scholarly journals Alternating Gyroid Network Structure in an ABC Miktoarm Terpolymer Comprised of Polystyrene and Two Polydienes

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1497 ◽  
Author(s):  
Dimitrios Moschovas ◽  
Gkreti-Maria Manesi ◽  
Andreas Karydis-Messinis ◽  
George Zapsas ◽  
Konstantinos Ntetsikas ◽  
...  
Keyword(s):  
Network Structure ◽  
Morphological Characterization ◽  
Degree Of Polymerization ◽  
Scanning Calorimetry ◽  
X Ray ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Three Phase ◽  
Microdomain Structure

The synthesis, molecular and morphological characterization of a 3-miktoarm star terpolymer of polystyrene (PS, M¯n = 61.0 kg/mol), polybutadiene (PB, M¯n = 38.2 kg/mol) and polyisoprene (PI, M¯n = 29.2 kg/mol), corresponding to volume fractions (φ) of 0.46, 0.31 and 0.23 respectively, was studied. The major difference of the present material from previous ABC miktoarm stars (which is a star architecture bearing three different segments, all connected to a single junction point) with the same block components is the high 3,4-microstructure (55%) of the PI chains. The interaction parameter and the degree of polymerization of the two polydienes is sufficiently positive to create a three-phase microdomain structure as evidenced by differential scanning calorimetry and transmission electron microscopy (TEM). These results in combination with small-angle X-ray scattering (SAXS) and birefringence experiments suggest a cubic tricontinuous network structure, based on the I4132 space group never reported previously for such an architecture.

scholarly journals Preparation and Characterization of Natural Zeolite Modified with Iron Nanoparticles

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Alvaro Ruíz-Baltazar ◽  
Rodrigo Esparza ◽  
Maykel Gonzalez ◽  
Gerardo Rosas ◽  
Ramiro Pérez
Keyword(s):  
Kinetic Models ◽  
Iron Nanoparticles ◽  
Morphological Characterization ◽  
Adsorption Kinetic ◽  
X Ray Diffraction ◽  
Modified Zeolite ◽  
X Ray ◽  
Transmission Electron ◽  
Zeolite Modification

This study is aimed at investigating the structural and morphological characterization of natural and modified zeolite obtained from the state of Oaxaca (Mexico). Iron nanoparticles were used for the zeolite modification. The iron nanoparticles were loaded on the zeolite surface by homogeneous nucleation. Adsorption kinetic models of pseudo first and second order were surveyed. The characterization of pristine and modified zeolite was performed by Fourier transform infrared (FTIR), transmission electron microscopy (TEM), and X-ray diffraction (XRD). From the results, three main phases were identified: clinoptilolite, mordenite, and feldspar. We could also determine the adsorption capacity of the zeolites by means of adsorption kinetic models.

Synthesis and Characterization of Organic/Inorganic Interpenetrating Polymer Networks

1995 ◽  
Vol 385 ◽  
Author(s):  
Barry J. Bauer ◽  
Catheryn L. Jackson ◽  
Da-Wei Liu
Keyword(s):  
Sol Gel ◽  
Polymer Networks ◽  
Interpenetrating Polymer Networks ◽  
X Ray ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Pure Phases ◽  
Hydrolysis Of ◽  
Polymerization Conditions

ABSTRACTInterpenetrating polymer networks have been synthesized by performing sol-gel chemistry and conventional organic polymerizations in mixtures of the monomers. The organic polymers were acrylates, and the inorganic phase was SiO2 formed by hydrolysis of orthosilicates. Polymerizations were conducted at a variety of relative rates, and the chemistry was designed to allow different amounts of grafting between the components. The morphology was characterized by transmission electron microscopy and small angle neutron and x-ray scattering. Wide variations in morphology were observed depending on the polymerization conditions, ranging from grossly phase separated to dendritic to finely divided structures (at a 100Å size scale). The phases ranged from mixtures of the two components to relatively pure phases. The interface between the phases ranged from very narrow to relatively broad.

Characterization of pitches by X-ray scattering and differential scanning calorimetry

Fuel ◽  
1993 ◽  
Vol 72 (9) ◽  
pp. 1301-1303 ◽  
Author(s):  
Henry Preiss ◽  
Klaus Szulzewsky ◽  
Peter Kölsch
Keyword(s):  
Differential Scanning Calorimetry ◽  
Scanning Calorimetry ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

Characterization of Nanocrystalline γ–Fe2O3Prepared by Wet Chemical Method

1999 ◽  
Vol 14 (4) ◽  
pp. 1570-1575 ◽  
Author(s):  
G. Ennas ◽  
G. Marongiu ◽  
A. Musinu ◽  
A. Falqui ◽  
P. Ballirano ◽  
...  
Keyword(s):  
Isothermal Treatment ◽  
X Ray Diffraction ◽  
Ferrous Chloride ◽  
Scanning Calorimetry ◽  
Direct Transformation ◽  
X Ray ◽  
Transmission Electron ◽  
Xrd Techniques ◽  
Kinetics Of

