Solid state properties of poly-β-hydroxybutyrate and of its oligomers

1981 ◽  
Vol 59 (1) ◽  
pp. 38-44 ◽  
Author(s):  
R. H. Marchessault ◽  
Suzanne Coulombe ◽  
Hiromichi Morikawa ◽  
Keizo Okamura ◽  
J. F. Revol

The solid state properties of poly-β-hydroxybutyrate (PHB) were investigated for samples with degrees of polymerization [Formula: see text] from 4 to 994. The observed melting points ranged from 47 °C to 180 °C. Electron diffractograms on carefully prepared single crystals of a high molecular weight sample provided data which confirmed the reported a and b parameters from X-ray fiber diffraction and provided clear justification for the P212121 space group. The observed intensities in the electron diffractogram, corresponding to (hk0) reflections, were compared with the predicted intensities for two proposed structures in the literature. The observed and calculated structure factors for both structures were in good agreement. Small angle X-ray diffraction of the meridional maximum for annealed "cold drawn" and "hot drawn" fibers showed a distinctly different dependence on temperature than the maximum for stacks of lamellar single crystals. For oligomers a long spacing was observed which was about twice the length of the sample [Formula: see text] multiplied by the crystalline advance per monomer.

Author(s):  
Kenneth M. Richter ◽  
John A. Schilling

The structural unit of solid state collagen complexes has been reported by Porter and Vanamee via EM and by Cowan, North and Randall via x-ray diffraction to be an ellipsoidal unit of 210-270 A. length by 50-100 A. diameter. It subsequently was independently demonstrated by us in dog tendon, dermis, and induced complexes. Its detailed morphologic, dimensional and molecular weight (MW) aspects have now been determined. It is pear-shaped in long profile with m diameters of 57 and 108 A. and m length of 263 A. (Fig. 1, tendon, KMnO4 fixation, Na-tungstate; Fig. 2a, schematic of unit in long, C, and x-sectional profiles of its thin, xB, and bulbous, xA portions; Fig. 2b, tendon essentially unmodified by ether and 0.4 N NaOH treatment, Na-tungstate). The unit consists of a uniquely coild cable, c, of ṁ 22.9 A. diameter and length of 2580-3316 A. The cable consists of three 2nd-strands, s, each of m 10.6 A.


1991 ◽  
Vol 46 (11) ◽  
pp. 947-950
Author(s):  
W.-M. Kuschke ◽  
P. Lamparter ◽  
S. Steeb

AbstractAmorphous Ni-Zr-alloys can be prepared by melt-spinning within a wide range of composition. Studies by X-ray diffraction yielded structure factors, pair correlation functions, total coordination numbers and atomic distances in dependence on the nickel concentration in the range of 25 up to 45 atomic percent. The change of the total coordination number and atomic distances turned out to be linear with the composition in this range. This is in good agreement with the linear composition dependence of the superconducting transition temperature, magnetic susceptibility, crystallization temperature, and electrical resistivity in the investigated range of composition.


2011 ◽  
Vol 34 (5-6) ◽  
pp. 153-153
Author(s):  
Libasse Diop

Abstract Solid-state and solution 117Sn nuclear magnetic resonance studies of C2O4(SnPh3)2 have been carried out and found to be in good agreement with the tetrahedral environment of the tin (IV) atom as found from the solid state structure, previously determined by a single crystal X-ray diffraction analysis.


2002 ◽  
Vol 55 (4) ◽  
pp. 271 ◽  
Author(s):  
N. B. Singh ◽  
A. Pathak ◽  
R. Fröhlich

Vapours of p-benzoquinone (BQ) have been found to react with solid 2,4,5-trichlorophenol (TCP). The reaction product (BQ-TCP) separated in the form of monoclinic single crystals, the structure of which was determined by X-ray diffraction to reveal that the two molecules are linked by a single hydrogen bond between the carbonyl oxygen of BQ and the phenolic hydrogen of TCP.


