Characterization of Stressed and Crosslinked Polymers by 13C-CP/MAS and NMR Imaging

1990 ◽  
Vol 217 ◽  
Author(s):  
Winfried Kuhn ◽  
Isolde Theis ◽  
Elmar Koeller
Keyword(s):  
Chemical Composition ◽  
Physical Properties ◽  
Chemical Reactions ◽  
Bulk Material ◽  
Mechanical Strain ◽  
Time Dependent ◽  
Nmr Imaging ◽  
Physical Behavior ◽  
Aging Conditions

ABSTRACTAging of polymers and elastomers is a time dependent alteration of the chemical composition and physical properties depending on the aging conditions. Chemical reactions and hence changes in the chemical composition result in many cases from influence by oxygen or solvents and treatment of the bulk material at high temperatures. Aging of the materials by mechanical strain as well as in an oxidative manner can alter the ratio of amorphous to crystalline portions in the polymer, break chemical bondings and hence can alter the physical behavior of the materials.

scholarly journals Nanoscale bubble domains with polar topologies in bulk ferroelectrics

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jie Yin ◽  
Hongxiang Zong ◽  
Hong Tao ◽  
Xuefei Tao ◽  
Haijun Wu ◽  
...  
Keyword(s):  
Physical Properties ◽  
Bulk Material ◽  
Condensed Matter ◽  
Time Dependent ◽  
Morphology Evolution ◽  
Contrast Imaging ◽  
Ferroelectric Films ◽  
Modulated Phases ◽  
Ferroelectric Memories ◽  
Z Contrast

AbstractMultitudinous topological configurations spawn oases of many physical properties and phenomena in condensed-matter physics. Nano-sized ferroelectric bubble domains with various polar topologies (e.g., vortices, skyrmions) achieved in ferroelectric films present great potential for valuable physical properties. However, experimentally manipulating bubble domains has remained elusive especially in the bulk form. Here, in any bulk material, we achieve self-confined bubble domains with multiple polar topologies in bulk Bi0.5Na0.5TiO3 ferroelectrics, especially skyrmions, as validated by direct Z-contrast imaging. This phenomenon is driven by the interplay of bulk, elastic and electrostatic energies of coexisting modulated phases with strong and weak spontaneous polarizations. We demonstrate reversable and tip-voltage magnitude/time-dependent donut-like domain morphology evolution towards continuously and reversibly modulated high-density nonvolatile ferroelectric memories.

scholarly journals The role of heat conduction to the formation of [WC]-type planetary nebulae

2011 ◽  
Vol 7 (S283) ◽  
pp. 494-495
Author(s):  
Christer Sandin ◽  
Matthias Steffen ◽  
Ralf Jacob ◽  
Detlef Schönberner ◽  
Ute Rühling ◽  
...  
Keyword(s):  
Heat Conduction ◽  
Chemical Composition ◽  
Physical Properties ◽  
Planetary Nebulae ◽  
Time Dependent ◽  
Diffuse Emission ◽  
Hydrodynamic Models ◽  
X Ray ◽  
Central Stars

AbstractX-ray observations of young Planetary Nebulæ (PNe) have revealed diffuse emission in extended regions around both H-rich and H-deficient central stars. In order to also reproduce physical properties of H-deficient objects, we have, at first, extended our time-dependent radiation-hydrodynamic models with heat conduction for such conditions. Here we present some of the important physical concepts, which determine how and when a hot wind-blown bubble forms. In this study we have had to consider the, largely unknown, evolution of the CSPN, the slow (AGB) wind, the fast hot-CSPN wind, and the chemical composition. The main conclusion of our work is that heat conduction is needed to explain X-ray properties of wind-blown bubbles also in H-deficient objects.

scholarly journals Characterization of corn landraces planted grown in the campos gerais region (Paraná, Brazil) for industrial utilization

2009 ◽  
Vol 52 (spe) ◽  
pp. 17-28 ◽  
Author(s):  
Alessandra Teixeira Barbosa Pinto ◽  
Joyce Pereira ◽  
Tatiana Roselena de Oliveira ◽  
Rosilene Aparecida Prestes ◽  
Rodrigo Rodrigues Mattielo ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Physical Properties ◽  
Plant Breeding ◽  
Dietary Fiber ◽  
Industrial Applications ◽  
Ether Extract ◽  
Industrial Utilization ◽  
Protein Contamination ◽  
Real Density

