Spectroscopic properties of polyacetylenes synthesized via three modifications of Ziegler-Natta catalytic system

Arbuckle, Georgia A.; Buecheler, Nancy M.; Hall, Jeremy L.; Valentine, Kathleen G.; Lefrant, S.; Mevellec, Jean‐Yves; Mulazzi, E.

doi:10.1016/0379-6779(96)80189-5

Cited by 14 publications

(16 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Before carbonization, we observed characteristic Raman peaks of trans-PA at 1475 and 1085 cm −1 [Fig. (1b)]35 which are assigned to C = C stretching vibration and mixed vibration of C-C stretching and C-H in-plane bending, respectively313536. For HCl doped PANI nanofibers, complex characteristic peaks at 1620, 1590, 1505, 1405, 1340, 1260, and 1170 cm −1 were observed [Fig.…”

Section: Resultsmentioning

confidence: 99%

Apparent Power Law Scaling of Variable Range Hopping Conduction in Carbonized Polymer Nanofibers

Kim

Lara‐Avila

et al. 2016

Sci Rep

View full text Add to dashboard Cite

We induce dramatic changes in the structure of conducting polymer nanofibers by carbonization at 800 °C and compare charge transport properties between carbonized and pristine nanofibers. Despite the profound structural differences, both types of systems display power law dependence of current with voltage and temperature, and all measurements can be scaled into a single universal curve. We analyze our experimental data in the framework of variable range hopping and argue that this mechanism can explain transport properties of pristine polymer nanofibers as well.

show abstract

Section: Resultsmentioning

confidence: 99%

Apparent Power Law Scaling of Variable Range Hopping Conduction in Carbonized Polymer Nanofibers

Kim

Lara‐Avila

et al. 2016

Sci Rep

View full text Add to dashboard Cite

show abstract

“…And these peaks were not present on the original Pd NS. Based on the literature data, 39,40 all the four observed Raman absorption peaks are ascribed to the presence of trans-polyacetylene. The band assignments are as follows: 1498.6 cm −1 to the totally symmetric CC stretching with considerable mixing of CH in-plane deformation; 1294.6 cm −l to the C−C symmetric stretching vibration; 1117.4 cm −1 to CH in-plane deformation with large CC stretch contributions and 1005.3 cm −l to C−H out ofplane wagging.…”

Section: * S Supporting Informationmentioning

confidence: 95%

C₂H₂ Treatment as a Facile Method to Boost the Catalysis of Pd Nanoparticulate Catalysts

2014

View full text Add to dashboard Cite

A facile method to boost the catalysis of Pd nanoparticulate catalysts by simple C2H2 treatment is developed. During the C2H2 treatment, Pd nanoparticles serve as active catalysts to polymerize C2H2 into trans-polyacetylene. The deposition of trans-polyacetylene layer on Pd nanoparticles makes their surface hydrophobic. Such a hydrophobic surface modification helps to accumulate more hydrophobic substrates during catalysis, making the modified Pd nanoparticulate catalysts more active than untreated catalysts in the catalytic reaction involving hydrophobic substrates. Moreover, the coating of polyacetylene on Pd creates encapsulated Pd nanocatalysts, stabilizing Pd nanoparticles against sintering or aggregation. Since the catalytic polymerization of polyacetylene on Pd is not facet dependent, the development is readily applied to enhance the catalysis of commercial Pd nanoparticulate catalysts by simple C2H2 treatment.

show abstract

“…28 The Raman spectrum of the typical PA film carbonized at 800°C presents a broad disorder band (D-band) at 1357 cm −1 and a strong graphite band (G-band) at 1601 cm −1 (Figure 8a,b). The D-and G-bands decrease and increase in intensity, respectively, and the two bands become sharp, after the graphitization at 2600−3000°C (Figure 8d).…”

Section: Journal Of the American Chemical Societymentioning

confidence: 98%

Macroscopically Aligned Graphite Films Prepared from Iodine-Doped Stretchable Polyacetylene Films Using Morphology-Retaining Carbonization

Matsushita

Akagi

2015

J. Am. Chem. Soc.

View full text Add to dashboard Cite

We prepared graphite films using typical Shirakawa-type and stretchable polyacetylene (PA) films as precursors through a morphology-retaining carbonization. A macroscopically aligned PA film was prepared from the drawable PA film using a mechanical-stretching procedure. The degree of orientation of the aligned PA film was evaluated by measuring polarized infrared absorption spectra and an azimuthal-angle profile of a Laue X-ray diffraction (XRD) pattern. The carbonization was performed from the iodine-doped PA films as precursors at 800 °C. The carbon films were subsequently graphitized at 1400-3000 °C, yielding graphite films with almost the same surface morphology as that of the original PA films and that of the carbon films as precursors. The typical PA film graphitized at 2600 °C exhibited tensile strengths of up to 224 MPa, moduli of up to 10 GPa, and an average electrical conductivity of 2.5 × 10(2) S/cm. In contrast, the graphite film prepared from the stretched PA film presented a Laue XRD pattern in which graphitic crystal structures are aligned parallel to the direction of stretching of the PA film. The anisotropic graphite film showed an enhanced conductivity of up to 1.5 × 10(3) S/cm along the stretching direction. We demonstrated that an iodine-doped PA film is a highly efficient carbon source for producing graphite films with good mechanical and electrical properties. The total yield of a graphite film is as high as 61-74% at up to 3000 °C, which is considerably higher than that of polyacrylonitrile-based carbon fiber and polyimide-based graphite film.

show abstract

Spectroscopic properties of polyacetylenes synthesized via three modifications of Ziegler-Natta catalytic system

Cited by 14 publications

References 20 publications

Apparent Power Law Scaling of Variable Range Hopping Conduction in Carbonized Polymer Nanofibers

Apparent Power Law Scaling of Variable Range Hopping Conduction in Carbonized Polymer Nanofibers

C₂H₂ Treatment as a Facile Method to Boost the Catalysis of Pd Nanoparticulate Catalysts

Macroscopically Aligned Graphite Films Prepared from Iodine-Doped Stretchable Polyacetylene Films Using Morphology-Retaining Carbonization

Contact Info

Product

Resources

About

Spectroscopic properties of polyacetylenes synthesized via three modifications of Ziegler-Natta catalytic system

Cited by 14 publications

References 20 publications

Apparent Power Law Scaling of Variable Range Hopping Conduction in Carbonized Polymer Nanofibers

Apparent Power Law Scaling of Variable Range Hopping Conduction in Carbonized Polymer Nanofibers

C2H2 Treatment as a Facile Method to Boost the Catalysis of Pd Nanoparticulate Catalysts

Macroscopically Aligned Graphite Films Prepared from Iodine-Doped Stretchable Polyacetylene Films Using Morphology-Retaining Carbonization

Contact Info

Product

Resources

About

C₂H₂ Treatment as a Facile Method to Boost the Catalysis of Pd Nanoparticulate Catalysts