Polyethylene surface modification

Keywords Polyethylene Surface modification Characterisation Grafting Radiation... 

Keywords Contact angle Cross-linked LDPE Photosulfonation Polyethylene Surface modification Zeta potential... 

E. Kiss, J. Samu, A. Toth, I. Bertoti, Novel ways of covalent attachment of poly (ethylene oxide) onto polyethylene surface modification and characterization by XPS and contact angle measurements. Langmuir 12, 1651—1657 (19%)... 

UV irradiation on a polymer surface produces chemical modification as well as wettability and bondability improvement. It causes chain scission and oxidation on polymer surfaces. -iven in the presence of an inert gas [45]. Carbonyls are found to be introduced onto polyethylenes on UV irradiation. Sivram et al. [46] have used photochemical treatments for surface modification of polymers. They have generated surfaces of vaying surface energies by simple organic reactions. 

Capillary electrophoretic separations are performed in small diameter tubes, made of Teflon, polyethylene, and other materials. The most frequently used material is fused silica. Fused silica capillaries are relatively inexpensive and are available in different internal and external diameters. An important advantage of a fused silica capillary is that the inner surface can be modified easily by either chemical or physical means. The chemistry of the silica surface is well established due to the popularity of silica surfaces in gas chromatography (GC) and liquid chromatography (LC). In capillary electrophoresis, the silica surface is responsible for the EOF. Using surface modification techniques, the zeta potential and correspondingly the EOF can be varied or eliminated. Column fabrication has been done on microchips.13... 

Formulation strategies for stabilization of proteins commonly include additives such as other proteins (e.g., serum albumin), amino acids, and surfactants to minimize adsorption to surfaces. Modification of protein structure to enhance stability by genetic engineering may also be feasible, as well as chemical modification such as formation of a conjugate with polyethylene glycol. 

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. 

Brown, J.R., P.J.C. Chappell, Z. Mathys (1992b). Plasma surface modification of advanced organic fibers, part III. Effects on the mechanical properties of aramid/vinylester and extended chain polyethylene/ vinylester composites. J. Mater. Sci. 27. 6475-6480. 

Gao. S. and Zeng, Y. (1993a). Surface modification of ultrahigh molecular weight polyethylene fibers by plasma treatment. I. Improving surface adhesion. J. Appi. Polym. Sci. 47, 2065-2071. 

Rochow, E.G. (1951). An Introduction to the Chemistry of Silane. 2nd, ed.. Chapman Hall. London. Rostami, H., Iskandarni, B. and Kamel, I. (1992). Surface modification of Spectra 900 polyethylene fibers using RE-plasma, Polym. Composites 13, 207-212. 

To improve the biomedical properties of SPUs, a number of attempts have so far been proposed. In particular, surface modifications by mobile, hydrophilic polyethylene glycol) (PEG) chains were extensively studied, and some of them proved to give fairly good results in terms of the antithrombogenicity. Nevertheless, as discussed in Sect. 3.1, the effect of PEG chains tethered onto the SPU surface should be carefully evaluated in detail with regard to clinical application as well as to fundamental considerations. 

Veronese, F.M., Largajolli, R., Boccu, E., Benassi, C.A., and Schiavon, O. (1985). Surface modification of proteins activation of monomethoxy-polyethylene glycols by phe-nylchloroformates and modification of ribonuclease and superoxide dismutase. Alied Biochem. Biotechnol., 11, 141-152. 

Abstract Polyolefins such as polyethylene, polypropylene and their copolymers have excellent bulk physical/chemical properties, are inexpensive and easy to process. Yet they have not gained considerable importance as speciality materials due to their inert surface. Polyethylene in particular holds a unique status due to its excellent manufacturer- and user-friendly properties. Thus, special surface properties, which polyethylene does not possess, such as printability, hydrophilicity, roughness, lubricity, selective permeability and adhesion of micro-organisms, underscore the need for tailoring the surface of this valuable commodity polymer. The present article reviews some of the existing and emerging techniques of surface modification and characterisation of polyethylene. 

Polyolefins are amongst the most widely used polymers. Polyethylene in particular holds a unique status due to its excellent user-friendly properties. Tailoring of its surface properties would open an avenue to the most lucrative markets. The present article reviews some of the existing as well as emerging techniques of surface modification and characterisation of polyethylene. 

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