Homogeneous maghemite (γ–Fe2O3) nanoparticles with an average crystal size around 5 nm were synthesized by successive hydrolysis, oxidation, and dehydration of tetrapyridino-ferrous chloride. Morphological, thermal, and structural properties were investigated by transmission electron microscopy (TEM), differential scanning calorimetry (DSC), and x-ray diffraction (XRD) techniques. Rietveld refinement indicated a cubic cell. The superstructure reflections, related to the ordering of cation lattice vacancies, were not detected in the diffraction pattern. Kinetics of the solid-state phase transition of nanocrystalline maghemite to hematite (α–Fe2O3), investigated by energy dispersive x-ray diffraction (EDXRD), indicates that direct transformation from nanocrystalline maghemite to microcrystalline hematite takes place during isothermal treatment at 385 °C. This temperature is lower than that observed both for microcrystalline maghemite and for nanocrystalline maghemite supported on silica.

scholarly journals Synthesis and Characterization of Orotic Acid Loaded Chitosan Inclusion Complex

2020 ◽  
Vol 10 (01) ◽  
pp. 1-4
Author(s):  
ABM Helal Uddin ◽  
Abdelkader Hassani ◽  
Abul K. Azad ◽  
Hamid H. Enezei ◽  
Siti A. Hussain
Keyword(s):  
Electron Microscopy ◽  
Inclusion Complex ◽  
Orotic Acid ◽  
Drug Delivery Systems ◽  
Freeze Drying ◽  
Synthesis And Characterization ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transmission Electron

The current study aims to improve drug release properties of orotic acid loaded with chitosan inclusion complex (OA/CS). The OA/CS inclusion complex was synthesized using the freeze-drying technique. The characterization of inclusion OA/CS was carried out using fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), differential scanning calorimetry (DSC), zeta sizer, and transmission electron microscopy (TEM). Furthermore, the size of OA/CS ranged between 58 nm and 200 nm, and the zeta potential was 30 mV. Thus, this study indicates that OA/CS has a promising future to develop a carrier for drug delivery systems further.

scholarly journals The disease associated Tau35 fragment has an increased propensity to aggregate compared to full-length tau

2021 ◽  
Author(s):  
Chen Lyu ◽  
Stefano Da Vela ◽  
Youssra K Al-Hilaly ◽  
Karen Marshall ◽  
Richard Thorogate ◽  
...  
Keyword(s):  
Progressive Increase ◽  
Full Length ◽  
Motor Dysfunction ◽  
Truncated Form ◽  
X Ray ◽  
Force Microscopy ◽  
X Ray Scattering ◽  
Atomic Force ◽  
Transmission Electron

Tau35 is a truncated form of tau found in human brain in a subset of tauopathies. Tau35 expression in mice recapitulates key features of human disease, including progressive increase in tau phosphorylation, along with cognitive and motor dysfunction. The appearance of aggregated tau suggests that Tau35 may have structural properties distinct from those of other tau species that could account for its pathological role in disease. To address this hypothesis, we performed a structural characterization of monomeric and aggregated Tau35 and compared the results to those of two longer isoforms, 2N3R and 2N4R tau. We used small angle X-ray scattering to show that Tau35, 2N3R and 2N4R tau all behave as disordered monomeric species but Tau35 exhibits higher rigidity. In the presence of the poly-anion heparin, Tau35 increases thioflavin T fluorescence significantly faster and to a greater extent than full-length tau, demonstrating a higher propensity to aggregate. We used atomic force microscopy, transmission electron microscopy and X-ray fiber diffraction to demonstrate that Tau35 aggregates are morphologically similar to previously reported tau fibrils but they are more densely packed. These data increase our understanding of the aggregation inducing properties of clinically relevant tau fragments and their potentially damaging role in the pathogenesis of human tauopathies.

Ultra Small Angle X-Ray Scattering Characterization of Temperature-Sensitive Ferrogels Prepared Using Magnetic Nanoparticles

2013 ◽  
Vol 1453 ◽  
Author(s):  
Kamlesh J. Suthar ◽  
Muralidhar K. Ghantasala ◽  
Derrick C. Mancini ◽  
Jan Ilavsky
Keyword(s):  
Small Angle ◽  
Quantum Interference ◽  
Solution Temperature ◽  
Temperature Sensitive ◽  
X Ray ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Hydrogel Particle ◽  
Ray Scattering

ABSTRACTTemperature-sensitive ferrogel prepared using Fe3O4 nanoparticles are characterized under varying temperature conditions. The nanoparticles were distributed in Nisopropylacrylamide (NIPAm) during their polymerization to form hydrogel. Particle distribution and agglomeration characteristics of the prepared ferrogels were investigated using ultra small angle x-ray scattering (USAXS) at various temperatures through the Lower Critical Solution Temperature (LCST). Transmission electron microscopy (TEM) was used to estimate the particle size distribution. The magnetic property was investigated using direct current superconducting quantum interference device (DC-SQUID) under hydrated conditions. The USAXS analysis showed an increase in the volume of particles without changing the agglomeration characteristics as the temperature is increased during the measurements. The ferrogel did not show any sedimentation or particle detachment from the gel under thermal cycling. Details of our results and analysis are presented.

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