particles decreased from 613.2 to 540.3 nm. Both SO4^（2-） and NO3^-enhanced aggregation of nano-TiO2in solution. As SO4^（2-） concentration was increased from 0 to 500 mg/L, the zeta potential decreased from 19.8 to 1.4 mV, and aggregate sizes increased from 613.2 to 961.3 nm.The trend for NO3^- fluctuation was similar to that for SO4^（2-） although the range of variation for NO3^- was relatively narrow. SO4^（2-） and NO3^-accelerated the aggregation rapidly, while PO4^（3-） did so slowly. These findings facilitate the understanding of aggregation and dispersion mechanisms of nano-TiO2 in aqueous solutions in the presence of anions of interest.
文摘The aggregation of common manganese diox- ide （MnO2） colloids has great impact on their surface reactivity and therefore on their fates as well as associated natural and synthetic contaminants in engineered （e.g. water treatment） and natural aquatic environments. Nevertheless, little is known about the aggregation kinetics of MnO2 colloids and the effect of humic acid （HA） and surfactants on these. In this study, the early stage aggregation kinetics of MnO2 nanoparticles in NaNO3 and Ca（NO3）2 solutions in the presence of HA and surfactants （i.e., sodium dodecyl sulfate （SDS）, and polyvinylpyrrolidone （PVP）） were modeled through time-resolved dynamic light scattering. In the presence of HA, MnO2 colloids were significantly stabilized with a critical coagulation concentration （CCC） of-300mmol · L-1 NaNO3 and 4 mmol.L-1 Ca（NO3）2. Electrophoretic mobility （EPM） measurements confirmed that steric hindrance may be primarily responsible for increasing colloidal stability in the presence of HA. Moreover, the molecular and/or chemical properties of HA might impact its stabilizing efficiency. In the case of PVP, only a slight increase of aggregation kinetics was observed, due to steric reactions originating from adsorbed layers of PVP on the MnO2 surface. Consequently, higher CCC values were obtained in the presence of PVP. However, there was a negligible reduction in MnO2 colloidal stability in the presence of 20 mg·L-1SDS.
基金International Science&Technology Innovation Program of Chinese Academy of Agricultural Sciences(Grant No.CAAS-ZDRW202110)the National Natural Science Foundation of China(Grant No.41771255).
文摘Low molecular weight organic acids(LMWOAs),as active components in the rhizosphere carbon cycling,may influence the environmental behaviors of biochar colloids.This study selected the pine-wood and wheat-straw biochars(PB and WB)as two typical biochars.The effects of typical LMWOAs(oxalic acid,citric acid,and malic acid)on aggregation kinetics of PB and WB colloids were investigated under pH 4 and 6 conditions.Critical coagulation concentrations(CCCs)of both PB and WB colloids were decreased with the LMWOAs regardless of the types of biochar and the solution pH,and the most significant effect occurred in pH 4 due to more LMWOAs sorption on the biochar colloids.The different types of LMWOAs caused various CCCs changes.For example,the CCC values of PB colloids decreased from 75 mM to 56,52,and 47 mM in the pH 4 NaCl solutions when 1 mM oxalic acid,citric acid,and malic acid were present in the suspensions,respectively.The chemical structure(functional groups)and molecular weight of LMWOAs,solution pH,and the electrophoretic mobility(EPM)of biochar co-influence the interactions between biochar colloids and LMWOAs,thus affecting the stability of biochar colloids in the presence of LMWOAs.The presence of LMWOAs accelerated the aggregation of colloidal biochar by increasing the interaction of surface bridging bonds(hydrogen bonding)and decreasing the repulsive force between colloidal biochar particles.This study showed that LMWOAs could accelerate the aggregation of biochar colloids in acidic or neutral environments and reduce the mobility of biochar colloids in soil rhizosphere.
基金National Natural Science Foundation of China,Grant/Award Numbers:22375075,22171106,21731002,21975104,22301103,22201101Guangdong Major Project of Basic and Applied Research,Grant/Award Number:2019B030302009+4 种基金Natural Science Foundation of Guangdong Province,Grant/Award Number:2022A1515011937Fundamental Research Funds for the Central Universities,Grant/Award Number:21622103China Postdoctoral Science Foundation,Grant/Award Numbers:2022M711327,2023T160269Guangdong Provincial Key Laboratory of Speed Capability Research,Grant/Award Number:2023B1212010009Jinan University。
文摘Chirality and luminescence are important for both chemistry and biology,which are highly influenced by aggregation.In this work,a pair of metalated tetraphenylethylene(TPE)-based organic cage enantiomers are reported,which fea-ture a quadrangular prismatic cage structure.These homochiral cages exhibit concentration-dependent chiral behaviors alongside a propensity for thermodynamic aggregation.Aggregation caused quench effect is found for these cages accom-panying the increasing of the concentrations.When a poor solvent is added to produce a kinetical aggregation,the aggregation-annihilation circular dichroism and aggregation-induced emission behaviors are observed for these enantiomeric cages.By comparing these observations with the photophysical behaviors of a pair of structurally similar organic molecular enantiomers,the unique photophysical proper-ties observed are intricately linked to the metal-integrated TPE-functionalized cage structures.