2021 ◽  
Author(s):  
Sivasubramani Vediyappan ◽  
Arumugam Raja ◽  
Ro Mu Jauhar ◽  
Ramachandran Kasthuri ◽  
Vishwanathan Vijayan ◽  
...  

Abstract 2-amino-5-nitropyridine 4-chlorobenzoic acid (1:1) (2A5NP4CBA), a potentially useful organic adduct compound has been synthesized and grown as optically transparent single crystals by conventional slow evaporation solution technique (SEST) for the first time in the literature. The formation of the new crystalline material was confirmed by the single-crystal X-ray diffraction (SXRD) analysis and the crystal structure of the grown crystal was found to be monoclinic. Fourier transform infrared (FTIR) spectrum has been recorded by the KBr pellet technique to determine the various vibrational functional groups in the title material. The powder X-ray diffraction (PXRD) and high-resolution X-ray diffraction (HRXRD) analyses have been carried out and the obtained results reveal that the grown crystal has a single-phase and is free from structural grain boundaries. The obtained less value (32 arc-s) of full width at half maximum (FWHM) for (001) plane indicates the excellent crystalline quality of the title 2A5NP4CBA single crystal. The linear optical properties were evaluated by the UV-vis-NIR absorption and transmittance analyses and the obtained results reveal that the grown crystal possesses more than 70% of optical transmittance window with the cut-off edge at 419 nm. The thermal analysis discloses that the grown crystal possesses good thermal stability of about 187°C. To determine the appropriateness of the grown crystal for the high-power laser application, laser damage threshold (LDT) analysis has been carried out by Nd: YAG laser of a wavelength of 1064 nm. The third-order nonlinear optical coefficients such as nonlinear absorption (β), nonlinear refraction (n 2 ) and nonlinear susceptibility (χ (3) ) have been evaluated by utilizing the single beam Z-scan technique using a solid-state laser of wavelength 532 nm. The calculated ꭓ (3) value is found to be reasonably good compared to other organic single crystals which are reported in the literature. The optical limiting (OL) behavior of the title crystal was evaluated using a solid-state laser at 532 nm and the limiting threshold was found to be 7.8 mW/cm 2 .


1982 ◽  
Vol 37 (5) ◽  
pp. 419-426 ◽  
Author(s):  
M. Polcarová ◽  
J. Brádler

Dynamical theory of the X-ray diffraction on a crystal containing misfit boundary was applied to the interpretation of the contrast observed in X-ray topographs on 90° magnetic domain walls in single crystals of an Fe-Si alloy. The integrated intensities were computed for several cases corresponding to the actual conditions of experiments. Good agreement of theoretical and experi­mental results was obtained.


2004 ◽  
Vol 59 (3) ◽  
pp. 281-285 ◽  
Author(s):  
Matthias Weil

Colourless single crystals of the compounds CdXO4 · 2 HgO (X = S, Se) were obtained under hydrothermal conditions (250 °C, 5 d), starting from stoichiometric amounts of HgO, CdSO4 ·7H2O and CdSeO4 ·2H2O, respectively. The crystal structures were determined from X-ray diffraction data sets. The CdXO4 · 2HgO compounds crystallise isotypically with two formula units in space group P1̅ (# 2) [CdSO4 · 2HgO (CdSeO4 · 2HgO): a = 6.793(2) (6.9097(5)) Å , b = 7.205(2) (7.1786(6)) Å , c=7.359(2) (7.4556(6)) Å ,α =73.224(6) (74.586(2))°, β =66.505(6) (68.229(1))°, γ =63.054(5) (63.886(1))°, 1670 (1786) structure factors, 92 parameters, R[F2 > 2σ(F2)] = 0.0379 (0.0244)] and are made up from zig-zag [O-Hg-O]∞ chains with very short bonds of d̅(Hg-O) 2.025 Å , distorted [CdO6] octahedra (d̅(Cd-O)= 2.297 Å ), and XO4 tetrahedra (d̅(S-O)= 1.458 Å , d̅(Se-O)= 1.633 Å ) as the main building blocks. The CdXO4 ·2HgO compounds reveal no structural relationship with the corresponding HgXO4 ·2HgO phases


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