This work has the objective of characterizing twenty corn landraces grown in the Campos Gerais region (Paraná State) in relation to its chemical composition (moisture, ash, protein, ether extract, dietary fiber and starch) and physical properties (weight of 1000 grains, real density, flotation index, granulometry and color). In addition, also the lab scale processing of the kernels from the varieties was carried out for producing starch; starch purity was evaluated by measuring its protein contamination. Amylose contents and viscoamylograph profile were also evaluated. The results showed that the evaluated landraces have differences in chemical composition as well as in pericarp/endosperm/germ proportions and consequently it should have different industrial applications and interest for plant breeding.

scholarly journals Investigations of quartz raw materials from the locality of Rekovac muncipality

2019 ◽  
Vol 73 (4) ◽  
pp. 265-274
Author(s):  
Slavica Mihajlovic ◽  
Zivko Sekulic ◽  
Jovica Stojanovic ◽  
Vladan Kasic ◽  
Iroslav Sokic ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Physical Properties ◽  
Quartz Sand ◽  
Raw Materials ◽  
Construction Materials ◽  
Size Fraction ◽  
Point Of View ◽  
Raw Material ◽  
Potential Applications

Quality of raw materials, including quartz sand and quartzite, varies from one deposit to another. Furthermore, the material quality determines in which industrial branches it can be used after certain preparation processes. Potential applications of quartz raw materials are: in the construction and refractory industry, ceramics and glass industry, then in metallurgy, foundry and also in production of water treatment filters. Geological investigations of the central Serbia region, in the Rekovac municipality, resulted in identification of occurrence of quartz sand ("Ursula") and quartzite ("Velika Krusevica"). Preliminary laboratory tests and characterization of the quartz sand size fraction -0.63+0.1 mm confirmed the possibility of applying this size fraction in the construction materials industry, while the quartzite can be used in refractory, glass and metallurgy industries. After determining the geological reserve of quartz sand "Ursula" and quartzite "Velika Krusevica", detailed investigations are required. Quality conditions from the aspect of chemical composition and physical properties of quartz sand and quartzite are mostly clearly defined by a special standard for this purpose. On the other hand, there are also application areas where standards does not exist, but users define their quality conditions. This example is with the application of quartz sand in the production of water glass. Chemical composition as well is not always the determining factor for the application of quartz raw material. For example, for quartz sand used for sandblasting, grain form is essential. From the economic analysis point of view, the prices of quartz raw materials vary depending on their chemical and physical properties. After all, what needs to be pointed out is the fact that these raw materials are very widespread in nature and that their exploitation is quite simple. After the raw material is excavated, it is stored and further sieved, washed, dried and processed according to customer requirements. All of these processes are cheaper than preparing, for example, limestone, and significaly cheaper than preparation of metal ores.

AFM + Raman Microscopy + SNOM + Tip-Enhanced Raman: Instrumentation and Applications

2010 ◽  
Vol 18 (6) ◽  
pp. 28-32 ◽  
Author(s):  
P. Dorozhkin ◽  
E. Kuznetsov ◽  
A. Schokin ◽  
S. Timofeev ◽  
V. Bykov
Keyword(s):  
Crystal Structure ◽  
Chemical Composition ◽  
Physical Properties ◽  
Force Microscopy ◽  
Research Fields ◽  
Inelastic Light Scattering ◽  
Atomic Force ◽  
Extensive Information ◽  
Local Stiffness

Atomic Force Microscopy (AFM) has developed into a very powerful tool for characterization of surfaces and nanoscale objects. Many physical properties of an object can be studied by AFM with nanometer-scale resolution. Local stiffness, elasticity, conductivity, capacitance, magnetization, surface potential and work function, friction, piezo response—these and many other physical properties can be studied with over 30 AFM modes. What is typically lacking in information provided by AFM studies is the chemical composition of the sample and information about its crystal structure. To obtain this information other characterization techniques are required, such as Raman and fluorescence microscopy. The Raman effect (inelastic light scattering) provides extensive information about sample chemical composition, quality of crystal structure, crystal orientation, presence of impurities and defects, and so on. Information provided by Raman and fluorescence spectroscopy is complementary to the information obtained by AFM. So it is a natural requirement in many research fields to integrate these techniques in one piece of equipment—to provide comprehensive physical, chemical, and structural characterization of the same object. Of course, for routine studies of various samples, it is important to be able to obtain AFM and Raman/fluorescence images of exactly the same sample area, preferably with the same sample scan.

