Effect of Volume Fraction on the Order−Disorder Transition in Low Molecular Weight Polystyrene-block-polyisoprene Copolymers. 2. Order−Disorder Transition Temperature Determined by Small-Angle X-ray Scattering

1996 ◽  
Vol 29 (6) ◽  
pp. 2113-2123 ◽  
Author(s):  
Toshihiro Ogawa ◽  
Naoki Sakamoto ◽  
Takeji Hashimoto ◽  
Chang Dae Han ◽  
Deog Man Baek
Keyword(s):  
Molecular Weight ◽  
Transition Temperature ◽  
Small Angle ◽  
Volume Fraction ◽  
Low Molecular Weight ◽  
Disorder Transition ◽  
X Ray ◽  
X Ray Scattering ◽  
Disorder Transition Temperature ◽  
Ray Scattering

scholarly journals Characterization of Crystal Microstructure Based on Small Angle X-ray Scattering (SAXS) Technique

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 443 ◽  
Author(s):  
Hongfan Wang ◽  
Jinjiang Xu ◽  
Shanhu Sun ◽  
Yanru Liu ◽  
Chunhua Zhu ◽  
...  
Keyword(s):  
Small Angle ◽  
Volume Fraction ◽  
Surface Effect ◽  
Crystal Surface ◽  
Particle Density ◽  
Test Results ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

Small-angle X-ray scattering (SAXS) is an effective method to obtain microstructural information of materials. However, due to the influence of crystal surface effects, SAXS has a deviation in the characterization of the crystal microstructure. In order to solve the influence of crystal surface effect on the internal defect signal, the microstructure of Octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) crystal was characterized by soaking the sample in the matching solution. We found that the absolute scattering intensity, specific surface and volume fraction of the sample in the matching solution are significantly lower than the initial sample, which solves the influence of the crystal surface effect on the test results. Comparing the scattering results of the samples in different electron density matching solutions, it was found that the best result was obtained when using GPL-107 perfluoropolyether (PFPE) matching solution and the same law was obtained by controlling the experiment with 2,4,6,8,10,12-hexanitrohexaazaisowurtzitane (CL-20) crystal. The fitting density was calculated according to the theoretical density and void volume fraction of the sample, and the calculated results are close to the test results of Particle Density Distribution Analyzer (PDDA). Based on this paper, we provide a method to obtain the correct information of crystal microstructure.

Observations of G-P Zone Reversion in Al-Zn-Mg Alloys by Small-Angle X-Ray Scattering and Transmission Electron Microscopy

1965 ◽  
Vol 9 ◽  
pp. 59-73
Author(s):  
R. W. Gould ◽  
E. A. Starke
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Small Angle ◽  
Volume Fraction ◽  
Magnesium Content ◽  
Mg Alloys ◽  
X Ray ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Ray Scattering

AbstractA study of the reversion process in Al-Zn-Mg alloys has been made using small-angle X-ray scattering and transmission electron microscopy techniques. The rate and mode of Guinier-Preston zone dissolutions was investigated as a function of magnesium content, prior zone radius, and reversion temperature. Results indicate that in this system the reversion process is characterized by the preferential dissolution of the smallest G-P zones present after cold aging with a corresponding decrease in the volume fraction of zones. The amount of reversion at a specific temperature is dependent on magnesium content, however, the rate of reversion is independent of magnesium content.

scholarly journals Phase densities and lamellar morphologies of semicrystalline polyethylenesviaabsolute small-angle X-ray scattering measurements

2015 ◽  
Vol 48 (5) ◽  
pp. 1498-1506 ◽  
Author(s):  
Monika Basiura-Cembala ◽  
Kurt Erlacher ◽  
Jan Skov Pedersen ◽  
Bart Goderis
Keyword(s):  
Amorphous Phase ◽  
Small Angle ◽  
Volume Fraction ◽  
Distribution Functions ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Scattering ◽  
Model Independent ◽  
The Absolute ◽  
Ray Scattering

With the crystalline volume fraction from small-angle X-ray scattering (SAXS) and the density of the crystalline phase from wide-angle X-ray diffraction, the amorphous phase density of two representative polyethylenes was calculated as a function of temperature using the absolute total SAXS scattering power or invariant. The density of the amorphous phase in semicrystalline polyethylene is crystallinity independent and is lower than melt-extrapolated values reported in the literature. Model-independent SAXS-based crystallinity values can be calculated with the aid of the densities of the crystalline and amorphous phase and the absolute SAXS invariant. Such model-independent crystallinity values can be used in SAXS curve-shape analysis procedures to obtain the average thickness of the crystalline and amorphous layers also in the case of non-ideal lamellar semicrystalline polymer morphologies for which the number-average long period cannot be retrieved from the maxima in correlation functions or interface distribution functions.

Sign in / Sign up

Export Citation Format

Share Document