Surface Modification of Substrates

Geerts et al. have undertaken a study of the alignment of phthalocyanine 19 columns in thick (a few micrometer) and thin (a few tens of nanometers) films and on the influence of confinement on the occurrence of homeotropic alignment [113]. The orientation of the columns in those films is characterized by polarized optical microscopy and atomic force microscopy as a function of the preparation method, the polarity and roughness of the substrate and the number of DLC-solid interfaces, i.e. one or two. The control of columnar alignment is determined by the 

Evans et al. studied the alignment behavior of discotic columnar phase on surfaces modified by self-assembled monolayer (SAM) [114]. They studied a 

Aida et al. have shown that o-phenylene octamers can be used as surface modifiers to obtain homeotropic ordering of a variety of DLCs [116]. The octa-meric o-phenylenes are known to fold helically into a cylindrical architecture that resembles to a pi-stacked column of DLCs. It has been found that the oligomers adhere to the glass substrate with its cylindrical axis orthogonal to the surface. Therefore it is speculated that this face-on orientation of the octamer likely nucleates the homeotropic ordering of the liquid crystalline discotic materials. 

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Several environment-friendly surface preparation for the treatment of mbber soles with radiations have been recently studied. These treatments are clean (no chemicals or reactions by-products are produced) and fast, and furthermore online bonding at shoe factory can be produced, so the future trend in surface modification of substrates in shoe industry will be likely directed to the industrial application of those treatments. Corona discharge, low-pressure RF gas plasma, and ultraviolet (UV) treatments have been successfully used at laboratory scale to improve the adhesion of several sole materials in shoe industry. Recently, surface modification of SBR and TR by UV radiation has been industrially demonstrated in shoe industry... 

The use of high frequency plasmas for the surface modification of substrates, for etching processes and similar ends, is increasing rapidly. The wide ranging interest in plasma processes is reflected in our case by work involving a large volume microwave plasma apparatus,... 

On the other hand, modification of substrate surfaces, especially semiconductor surfaces, has been an intensively... 

The improvement of its activity and stability has been approach by the use of GE tools (see Refs. [398] and [399], respectively). A process drawback is the fact that the oxidation of hydrophobic compounds in an organic solvent becomes limited by substrate partition between the active site of the enzyme and the bulk solvent [398], To provide the biocatalyst soluble with a hydrophobic active site access, keeping its solubility in organic solvents, a double chemical modification on horse heart cytochrome c has been performed [400,401], First, to increase the active-site hydrophobicity, a methyl esterification on the heme propionates was performed. Then, polyethylene glycol (PEG) was used for a surface modification of the protein, yielding a protein-polymer conjugates that are soluble in organic solvents. 

Fig. 9 Surface modification of cells with ssDNA-PEG-lipid. (a) Real-time monitoring of PEG-lipid incorporation into a supported lipid membrane by SPR. (r) A suspension of small unilamellar vesicles (SUV) of egg yolk lecithin (70 pg/mL) was applied to a CH3-SAM surface. A PEG-lipid solution (100 pg/mL) was then applied, (ii) Three types of PEG-lipids were compared PEG-DMPE (C14), PEG-DPPE (C16), and PEG-DSPE (C18) with acyl chains of 14, 16, and 18 carbons, respectively, (b) Confocal laser scanning microscopic image of an CCRF-CEM cell displays immobilized FITC-oligo(dA)2o hybridized to membrane-incorporated oligo(dT)20-PEG-lipid. (c) SPR sensorigrams of interaction between oligo(dA)2o-urokinase and the oligo (dT)2o-PEG-lipid incorporated into the cell surface, (i) BSA solution was applied to block nonspecific sites on the oligo(dT)20-incorporated substrate, (ii) Oligo(dA)20-urokinase (solid line) or oligo(dT)20-urokinase (dotted line) was applied...

In the category of silicone coatings used for surface modification of the specific substrates, functional silicone fluids are often used, which can selectively interact with the chemical groups of the substrate, thus modifying its surface properties. The use of functional silicones in the textile industry has been discussed in a number of recent publications.5 421 422 The use of different types of high-performace silicone-coated textiles, which include elastomers and resins, has recently been reviewed.423 The use of functional silicones in personal-care products, for example, in shampoos and hair conditioners, mentioned before,381 provides another well-known example. 

Zhao and Brittain [280-282] reported the LCSIP of styrene on planar silicon wafers using surface modifications of 2-(4-(ll-triethoxysilylundecyl)phenyl-2-methoxy-propane or 2-(4-trichlorosilylphenyl)-2-methoxy-d3-propane respectively. Growth of PS brushes from these SAMs has been successfully achieved factors that influence PS thickness included solvent polarity, additives and TiC concentration. Sequential polymerization by monomer addition to the same silicate substrate bearing the Hving polymer chains resulted in thicker PS films. FTIR-ATR studies using a deuterated initiator indicated that the initiator efficiency is low, and the... 

Recently, Caster et al. described the surface modification of multifilament fibers such as nylon or Kevlar [70]. Coating techniques using preformed ROMP-based polymers and process contact metathesis polymerization (CMP), initially described by Grubbs et al. [71], were both used. The latter involves a procedure where the initiator is physisorbed onto the surface of a substrate and fed with a ROMP-active monomer that finally encapsulates the substrate. These modified fibers showed improved adhesion to natural rubber elastomers. 

In the following section, a new technique of surface modification of fillers and curing agents will be discussed plasma polymerization. This technique allows for surface coating of powders, whereby the chemical structure of the coating is determined by the monomer used for the process. The morphology of the substrate is preserved, which is an important precondition for filler treatment. The polarity of the functional groups can be chosen to fit the matrix of the polymer wherein it will be applied. 

Plasma treatment of powder substrates is difficult compared to that of a flat substrate. The main reason for this is the agglomeration of powders and the large surface area per unit mass of the powder. In order to modify the surface, each powder particle must be exposed to plasma. Unexposed regions are seldom modified. Therefore, the surface modification of powder substrates by plasma has to be dealt with differently. 

In conclusion, we would like to dwell on the fact that the present study demonstrates the feasability of a photochemical treatment, through a grafting reaction, of a cellulosic substrate. It is obvious that the results cannot be easily extrapolated to the case of an industrial process of surface modification of the pulps. In fact, due to its low penetration, UV light can be... 

MODIFICATION OF SURFACE ENERGY OF SUBSTRATE 1.1. Plasma Treatments of Low-Density Polyethylene... 

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