Fluorescence spectra of poly

Figure 2 Fluorescence spectra of Poly (VBuPBD) at room temperature (solid line) and 77k (dashed line)...

Figure 8. Time-resolved fluorescence spectra of poly[Lys(Z)2" pyrAla] in N2-bubbled trimethyl phosphate at room temperature. [Pyr]=2xl0 M.

The fluorescence spectra of poly(ACN-co-MAN) showed monomer emission at 346 nm and excimer emission at 405 nm. The intensity of the excimer emission band decreased as the percentage of ACN decreased from 14 to 5 and shifted to a longer wavelength at 412 nm. Corresponding Iq/Im ratios decreased from 0.33 ro 0.13, respectively. 

Depth-distribution of fluorescent dopants in cast polymer film (4) Fluorescence spectra of poly(N-vinylcarbazole) (PVCz) film doped with perylene are shown in Fig. 6. They consist of two broad structureless excimer bands of the polymer with a shoulder at 375 nm and a peak at 420 nra, and perylene band with a vibrational structure above 450 nm. It is worth noting that the perylene fluorescence intensity under the TIR condition is relatively weaker than that under the normal one. Since the boundary surface is selectively excited under the former condition, the structure near the surface should be different from the bulk. It is well known that the excitation energy migrates over carbazolyl chromophores and is trapped in the doped perylene efficiently. Therefore, the present result means that energy migration efficiency in the host polymer and/or the dopant concentration are a function of the depth from the interface. 

FIGURE 12. Fluorescence spectra of poly(styrene) in ethyl acetate as function of concentration, normalized at 300 nm. Concentrations in g/z (1)... 

FIGURE 15. Gated time-resolved fluorescence spectra of poly(l-vinylnaphthalene) in dichloromethane solution, as in Figure 13. (a) Early gate At = 0,... 

Figure 4.8 Fluorescence spectra of poly(phenyl methacrylate) in THF, 4.8 x 10 M, at 266 K (1) and of phenyl methacrylate in TFIF (2)...

For example, Moore has observed anomalous shifts in the fluorescence spectra of poly(aiylacetylene) dendrimers with generation number and in this case a dramatic transition was observed between generation 4 and 5 in pentane (P). 

Fluorescence and phosphorescence spectra of poly(propynoic acid)(FPA), polyphenylene (PP), and DPAcN show that the difference of energies between the lower excited singlet and triplet states, as observed in the case of PP (583 nm) and DPAcN (528 nm), is considerably greater than that of poly(propynoic acid) (270—300 nm) which besides transitions may undergo rr - transitions. PCSs showing only... 

Figure 4. Fluorescence spectra of (a) poly(styrene) and (b) styrene/maleic anhydride alternating copolymer in tetrahydrofuran at 20°C. Excitation wavelength 265 nm.

A similar approach was taken by Moore [27], utilizing poly(phenyl acetylene) dendrimers with a dimethylbenzene moiety attached at the core of the dendrimer. An anomalous shift (41 nm) in the fluorescence spectra of the probe in various nonpolar hydrocarbon solvents was observed for G5 and G6, but not for G1 to G4. This observation confirmed significant in the size and shape changes for these dendrimers between G4 and G5. 

The use of PCA for the classification of both natural and synthetic polymers was demonstrated by Vazquez et al. [119]. In their work, the researchers recorded Totai X-Ray Fluorescence (TXRF) spectra of scleroglucan, xanthan, glucomannan, poly(ethylene oxide), and polyacrylamide and subjected the resulting spectral data to PCA. To the naked eye, the X-ray fluorescence spectra of the polymers look virtually identical. However, when subjected to PCA it could be shown that the first two principal components contain approximately 96% of the variance in the dataset. When plotting the scores of the two components against each other, six distinct clusters are observed, which clearly differentiate the individual polymers. 

Figure 2. (a) Fluorescence spectra of eosine-poly-L-lysine immobilized between two PSFs (1) and between two glass slides (2) (b) Fluorescence spectra of hematoxylin-eosine-poly-L-lysine immobilized betweai two PSFs (1) and between two glass slides (2). 

Polyfluorene was first synthesized by Fukuda et al. via oxidative polymerization of huorene monomers using ferric chloride as a catalyst.2,11 Both mono- and dialkyl-substituted polyfluorenes were synthesized. Figure 10.1 shows the repeat unit of poly(9,9/-dialkyl-huorene-2,7-diyl). The polymers are soluble in common solvents such as chloroform, dichloromethane, and toluene. Figure 10.2 shows the absorption and fluorescence spectra of a solution of poly(9,9/-dihexylfluorene-2,7-diyl) (PDHF) in chloroform.11 The onset of the tt-tt absorption is at 420 nm, rising to a peak at 380 nm, yielding an optical gap of 2.95 eV. The fluorescence spectrum contains vibronic peaks at 417 and 440 nm and a shoulder at 470 480 nm. 

