Report No xxxx - Instytut Fizyki JÄdrowej PAN

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THE GLASS TRANSITION TIME SCALE AND CONFIGURATIONAL ENTROPY IN POLYMERS: AN EXPERIMENTAL MOLECULAR VIEW J. E. Wolak, X. Jia, Jeffery L. White Department of Chemistry, North Carolina State University, Campus Box 8204, Raleigh, North Carolina 27695-8204 We report direct experimental observation of local conformational dynamics in a polymer chain at the calorimetric glass transition temperature T g . Variable-temperature 2D solid-state exchange NMR, at natural abundance, reveals segmental dynamics in pure polyisobutylene (PIB) occurring on a timescale of several seconds over the T g range observed by DSC (203-208 K). To our knowledge, this is the first direct observation of molecular-level conformer interchange (trans-trans/trans-gauche/gauche-gauche) at the caloric glass transition temperature. Our results provide a chronologically accurate and pedagogically advantageous demonstration of molecular processes during a polymer phase transition, relative to traditional bulk mechanical and calorimetric techniques. tt tg/gt gg More importantly, we use a miscible blend, PIB with PEB66 (polyethylene-co-1- butene in which the concentration of 1-butene comonomer units is 66 weight %), to demonstrate a general strategy for quantitative evaluation of configurational entropy changes via combination of temperature-dependent 2D exchange NMR and Adams-Gibbs theory. Our results on the T g timescale are directly relevant to fundamental understanding of the T g length-scale, i.e., the dimension of cooperatively rearranging regions. 96
13 C CPMAS NMR OF ANTHOCYANINS AND THEIR SUGAR DERIVATIVES Michał Wolniak 1 , * Jan Oszmiański 2 , Iwona Wawer 1 1 Department of Physical Chemistry, Faculty of Pharmacy, Medical University of Warsaw, Banacha 1, 02-097 Warsaw, Poland; 2 Department of Fruit and Vegetable Processing, Agricultural University, Norwida 25, 50-375 Wrocław, Poland Anthocyanins are water-soluble pigments, widely distributed in the plant kingdom. They are second order metabolites and are responsible for a great variety of colors that occur in petals, fruits and vegetables [1]. Unfortunately, unlike flavonoids, anthocyanins received much less attention. It seemed interesting to examine the structure of anthocyanins in the solid state. The studied compounds: cyanidin chloride was purchased from Carl-Roth, cyanidin galactoside and cyanidin rutinoside were obtained from Agricultural University, Wrocław. NMR spectrometers: cross-polarization (CP) magic-angle spinning (MAS) solid-state 13 C NMR spectra were recorded on a Bruker AVANCE DSX-400 instrument at 100.61 MHz. The samples were spun at 8 kHz in 4mm ZrO 2 rotor. 13 C Chemical shifts were calibrated indirectly through the glycine CO signal recorded at 176.03ppm relative to TMS. 1 H and 13 C NMR spectra for the samples in acetone and methanol were recorded on a Bruker Avance 500 MHz spectrometer equipped with an inverse detection probe. The experiments were run using standard Bruker software. The structure of cyanidin and its derivatives: OH Cl 2' 3' 4' HO 8 O 1' 7 9 2 6' 5' 6 10 3 5 4 OH OR OH 1.R=H cyanidin; 2.R=galactose, cyanidin galactoside; 3.R=rutinose, cyanidin rutinoside. 13 C NMR spectra of 1-3 were recorded for solution and solid state. Unfortunately, the correct assignment of the signals is not an easy task. Positive charge at oxygen atom of flavylium cation and the presence of chloride anion makes the comparison of cyanidin chloride with similar compounds somewhat difficult. The signals in CPMAS spectra were assigned with the aid of solution data. Some signals were identified using dipolar dephasing and short contact time sequences. NMR shielding constants were calculated using GIAO DFT method, as an aid in the reliable spectra assignment. 97
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The Henryk Niewodniczański INSTITU
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Contents R. Banyś, A. Słowik, M.
