Polyelectrolyte complexes based on pectin, and poly(4-vinylpyridine): structure and thermomechanical properties

SummaryThe effect of negatively-charged polymers, used in some artificial devices, on plasma clotting and kinin systems was studied in vitro using polyelectrolyte complexes.Contact activation was observed as an immediate, transient and surface-dependent phenomenon. After incubation of the plasma with the polymer a small decrease of factor XII activity was noticed, which corresponded to a greater reduction of prekallikrein activity and to a marked kinin release. No significant decrease of factor XII, prekallikrein, HMW kininogen could be detected immunologically. Only the initial contact of the plasma with the polyelectrolyte lead to activation, subsequently the surface became inert.Beside contact activation, factor V activity also decreased in the plasma. The decrease was surface and time-dependent. It was independent of contact factor activation, and appeared to be related to the sulfonated groups of the polymer. If purified factor V was used instead of plasma factor V, inactivation was immediate and not time-dependent suggesting a direct adsorption on the surface. A second incubation of the plasma-contacted polymer with fresh plasma resulted in a further loss of Factor V activity.

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Structural peculiarity and termomechanical properties of polyelectrolyte complexes and metal-containing nanocomposites based on functionalized starch and polyethyleneimine

Polymer journal ◽

10.15407/polymerj.41.01.034 ◽

2019 ◽

Vol 41 (1) ◽

pp. 34-40 ◽

Cited By ~ 1

Author(s):

V.I. Shtompel ◽

◽

V.L. Demchenko ◽

S.I. Sinelnikov ◽

O.A. Radchenko ◽

...

Keyword(s):

Polyelectrolyte Complexes ◽

Structural Peculiarity

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Materials Issues and Characterization of Low-k Dielectric Materials

MRS Bulletin ◽

10.1557/s0883769400034205 ◽

1997 ◽

Vol 22 (10) ◽

pp. 49-54 ◽

Cited By ~ 15

Author(s):

E. Todd Ryan ◽

Andrew J. McKerrow ◽

Jihperng Leu ◽

Paul S. Ho

Keyword(s):

Process Integration ◽

Dielectric Materials ◽

Propagation Delay ◽

Thermomechanical Properties ◽

General Criterion ◽

Crosstalk Noise ◽

Total Delay ◽

Interlayer Dielectrics ◽

Performance Improvements ◽

And Performance

Continuing improvement in device density and performance has significantly affected the dimensions and complexity of the wiring structure for on-chip interconnects. These enhancements have led to a reduction in the wiring pitch and an increase in the number of wiring levels to fulfill demands for density and performance improvements. As device dimensions shrink to less than 0.25 μm, the propagation delay, crosstalk noise, and power dissipation due to resistance-capacitance (RC) coupling become significant. Accordingly the interconnect delay now constitutes a major fraction of the total delay limiting the overall chip performance. Equally important is the processing complexity due to an increase in the number of wiring levels. This inevitably drives cost up by lowering the manufacturing yield due to an increase in defects and processing complexity.To address these problems, new materials for use as metal lines and interlayer dielectrics (ILDs) and alternative architectures have surfaced to replace the current Al(Cu)/SiO2 interconnect technology. These alternative architectures will require the introduction of low-dielectric-constant k materials as the interlayer dielectrics and/or low-resistivity conductors such as copper. The electrical and thermomechanical properties of SiO2 are ideal for ILD applications, and a change to material with different properties has important process-integration implications. To facilitate the choice of an alternative ILD, it is necessary to establish general criterion for evaluating thin-film properties of candidate low-k materials, which can be later correlated with process-integration problems.

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