The diffusion coefficients(Dapp) and the heterogeneous electron transfer rate constants(ks)for ferrocene in several polymer solvents were determined by using steady-stae voltammetry. Thetemperature dependence of the t...The diffusion coefficients(Dapp) and the heterogeneous electron transfer rate constants(ks)for ferrocene in several polymer solvents were determined by using steady-stae voltammetry. Thetemperature dependence of the two parameters indicates Arrhenius behavior. The polymer solventeffects on diffusion and electron transfer dynamics of ferrocene were discussed展开更多
The present paper describes experiments aimed at delineating significant chemical characteristics of electrochemical reactions in polymeric solutions, including how rigid solvent environments affect mass transport rat...The present paper describes experiments aimed at delineating significant chemical characteristics of electrochemical reactions in polymeric solutions, including how rigid solvent environments affect mass transport rates, and also discusses the possibility that the microelectrode coated with poly(ethylene oxide)(PEO) film can be used as gas sensor.展开更多
A new solvent polymeric membrane (SPM)pH2sensor based on 4,4'-bis (N, N-didecylamino)methyl)azobenzene as neutral carricr has been reported. It has excellent pH response characteristics with the linear response ra...A new solvent polymeric membrane (SPM)pH2sensor based on 4,4'-bis (N, N-didecylamino)methyl)azobenzene as neutral carricr has been reported. It has excellent pH response characteristics with the linear response range (1.7—13.2)much wider than that of similar SPM pH sensors reported so far. The sensor has a theoretical Nernstian response of 57.4+0.2V/pH(at 20℃)without super—Nernstian response phenomenon.展开更多
The Vrentas-Duda free-volume theory has been extensively used tocorrelated or predict the solvent diffusion coefficient of apolymer/solvent system. The energy term in the free volume diffusionequation is difficult to ...The Vrentas-Duda free-volume theory has been extensively used tocorrelated or predict the solvent diffusion coefficient of apolymer/solvent system. The energy term in the free volume diffusionequation is difficult to estimate, so the energy term was usuallyneglected in previous predictive versions of the free volumediffusion coefficient equation. Recent studies show that the energyeffect is very important even above the glass transition temperatureof the system. In this paper, a new evaluating method of the energyterm is proposed, that is, the diffusion energy at different solventconcentrations is assumed to be a linear function of the solventdiffusion energy in pure solvents and that in polymers under thecondition that the solvent in infinite dilution.展开更多
Molecular dynamics method is used to study the conformation behavior of a semi-flexible polymer chain confined in a cylinder channel.A novel helix-like structure is found to form during the simulation.Moreover,the det...Molecular dynamics method is used to study the conformation behavior of a semi-flexible polymer chain confined in a cylinder channel.A novel helix-like structure is found to form during the simulation.Moreover,the detailed characteristic parameters and formation probability of these helix-like structures under moderate conditions are investigated.We find that the structure is not a perfect helix,but a bundle of elliptical turns.In addition,we conduct a statistical analysis for the chain monomer distribution along the radial direction.This research contributes to our understanding of the microscopic conformation of polymer chains in confined environments filled with a solvent.展开更多
Anion-selective electrodes based on dissociated ion-exchangers such as lipophilicquaternary ammonium or phosphonium species always display classical Hofmeister be-havior in the following order: ClO<sub>4</sub...Anion-selective electrodes based on dissociated ion-exchangers such as lipophilicquaternary ammonium or phosphonium species always display classical Hofmeister be-havior in the following order: ClO<sub>4</sub><sup>-</sup>】SCN<sup>-</sup>】I<sup>-</sup>】Br<sup>-</sup>】NO<sub>2</sub><sup>-</sup>】Cl<sup>-</sup>】SO<sub>4</sub><sup>2-</sup>.A new sol-vent polymeric membrane electrode based on Schiff base complexes of Co（Ⅱ）[Co（Ⅱ）S]and showing excellent selectivity toward iodide ion is for the first time prepared inour work. The resulting electrodes exhibit fairly low detection limits andpotentiometric anion-selectivity sequences deviated from the Hofmeister pattern.Bis（salicylaldehyde） ethylenediiminecobalt（Ⅱ） [Co（Ⅱ）（salen）], bis（salicylaldehyde）-phenyldiiminecobalt（Ⅱ） [Co（Ⅱ）（salophen）],展开更多
The equilibrium swelling of the system Polystyrene (PS) (M = 1.7 × 10s, monodisperse)/diethyl ether at 30 °C and 35 °C has been studied in detail in quiescent state for a time span over 150 d. Arguments...The equilibrium swelling of the system Polystyrene (PS) (M = 1.7 × 10s, monodisperse)/diethyl ether at 30 °C and 35 °C has been studied in detail in quiescent state for a time span over 150 d. Arguments are given to show that the swelling process in a “non-solvent” is a network swelling rather than a phase separation process. It is different from the cloud point curve (CPC) experiment studied in literature, where the experiment starts from a one-phase solution, so that the cohesional entanglement present in the solid polymer is disrupted by dissolution. The cohesional entanglement structure of the solid polymer, on the contrary, is retained in the concentrated phase on swelling, at least in the initial stage. The course