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J. Kolmas, M. Uniczko, E. Kalinowsk
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Ł. Popenda, Z. Gdaniec, G. Dominia
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USEFULNESS OF PROTON MAGNETIC RESON
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INFLUENCE OF PARAMAGNETIC IONS ON F
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NMR RELAXATION OF PAPER SAMPLES Bar
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SPIN-LATTICE RELAXATION OF D 2 QUAN
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INVESTIGATION OF NEUROPROTECTING EF
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OPTICAL PUMPING OF 3 He Katarzyna C
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NMR STUDY OF GELATION PROCESS OF LO
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MRI INVESTIGATIONS OF HYDROGEL FORM
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CHEMICAL SHIFT TITRATION AT THE INT
Page 27 and 28:
LOCAL DYNAMICS AND ORGANIZATION OF
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1 H NMR DETECTION OF σ-ADDUCTS IN
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HYDRATION OF WHEAT PHOTOSYNTHETIC M
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References: 1. H. Harańczyk On wat
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(EDV) and end-systolic (ESV) volume
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THE MOST STABLE POLYMORPHIC FORM OF
Page 39 and 40:
A DETERMINATION OF ABSOLUTE SHIELDI
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DIAGNOTIC VALUE OF MRI IN CONVERSIO
Page 43 and 44:
NMR AND FTIR STUDY OF MOLECULAR DYN
Page 45 and 46: EFFECTS OF INTERMOLECULAR INTERACTI
Page 47 and 48: 600000 Integral of 1D MRI profils [
Page 49 and 50: simultaneous analyse of the tempera
Page 51 and 52: 1 H NMR STUDIES OF PLATINUM(II) CHL
Page 53 and 54: 35 Cl-NQR STUDY OF ELECTRONIC STRUC
Page 55 and 56: 35 Cl- NQR AND 1 H-NMR STUDY OF MOL
Page 57 and 58: THE SYNTHESIS AND NMR ANALYSIS OF T
Page 59 and 60: STUDY OF MOTIONAL PROCESSES OF DRAW
Page 61 and 62: intensity (arb. units) 0,20 0,15 0,
Page 63 and 64: data for Cβ-nonplanar model 3 are
Page 65 and 66: T 1 DISPERSION AND SELF-DIFFUSION N
Page 67 and 68: A LOW FIELD MRI SYSTEM FOR HYPERPOL
Page 69 and 70: 1 H MAS NMR OF FLAVONOIDS Katarzyna
Page 71 and 72: EFFECT OF TEMPERATURE ON LIPOSOME S
Page 73 and 74: 1 H, 13 C NMR AND GIAO/DFT CALCULAT
Page 75 and 76: NMR STUDY OF THE HUMIC ACIDS EXTRAC
Page 77 and 78: NMR STUDY OF LAYERED ANGANITE La 1.
Page 79 and 80: MAGNETIC SUSCEPTIBILITY EVALUATION
Page 81 and 82: A NOVEL SOURCE OF MAGNETIC FIELD FO
Page 83 and 84: DETERMINATION OF AMINO ACIDS IN BOD
Page 85 and 86: MOLECULAR DYNAMICS OF TERT-BUTYL CH
Page 87 and 88: MR MICROSCOPY IN COMPARISON OF YOUN
Page 89 and 90: NH CH CH 2 NH CH CO COONa n CH 2 m
Page 91 and 92: 35 Cl-NQR STUDY OF MOLECULAR DYNAMI
Page 93 and 94: 35 Cl-NQR STUDY OF THE SUBSTITUENT
Page 95: 13 C AND 1 H NUCLEAR MAGNETIC SHIEL
Page 99 and 100: INVESTIGATION OF TRANSESTERIFICATIO
Page 101 and 102: T 2 RELAXATION MAP OF ARTICULAR CAR
Page 103 and 104: MICROTOMOGRAPHY STUDIES OF TABLETS
Page 105 and 106: MAPPING OF THE BI-EXPONENTIAL DIFFU
Page 107 and 108: DEUTERIUM NMR IN RMn 2 D 2 (R = Y,
Page 109 and 110: The neutron scattering (IINS, QNS,
Page 111 and 112: STRUCTURE OF 4-QUINOLINONES ANALYSE
Page 113: NMR MULTIPOLE RELAXATION IN THE ROT
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