Structure and photoluminescent features of di-amide cross-linked alkylene-siloxane hybrids

Nunes, S. C. (author): Universidade de Tras-os-Montes e Alto Douro,University of Trás-os-Montes and Alto Douro

Bermudez, V. D. (author): Universidade de Tras-os-Montes e Alto Douro,University of Trás-os-Montes and Alto Douro

Cybinska, J. (author): Universidade de Aveiro,University of Aveiro,Uniwersytet Wrocławski,University of Wrocław

Ostrovskii, Denis, 1967 (author): Chalmers tekniska högskola,Chalmers University of Technology

(creator_code:org_t)

Royal Society of Chemistry (RSC), 2005
2005
English.
In: Journal of Materials Chemistry. - : Royal Society of Chemistry (RSC). - 1364-5501 .- 0959-9428. ; 15:35-36, s. 3876-3886

Related links:: http://dx.doi.org/10...; show more...; http://repositorium....; https://doi.org/10.1...; https://research.cha...; show less...

Abstract Subject headings

Novel amide cross-linked alkylene-siloxane hybrid materials (di-amidosils) synthesized by the sol-gel process have been investigated. Two samples identified by the notation d-A(x) with x = 4 and 8 (where x is the number of methylene groups of the alkylene chain) have been produced as transparent, amorphous, rigid monoliths. The d-A(8) material is thermally stable up to approximately 245°C. In this hybrid the siliceous framework is mainly composed of [-(CH2)Si(OSi)3)] and [-(CH 2)Si(OSi)2(OH)] substructures. Structural unit distances of 4.1 and 4.2 Å and average interparticle distances of 12 and 17 A have been determined for d-A(4) and d-A(8), respectively. In these compounds the alkylene chains are disordered and adopt gauche conformations. While a negligible proportion of the amide linkages remain non-bonded, the great majority of these groups belong to highly disordered strong hydrogen-bonded amide-amide associations. The hybrids introduced are room temperature white light emitters, presenting an intense, broad emission band in the blue/purplish-blue spectral region. The origin of such a band has been ascribed to the convolution of donor-acceptor pair (D-A) recombinations that occur in the NH groups of the amide linkages and in the siliceous nanodomains. The maximum quantum yield value of the d-A(8) di-amidosil is 5.4%.

By the author/editor: Nunes, S. C.; Bermudez, V. D.; Cybinska, J.; Ferreira, R. A. ...; Legendziewicz, J ...; Carlos, L. D.; show more...; Silva, M. M.; Smith, M. J.; Ostrovskii, Deni ...; Rocha, J.; show less...

About the subject

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.