Spectroscopic studies of a soluble and stable polyacetylene blend

Sariciftci, Niyazi Serdar; Kobryanskii, V.M.; Reghu, M.; Smilowitz, Laura; Halvorson, C.; Hagler, T.W.; Mihailović, D.; Heeger, Alan J.

doi:10.1016/0379-6779(93)90888-4

Cited by 52 publications

(8 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This synthetic route utilizes transition metal ions complexed with poly(vinylbutyral) (PVB) as the polymerization catalyst and yields highly stable blends of PA with PVB. The absorption spectrum of this material is shown in the inset of Figure for comparison . The agreement between calculation and measurement is good, even though the experimental absorption peak is shifted to somewhat higher energy and is broader.…”

Section: Applicationsmentioning

confidence: 69%

“…Figure b). It is difficult to see why electronic interband transitions should be forbidden in a Peierls distorted H chain, whereas it is known that such transitions are responsible for the relatively intense low-energy π* ← π absorption band in the topologically similar polyacetylene …”

Section: Methodsmentioning

confidence: 99%

“…As the simplest member of the class of conducting polymers, (all- trans )-polyacetylene (PA) has attracted multidisciplinary interest and extensive research activity since the early 1970s, when a new and more easily accessible synthesis for PA was found. , Moreover, PA is of significant historical importance for quantum chemistry since the early LCAO-MO studies of linear polyenes by Lennard-Jones and Coulson . Doped PA exhibits the largest electrical conductivity observed in any conducting polymer, with values reported in excess of 10 5 S/cm, and exhibits interesting optical properties …”

Section: Applicationsmentioning

confidence: 99%

“…Only transitions with the light vector parallel to the chain axis are considered. In the inset the transmission spectrum of a spin cast film of trans -polyacetylene with poly(vinylbutyral) (PA-PVB) taken from ref is given for comparison. …”

Section: Applicationsmentioning

confidence: 99%

“…It will be shown that the velocity formulation on general grounds cannot yield satisfactory results if used in conjunction with extended Hückel tight-binding crystal orbitals. Besides attempting a description of the spectral features of the low-energy transitions that are well-known and have been discussed in the literature, ,,, we place the question of the nature of the crystal orbitals (COs) engaged and the origin in k space of these transitions into the foreground, facts that are often difficult to unambiguously determine from experimental data.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Electronic Transition Oscillator Strengths in Solids: An Extended Hückel Tight-Binding Approach

Rytz

Calzaferri

1997

J. Phys. Chem. B

View full text Add to dashboard Cite

A method for calculating electronic dipole-induced transitions in solids based on extended Hückel tight-binding (EHTB) wave functions is presented. The proposed computational treatment relies on the position formulation for intensity calculations. It is compared with the well-known velocity method that involves differentiation of the wave functions with respect to the electron positions. The described CEDiT (crystal electronic dipole-induced transitions) computations are applied to interpret the low-energy absorption spectrum of polyacetylene and the group VIA transition metal dichalcogenide MoS2. Good agreement between calculation and experimental absorption spectra is obtained. In the case of polyacetylene the first prominent absorption band is due to π* ← π transitions about the Z point of the irreducible Brillouin zone. The high density of states (DOS) encountered at Z can be identified as responsible for the characteristic shape of this band. For MoS2 we plot the oscillator strengths of the first four prominent electronic transitions as a function of the k vector in the irreducible Brillouin zone. The excitonic transitions A and B are due to resonance of two almost degenerate interband absorptions confined to a relatively well-defined region in k space at about k A = (22/57, 2/57) and k B = (1/3, 2/57), respectively. The origin in k space of the interband absorptions C and D is also discussed.

show abstract

Section: Applicationsmentioning

confidence: 69%

Section: Methodsmentioning

confidence: 99%

Section: Applicationsmentioning

confidence: 99%

Section: Applicationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Electronic Transition Oscillator Strengths in Solids: An Extended Hückel Tight-Binding Approach

Rytz

Calzaferri

1997

J. Phys. Chem. B

View full text Add to dashboard Cite

show abstract

Vinyl Acetal Polymers

Knapczyk

2000

Kirk-Othmer Encyclopedia of Chemical Technology

View full text Add to dashboard Cite

Poly(vinyl acetal) resins are made by the acid‐catalyzed acetalization of poly(vinyl alcohol) with aldehydes. The reaction favors formation of the 1,3‐dioxane ring, which is a characteristic feature of this class of resins. As of this writing (ca 1997), only poly(vinyl butyral) and poly(vinyl formal) are made in sizable commercial quantities. Most poly(vinyl butyral) is plasticized and made into interlayer for vehicle and architectural safety glazing. The primary use for poly(vinyl formal) is as an important component in coatings for electrical wire and cable insulation. Applications for poly(vinyl butyral) and poly(vinyl formal) resins make use of their toughness, resilience, optical clarity, high pigment/filler binding capacity, and the high adhesion the resins may provide when appropriately formulated. The history and general characteristics of poly(vinyl acetal) resins are briefly reviewed. Chemical and physical characteristics, manufacture, and principal applications are discussed. Special attention is given to poly(vinyl butyral) and its use for safety glazing interlayer, because glazing interlayer is by far the largest single application for the poly(vinyl acetal) class of resins.

show abstract

Classes of CPs: Part 1

Chandrasekhar

1999

Conducting Polymers, Fundamentals and Applications

View full text Add to dashboard Cite

Spectroscopic studies of a soluble and stable polyacetylene blend

Cited by 52 publications

References 28 publications

Electronic Transition Oscillator Strengths in Solids: An Extended Hückel Tight-Binding Approach

Electronic Transition Oscillator Strengths in Solids: An Extended Hückel Tight-Binding Approach

Vinyl Acetal Polymers

Classes of CPs: Part 1

Contact Info

Product

Resources

About