Electrical Conductivity of Thermoplastic Elastomers Modified with Gaseous Fluorine

2017 ◽  
Vol 44 (2) ◽  
pp. 15-20
Author(s):  
G.N. Petrova ◽  
T.V. Rumyantseva ◽  
V.G. Nazarov ◽  
Yu.A. Sapego
Keyword(s):  
Electrical Conductivity ◽  
Volume Resistivity ◽  
Thermoplastic Elastomers ◽  
Surface Reactivity ◽  
Ethanol Treatment ◽  
Atomic Force ◽  
Fold Reduction ◽  
Phosphorus Containing ◽  
Surface Fluorination ◽  
Gaseous Fluorine

The electrical conductivity of thermoplastic elastomers (TPEs) modified with gaseous chlorine was studied. A TPE based on polyether (‘Vitur’-grade polyurethane) and the same TPE but with phosphorus-containing fireproofing agent were held in gaseous fluorine for 1 and 3 h, and were also treated with alcohol after fluorination. The surface morphology of specimens was studied using an atomic force microscope (AFM). The changes in morphology were similar to the changes observed after the surface fluorination of rubbers. The volume and surface resistivities were measured using an Agilent 4339B instrument (USA). In all cases, the volume resistivities of modified TPEs were two orders of magnitude lower than those of the initial TPEs. The introduction of a fireproofing agent leads to a 2.5-fold reduction in volume resistivity, and a 100-fold reduction in surface reactivity. The influence of the fireproofing agent is associated with it having an effect similar to that of fillers, and with the formation of a thin layer on the surface of specimens. it was shown that ethanol treatment leads to a reduction in volume resistivity.

scholarly journals The Mechanical Properties, Secondary Structure, and Osteogenic Activity of Photopolymerized Fibroin

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 646 ◽  
Author(s):  
Ivan Bessonov ◽  
Anastasia Moysenovich ◽  
Anastasia Arkhipova ◽  
Mariam Ezernitskaya ◽  
Yuri Efremov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Atomic Force Microscopy ◽  
Elasticity Modulus ◽  
Polymer Network ◽  
Beta Sheet ◽  
Ethanol Treatment ◽  
Force Microscopy ◽  
Osteogenic Activity ◽  
Atomic Force ◽  
Crystalline Domains

Previously, we have described the preparation of a novel fibroin methacrylamide (FbMA), a polymer network with improved functionality, capable of photocrosslinking into Fb hydrogels with elevated stiffness. However, it was unclear how this new functionality affects the structure of the material and its beta-sheet-associated crystallinity. Here, we show that the proposed method of Fb methacrylation does not disturb the protein’s ability to self-aggregate into the stable beta-sheet-based crystalline domains. Fourier transform infrared spectroscopy (FTIR) shows that, although the precursor ethanol-untreated Fb films exhibited a slightly higher degree of beta-sheet content than the FbMA films (46.9% for Fb-F-aq and 41.5% for FbMA-F-aq), both materials could equally achieve the highest possible beta-sheet content after ethanol treatment (49.8% for Fb-F-et and 49.0% for FbMA-F-et). The elasticity modulus for the FbMA-F-et films was twofold higher than that of the Fb-F-et as measured by the uniaxial tension (130 ± 1 MPa vs. 64 ± 6 MPa), and 1.4 times higher (51 ± 11 MPa vs. 36 ± 4 MPa) as measured by atomic force microscopy. The culturing of human MG63 osteoblast-like cells on Fb-F-et, FbMA-F-et-w/oUV, and FbMA-F-et substrates revealed that the photocrosslinking-induced increment of stiffness increases the area covered by the cells, rearrangement of actin cytoskeleton, and vinculin distribution in focal contacts, altogether enhancing the osteoinductive activity of the substrate.

scholarly journals The Potential of High-Fluence Ion Irradiation for Processing and Recovery of Diamond Tools

Coatings ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1243
Author(s):  
Anatoly M. Borisov ◽  
Valery A. Kazakov ◽  
Eugenia S. Mashkova ◽  
Mikhail A. Ovchinnikov ◽  
Sergey N. Grigoriev ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Ion Irradiation ◽  
Diamond Structure ◽  
High Fluence ◽  
Carbon Ions ◽  
Atomic Force ◽  
Synthetic Diamonds ◽  
Argon Ions ◽  
20 Nm ◽  
Scanning Electron

The graphitization and surface growth of synthetic diamonds by high-fluence irradiation with 30 keV argon and carbon ions have been experimentally studied. scanning electron microscope (SEM) and atomic force microscope (AFM) show removal of traces of mechanical polishing. The ion-induced roughness does not exceed 20 nm. Raman spectroscopy and the measurement of electrical conductivity confirm the graphitization of the surface layer when irradiated with argon ions at the temperature of 230 °C and the diamond structure of the synthesized layer when irradiated with carbon ions at the temperature of 650 °C.

