DLC-Coated Ferroelectric Membranes as Vascular Patches: Physico-Chemical Properties and Biocompatibility

In this paper, the results on the fabrication of ferroelectric membranes as vascular patches with modified surfaces are presented. For the modification of a membrane surface contacting blood, DLC coating was deposited using the pulsed vacuum arc deposition technique. The physico-chemical properties and cytotoxicity of the membranes modified under various conditions were studied. It was found that DLC coatings do not affect membrane microstructure, preserving its crystal structure as well as its high strength and elongation. It was revealed that an increase in the capacitor storage voltage results in the rise in sp2- and sp-hybridized carbon concentration, which makes it possible to control the chemical structure and surface energy of the modified surface. The experiments with 3T3L1 fibroblasts showed no toxic effects of the materials extracts.

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The role of membrane surface charge and solute physico-chemical properties in the rejection of organic acids by NF membranes

Journal of Membrane Science ◽

10.1016/j.memsci.2004.09.041 ◽

2005 ◽

Vol 249 (1-2) ◽

pp. 227-234 ◽

Cited By ~ 211

Author(s):

Christopher Bellona ◽

Jörg E. Drewes

Keyword(s):

Organic Acids ◽

Surface Charge ◽

Membrane Surface ◽

Chemical Properties ◽

Physico Chemical ◽

Membrane Surface Charge

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DLC Coatings on Spherical Elements of HIP Endoprostheses

European Journal of Engineering and Formal Sciences ◽

10.2478/ejef-2018-0015 ◽

2018 ◽

Vol 2 (3) ◽

pp. 41-47

Author(s):

V. V. Vasylyev ◽

V. E. Strel’nitskij ◽

V. B. Makarov ◽

M. A. Skoryk ◽

G. O. Lazarenko

Keyword(s):

Hip Joint ◽

High Hardness ◽

Plasma Source ◽

Hard Coatings ◽

Vacuum Arc ◽

Diamond Like Carbon ◽

Dlc Coatings ◽

Dlc Coating ◽

High Adhesion ◽

High Level

Abstract Hard coatings are increasingly being used in medicine to protect metal endoprostheses The experimental process for the high-productive synthesis of high-quality diamond-like carbon (DLC) coatings with high hardness and a sufficiently high level of adhesion to the spherical shaped parts of the hip joint made from the stainless steel or cobalt-chrome alloy have been developed. DLC coating deposition was performed by vacuum-arc method from a high-productive source of the filtered vacuum-arc carbon plasma of rectilinear type with a "magnetic island". The high degree of thickness uniformity in the coating on the head of the hip joint with a high adhesion to the metal joint base was developed. Modernization of the vacuum arc plasma source allowed to accelerate the cathode spot motion, exclude substrate overheating and increase the diamond-like carbon hardness up to 30-40 GPa. The high adhesion level was achieved as a result of the high voltage pulsed of substrate bias potential use and multilayer architecture of DLC coating. The DLC coating on the heads of hip endoprosthesis did not peel off when boiling endoprosthesis or when immersing it into the liquid nitrogen.

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DLC Coatings on Spherical Elements of HIP Endoprostheses

European Journal of Engineering and Formal Sciences ◽

10.26417/ejef.v2i3.p42-47 ◽

2018 ◽

Vol 2 (3) ◽

pp. 42

Author(s):

V.V. Vasylyev ◽

Strel'nitskij V.E. ◽

V. B. Makarov

Keyword(s):

