Surface-modification processe

Numerous schemes can be devised to classify deposition processes. The scheme used herein is based on the dimensions of the depositing species, ie, atoms and molecules, softened particles, Hquid droplets, bulk quantities, or the use of a surface-modification process (1,2). Coating methods are as foHow (2) ... 

In addition, there are many surface modification processes that use triplet sensitizers to permit oxidation reactions. In a typical process, polyisocyanate is applied on a polyolefin together with a sensitizer such as benzo-phenone and then irradiated with UV light. As shown in Eq. (15) the sensitizer has an oxidizing effect to produce hydroxyl groups over the polymer surface. These hydroxyl groups finally react with isocyanate to provide a functional polymer [56,57]. 

Wear and corrosion protection can be provided by the well-established techniques of hard-facing and plating or by surface-modification processes such as bonding, nitriding, carburizing, and ion implantation. The protection these processes afford is adequate in most environments but may fail over a period of time if the conditions are too severe. 

Classic solid phase substrates used in biotesting, such as microtiter plates, membrane filters or microscope slides, have been the first supports used for NA immobilization in array fabrication [27]. Desired attributes of any DNA array substrate include (i) chemical homogeneity (ii) thermal and chemical stability (iii) ability to control surface chemical properties such as polarity or hydrophobicity (iv) ability to be activated with a wide range of chemical functionalities (v) reproducibihty of the surface modification processes involved (vi) inert with respect to enzymatic activity especially ones involved in DNA manipulation and (vii) ultra-low intrinsic fluorescence. 

PDMS in its native form does not possess reactive groups that can be used for the covalent attachment of NAs [51]. However, the PDMS surface can be plasma induced oxidized and then fimctionaUzed with organosilanes carrying the desired head group. For example, a PDMS surface has been modified with 3-mercaptotrimethoxysilane to yield a thiol-terminated surface, to which a 5 -acrylamide modified DNA has been covalently attached [52]. See Fig. 13 for a representation of the PDMS surface-modification process. 

Structures of immobilized rhodium complexes on the sihca support have been proposed on the basis of the data obtained from C, P and Si MAS-NMR. NMR spectra of the rhodium-modified solid materials confirmed that trimethylsiloxide ligand was removed from the rhodium coordination sphere during the immobilization process. Formation of a new covalent bond between the rhodium organo-metallic moiety and the silica support occurs, probably with evolution of trimethylsilanol, which is rapidly converted into disiloxane (Me3Si)20. The presence of this molecule in the solution obtained after the silica surface modification process was confirmed by GCMS analysis. 

Fairbrother, FI. CAREER Exploring the Mechanisms of Organic Surface Modification Processes. 2000 (NSF CHE 9985372). 

Chemical vapor deposition (CVD) is an atomistic surface modification process where a thin solid coating is deposited on an underlying heated substrate via a chemical reaction from the vapor or gas phase. The occurrence of this chemical reaction is an essential characteristic of the CVD method. The chemical reaction is generally activated thermally by resistance heat, RF, plasma and laser. Furthermore, the effects of the process variables such as temperature, pressure, flow rates, and input concentrations on these reactions must be understood. With proper selection of process parameters, the coating structure/properties such as hardness, toughness, elastic modulus, adhesion, thermal shock resistance and corrosion, wear and oxidation resistance can be controlled or tailored for a variety of applications. The optimum experimental parameters and the level to which... 

Among the many kinds of the surface modification process, the fluid bed processes can most easily produce multilayered particle structure with each layer being monolithic, random multiphase structure, ordered multiphase structure, and so on (Fig. 5). The combination of the different components and layers can produce almost infinite types of functional particles. As an example, designs and preparations of several thermosensitive controlled-release particles will be described below. 

Fedorov, M. Vikhoreva, G. Khdeeva, N. Mashkova, A. Bonartseva, G. and Gal-braikh, L. [Modeling of surface modification process of surgical suture]. Chimi-cheskie Volokna. 2005, (6), 22-28, [Article in Russian]. 

As effective as these surface modification processes might be, they present limitations in terms of the extent to which the surfaces of polymers can be modified. Plasma-induced grafting offers another method by which chemical functional groups can be incorporated. In this process, free radicals are generated on the surface of a polymer through the use of an inert gas plasma. Because of the nonreactive nature of the inert gas plasma, surface chemical modification of the polymer does not occur. If the polymer surface that has been... 

Fig. 14 Reaction steps involved in the surface modification process, (a) Coupling of biotin to the SAM of cysteamine through EDC catalyzed amidation. (b) Binding of streptavidin to the preformed biotin layer, (c) Binding of the glutamate transporter to the streptavidin/biotin layer via the genetically engineered strep-tag at the N-terminus of the membrane protein. [Reprinted from ref 100 by permission of the Royal Society of Chemistry copyright 2008.]...

For many industrial applications of polyolefin materials that depend on adhesive bonding, surface treatment by cold plasma became preferred in industrial process. The plasma treatment is a surface modification process by which the bulk properties of the material are retained [51]. Plasma surface treatment is a very effective way to... 

Fig. 8.8 Surface modification processes using the plasma dischaige [53]...

The surface of any material governs its interactions with the environment. Knowledge over and control of these interaction is especially important when a material is in contact with the biosystem, for example, when applied as transplant, in tissue engineering, in cell cultures, and in blood contact, as weU as in biosensors in medicinal diagnosis, fluids analysis, environmental moititoring, and many other areas. Whereas, on the one hand, the bulk properties of the material are essential for its successful application, for example, as a catheter or a heart valve, special attention has to be paid to render to the surface suitable biocompatible or bioactive properties, no matter of the chemical composition of the bulk material. This is usually achieved by any surface modification process by low molar mass or polymeric compounds. An essential feature of such a modification procedure is the need for a permanent and bioresistant surface finish [87]. 

Surface Modification Processes The process of surface phosphonylation for polyethylene and nylon-12 has been adequately described elsewhere (7). Following phosphonylation, the phosphonyl dichloride moieties were then subsequently converted to potassium and calcium phosphonate moieties as also described elsewhere (7). 

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