Theoretical and experimental investigation of absorption and Raman spectra of poly(paraphenylene vinylene)

Surface-Enhanced Raman Scattering of MEH-PPV on Gold and Silver Nanoparticles

“…MEH-PPV presents a strong emission in the range of 500 to 650 nm, overlapping the Raman spectra in visible exciting radiation (Supplementary material - Figure S5). The assignment of vibrational modes was based on previously vibrational studies of PPV and MEH-PPV [18][19][20][21][22]28]. In the high frequency region, the spectrum at 785 nm presents bands assigned primarily to the backbone modes at 1623 cm Journal of Spectroscopy Figure 3 shows the SERS spectrum of MEH-PPV on gold nanostars.…”

“…The correct choice of exciting radiation allows the use of Raman spectroscopy to investigate different chromophoric segments or to probe modifications in the polymer chains after doping [15][16][17]. Theoretical and experimental vibrational studies of PPV and its oligomers are well reported in the literature describing the structure and the modifications in the neutral and conducting states (n-doped and p-doped) [18][19][20][21][22]. This vibrational characterization has been extended to the PPVbased polymers such as the MEH-PPV, since the polymer backbones are similar [23][24][25][26].…”

Influence of TiO2 nanoparticles on the optical and structural properties of PPV thin films converted at low temperatures

“…The pure PPV sample was made with the 1:1 mol/mol proportion between PTHT and DBS (sodium dodecylbenzenesulfonate) [19]. The assignments of the most important Raman peaks are shown in Table 1 [22][23][24]. The peaks at 1284 and 1496 cm -1 are exclusive from the dye, since the naphthalene group and the C-N bound are only present in Reactive Black 5's structure.…”

Processos radiativos e não radiativos em polímeros conjugados emissores de luz.

“…As transições ópticas passam a ser entre estados eletrônicos-vibracionais (seção 2. intensidades entre as linhas de zero-fônon e suas réplicas. As energias de fônons ηω podem ser obtidas através de medidas de infravermelho e Raman [54]. Neste trabalho, estamos interessados na dependência destes parâmetros com a temperatura T e o grau ou tamanho de conjugação n, de acordo com as relações…”

“…. O modo em 1170 cm -1 é associado a modos vibracionais do PPV com origem no estiramento C -C e dobramento C -H do anel fenil no plano [54] . Já o modo em 1550 cm -1 é devido a vibrações da ligação C=C do anel de fenil [54] .…”