Most notable among the Dow copolymers is poly(9,9-dioctylfluorene-a//-benzothiadiazole) (F8BT). Figure 10.24 shows the absorption and fluorescence spectra of a blend containing 95% PFO and 5% F8BT the copolymer repeat unit... 

Figure 3.103. Fluorescence spectra of a 7-mm long and 10-mm diameter ASPT doped poly-HEMA (HEMA = hydroxyethylmethacrylate) rod excited with 1.06-pm radiation, (a) Excitation energy is below the lasing threshold and (b) the spectra were recorded above the lasing threshold energy. Solid line 0.4 mJ dotted line 0.5 mJ long dashed 0.8 mJ. (From Ref. [158] with permission of the American Institute of Physics.)...

CPF spectroscopy measures a difference in intensities of left-and right-circularly polarized components of a fluorescence emitted from a chiral fluorophore and reflects the chirality of conformations and interactions in the excited state (2 ). Figure 1 shows CPF spectra of poly(l- and 2-napAla)s measured in DMF solution (12). The ordinate of the CPF spectra is the Kuhn s emission dissymmetry factor g, ... 

Figure 7. Fluorescence (lower curves) and CPF (upper curves) spectra of poly(Lys(Z) -pyrAla] in N -bubbled trimethyl phosphate, 5°C, [Pyr] = 1,8x10 M. (---------) m=2, (----) m=3.

Figure 3. Absorption and emission spectra of poly(methylphenyl-silylene) in 2-methyltetrahydrofuran at 77 K. The fluorescence spectrum vas measured with a resolution of 0.265nm. The long wavelength emission vas measured with a resolution of 1.32nm ...

Figure 5- Polarization of fluorescence spectra of a dilute solution of poly(methyl n-propylsilylene) in 7 3 3-methylpentane isopentane at TT K. Excitation wavelengths , 297 nm A, 313nm , 33 nm , 338nm.

Fig. 6. Normalized fluorescence spectra of cast poly(N-vinylcarbazole) film doped with 6.2x10 mole perylene per mole carbazole unit. (A) total internal reflection condition with =73.6°. (B) normal excitation condition. Both spectra are...

Figure 8.9 Electronic absorption and fluorescence spectra of If measured at 20 l< in poly(vinyl butyral) film. The two emission curves correspond to excitation of different fractions of the ground state tautomeric forms.

Figure 2. Confocal laser scanning microscopic image (A) fluorescence of pectin, (B) fluorescence of soybean flour protein, (C) fluorescence spectra of pectin and soybean flour protein, and (D) reflection of poly(ethylene oxide). Field width A, B and D, 480 pm.

Fullerene-styrene copolymers have been prepared in radical initiated and thermal polymerization reactions [148-151]. In radical copolymerizations of Cgg and styrene, copolymers with Cgg contents up to 50% (wt/wt) can be obtained [150]. Electronic absorption spectra of the copolymers are very different from that of monomeric C o (Fig. 36). The absorptivities per unit weight concentration of the copolymers j increase with increasing C q contents in the copolymers in a nearly linear relationship (Fig. 37). Fluorescence spectra of the Cgg-styrene copolymers, blue-shifted from the spectrum of monomeric Cgo, are dependent on excitation wavelengths in a systematic fashion [149]. Interestingly, the observed absorption and fluorescence spectral profiles of CgQ-styrene and Cyg-styrene copolymers are very similar, even though the spectra of monomeric CgQ and C70 are very different. The absorption and fluorescence spectra of the fullerene-styrene copolymers are also similar to those of the pendant Cgg-poly-styrene polymer (19) prepared in a Friedel-Crafts type reaction [150,156]. 

Figure 11.24 Fluorescence spectra of 27.1 nM ACRAM in THF with and without photoresist solution formulated from poly(CBN-a/t-MAH) and TPSHFA (4.41 x 10 M). (1) +0 [xL of photoresist/THF. (2) +35 [xL of photoresist/THF. (3) +60 xL of photoresist/THF. (4) +120 xL of photoresist/THF. (Reprinted with permission from American Chemical Society.

FIGURE n. Absorption and fluorescence spectra of (a) ethylbenzene, (b) isotactic poly(styrene) in... 

FIGURE 13. Gated time-resolved fluorescence spectra of atactic poly(styrene) in dichloromethane solution, (a) Early gated spectrum, delay At = O jg, gate width 6t = 3 nsec, (b) Late gated spetrum. At = 45 nsec, 6t = 3 nsec [after figure In J. Polym. Sci., Phys. Ed., 1978, 16, 1499.]... 

---