Solubility enhancement has been a priority to overcome poor solubility with optoelectronic molecules for solution-processable devices. This study aims to obtain experimental data on the effect of particle sizes on the...Solubility enhancement has been a priority to overcome poor solubility with optoelectronic molecules for solution-processable devices. This study aims to obtain experimental data on the effect of particle sizes on the solubility properties of several typical optoelectronic molecules in organic solvents, including the solubility results of 1,3-bis(9-carbazolyl)benzene(m CP), 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)ben zene(TPBi) and 2-(4-tert-butylphenyl)-5-(4-biphenyl)-1,3,4-oxadiazole(PBD) in ethanol and acetonitrile,respectively. Nanoparticles of m CP, TPBi and PBD with sizes from dozens to several hundred nanometers were prepared by solvent antisolvent precipitation method and their solubility were determined by using isothermal saturation method. The saturation solubility of nanoparticles of three kinds of optoelectronic molecules exhibited increase of 12.9%-25.7% in comparison to the same raw materials in the form of microparticles. The experimental evidence indicates that nanonization technology is a feasible way to make optoelectronic molecules dissolve in liquids with enhanced solubility.展开更多
The aim of this study was to produce niflumic acid nanoparticles without using an organic solvent, in order to achieve an increased rate of dissolution of the final products. Co-grinding with excipients was used to de...The aim of this study was to produce niflumic acid nanoparticles without using an organic solvent, in order to achieve an increased rate of dissolution of the final products. Co-grinding with excipients was used to decrease the particle size. Poloxamer 188 (P) and mannitol (M) applied as co-grinding materials stabilized the system, preventing aggregation of the nanocrystals. The morphology and particle size distribution of the products were visualized by using scanning electron microscopy and laser diffraction. The crystalline states of the samples were investigated by differential scanning calorimetry and X-ray powder diffraction. The rate of dissolution of niflumic acid was measured with a paddle method from simulated media. It was concluded that the particles produced were in the nanometer range (the mean particle size was ~250 nm) and the nanoparticles maintained their crystallinity during the process. The rate of dissolution of the coground sample was significantly improved.展开更多
The paper explores the degree of pollution of organochlorine pesticides in fish and water in the dam at Kpassa on a tributary of Okpara River that is pumped by Benin National Water agency (SONEB) in supplying drinking...The paper explores the degree of pollution of organochlorine pesticides in fish and water in the dam at Kpassa on a tributary of Okpara River that is pumped by Benin National Water agency (SONEB) in supplying drinking water to supply the city of Parakou. Doing so, fourteen parameters of organochlorine are analyzed. Most of obtain organoclorine concentration in water and fish below is indicated critical values. However, DDT and endrine concentration in water is slightly above legal tolerable values. Hexachlorobenen and dieldrine concentrations are three times higher than legal limit value while aldrine is ten times higher. However, heptachlore is double concentrated in fishery while aldrine (endrine, dieldrine aldrine, lindane, hexachloro-benzene, DDT) is found in the dam fish and surface water three times concentrated than tolerated value. These levels of concentrations result from the intensification of organoclorine pesticide used in agriculture especially in cotton production. These are caused by the chemical application accumulated in soil and through the food value chain system. Therefore, it is very important to extract sediment from the reservoir by dredging in oder to renew the ecosystem of the dam. To persistently manage the basin water resources, it is imperatively important to observe a significant behaviour changed from all stakeholders.展开更多
Single crystallization is an important strategy to resolve intergranular cracks and unnecessary side reactions with electrolytes in layered transition metal oxide cathodes LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NMC811).Due t...Single crystallization is an important strategy to resolve intergranular cracks and unnecessary side reactions with electrolytes in layered transition metal oxide cathodes LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NMC811).Due to the limitations of high-temperature sintering and multi-step calcination,single crystal NMC811 generally shows irregular particles with a size of 2-3μm.However,the prolonged Li-ion diffusion pathway and the stress generated by the uneven de-/intercalation sluggish Li-ion diffusion kinetics,what is more,cause structural damage such as intragranular cracks.A slow Li extraction rate or particle size reduction will ameliorate the structural damage and improve the cycling stability.As the most promising cathodes for next-generation power batteries,NMC811 required fast charge performance and cycle stability.Particle size reduction appears to be the displacement option.Nanonization is an effective strategy to mitigate intragranular cracks of single crystal NMC811.However,the serious aggregation and increased specific surface area become new challenges.In this article,we synthesized monodisperse nanoscale single crystal NMC811 by molten salt method and modified the surface by LiNbO3 coating.The electrochemical performance shows that nanoscale single crystal NMC811 has faster kinetic and higher capacity retention,so the strategy of combining nanonization and surface coating is an alternative way to prepare high specific capacity and cycle stable single crystal NMC811.展开更多
基金financial support from National Natural Science Foundation of China (22288102)the Fundamental Research Funds for the Central Universities of China (buctrc202016)。
文摘Solubility enhancement has been a priority to overcome poor solubility with optoelectronic molecules for solution-processable devices. This study aims to obtain experimental data on the effect of particle sizes on the solubility properties of several typical optoelectronic molecules in organic solvents, including the solubility results of 1,3-bis(9-carbazolyl)benzene(m CP), 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)ben zene(TPBi) and 2-(4-tert-butylphenyl)-5-(4-biphenyl)-1,3,4-oxadiazole(PBD) in ethanol and acetonitrile,respectively. Nanoparticles of m CP, TPBi and PBD with sizes from dozens to several hundred nanometers were prepared by solvent antisolvent precipitation method and their solubility were determined by using isothermal saturation method. The saturation solubility of nanoparticles of three kinds of optoelectronic molecules exhibited increase of 12.9%-25.7% in comparison to the same raw materials in the form of microparticles. The experimental evidence indicates that nanonization technology is a feasible way to make optoelectronic molecules dissolve in liquids with enhanced solubility.
