Crystalline and Lamellar Structure of Polypropylene Fibrillated Fibres

2013 ◽  
Vol 203-204 ◽  
pp. 439-442
Author(s):  
Marcin Bączek ◽  
Czesław Ślusarczyk ◽  
Jan Broda
Keyword(s):  
Small Angle ◽  
Crystalline Phase ◽  
Lamellar Structure ◽  
Draw Ratio ◽  
Crystallinity Index ◽  
Orientation Factor ◽  
Processing Conditions ◽  
X Ray ◽  
X Ray Scattering ◽  
The Impact

The effects of processing conditions on the structure of polypropylene fibrillated fibres were studied using a combination of wide- and small-angle X-ray scattering methods. In particular the impact of selected stages of processing on the crystalline and lamellar structure of PP were analyzed. It was stated that crystalline phase is built from α crystals. The crystallinity index as well as the Herman orientation factor of the crystalline phase is found to have a correlation only with the draw ratio of the PP film. The lamellar structure also changes with the draw ratio.

Free volume and lamellar structure of poly vinyl alcohol-nanosized BaTiO3 composite: Positron annihilation and small angle X-ray scattering study

2016 ◽  
Vol 84 ◽  
pp. 100-110 ◽  
Author(s):  
Sandeep K. Sharma ◽  
Jyoti Prakash ◽  
Jitendra Bahadur ◽  
Manjulata Sahu ◽  
Subhashish Mazumder ◽  
...  
Keyword(s):  
Positron Annihilation ◽  
Free Volume ◽  
Small Angle ◽  
Vinyl Alcohol ◽  
Lamellar Structure ◽  
Poly Vinyl Alcohol ◽  
X Ray ◽  
X Ray Scattering ◽  
Scattering Study ◽  
Ray Scattering

Study of Microstructure in Polyethylene Terephthalate(PET) Fiber Using SAXS

2011 ◽  
Vol 332-334 ◽  
pp. 1171-1175
Author(s):  
Xiao Yun Li ◽  
Xiu Hong Li ◽  
Yu Zhu Wang ◽  
Jie Wang
Keyword(s):  
Experimental Method ◽  
Polyethylene Terephthalate ◽  
Small Angle ◽  
Lamellar Structure ◽  
Fiber Diameter ◽  
Saxs Data ◽  
X Ray ◽  
X Ray Scattering ◽  
Edge Scattering ◽  
Pet Fibers

An experimental method was developed in this work to study the PET fibers by synchrotron small-angle X-ray scattering (SAXS). Compared with the traditional measurement in air, the new method measured in the glycerin is helpful to eliminate edge scattering arising from the fiber edge. The results showed that intensity from edge scattering is so high as to cover the microstructure information. PET fiber with a diameter of 25 μm was measured by the new experimental method, and a lobed shape can be seen clearly on the meridian which didn't emerge in traditional measurement. The SAXS data were evaluated to extract parameters of lamellar structure and microvoids. In addition, the effect of fiber diameter on edge scattering was also investigated.

Liquid Crystalline Phase Behavior of Well-Defined Cylindrical Block Copolymer Micelles Using Synchrotron Small-Angle X-ray Scattering

2015 ◽  
Vol 48 (5) ◽  
pp. 1579-1591 ◽  
Author(s):  
Dominic W. Hayward ◽  
Joe B. Gilroy ◽  
Paul A. Rupar ◽  
Laurent Chabanne ◽  
Claire Pizzey ◽  
...  
Keyword(s):  
Block Copolymer ◽  
Phase Behavior ◽  
Small Angle ◽  
Crystalline Phase ◽  
Liquid Crystalline ◽  
X Ray ◽  
X Ray Scattering ◽  
Block Copolymer Micelles ◽  
Copolymer Micelles ◽  
Cylindrical Block

Cocrystallization in random copolymers of poly(β-hydroxybutyrate-co-β-hydroxyvalerate) and its effect on crystalline morphology

1995 ◽  
Vol 73 (11) ◽  
pp. 2094-2100 ◽  
Author(s):  
William J. Orts ◽  
David L. VanderHart ◽  
Terry L. Bluhm ◽  
Robert H. Marchessault
Keyword(s):  
Solid State ◽  
Small Angle ◽  
Crystalline Phase ◽  
Solid State Nmr ◽  
Composition Range ◽  
Crystalline Lattice ◽  
Crystalline Morphology ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

