Structural Evolution and Viscous Dissipation During Spinodal Demixing of a Biopolymeric Solution

1995 ◽  
pp. 61-74 ◽  
Author(s):  
A. Emanuele ◽  
and M. B. Palma-Vittorelli
Keyword(s):  
Viscous Dissipation ◽  
Structural Evolution

Microstructure and reactivity of small metal particles: The role of Ce additives

1992 ◽  
Vol 50 (1) ◽  
pp. 318-319
Author(s):  
L.D. Schmidt ◽  
K. R. Krause ◽  
J. M. Schwartz ◽  
X. Chu
Keyword(s):  
Atmospheric Pressure ◽  
Noble Metals ◽  
Mixed Oxides ◽  
Catalytic Properties ◽  
Chemical Shifts ◽  
Catalytic Converter ◽  
Structural Evolution ◽  
Single Particles ◽  
Small Metal Particles

The evolution of microstructures of 10- to 100-Å diameter particles of Rh and Pt on SiO2 and Al2O3 following treatment in reducing, oxidizing, and reacting conditions have been characterized by TEM. We are able to transfer particles repeatedly between microscope and a reactor furnace so that the structural evolution of single particles can be examined following treatments in gases at atmospheric pressure. We are especially interested in the role of Ce additives on noble metals such as Pt and Rh. These systems are crucial in the automotive catalytic converter, and rare earths can significantly modify catalytic properties in many reactions. In particular, we are concerned with the oxidation state of Ce and its role in formation of mixed oxides with metals or with the support. For this we employ EELS in TEM, a technique uniquely suited to detect chemical shifts with ∼30Å resolution.

Electrodeposition of Strained-Layer Superlattices

1996 ◽  
Vol 451 ◽  
Author(s):  
T. P. Moffat
Keyword(s):  
Charge Transfer ◽  
Mass Transport ◽  
Structural Evolution ◽  
Iron Group ◽  
Morphological Instability ◽  
Group Metal ◽  
Iron Group Metal ◽  
Transport Control ◽  
Strained Layer Superlattices ◽  
Interfacial Charge

ABSTRACTA variety of Cu/(Ni, Co) multilayers have been grown on Cu single crystals by pulse plating from an alloy electroplating bath. Copper is deposited under mass transport control while the iron group metal is deposited under interfacial charge transfer control. The structural evolution of these films is influenced by the morphological instability of the mass transport limited copper deposition reaction and the development of growth twins during iron-group metal deposition. Specular films have been obtained for growth on Cu(100) while rough, defective films were typically obtained for growth on Cu(111) and Cu(110).

Pattern Formation in Thin Polymer Films: A New Morphology

2000 ◽  
Vol 629 ◽  
Author(s):  
Jean-Loup Masson ◽  
Peter F. Green
Keyword(s):  
Growth Rate ◽  
Pattern Formation ◽  
Early Stage ◽  
Structural Evolution ◽  
Distinct Form ◽  
Thin Polymer Films ◽  
Intermediate Morphology ◽  
Thin Polymer ◽  
Nonwetting Liquid ◽  
Cylindrical Holes

ABSTRACTResearchers have shown that thin, nonwetting, liquid homopolymer films dewet substrates, forming patterns that reflect fluctuations in the local film thickness. These patterns have been shown to be either discrete cylindrical holes or bicontinuous “spinodal-like” patterns. In this paper we show the existence of a new morphology. During the early stage of dewetting, discrete highly asymmetric holes appear spontaneously throughout the film. The nucleation rate of these holes is faster than their growth rate. The morphology of the late stage of evolution, after 18 days, is characterized by a bicontinuous pattern, distinct form conventional spinodal dewetting patterns. This morphology has been observed for a range of film thicknesses between 7.5 and 21nm. The structural evolution of this intermediate morphology is discussed.

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