Poly solid-state spectrum

Fig. 35. C-NMR-spectra of aqueous dispersions of poly- -butylcyanoacrylate nanocapsules after 3 h of annealing at different temperatures (a) 50°C, (b) 100°C, (c) 130°C. The ( H)- C crosspolarization spectra (tcp = 1 ms, left column) indicate the loss of the solid capsule wall at higher temperatures (see also Fig. 36). The narrow signals superimposed on the solid-state spectrum of the polymer derive partially from the adsorption of the triglyceride oil and the surfactant to the capsule surface (compare Section 4.4), partially from the residual cp in the liquid phase. The direct excitation spectra (right column) show the liquid and dissolved components with an increasing indication for traces of the n-butylcyanoacrylate monomer which results from depolymerization of the capsule wall material (arrows, see also Fig. 37). ...

Fig. 15.2.38. (a) C- H NMR solution spectrum of poly(PhMA) and (b) C CP-MAS NMR solid-state spectrum of the PhMA-co-HyDA polymer. 

Figure 4,7. (a) Solid state and CHClj solution spectrum of poly(4,4 -didecyl-2,2 -bithioplienc) (b) CHClj solution spectrum of poly(3-decyltliiopliene) prepared with FeCft (c) Solid State spectrum of poly(3-decylthioplicne) prepared with FeCIs [54]. 

In the central part (Sect. 3), the simulation technique will be explained in detail and illustrated by the example of atactic poly(propylene) (Sects. 3.1-3.3). Special sections are devoted to the simulation of the solid state spectrum (Sect. 3.4), the correlation of chemical shift and geometry (Sect. 3.5), a molecular orbital (MO) analysis (Sect. 3.6), the configurational splitting in solution (Sect. 3.7) and the role of the anisotropy of the chemical shift as a source of structural information (Sect. 3.8). 

Fig. 13. Experimental solid state spectrum of atactic poly(propylene) (top) and solution spectrum of configurational splitting in the methylene region (bottom). The broadening in the solid state spectrum is appreciably larger than the configurational splitting. Reprinted with minor changes from [63]...

Fig. 34. Model molecule for PE, definition of the dihedral angles and label of the atoms in the central part of the model molecule (a). Experimental (b) and simulated (c) solid state spectrum of poly (ethylene). The fine lines reflect the contributions of the various conformations (Eq. (3.15), slightly broadened for typographical reasons), whereas the bold line is the overall simulation (Eq. (3.16)). The width of the resonance is slightly overestimated by the simulation. The small upheld peak in the experimental spectrum (at 24 ppm) is most likely due to endgroups which are much enhanced by the technique of recording...

This angular dependence of the interaction parameter can be extended by using the rotational isomeric state approximation to calculate the conformer populations. This approach was used to interpret the solid-state spectrum of poly(3-methyl-l-pentene), which in the amorphous state can have either a four-fold right-handed helix or a nearly equi-energetic four-fold left-handed helix. Three of the six ehemical shifts of a right-handed unit differ from the corresponding resonances of a left-handed unit, and these stereochemical differences are observed [35]. 

Poly(2,5-pyridyl) commonly know as poly(pyridine) has been the subject of considerable research effort as it luminesces in the blue region of the spectrum and may have uses in light emitting diodes (LEDs). Vaschetto and co-workers [103] reported a series of calculations on the molecule and its oligomers. The calculations included both the B3LYP and B3P88 density functions, Hartree-Fock calculations and a periodic solid-state DFT calculation using linear muffin tintype orbitals (LMTO). 

Figure 14 The left hand side shows the band structures of poly(pyridine) calculated using a DFT-LMTO method for helical polymers. The right hand side shows its calculated density of states spectrum (solid line) and the experimental UPS spectrum (dashed line). The UPS spectrum was taken from Miyamae et al. [104]. Reproduced with permission from Vaschetto et al. [103], Figure 6. Copyright 1997 the American Chemical Society.