Hip Joint ◽

High Hardness ◽

Plasma Source ◽

Hard Coatings ◽

Vacuum Arc ◽

Diamond Like Carbon ◽

Dlc Coatings ◽

Dlc Coating ◽

High Adhesion ◽

High Level

Hard coatings are increasingly being used in medicine to protect metal endoprostheses The experimental process for the high-productive synthesis of high-quality diamond-like carbon (DLC) coatings with high hardness and a sufficiently high level of adhesion to the spherical shaped parts of the hip joint made from the stainless steel or cobalt-chrome alloy have been developed. DLC coating deposition was performed by vacuum-arc method from a high-productive source of the filtered vacuum-arc carbon plasma of rectilinear type with a "magnetic island". The high degree of thickness uniformity in the coating on the head of the hip joint with a high adhesion to the metal joint base was developed. Modernization of the vacuum arc plasma source allowed to accelerate the cathode spot motion, exclude substrate overheating and increase the diamond-like carbon hardness up to 30-40 GPa. The high adhesion level was achieved as a result of the high voltage pulsed of substrate bias potential use and multilayer architecture of DLC coating. The DLC coating on the heads of hip endoprosthesis did not peel off when boiling endoprosthesis or when immersing it into the liquid nitrogen. JEL O31

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Fabrication, Properties and Microstructures of High Strength and High Conductivity Copper-Silver Wires / Otrzymywanie Oraz Własności I Mikrostruktura Wysokowytrzymałych I Wysoko Przewodzących Drutów Ze Stopów Cu-Ag

Archives of Metallurgy and Materials ◽

10.2478/v10172-012-0141-1 ◽

2012 ◽

Vol 57 (4) ◽

pp. 1261-1270 ◽

Cited By ~ 3

Author(s):

A. Kawecki ◽

T. Knych ◽

E. Sieja-Smaga ◽

A. Mamala ◽

P. Kwaśniewski ◽

...

Keyword(s):

Heat Treatment ◽

Electrical Conductivity ◽

Chemical Properties ◽

High Strength ◽

Treatment Method ◽

Silver Addition ◽

Research Results ◽

High Deformation ◽

Paper Manufacturing ◽

Physico Chemical

Research results of manufacturing composite filamentary nanostructure Cu-Ag alloys with silver addition from 5 to 15% wt. are presented in the paper. Manufacturing technology of these composites and variable solubility of silver in copper and copper in silver in the range of solid solutions. Suitable quantity and processing sequences of high deformation plastic working and heat treatment allows to obtain wires constituted from Cu and Ag fibres with nanometric transverse dimensions and in consequence provide to optimum superposition of high mechanical strength, high electrical conductivity and sufficient ductility of Cu-Ag alloys. The paper presents the method of continuous casting of alloys, selected physico-chemical properties and degree of deformation. Influence of chosen heat treatment method over electrical and mechanical properties of both casts and micro wires on mechanical and electrical properties of cast materials during converting them into micro wires with tensile strength higher than 1200 MPa and electrical conductivity higher than 40 MS/m are presented too. Research results of optical and scanning microscopy structure analysis were presented for casts and wires submitted to various thermo-mechanical strengthening.

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Effect of Ti Transition Layer Thickness on the Structure, Mechanical and Adhesion Properties of Ti-DLC Coatings on Aluminum Alloys

Materials ◽

10.3390/ma11091742 ◽

2018 ◽

Vol 11 (9) ◽

pp. 1742 ◽

Cited By ~ 10

Author(s):

Hongshuai Cao ◽

Fugang Qi ◽

Xiaoping Ouyang ◽

Nie Zhao ◽

Yun Zhou ◽

...

Keyword(s):

Aluminum Alloys ◽

Layer Thickness ◽

Photoelectron Spectroscopy ◽

Transition Layer ◽

Scratch Test ◽

Vacuum Arc ◽

Adhesion Properties ◽

Dlc Coatings ◽

Dlc Coating ◽

Filtered Cathodic Vacuum Arc

Multilayers of Ti doped diamond-like carbon (Ti-DLC) coatings were deposited on aluminum alloys by filtered cathodic vacuum arc (FCVA) technology using C2H2 as a reactive gas. The effect of different Ti transition layer thicknesses on the structure, mechanical and adhesion properties of the coatings, was investigated by scanning electron microscopy (SEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), nanoindentation and a scratch tester. The results showed that the Ti transition layer could improve interfacial transition between the coating and the substrate, which was beneficial in obtaining excellent adhesion of the coatings. The Ti transition layer thickness had no significant influence on the composition and structure of the coatings, whereas it affected the distortion of the sp2-C bond angle and length. Nanoindentation and scratch test results indicated that the mechanical and adhesion properties of the Ti-DLC coatings depended on the Ti transition layer thickness. The Ti transition layer proved favorable in decreasing the residual compressive stress of the coating. As the Ti transition layer thickness increased, the hardness value of the coating gradually decreased. However, its elastic modulus and adhesion exhibited an initial decrease followed by an increasing fluctuation. Among them, the Ti-DLC coating with a Ti transition layer thickness of 1.1 μm exhibited superior mechanical properties.

