Study on effect of supercritical CO2 on structural ordering and charge transporting property in thiophene-based block copolymer

2022 ◽  
Author(s):  
Satomi Hosokawa ◽  
Eri Tomita ◽  
Shinji Kanehashi ◽  
Kenji Ogino
Keyword(s):  
Supercritical Co2 ◽  
Hole Mobility ◽  
Amorphous Region ◽  
Crystalline Region ◽  
Space Charge Limited Current ◽  
Conjugation Length ◽  
Enhanced Mobility ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Effective Conjugation Length

Abstract We reported that supercritical (sc) annealing of poly(3-hexylthiophene) (P3HT), and its block copolymers with poly(ethylene oxide) (PEO) and polystyrene (PSt) brought about improvements in the crystal structure and hole mobility, determined by the space charge limited current (SCLC) measurement. P3HT-b-PEO showed the largest increase in mobility. From XRD profile, it was found that the treatment with scCO2 increased the crystallite size and crystallinity. UV-vis spectra showed that the effective conjugation length in the scCO2 treated films was increased compared to the as-spun, suggesting that CO2 molecules are incorporated into domains of the second block domains and P3HT amorphous region, and assist to alter the characteristics of the crystalline region. Then, it was considered that the change in the crystalline structure and the improvement of P3HT chains packing led to the enhanced mobility. Since PEO is known to have a higher affinity for CO2, the increase of mobility was specifically intensive.

Vesicle formation of polystyrene-block-poly (ethylene oxide) block copolymers induced by supercritical CO2 treatment

Polymer ◽  
2010 ◽  
Vol 51 (16) ◽  
pp. 3808-3813 ◽  
Author(s):  
Limei Xu ◽  
Xiaokai Zhang ◽  
Hui Yang ◽  
Xue Li ◽  
Chunsheng Li ◽  
...  
Keyword(s):  
Block Copolymers ◽  
Ethylene Oxide ◽  
Supercritical Co2 ◽  
Vesicle Formation ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Co2 Treatment

scholarly journals Ionic Conductance, Thermal and Morphological Behavior of PEO-Graphene Oxide-Salts Composites

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Mohammad Saleem Khan ◽  
Abdul Shakoor
Keyword(s):  
Thermal Stability ◽  
Graphene Oxide ◽  
Amorphous Region ◽  
Activation Energies ◽  
Sem Analysis ◽  
Polymer Chains ◽  
Oxide Addition ◽  
Different Temperatures ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

Thin films composites of poly(ethylene oxide)-graphene oxide were fabricated with and without lithium salts by solvent cast method. The ionic conductivity of these composites was studied at various concentrations of salt polymer-GO complexes and at different temperatures. The effects of temperature and graphene oxide concentration were measured from Arrhenius conductance plots. It is shown that the addition of salts in pure PEO increases conductance many times. The graphene oxide addition has enhanced the conductance approximately 1000 times as compared to that of pure PEO. The activation energies were determined for all the systems which gave higher values for pure PEO and the value decreased with the addition of LiClO4and LiCl salts and further decreases with the addition of graphene oxide. The composite has also lowered the activation energy values which mean that incorporation of GO in PEO has decreased crystallinity and the amorphous region has increased the local mobility of polymer chains resulting in lower activation energies. SEM analysis shows uniform distribution of GO in polymer matrix. The thermal stability studies reveal that incorporation of GO has somewhat enhanced the thermal stability of the films.

The Structure of Radiation Cross-Linked Poly (ethylene oxide) Gels

1971 ◽  
Vol 29 ◽  
pp. 76-77
Author(s):  
C. E. Cluthe ◽  
G. G. Cocks
Keyword(s):  
Molecular Weight ◽  
Ethylene Oxide ◽  
Parallel Plate ◽  
Average Molecular Weight ◽  
Radical Reaction ◽  
Free Radical Reaction ◽  
Nitrogen Gas ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Initial Viscosity

Aqueous solutions of a 1 weight-per cent poly (ethylene oxide) (PEO) were degassed under vacuum, transferred to a parallel plate viscometer under a nitrogen gas blanket, and exposed to Co60 gamma radiation. The Co60 source was rated at 4000 curies, and the dose ratewas 3.8x105 rads/hr. The poly (ethylene oxide) employed in the irradiations had an initial viscosity average molecular weight of 2.1 x 106.The solutions were gelled by a free radical reaction with dosages ranging from 5x104 rads to 4.8x106 rads.

On the Properties of an Ion Conductive System Incorporated in Hybrid Films

2000 ◽  
Vol 628 ◽  
Author(s):  
G. González ◽  
P. J. Retuert ◽  
S. Fuentes
Keyword(s):  
Electrochemical Impedance ◽  
Ternary Phase Diagram ◽  
Lithium Perchlorate ◽  
Molar Ratio ◽  
Ionic Conductors ◽  
X Ray Diffraction ◽  
Poly Ethylene Oxide ◽  
Ion Conducting ◽  
Poly Ethylene ◽  
High Degree

ABSTRACTBlending the biopolymer chitosan (CHI) with poly (aminopropilsiloxane) oligomers (pAPS), and poly (ethylene oxide) (PEO) in the presence of lithium perchlorate lead to ion conducting products whose conductivity depends on the composition of the mixture. A ternary phase diagram for mixtures containing 0.2 M LiClO4 shows a zone in which the physical properties of the products - transparent, flexible, mechanically robust films - indicate a high degree of molecular compatibilization of the components. Comparison of these films with binary CHI-pAPS nanocomposites as well as the microscopic aspect, thermal behavior, and X-ray diffraction pattern of the product with the composition PEO/CHI/pAPS/LiClO4 1:0.5:0.6:0.2 molar ratio indicates that these films may be described as a layered nanocomposite. In this composite, lithium species coordinated by PEO and pAPS should be inserted into chitosan layers. Electrochemical impedance spectroscopy measurements indicate the films are pure ionic conductors with a maximal bulk conductivity of 1.7*10-5 Scm-1 at 40 °C and a sample-electrode interface capacitance of about 1.2*10-9 F.