Correlation between surface forces and surface reactivity in the setting of plaster by atomic force microscopy

2000 ◽  
Vol 161 (3-4) ◽  
pp. 316-322 ◽  
Author(s):  
Eric Finot ◽  
Eric Lesniewska ◽  
Jean-Pierre Goudonnet ◽  
Jean Claude Mutin
Keyword(s):  
Atomic Force Microscopy ◽  
Surface Reactivity ◽  
Surface Forces ◽  
Force Microscopy ◽  
Atomic Force

scholarly journals The Molecular Weight Dependence of Thermoelectric Properties of Poly (3-Hexylthiophene)

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1404 ◽  
Author(s):  
Saeed Mardi ◽  
Marialilia Pea ◽  
Andrea Notargiacomo ◽  
Narges Yaghoobi Nia ◽  
Aldo Di Carlo ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Molecular Weight ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Thermoelectric Power Factor ◽  
Force Microscopy ◽  
Atomic Force ◽  
Molecular Weight Dependence ◽  
Vis Spectroscopy ◽  
Afm Analysis

Organic materials have been found to be promising candidates for low-temperature thermoelectric applications. In particular, poly (3-hexylthiophene) (P3HT) has been attracting great interest due to its desirable intrinsic properties, such as excellent solution processability, chemical and thermal stability, and high field-effect mobility. However, its poor electrical conductivity has limited its application as a thermoelectric material. It is therefore important to improve the electrical conductivity of P3HT layers. In this work, we studied how molecular weight (MW) influences the thermoelectric properties of P3HT films. The films were doped with lithium bis(trifluoromethane sulfonyl) imide salt (LiTFSI) and 4-tert butylpyridine (TBP). Various P3HT layers with different MWs ranging from 21 to 94 kDa were investigated. UV–Vis spectroscopy and atomic force microscopy (AFM) analysis were performed to investigate the morphology and structure features of thin films with different MWs. The electrical conductivity initially increased when the MW increased and then decreased at the highest MW, whereas the Seebeck coefficient had a trend of reducing as the MW grew. The maximum thermoelectric power factor (1.87 μW/mK2) was obtained for MW of 77 kDa at 333 K. At this temperature, the electrical conductivity and Seebeck coefficient of this MW were 65.5 S/m and 169 μV/K, respectively.

scholarly journals Fully soluble self-doped poly(3,4-ethylenedioxythiophene) with an electrical conductivity greater than 1000 S cm−1

2019 ◽  
Vol 5 (4) ◽  
pp. eaav9492 ◽  
Author(s):  
Hirokazu Yano ◽  
Kazuki Kudo ◽  
Kazumasa Marumo ◽  
Hidenori Okuzaki
Keyword(s):  
Electrical Conductivity ◽  
Critical Parameter ◽  
Colloidal Particles ◽  
Average Distance ◽  
Charge Carriers ◽  
High Electrical Conductivity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Atomic Force ◽  
Technical Issues

Wet-processable and highly conductive polymers are promising candidates for key materials in organic electronics. Poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) is commercially available as a water dispersion of colloidal particles but has some technical issues with PSS. Here, we developed a novel fully soluble self-doped PEDOT (S-PEDOT) with an electrical conductivity as high as 1089 S cm−1without additives (solvent effect). Our results indicate that the molecular weight of S-PEDOT is the critical parameter for increasing the number of nanocrystals, corresponding to the S-PEDOT crystallites evaluated by x-ray diffraction and conductive atomic force microscopic analyses as having high electrical conductivity, which reduced both the average distance between adjacent nanocrystals and the activation energy for the hopping of charge carriers, leading to the highest bulk conductivity.

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