First introduced to polymer chemistry by Schaefer and collaborators, CP-MAS spectroscopy has already yielded interesting results in both stractural and dynamic studies. The comparison of spectra in solution and in bulk permits identification of frozen conformations, distinction between spectra of crystalline and amorphous phases and measurement of the rate of several eonformational transitions. For example, the C spectrum of the poly(phenylene oxide), 74, in solution consists of five signals while the CP-MAS spectrum displays six. In the solid state the resonance of the aromatic CH appears split into two components. The phenomenon is attributed to the forbidden rotation of the benzene ring around the O. .. O axis, which makes the two carbon atoms indicated with an asterisk no longer equivalent. 

Poly(Pro) can assume two very different conformations poly(Pro)I, a right-handed helix of all cw-peptidestl43] and poly(Pro)II, a left-handed helix of all trans-peptides.[144] Poly(Pro)I is found only in the solid state and in solution in solvents of low polarity, e.g. higher alcohols. Poly(Pro)II is the conformation found in water, TFE, and other polar solvents, and the focus will be on it in this section. The CD spectra of both forms are shown in Figure 8. The poly(Pro)II CD spectrum is characterized by a weak positive nm maximum at 226 nm and a... 

The poly(3, 4 -alkylterthiophene), PTT (2) used in our studies is prepared by FeCl3-mediated oxidative coupling polymerization [39]. PTT with a long alkyl side-chain (R > C6) for example PTT-10 (2, R = n-Ci0H2i) has an ability to self-organize in the solid state as reflected by a bathochromic shift in its UV-visible absorption spectra from solution to thin film (Fig. 4.1a). The solution spectrum of PTT-10 also has a progressive bathochromic shift with concomitant appearance of a longer-... 

There has been a great deal of interest since the mid 1970s in photoelectron spectrometry and the ionization potentials of various A,B-diheteropentalenes have been summarized <84CHEC-I(4)1037>. The photoelectron spectrum of thieno[3,2-6]thiophene (12) was measured in the solid state as well as in the gas phase and has been investigated in comparison with linearly polycondensed poly thiophenes, (66) and (67) <92JCS(P2)765>. 

Figure 15.21. CP/MAS spectra l3C inp-dimethoxybenzene (note splitting induced in ortho carbons due to the asymmetry of the methoxy group), 29Si in poly-[dimethy lsiloxane) (PDMS), and 31P in bone mineral [roughly equivalent to Ca50H(P04)3]. (29Si spectrum reprinted with permission from Beshah K, Mark JE, Himstedt A, Ackerman JL. Characterization of PDMS model junctions and networks by solution and solid state silicon-29 NMR spectroscopy. J Polymer Sci B Polymer Phys. 1986 24 1207-1225. Copyright 1986 John Wiley Sons.)...

Superlattice and low-dimensional physics are some of the most interesting subjects in solid-state physics. A challenging problem in this field is the formation of quantum wire and quantum box structures by using ultra-high technology such as MBE, MOCVD (metallorganic chemical vapor deposition), and related frontier microprocessing. However, this problem has not yet been solved. Poly silane is probably a perfect quantum wire in itself The absorption spectrum of polysilane clearly shows the characteristics of a one-dimensional quantum wire. Even a quantum box or a one-dimensional superlattice can be formed by chemical polymerization, which may be the simplest way. 

Miscibility of amorphous poly(benzyl methacrylate) (PBzMA) and semicrystalline poly(ethylene oxide) (PEO) blends were investigated by solid state NMR. Figure 6 shows the T CP/MAS NMR spectrum of the PBzMA/PEO blend in 80/20 composition and the CP/MAS NMR spectra of various compositions are shown in Fig. 7. The logarithmic plots of C... 

Solid-state H - F-CPMAS, F - H CPMAS, and H fast MAS NMR spectra have been investigated for a semicrystalline polymer, namely poly(vinyl fluoride) (PVF), together with its solution-state F spectrum and static solid-state H pulsed and broad line NMR measurements. ... 

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