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Decoration of specific sites on freeze-fractured membranes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100081565 ◽

1978 ◽

Vol 36 (2) ◽

pp. 140-141

Author(s):

H. Gross ◽

H. Moor

Keyword(s):

Pure Water ◽

Freeze Fracture ◽

Chemical Properties ◽

Surface Forces ◽

Sulfate Pentahydrate ◽

Copper Sulfate Pentahydrate ◽

Physico Chemical ◽

Water Of Hydration ◽

Small Container ◽

Binding Forces

Fracturing under ultrahigh vacuum (UHV, p ≤ 10-9 Torr) produces membrane fracture faces devoid of contamination. Such clean surfaces are a prerequisite foe studies of interactions between condensing molecules is possible and surface forces are unequally distributed, the condensate will accumulate at places with high binding forces; crystallites will arise which may be useful a probes for surface sites with specific physico-chemical properties. Specific “decoration” with crystallites can be achieved nby exposing membrane fracture faces to water vopour. A device was developed which enables the production of pure water vapour and the controlled variation of its partial pressure in an UHV freeze-fracture apparatus (Fig.1a). Under vaccum (≤ 10-3 Torr), small container filled with copper-sulfate-pentahydrate is heated with a heating coil, with the temperature controlled by means of a thermocouple. The water of hydration thereby released enters a storage vessel.

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PHYSICO CHEMICAL PROPERTIES OF NICKEL OXIDE AT HIGH TEMPERATURE

Le Journal de Physique Colloques ◽

10.1051/jphyscol:1976798 ◽

1976 ◽

Vol 37 (C7) ◽

pp. C7-438-C7-442 ◽

Cited By ~ 2

Author(s):

R. FARHI ◽

G. PETOT-ERVAS

Keyword(s):

High Temperature ◽

Nickel Oxide ◽

Chemical Properties ◽

Physico Chemical

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Physico-Chemical Properties of Recombinant Desulphatohirudin

Thrombosis and Haemostasis ◽

10.1055/s-0038-1645073 ◽

1990 ◽

Vol 63 (03) ◽

pp. 499-504 ◽

Cited By ~ 4

Author(s):

A Electricwala ◽

L Irons ◽

R Wait ◽

R J G Carr ◽

R J Ling ◽

...

Keyword(s):

Molecular Weight ◽

Gel Filtration ◽

Chemical Properties ◽

Alpha Helix ◽

Apparent Molecular Weight ◽

Correlation Spectroscopy ◽

Nmr Studies ◽

Recombinant Hirudin ◽

Physico Chemical ◽

Recombinant Molecule

SummaryPhysico-chemical properties of recombinant desulphatohirudin expressed in yeast (CIBA GEIGY code No. CGP 39393) were reinvestigated. As previously reported for natural hirudin, the recombinant molecule exhibited abnormal behaviour by gel filtration with an apparent molecular weight greater than that based on the primary structure. However, molecular weight estimation by SDS gel electrophoresis, FAB-mass spectrometry and Photon Correlation Spectroscopy were in agreement with the theoretical molecular weight, with little suggestion of dimer or aggregate formation. Circular dichroism studies of the recombinant molecule show similar spectra at different pH values but are markedly different from that reported by Konno et al. (13) for a natural hirudin-variant. Our CD studies indicate the presence of about 60% beta sheet and the absence of alpha helix in the secondary structure of recombinant hirudin, in agreement with the conformation determined by NMR studies (17)

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