Interfacial Segregation Effects in Mixtures of Homopolymers with Copolymers.

1989 ◽  
Vol 171 ◽  
Author(s):  
Vijay S. Wakharkar ◽  
Thomas P. Russell ◽  
Vaughn R. Deline
Keyword(s):  
Mass Spectroscopy ◽  
Diblock Copolymers ◽  
Large Range ◽  
Surface Enrichment ◽  
Molecular Weights ◽  
Polymer Interface ◽  
Segregation Process ◽  
Interfacial Segregation ◽  
Kinetics Of ◽  
Secondary Ion

ABSTRACTSecondary Ion Mass Spectroscopy (SIMS) has been used to study the surface and interfacial segregation of diblock copolymers in mixtures of the copolymer in the homopolymer. Symmetric, diblock copolymers of polystyrene (PS) and poly(methyl methacrylate) (PMMA), in either the PS or the PMMA homopolymers were investigated. In mixtures of the copolymer with the PS homopolymer, systematic surface enrichment of the copolymer as well as segregation of the copolymer to the polymer/Si interface or in the case of bilayered filmsto the polymer/polymer interface occurs with annealing treatments. These segregation effects persist over a large range of homopolymer molecular weights with changes in the kinetics of the segregation process being predominant.

Secondary ion mass spectroscopy (SIMS) and kinetics of the catalysis of bisulphite oxidation by aqueous iron

1996 ◽  
Vol 74 (11) ◽  
pp. 2217-2220 ◽  
Author(s):  
R.R. Martin ◽  
Jinjiang Li
Keyword(s):  
Catalytic Activity ◽  
Key Words ◽  
Molecular Oxygen ◽  
Mass Spectroscopy ◽  
Oxidation Mechanism ◽  
Cloud Water ◽  
Secondary Ion Mass Spectroscopy ◽  
Aqueous Oxidation ◽  
Kinetics Of ◽  
Secondary Ion

The catalytic activity of Fe(II) and Fe(III) in the aqueous oxidation of bisulphite by molecular oxygen at bisulphite concentrations similar to those in cloud water has been studied. Secondary Ion Mass Spectroscopy (SIMS) of insoluble sulphates derived from bisulphite after oxidation by 18O2 gives different 18O/32S ratios for Fe(II) and Fe(III), indicating that the oxidation mechanism is different in these two species. Key words: oxidation, bisulphite, iron, secondary ion mass spectroscopy.

Investigation of Proximity Rtd for Submicron Junctions in Vlsi Si Devices

1993 ◽  
Vol 303 ◽  
Author(s):  
W. Zagozdzon-Wosik ◽  
P. Grabiec ◽  
F. Romero-Borja ◽  
L. T. Wood ◽  
G. Lux
Keyword(s):  
Sheet Resistance ◽  
Thermal Diffusion ◽  
Mass Spectroscopy ◽  
Secondary Ion Mass Spectroscopy ◽  
Si Doping ◽  
Shallow Junctions ◽  
Rapid Thermal Diffusion ◽  
Kinetics Of ◽  
Secondary Ion

ABSTRACTProximity rapid thermal diffusion is presented as a doping process for fabrication of very shallow junctions. The kinetics of Si doping with B, P and As is investigated using sheet resistance measurements, secondary ion mass spectroscopy and FTIR analyses. The efficiency of doping is affected by the dopant transport in the SOD which depends on the structure and composition of the SOD.