Effect of High Salt Concentration on Ion Clustering and Transport in Polymer Solid Electrolytes: a Molecular Dynamics Study of PEO-LiTFSI

2018 ◽  
Author(s):  
Nicola Molinari ◽  
Jonathan P. Mailoa ◽  
Boris Kozinsky
Keyword(s):  
Polymer Electrolyte ◽  
Salt Concentration ◽  
Rational Design ◽  
Material System ◽  
Ion Dynamics ◽  
High Concentration ◽  
Anion Clusters ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

<div> <div> <div> <p>The model and analysis methods developed in this work are generally applicable to any polymer electrolyte/cation-anion combination, but we focus on the currently most prominent polymer electrolyte material system: poly(ethylene) oxide/Li- bis(trifluoromethane) sulfonamide (PEO + LiTFSI). The obtained results are surprising and challenge the conventional understanding of ionic transport in polymer electrolytes: the investigation of a technologically relevant salt concentration range (1 - 4 M) revealed the central role of the anion in coordinating and hindering Li ion movement. Our results provide insights into correlated ion dynamics, at the same time enabling rational design of better PEO-based electrolytes. In particular, we report the following novel observations. 1. Strong binding of the Li cation with the polymer competes with significant correlation of the cation with the salt anion. 2. The appearance of cation-anion clusters, especially at high concentration. 3. The asymmetry in the composition (and therefore charge) of such clusters; specifically, we find the tendency for clusters to have a higher number of anions than cations.</p> </div> </div> </div>

Effect of High Salt Concentration on Ion Clustering and Transport in Polymer Solid Electrolytes: a Molecular Dynamics Study of PEO-LiTFSI

2018 ◽  
Author(s):  
Nicola Molinari ◽  
Jonathan P. Mailoa ◽  
Boris Kozinsky
Keyword(s):  
Polymer Electrolyte ◽  
Salt Concentration ◽  
Rational Design ◽  
Material System ◽  
Ion Dynamics ◽  
High Concentration ◽  
Anion Clusters ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

<div> <div> <div> <p>The model and analysis methods developed in this work are generally applicable to any polymer electrolyte/cation-anion combination, but we focus on the currently most prominent polymer electrolyte material system: poly(ethylene) oxide/Li- bis(trifluoromethane) sulfonamide (PEO + LiTFSI). The obtained results are surprising and challenge the conventional understanding of ionic transport in polymer electrolytes: the investigation of a technologically relevant salt concentration range (1 - 4 M) revealed the central role of the anion in coordinating and hindering Li ion movement. Our results provide insights into correlated ion dynamics, at the same time enabling rational design of better PEO-based electrolytes. In particular, we report the following novel observations. 1. Strong binding of the Li cation with the polymer competes with significant correlation of the cation with the salt anion. 2. The appearance of cation-anion clusters, especially at high concentration. 3. The asymmetry in the composition (and therefore charge) of such clusters; specifically, we find the tendency for clusters to have a higher number of anions than cations.</p> </div> </div> </div>

Plant Oil-Based Nanoemulsions: Preparation and Efficacy for Hair Treatment

2020 ◽  
Vol 04 ◽  
Author(s):  
Lívia Gonçalves Ferreira Rodrigues ◽  
Juliana Falcão Alves de Carvalho ◽  
Cristal dos Santos Cerqueira Pinto ◽  
Elisabete Pereira Santos ◽  
Claudia Regina Elias Mansur
Keyword(s):  
Human Hair ◽  
Mechanical Tests ◽  
Plant Oils ◽  
Plant Oil ◽  
Oil In Water ◽  
Hair Samples ◽  
Poly Ethylene Oxide ◽  
Treatment Objective ◽  
Poly Ethylene ◽  
Average Size

Background:: The use of polymers in hair care products is widespread, and silicones in particular are extensively used in cosmetic formulations. In addition, plant oils can also be used for hair treatment. Objective: In the present work, oil-in-water (O/W) nanoemulsions were prepared to repair chemical damage to human hair samples, to investigate the combined use of a silicone polyether copolymer (surfactant) that has a branch composed of poly(ethylene oxide) in its chains, and two types of plant oils: coconut and ojon oil. Materials and Methods:: Surfactant-oil-water formulations were obtained by ultrasonic processing. The nanoemulsions were then applied to human hair strands previously damaged with sodium hydroxide, to compare the treated strands with untreated ones. The efficacy of the formulations was investigated by scanning electron microscopy, thermogravimetric analysis and mechanical tests. Results and Discussion:: Stables nanoemulsions were obtained with average size of the dispersed droplets up to 400 nm. The micrographs suggest that the action mechanism of the nanoemulsions depends not only on the type of plant oil used and size of the droplets dispersed in the system, but also on the type of hair that receives the treatment. The thermal analysis showed that the use of nanoemulsion changed the temperature of keratin interconversion to higher values, which can make hair fibers more resistant to heat. Hair resistance was improved when comparing virgin samples to the damaged ones. Conclusion:: The nanoemulsions were efficient in the treatment of the hair samples, which showed a significant improvement of their mechanical properties.

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