文摘The aim of this study was to produce niflumic acid nanoparticles without using an organic solvent, in order to achieve an increased rate of dissolution of the final products. Co-grinding with excipients was used to decrease the particle size. Poloxamer 188 (P) and mannitol (M) applied as co-grinding materials stabilized the system, preventing aggregation of the nanocrystals. The morphology and particle size distribution of the products were visualized by using scanning electron microscopy and laser diffraction. The crystalline states of the samples were investigated by differential scanning calorimetry and X-ray powder diffraction. The rate of dissolution of niflumic acid was measured with a paddle method from simulated media. It was concluded that the particles produced were in the nanometer range (the mean particle size was ~250 nm) and the nanoparticles maintained their crystallinity during the process. The rate of dissolution of the coground sample was significantly improved.
文摘The paper explores the degree of pollution of organochlorine pesticides in fish and water in the dam at Kpassa on a tributary of Okpara River that is pumped by Benin National Water agency (SONEB) in supplying drinking water to supply the city of Parakou. Doing so, fourteen parameters of organochlorine are analyzed. Most of obtain organoclorine concentration in water and fish below is indicated critical values. However, DDT and endrine concentration in water is slightly above legal tolerable values. Hexachlorobenen and dieldrine concentrations are three times higher than legal limit value while aldrine is ten times higher. However, heptachlore is double concentrated in fishery while aldrine (endrine, dieldrine aldrine, lindane, hexachloro-benzene, DDT) is found in the dam fish and surface water three times concentrated than tolerated value. These levels of concentrations result from the intensification of organoclorine pesticide used in agriculture especially in cotton production. These are caused by the chemical application accumulated in soil and through the food value chain system. Therefore, it is very important to extract sediment from the reservoir by dredging in oder to renew the ecosystem of the dam. To persistently manage the basin water resources, it is imperatively important to observe a significant behaviour changed from all stakeholders.
基金financially supported by the National Natural Science Foundation of China(Nos.52022088,51971245,51772262,U20A20336,21935009)Natural Science Foundation of Hebei Province(Nos.F2021203097,B2020203037)China Postdoctoral Science Foundation(No.2021M702756)。
文摘Single crystallization is an important strategy to resolve intergranular cracks and unnecessary side reactions with electrolytes in layered transition metal oxide cathodes LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NMC811).Due to the limitations of high-temperature sintering and multi-step calcination,single crystal NMC811 generally shows irregular particles with a size of 2-3μm.However,the prolonged Li-ion diffusion pathway and the stress generated by the uneven de-/intercalation sluggish Li-ion diffusion kinetics,what is more,cause structural damage such as intragranular cracks.A slow Li extraction rate or particle size reduction will ameliorate the structural damage and improve the cycling stability.As the most promising cathodes for next-generation power batteries,NMC811 required fast charge performance and cycle stability.Particle size reduction appears to be the displacement option.Nanonization is an effective strategy to mitigate intragranular cracks of single crystal NMC811.However,the serious aggregation and increased specific surface area become new challenges.In this article,we synthesized monodisperse nanoscale single crystal NMC811 by molten salt method and modified the surface by LiNbO3 coating.The electrochemical performance shows that nanoscale single crystal NMC811 has faster kinetic and higher capacity retention,so the strategy of combining nanonization and surface coating is an alternative way to prepare high specific capacity and cycle stable single crystal NMC811.