of swelling as presented by the curve Va(t) was found to proceed in three stages, where Va is the volume of the concentrated phase. In the first and third stages of Va(t), the curve goes up smoothly, while in the second stage the curve Va(t) shows large up and down jumps, indicating probably a readjustment in the network structure. Some results on a monodisperse PS sample of M = 5.8 × 105 and a polydisperse sample of M = 2.0 × 105 are also given. The values of Va observed at swelling equilibrium are not in accord with the expected cloud point temperature. The cloud point curve represents a phase separation process occurring in local regions (space limited to μm) and in time scale of the order of minute, while the process Va(t) occurred in the whole space of the concentrated phase, in time scale of days. For quantitative characterization of the network present in the concentrated phase, a precise value of the polymer-solvent interaction parameter x is needed.展开更多
Polymer–solvent systems exhibit complex solvation behaviours encompassing a diverse range of phenomena,including swelling,gelation,and dispersion.Accurate interpretation is often hindered by subjectivity,particularly...Polymer–solvent systems exhibit complex solvation behaviours encompassing a diverse range of phenomena,including swelling,gelation,and dispersion.Accurate interpretation is often hindered by subjectivity,particularly in manual rapid screening assessments.While computer vision models hold significant promise to replace the reliance on human evaluation for inference,their adoption is limited by the lack of domain-specific datasets tailored,in our case,to polymer–solvent systems.To bridge this gap,we conducted extensive screenings of polymers with diverse physical and chemical properties across various solvents,capturing solvation characteristics through images,videos,and image–text captions.This dataset informed the development of a multi-model vision assistant,integrating computer vision and vision-language approaches to autonomously detect,infer,and contextualise polymer–solvent interactions.The system combines a 2D-CNN module for static solvation state classification,a hybrid 2D/3D-CNN module to capture temporal dynamics,and a BLIP-2-based contextualisation module to generate descriptive captions for solvation behaviours,including vial orientation,solvent discolouration,and polymer interaction states.Computationally efficient,this vision assistant provides an accurate,objective,and scalable solution in interpreting solvation behaviours,fit for autonomous platforms and high-throughput workflows in material discovery and analysis.展开更多
文摘The diffusion coefficients(Dapp) and the heterogeneous electron transfer rate constants(ks)for ferrocene in several polymer solvents were determined by using steady-stae voltammetry. Thetemperature dependence of the two parameters indicates Arrhenius behavior. The polymer solventeffects on diffusion and electron transfer dynamics of ferrocene were discussed
文摘The present paper describes experiments aimed at delineating significant chemical characteristics of electrochemical reactions in polymeric solutions, including how rigid solvent environments affect mass transport rates, and also discusses the possibility that the microelectrode coated with poly(ethylene oxide)(PEO) film can be used as gas sensor.
基金Project supported by the National Natural Science Foundation of China partially by Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Academia Sinica.
文摘A new solvent polymeric membrane (SPM)pH2sensor based on 4,4'-bis (N, N-didecylamino)methyl)azobenzene as neutral carricr has been reported. It has excellent pH response characteristics with the linear response range (1.7—13.2)much wider than that of similar SPM pH sensors reported so far. The sensor has a theoretical Nernstian response of 57.4+0.2V/pH(at 20℃)without super—Nernstian response phenomenon.
基金Supported by the National Nature Science Foundation of China (No. 20076038).
文摘The Vrentas-Duda free-volume theory has been extensively used tocorrelated or predict the solvent diffusion coefficient of apolymer/solvent system. The energy term in the free volume diffusionequation is difficult to estimate, so the energy term was usuallyneglected in previous predictive versions of the free volumediffusion coefficient equation. Recent studies show that the energyeffect is very important even above the glass transition temperatureof the system. In this paper, a new evaluating method of the energyterm is proposed, that is, the diffusion energy at different solventconcentrations is assumed to be a linear function of the solventdiffusion energy in pure solvents and that in polymers under thecondition that the solvent in infinite dilution.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11504033 and 11404290)the General Research Fund of Hong Kong Research Council of China(Grant No.15301014)
文摘Molecular dynamics method is used to study the conformation behavior of a semi-flexible polymer chain confined in a cylinder channel.A novel helix-like structure is found to form during the simulation.Moreover,the detailed characteristic parameters and formation probability of these helix-like structures under moderate conditions are investigated.We find that the structure is not a perfect helix,but a bundle of elliptical turns.In addition,we conduct a statistical analysis for the chain monomer distribution along the radial direction.This research contributes to our understanding of the microscopic conformation of polymer chains in confined environments filled with a solvent.