Small-angle X-ray scattering (SAXS) and solid state CPMAS l3C NMR were used to describe the crystalline morphology of a series of bacterially produced poly(β-hydroxybutyrate-co-β-hydroxyvalerate) copolymers containing random distributions of 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (3HV). Modeling of SAXS results showed that the morphology of this isodimorphic system is better described by two phases, crystalline and amorphous, having defects within each domain. This is in contrast to a model with a large interfacial region between phases. For the 3HV composition range 0–27 mol%, the polymer crystallizes in a poly(β-hydroxybutyrate)-type crystalline lattice. Solid state NMR results showed that there is significant incorporation of the 3HV minor component into the poly(β-hydroxybutyrate) crystalline phase over this composition range. The ratio of the 3HV content in the crystalline phase relative to the overall 3HV content is not linear, but increases with increasing 3HV. For the 21 and 27% 3HV samples, the 3HV content in the crystalline phase is as much as 2/3 of the overall 3HV content. Inclusion of 3HV is correlated to an increase in crystalline disorder (as measured by SAXS), implying that it is easier to accommodate the bulkier 3HV comonomer into a crystalline region that already contains defects. Keywords: bacterial polyesters, poly(3-hydroxyalkanates), small-angle X-ray scattering, solid state NMR, cocrystallization.

scholarly journals Rapid screening of in cellulo grown protein crystals via a small-angle X-ray scattering/X-ray powder diffraction synergistic approach

2020 ◽  
Vol 53 (5) ◽  
pp. 1169-1180 ◽  
Author(s):  
Janine Mia Lahey-Rudolph ◽  
Robert Schönherr ◽  
Cy M. Jeffries ◽  
Clément E. Blanchet ◽  
Juliane Boger ◽  
...  
Keyword(s):  
Cell Culture ◽  
Small Angle ◽  
Living Cells ◽  
Protein Crystals ◽  
Rapid Screening ◽  
X Ray ◽  
X Ray Scattering ◽  
A Cell ◽  
The Impact ◽  
Ray Scattering

Crystallization of recombinant proteins in living cells is an exciting new approach for structural biology that provides an alternative to the time-consuming optimization of protein purification and extensive crystal screening steps. Exploiting the potential of this approach requires a more detailed understanding of the cellular processes involved and versatile screening strategies for crystals in a cell culture. Particularly if the target protein forms crystalline structures of unknown morphology only in a small fraction of cells, their detection by applying standard visualization techniques can be time consuming and difficult owing to the environmental challenges imposed by the living cells. In this study, a high-brilliance and low-background bioSAXS beamline is employed for rapid and sensitive detection of protein microcrystals grown within insect cells. On the basis of the presence of Bragg peaks in the recorded small-angle X-ray scattering profiles, it is possible to assess within seconds whether a cell culture contains microcrystals, even in a small percentage of cells. Since such information cannot be obtained by other established detection methods in this time frame, this screening approach has the potential to overcome one of the bottlenecks of intracellular crystal detection. Moreover, the association of the Bragg peak positions in the scattering curves with the unit-cell composition of the protein crystals raises the possibility of investigating the impact of environmental conditions on the crystal structure of the intracellular protein crystals. This information provides valuable insights helping to further understand the in cellulo crystallization process.

scholarly journals Small-Angle X-Ray Scattering Analysis of the Bifunctional Antibiotic Resistance Enzyme Aminoglycoside (6′) Acetyltransferase-Ie/Aminoglycoside (2″) Phosphotransferase-Ia Reveals a Rigid Solution Structure

2012 ◽  
Vol 56 (4) ◽  
pp. 1899-1906 ◽  
Author(s):  
Shane J. Caldwell ◽  
Albert M. Berghuis
Keyword(s):  
Small Angle ◽  
Active Sites ◽  
Solution Structure ◽  
Coenzyme A ◽  
Radius Of Gyration ◽  
Bifunctional Enzyme ◽  
X Ray ◽  
X Ray Scattering ◽  
The Impact ◽  
Ray Scattering

ABSTRACTAminoglycoside (6′) acetyltransferase-Ie/aminoglycoside (2″) phosphotransferase-Ia [AAC(6′)-Ie/APH(2″)-Ia] is one of the most problematic aminoglycoside resistance factors in clinical pathogens, conferring resistance to almost every aminoglycoside antibiotic available to modern medicine. Despite 3 decades of research, our understanding of the structure of this bifunctional enzyme remains limited. We used small-angle X-ray scattering (SAXS) to model the structure of this bifunctional enzyme in solution and to study the impact of substrate binding on the enzyme. It was observed that the enzyme adopts a rigid conformation in solution, where the N-terminal AAC domain is fixed to the C-terminal APH domain and not loosely tethered. The addition of acetyl-coenzyme A, coenzyme A, GDP, guanosine 5′-[β,γ-imido]triphosphate (GMPPNP), and combinations thereof to the protein resulted in only modest changes to the radius of gyration (RG) of the enzyme, which were not consistent with any large changes in enzyme structure upon binding. These results imply some selective advantage to the bifunctional enzyme beyond coexpression as a single polypeptide, likely linked to an improvement in enzymatic properties. We propose that the rigid structure contributes to improved electrostatic steering of aminoglycoside substrates toward the two active sites, which may provide such an advantage.

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