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Resulting Properties (resulting + property)

Distribution by Scientific Domains
Polymers and Materials Science75%

Selected Abstracts

Thin Films: Self-Assembled Heteroepitaxial Oxide Nanocomposite Thin Film Structures: Designing Interface-Induced Functionality in Electronic Materials (Adv. Funct.

ADVANCED FUNCTIONAL MATERIALS, Issue 13 2010
Mater.
Achieving self-assembling/self-organizing systems is the holy grail of nanotechnology, as presented in the Feature Article by J. L. MacManus-Driscoll on page 2035. Multifunctionality or enhanced functionality can emerge as a result of self-assembly of two oxides in nano-composite films. Checkerboards, ordered nanochains, nanorods, or random nanoparticle structures are all possible structures and they influence the resulting properties in different ways. It is now possible to predict the nanocomposite structure that will form from a given starting composition. [source]

Properties of Ionic-Conducting ,-Bi2O3 Containing Mixed Dopants

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 11 2002
Stephen D. Nunn
,-Bi2O3 compositions were prepared to evaluate the effect on properties of using mixed dopants. Baseline compositions containing 28 mol% of the alkaline-earth oxides CaO, SrO, or BaO were used for comparison. When the alkaline earths were combined in pairs to dope the bismuth oxide, the resulting properties were intermediate between the baseline end members. The data suggest that the transformation temperature for forming the high-conductivity ,1 phase can be varied continuously over a temperature range of about 565° to 750°C. Utilization of additional additives having different ionic size or valence charge compared with the alkaline earths resulted in no observed property changes that could be attributed to the additive alone. The most important variables influencing the conductivity level and phase transformation temperature of ,-Bi2O3 were the type and the amount of the alkaline-earth dopant in the composition. [source]

Effect of molecular weight and end capping on poly(lactic- co -glycolic acid) ultrasound contrast agents

POLYMER ENGINEERING & SCIENCE, Issue 9 2008
J.R. Eisenbrey
Ultrasound contrast agents (CA) consist of stabilized gas bubbles that, when injected intravenously, provide an acoustic impedance mismatch, producing additional contrast to a diagnostic ultrasound scan. These agents must be smaller than 8 ,m in order to pass safely through the capillaries, contain gas for an impedance mismatch and should be stable enough to survive the duration of the imaging session. A double emulsion technique has previously been optimized within our laboratory to create CA with 50:50 poly (lactic- co -glycolic acid) (PLGA). Although a great deal of research has focused on the effects of molecular weight and end capping on solid PLGA particles, very little has been done to examine the effects of these parameters on hollow CAs formed in a double emulsion. Non-end capped PLGA was found to provide maximum enhancement at a molecular weight of 66.0 kDa, giving an ultrasound enhancement of roughly 18.5 dB. The enhancement demonstrated by CA formed using the end-capped PLGA rose to a maximum enhancement of 19 dB at the highest commercially available molecular weight of 82.4 kDa. A strong correlation was seen between ultrasound enhancement, stability under ultrasonic conditions, surface morphology and zeta potential. This study shows the influence of polymer characteristics on the resulting properties of CA and the ability to tailor CAs to particular applications by varying the polymer choice. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers [source]

Embedded Phases: A Way to Active and Stable Catalysts

CHEMSUSCHEM CHEMISTRY AND SUSTAINABILITY, ENERGY & MATERIALS, Issue 1 2010
Loredana De, Rogatis Dr.
Abstract Industrial catalysts are typically made of nanosized metal particles, carried by a solid support. The extremely small size of the particles maximizes the surface area exposed to the reactant, leading to higher reactivity. Moreover, the higher the number of metal atoms in contact with the support, the better the catalyst performance. In addition, peculiar properties have been observed for some metal/metal oxide particles of critical sizes. However, thermal stability of these nanostructures is limited by their size; smaller the particle size, the lower the thermal stability. The ability to fabricate and control the structure of nanoparticles allows to influence the resulting properties and, ultimately, to design stable catalysts with the desired characteristics. Tuning particle sizes provides the possibility to modulate the catalytic activity. Unique and unexpected properties have been observed by confining/embedding metal nanoparticles in inorganic channels or cavities, which indeed offers new opportunities for the design of advanced catalytic sytems. Innovation in catalyst design is a powerful tool in realizing the goals of more green, efficient and sustainable industrial processes. The present Review focuses on the catalytic performance of noble metal- and non precious metal-based embedded catalysts with respect to traditional impregnated systems. Emphasis is dedicated to the improved thermal stability of these nanostructures compared to conventional systems. [source]