基金National Natural Science Foundation of ChinaElectroanalytical Chemistry Laboratory, Changchun Institute of Applied Chemistry, Academia Sinica.
文摘Anion-selective electrodes based on dissociated ion-exchangers such as lipophilicquaternary ammonium or phosphonium species always display classical Hofmeister be-havior in the following order: ClO<sub>4</sub><sup>-</sup>】SCN<sup>-</sup>】I<sup>-</sup>】Br<sup>-</sup>】NO<sub>2</sub><sup>-</sup>】Cl<sup>-</sup>】SO<sub>4</sub><sup>2-</sup>.A new sol-vent polymeric membrane electrode based on Schiff base complexes of Co（Ⅱ）[Co（Ⅱ）S]and showing excellent selectivity toward iodide ion is for the first time prepared inour work. The resulting electrodes exhibit fairly low detection limits andpotentiometric anion-selectivity sequences deviated from the Hofmeister pattern.Bis（salicylaldehyde） ethylenediiminecobalt（Ⅱ） [Co（Ⅱ）（salen）], bis（salicylaldehyde）-phenyldiiminecobalt（Ⅱ） [Co（Ⅱ）（salophen）],
文摘The equilibrium swelling of the system Polystyrene (PS) (M = 1.7 × 10s, monodisperse)/diethyl ether at 30 °C and 35 °C has been studied in detail in quiescent state for a time span over 150 d. Arguments are given to show that the swelling process in a “non-solvent” is a network swelling rather than a phase separation process. It is different from the cloud point curve (CPC) experiment studied in literature, where the experiment starts from a one-phase solution, so that the cohesional entanglement present in the solid polymer is disrupted by dissolution. The cohesional entanglement structure of the solid polymer, on the contrary, is retained in the concentrated phase on swelling, at least in the initial stage. The course of swelling as presented by the curve Va(t) was found to proceed in three stages, where Va is the volume of the concentrated phase. In the first and third stages of Va(t), the curve goes up smoothly, while in the second stage the curve Va(t) shows large up and down jumps, indicating probably a readjustment in the network structure. Some results on a monodisperse PS sample of M = 5.8 × 105 and a polydisperse sample of M = 2.0 × 105 are also given. The values of Va observed at swelling equilibrium are not in accord with the expected cloud point temperature. The cloud point curve represents a phase separation process occurring in local regions (space limited to μm) and in time scale of the order of minute, while the process Va(t) occurred in the whole space of the concentrated phase, in time scale of days. For quantitative characterization of the network present in the concentrated phase, a precise value of the polymer-solvent interaction parameter x is needed.
基金Green Rose Chemistry for their collaboration in this research and for providing both financial and technical support through an Innovate UK grant(10097443),subcontracted to the Innovation Centre in Digital Molecular Technologies(iDMT,Yusuf Hamied Department of Chemistry,University of Cambridge)Z.J.L.acknowledges support from the Marie Skłodowska-Curie Actions Innovative Training Networks through a Marie Curie Fellowship(101072732)as part of Horizon Europe 2021,underwritten by United Kingdom Research and Innovation(UKRI EP/X034763/1)+1 种基金Z.E.acknowledges financial support from the Mastercard Foundation ScholarshipThis work was further supported by the facilities and resources provided by the Innovation Centre in Digital Molecular Technologies,An element in Fig.1a was created using BioRender templates and modified prior to use.
文摘Polymer–solvent systems exhibit complex solvation behaviours encompassing a diverse range of phenomena,including swelling,gelation,and dispersion.Accurate interpretation is often hindered by subjectivity,particularly in manual rapid screening assessments.While computer vision models hold significant promise to replace the reliance on human evaluation for inference,their adoption is limited by the lack of domain-specific datasets tailored,in our case,to polymer–solvent systems.To bridge this gap,we conducted extensive screenings of polymers with diverse physical and chemical properties across various solvents,capturing solvation characteristics through images,videos,and image–text captions.This dataset informed the development of a multi-model vision assistant,integrating computer vision and vision-language approaches to autonomously detect,infer,and contextualise polymer–solvent interactions.The system combines a 2D-CNN module for static solvation state classification,a hybrid 2D/3D-CNN module to capture temporal dynamics,and a BLIP-2-based contextualisation module to generate descriptive captions for solvation behaviours,including vial orientation,solvent discolouration,and polymer interaction states.Computationally efficient,this vision assistant provides an accurate,objective,and scalable solution in interpreting solvation behaviours,fit for autonomous platforms and high-throughput workflows in material discovery and analysis.