Platelet Microtubule Subunit Proteins

1979 ◽  
Vol 42 (05) ◽  
pp. 1630-1633 ◽  
Author(s):  
A G Castle ◽  
N Crawford
Keyword(s):  
Epithelial Cells ◽  
Gel Electrophoresis ◽  
Blood Platelets ◽  
Polyacrylamide Gel Electrophoresis ◽  
Polyacrylamide Gel ◽  
Lens Epithelial Cells ◽  
Molecular Weights ◽  
Kinetics Of ◽  
Microtubular Structures

SummaryBlood platelets contain microtubule proteins (tubulin and HMWs) which can be polymerised “in vitro” to form structures which resemble the microtubules seen in the intact platelet. Platelet tubulin is composed of two non-identical subunits a and p tubulin which have molecular weights around 55,000 but can be resolved in alkaline SDS-polyacrylamide gel electrophoresis. These subunits associate as dimers with sedimentation coefficients of about 5.7 S although it is not known whether the dimer protein is a homo- or hetero-dimer. The dimer tubulin binds the anti-mitotic drug colchicine and the kinetics of this binding are similar to those reported for neurotubulins. Platelet microtubules also contain two HMW proteins which appear to be essential and integral components of the fully assembled microtubule. These proteins have molecular weights greater than 200,000 daltons. Fluorescent labelled antibodies to platelet and brain tubulins stain long filamentous microtubular structures in bovine lens epithelial cells and this pattern of staining is prevented by exposing the cells to conditions known to cause depolymerisation of cell microtubules.

Adsorption Kinetics of Diblock Copolymers from a Micellar Solution on Silica and Titania

1998 ◽  
Vol 31 (26) ◽  
pp. 9281-9294 ◽  
Author(s):  
H. D. Bijsterbosch ◽  
M. A. Cohen Stuart ◽  
G. J. Fleer
Keyword(s):  
Adsorption Kinetics ◽  
Micellar Solution ◽  
Diblock Copolymers ◽  
Kinetics Of ◽  
Silica And Titania

Oxygen Precipitation Along Individual Ion Tracks During High Dose O+ Implantation into Silicon

1987 ◽  
Vol 93 ◽  
Author(s):  
Witold P. Maszara
Keyword(s):  
Silicon Layer ◽  
High Dose ◽  
Regular Array ◽  
Ion Tracks ◽  
Oxygen Precipitation ◽  
Transmission Electron ◽  
Oxygen Gas ◽  
Kinetics Of ◽  
Secondary Ion ◽  
Lattice Matched

ABSTRACTSilicon wafers with and without protective1Ahermil oxide were implanted with oxygen at 150keV with doses 1.6 – 2.0×1018 cm−2. Transmission electron microscopy (TEM) and secondary ion mass spectroscopy (SIMS) were used to study the top silicon layer remaining above the implanted buried oxide. regular array of spheroidal voids filled with oxygen gas was observed only in the samples that were not protected by the oxide. The voids were aligned into individual columns whose crystallographic orientation with respect to the host silicon lattice matched the direction of the implantation. The origin and the kinetics of their formation are discussed.

Effect of Point Defect Injection on B diffusion in C containing Si and SiGe

2004 ◽  
Vol 809 ◽  
Author(s):  
Mudith S. A. Karunaratne ◽  
Janet M. Bonar ◽  
Jing Zhang ◽  
Arthur F. W. Willoughby
Keyword(s):  
Computer Simulation ◽  
Point Defect ◽  
Mass Spectroscopy ◽  
Diffusion Coefficients ◽  
Secondary Ion Mass Spectroscopy ◽  
Annealing Conditions ◽  
Defect Injection ◽  
Before And After ◽  
Secondary Ion

ABSTRACTIn this paper, we compare B diffusion in epitaxial Si, Si with 0.1%C, SiGe with 11% Ge and SiGe:C with 11%Ge and 0.1%C at 1000°C under interstitial, vacancy and non-injection annealing conditions. Diffusion coefficients of B in each material were extracted by computer simulation, using secondary ion mass spectroscopy (SIMS) profiles obtained from samples before and after annealing.Interstitial injection enhances B diffusion considerably in all materials compared to inert annealing. In samples which experienced vacancy injection, B diffusion was suppressed. The results are consistent with the view that B diffusion in these materials occurs primarily via interstitialcy type defects.

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