Extraction and characterization of palm fibers and their use to produce wool- and polyester-blended nonwovens

2019 ◽  
pp. 152808371987700 ◽  
Author(s):  
Laila Sajid ◽  
Oussama Azmami ◽  
Zakia El ahmadi ◽  
Abbès Benayada ◽  
Said Gmouh
Keyword(s):  
Thermal Conductivity ◽  
Tensile Strength ◽  
Thermal Properties ◽  
Chemical Composition ◽  
Physical Properties ◽  
Structural Properties ◽  
Surface Density ◽  
Air Permeability ◽  
Mechanical And Physical Properties

The aim of this work is the production of new nonwovens materials based on wool, polyester and palm fibers ( Washingtonia). The extraction of palm fibers was achieved by the combination of alkaline and bleaching treatments. Chemical composition, mechanical and physical properties of the extracted fibers were first determined. Then, two types of blended nonwovens based on Palm/Wool (P/W) and Palm/Polyester (P/PES) mixtures were produced using the needling technique. The physical and structural properties of produced nonwovens were studied such as surface density, tensile strength, porosity and thermal properties. The results showed that the porosity lies between 83.81% and 86.93% for (P/W) mixtures and between 78.01% and 86.93% for (P/PES) mixtures. The air permeability was found to be between 61.56 m3.m−2.min−1 and 129.01 m3.m−2.min−1 for P/W blend nonwovens and between 22.75 m3.m−2.min−1 and 129.01 m3.m−2.min−1 for P/PES blend ones. The thermal conductivity varies between 36.45 mW/m.K and 43.88 mW/m.K for P/W nonwovens and between 36.45 mW/m.K and 47.70 mW/m.K for P/PES nonwovens. Moreover, the tensile strength of blended nonwovens is found to be higher than that of non-blended ones.

scholarly journals Nanoscale bubble domains with polar topologies in bulk ferroelectrics

2020 ◽  
Author(s):  
Stephen Pennycook ◽  
Jie Yin ◽  
Hongxiang Zong ◽  
Hong Tao ◽  
Xuefei Tao ◽  
...  
Keyword(s):  
Physical Properties ◽  
Bulk Material ◽  
Condensed Matter ◽  
Time Dependent ◽  
Morphology Evolution ◽  
Contrast Imaging ◽  
Modulated Phases ◽  
Ferroelectric Memories ◽  
Z Contrast ◽  
First Time

Abstract Multitudinous topological configurations spawn new oases of novel phenomena and physical properties in condensed-matter physics1. Nano-sized ferroelectric bubble domains with various polar topologies (e.g., vortices, skyrmions) achieved in ferroelectric films present great potential for valuable physical properties2–5. However, experimentally manipulating bubble domains has remained elusive especially in the bulk form. Here, for the first time in any bulk material, we achieve self-confined bubble domains with multiple polar topologies in bulk Bi0.5Na0.5TiO3 ferroelectrics, especially skyrmions, as validated by direct Z-contrast imaging. This phenomenon is driven by the interplay of bulk, elastic and electrostatic energies of coexisting modulated phases with strong and weak spontaneous polarizations. We demonstrate reversable and tip-voltage magnitude/time-dependent donut-like domain morphology evolution towards continuously and reversibly modulated high-density nonvolatile ferroelectric memories.

CBED analysis of impurity distributions in AlN

1990 ◽  
Vol 48 (4) ◽  
pp. 214-215
Author(s):  
Daniel Callahan ◽  
G. Thomas
Keyword(s):  
Aluminum Nitride ◽  
Bulk Material ◽  
Strong Dependence ◽  
Lattice Parameter ◽  
Promising Technique ◽  
Nitride Ceramics ◽  
Surface Phases ◽  
Convergent Beam ◽  
Oxygen Impurities

Oxygen impurities may significantly influence the properties of nitride ceramics with a strong dependence on the microstructural distribution of the impurity. For example, amorphous oxygen-rich grain boundary phases are well-known to cause high-temperature mechanical strength degradation in silicon nitride whereas solutionized oxygen is known to decrease the thermal conductivity of aluminum nitride. Microanalytical characterization of these impurities by spectral methods in the AEM is complicated by reactions which form oxygen-rich surface phases not representative of the bulk material. Furthermore, the impurity concentrations found in higher quality ceramics may be too low to measure by EDS or PEELS. Consequently an alternate method for the characterization of impurities in these ceramics has been investigated.Convergent beam electron diffraction (CBED) is a promising technique for the study of impurity distributions in aluminum nitride ceramics. Oxygen is known to enter into stoichiometric solutions with AIN with a consequent decrease in lattice parameter.

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