Physical properties of highly oriented polyacetylene films

Montaner, A.; Rolland, M.; Sauvajol, Jean‐Louis; Galtier, M.; Almairac, R.; Ribet, J.L.

doi:10.1016/0032-3861(88)90022-5

Cited by 41 publications

(12 citation statements)

References 9 publications

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“…The polyacetylene film showed neither helical morphology in the SEM photograph nor the Cotton effect in the CD spectrum: the morphology observed was composed of fibrils that were locally aligned owing to spontaneous orientation of the LC solvent. This has also been confirmed in previous studies 12b–e. Second, acetylene polymerization was performed in toluene and a small amount (less than 10%) of a chiral dopant.…”

Section: Characterization Of H‐pa Filmsupporting

confidence: 80%

“…Acetylene gas of six‐nine grade (99.9999% purity) was used without further purification. The apparatus and procedure employed were similar to those in earlier studies12c,d except for the polymerization temperature. Here, the polymerization temperature was kept between 17 and 18°C to maintain the chiral nematic phase by circulating cooled ethanol through an outer flask enveloping the Schlenk flask.…”

Section: Acetylene Polymerization In N*‐lcmentioning

confidence: 99%

“…The introduction of a liquid crystal (LC) group into the side chain is one approach to align the polymer under an external force such as shear stress, rubbing, or a magnetic field 8–10. On the other hand, the use of nematic LC (N‐LC) as a solvent gave us directly aligned polyacetylene with the aid of gravity flow or a magnetic force field 11,12…”

Section: Introductionmentioning

confidence: 99%

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Helical polyacetylene—Origins and synthesis

Akagi

Mori

2008

The Chemical Record

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We present the origins and synthesis of helical polyacetylene (H-PA) by focusing on its peculiar spiral morphology. Interfacial polymerization of acetylene was carried out in an asymmetric reaction field consisting of chiral nematic liquid crystal (N*-LC) and Ziegler-Natta catalyst. As the N*-LC is composed of nematic liquid crystal and a chiral compound such as a binaphthyl derivative with either the R- or S-configuration, the screw directions of the polyacetylene chain and fibril bundle--and even the spiral morphology--are rigorously controlled by the chirality of the selected compound. Interestingly, the screw directions of the fibril and the bundle in H-PA were found to be opposite to that of N*-LC. It is worthwhile to emphasize that the hierarchical spiral morphology involving the primary to higher order structure is generated in a synthetic polymer such as polyacetylene by using N*-LC as an asymmetric polymerization solvent.

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Section: Characterization Of H‐pa Filmsupporting

confidence: 80%

Section: Acetylene Polymerization In N*‐lcmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Helical polyacetylene—Origins and synthesis

Akagi

Mori

2008

The Chemical Record

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Section: Introductionmentioning

confidence: 99%

A Meta‐Analysis of Conductive and Strong Carbon Nanotube Materials

2021

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A study of 1304 data points collated over 266 papers statistically evaluates the relationships between carbon nanotube (CNT) material characteristics, including: electrical, mechanical, and thermal properties; ampacity; density; purity; microstructure alignment; molecular dimensions and graphitic perfection; and doping. Compared to conductive polymers and graphitic intercalation compounds, which have exceeded the electrical conductivity of copper, CNT materials are currently one‐sixth of copper's conductivity, mechanically on‐par with synthetic or carbon fibers, and exceed all the other materials in terms of a multifunctional metric. Doped, aligned few‐wall CNTs (FWCNTs) are the most superior CNT category; from this, the acid‐spun fiber subset are the most conductive, and the subset of fibers directly spun from floating catalyst chemical vapor deposition are strongest on a weight basis. The thermal conductivity of multiwall CNT material rivals that of FWCNT materials. Ampacity follows a diameter‐dependent power‐law from nanometer to millimeter scales. Undoped, aligned FWCNT material reaches the intrinsic conductivity of CNT bundles and single‐crystal graphite, illustrating an intrinsic limit requiring doping for copper‐level conductivities. Comparing an assembly of CNTs (forming mesoscopic bundles, then macroscopic material) to an assembly of graphene (forming single‐crystal graphite crystallites, then carbon fiber), the ≈1 µm room‐temperature, phonon‐limited mean‐free‐path shared between graphene, metallic CNTs, and activated semiconducting CNTs is highlighted, deemphasizing all metallic helicities for CNT power transmission applications.

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“…The first one is the preparation of oriented polyacetylene either via precursor polymers [7 which can be oriented during the conversion to the final polyacetylene [8][9][10][11][12][13], or using specially treated catalysts followed by orientation of the films applying mechanical force [14, Also, the polymerization of acetylene in nematic solvents has been described by various groups [16][17][18][19][20][21].…”

Section: Introductionmentioning

confidence: 99%