To understand and control the interfacial properties of polydiacetylenes(PDAs)vesicles withπ-conjugated backbone is very important for their colorimetric sensing of chemical and biological targets.In this work,we ado...To understand and control the interfacial properties of polydiacetylenes(PDAs)vesicles withπ-conjugated backbone is very important for their colorimetric sensing of chemical and biological targets.In this work,we adopted 10,12-pentacosadiynoic acid(PCDA)as the model molecule to prepare PDAs vesicles in aqueous solution with different forms(from monomer to blue-to-purple-to-red phase)by controlling the UV irradiation dose.The variations of the interfacial conformation of PDAs vesicles during chromatic transitions were inspected by the adsorption behaviors of probe molecules(4-(4-diethylaminostyry)-1-methylpyridinium iodide,D289)on vesicle surface with surface-specific second harmonic generation(SHG)and zeta potential measurements.Resonant SHG signal from D289 adsorbed on vesicle surface attenuated sharply,and the adsorption free energy as well as the corresponding two-photon fluorescence signal decreased slightly in chromatic transitions.While,the change in the surface density of the adsorbed D289 molecules for PDAs vesicles with different forms was relatively small as estimated from zeta potential measurements.The attenuation of the SHG intensity was thus attributed to the overall order-disorder transition and the changed orientation of D289 molecules caused by the gradual distortion of carboxyl head group driven by backbone perturbation.展开更多
Two non-ionic hydro-fluorocarbon hybrid surfactants with and without hydroxyl groups were synthesized and compared.They exhibited good thermal stability and superior surface activity.It was observed that the hydroxyl ...Two non-ionic hydro-fluorocarbon hybrid surfactants with and without hydroxyl groups were synthesized and compared.They exhibited good thermal stability and superior surface activity.It was observed that the hydroxyl group had a profound effect on modifying the surface tension of their solutions and the morphology of the formed micelles.This effect may be attributed to the rearranging of the alkane group from above the air/aqueous surface to below it and the disrupting of the interfacial water structure induced by the hydroxyl groups.This work provides a strategy to weaken the immiscibility between hydrocarbon and fluorocarbon chains by modifying their orientational structure at the interface,thus it is helpful for the design of surfactants with varied interfacial properties.展开更多
Li-rich manganese-based oxide has been identified as the most promising cathode material for next-generation Li-ion batteries,due to its high capacity,high operating voltage,safety,and low cost.Nevertheless,its wide a...Li-rich manganese-based oxide has been identified as the most promising cathode material for next-generation Li-ion batteries,due to its high capacity,high operating voltage,safety,and low cost.Nevertheless,its wide application is restricted by low initial Columbic efficiency,undesirable cycle stability,and poor rate performances.To tackle these issues,single-crystal Li_(1.2)Mn_(0.54)Co_(0.13)Ni_(0.13)O_(2) is synthesized by a self-combustion method.Compared with the poly-crystal Li-rich cathode,the specific discharge capacity of the single-crystal sample increased from 252.0 to304.6 mAh·g^(-1) at 0.1 C.展开更多
基金This work was supported by the National Natural Science Foundation of China(No.21403292,No.21403293,No.21473249,and No.21673285),and the funding from the Shenzhen city(No.JCYJ20170307150520453).
文摘To understand and control the interfacial properties of polydiacetylenes(PDAs)vesicles withπ-conjugated backbone is very important for their colorimetric sensing of chemical and biological targets.In this work,we adopted 10,12-pentacosadiynoic acid(PCDA)as the model molecule to prepare PDAs vesicles in aqueous solution with different forms(from monomer to blue-to-purple-to-red phase)by controlling the UV irradiation dose.The variations of the interfacial conformation of PDAs vesicles during chromatic transitions were inspected by the adsorption behaviors of probe molecules(4-(4-diethylaminostyry)-1-methylpyridinium iodide,D289)on vesicle surface with surface-specific second harmonic generation(SHG)and zeta potential measurements.Resonant SHG signal from D289 adsorbed on vesicle surface attenuated sharply,and the adsorption free energy as well as the corresponding two-photon fluorescence signal decreased slightly in chromatic transitions.While,the change in the surface density of the adsorbed D289 molecules for PDAs vesicles with different forms was relatively small as estimated from zeta potential measurements.The attenuation of the SHG intensity was thus attributed to the overall order-disorder transition and the changed orientation of D289 molecules caused by the gradual distortion of carboxyl head group driven by backbone perturbation.
基金supported by the National Natural Science Foundation of China(No.21673285 and No.21973022)the Guangdong Basic and Applied Basic Research Foundation(No.2019A1515012117)the Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme 2019(No.GDUPS2019)。
文摘Two non-ionic hydro-fluorocarbon hybrid surfactants with and without hydroxyl groups were synthesized and compared.They exhibited good thermal stability and superior surface activity.It was observed that the hydroxyl group had a profound effect on modifying the surface tension of their solutions and the morphology of the formed micelles.This effect may be attributed to the rearranging of the alkane group from above the air/aqueous surface to below it and the disrupting of the interfacial water structure induced by the hydroxyl groups.This work provides a strategy to weaken the immiscibility between hydrocarbon and fluorocarbon chains by modifying their orientational structure at the interface,thus it is helpful for the design of surfactants with varied interfacial properties.
基金financially supported by the Stable Supporting Fund of Shenzhen(No.GXWD2020123015542700320200728114835006)。
文摘Li-rich manganese-based oxide has been identified as the most promising cathode material for next-generation Li-ion batteries,due to its high capacity,high operating voltage,safety,and low cost.Nevertheless,its wide application is restricted by low initial Columbic efficiency,undesirable cycle stability,and poor rate performances.To tackle these issues,single-crystal Li_(1.2)Mn_(0.54)Co_(0.13)Ni_(0.13)O_(2) is synthesized by a self-combustion method.Compared with the poly-crystal Li-rich cathode,the specific discharge capacity of the single-crystal sample increased from 252.0 to304.6 mAh·g^(-1) at 0.1 C.
