Modification of surface properties

In many applications polyolefins are integrated in different components and composite materials, or they are subjected to more or less aggressive media. Two opposite surface characteristics are usually required  

Several practical and economical methods have been developed over the years in order to modify PE surfaces for improved adhesion, wettability, printability, dye uptake, and so on. These methods include mechanical and wet chemical treatments, and gas-phase processes like corona discharge, flame, UV/ozone, glow discharge plasmas, and particle beam bombardment. 

UV irradiation of polyolefins may induce changes in their colour and degradation of their physical properties (surface as well as bulk properties). Ozone-generating UV radiation is widely used to clean organic contaminants from various surfaces, while the combined effects of UV radiation and ozone lead to fully oxidised surfaces, increasing the wettability, adhesive properties, and dyeability of polyolefin surfaces. 

The impact of energetic ions on polymeric materials is very important for the modification of the first few nanometres of the polymer surface. This treatment has disturbing and damaging effects on surfaces, but is also sometimes used to probe surface properties. Bombardment with low-energy ions alters the structure, morphology, and chemical properties of materials. The main properties that can be modified using this procedure are rheological properties, electrical conductivity, optical and mechanical properties, surface texture, crystalline state, biocompatibility, and adhesive and surface properties. 

Sample Photoinidator Crosslinking agent Young s modulus (MPa) Water contact angle (degree) 

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The concentration of a small molecule reactant inside the polymer coils can be lower than outside when one uses a poor solvent for the polymer. This results in lower local and overall reaction rates. In the extreme, a poor solvent results in reaction occurring only on the surfaces of a polymer. Surface reactions are advantageous for applications requiring modification of surface properties without affecting the bulk physical properties of a polymer, such as modification of surface dyeability, biocompatibility, adhesive and frictional behavior, and coatability [Ward and McCarthy, 1989]. 

Modification of surface properties Antistatic agent Slip agent Antiblocking agent Adhesion promoter Corrosion inhibitor Surfactant ... 

Ashworth, V. Grant, W.A. Procter R.P.M., Eds. Proc. Int. Conf. Modification of Surface Properties. Ion Implantation Oxford Press, New York, 1987. 

Supported organotransition metal complexes have important applications in the design and modeling of new catalysts. They are of interest in the modification of surface properties of solids, including electrodes, and as stoichiometric reagents. 

The appearance of the products of the reaction of collagen and various monomers often varied considerably from the original collagen powder 45, 48). With some monomers, the graft copolymer consisted of powders while with others mats or films were formed. The modification of surface properties could often be detected by visual inspection. 

The modification of surface properties by covalent bonding of various organic groups is by now a well-established procedure for a broad range of solids. The use of inorganic layered compounds as substrates for such chemistry is, however, quite limited in its known scope, particularly when the "surface" is meant to include both external and internal basal sites. The primary motivation for preparing covalently anchored layered compounds should be apparent not only would such products enjoy the very significant... 

Methods of modification of surface properties of complex carbon-mineral adsorbents distinguishing those used on the commercial scale and on the laboratory scale are presented in the review paper [2]. However, not all methods can be applied in both cases. Some attention is paid to the latest publications not included in the quoted paper. 

Surface Activity of Block Copolymers. Modification of surface properties of a homopolymer by incorporating a small proportion of block copolymer has been studied for several block copolymer-homopolymer blends. LeGrand... 

Complex formation is important in the chemistry of natural and wastewaters from several standpoints. Complexes modify metal species in solution, generally reducing the free metal ion concentration so that effect and properties which depend on free metal ion concentration are altered. These effects include such aspects as the modification of solubility, the toxicity and possibly the biostimulatory properties of metals, the modification of surface properties of solids, and the adsorption of metals from solutions. 

The action of compression plasma flows (CPF), generated by quasi-stationary plasma accelerators, upon solid surfaces leads to a substantial modification of surface properties of exposed materials [1-3]. It was found that exposure of silicon crystals to CPF causes formation of sub-micron bulk periodic structures on its surface. These structures are of great interest for development of nanoelectronic devices. 

The formation of complexes modifies the metal species dissolved in pore fluid and those sorbed on soil particle surfaces interactively. The formation of complexes reduces the concentration of free metal ions in the dissolved phase. As a result, concentration-dependent properties of metals are altered. The effects include (a) modification of solubility, toxicity, and possibility biostimulatory properties of metals (b) modification of surface properties of solids and (c) sorption of metals from solution (Snoeyink and Jenkins, 1980). As a result, chelating agents can enhance the electrochemical remediation of subsurface contamination. 

KoSikovd, B., Rvajovd, A., Demianova, V. The effect of adding lignin on modification of surface properties of polypropylene. Eur. Polym. J 31, 953-956 (1995)... 

K.V. Pandiyaraj, V. Selvarajan, R.R. Deshmukh, C. Gao, Modification of surface properties of polypropylene (PP) film using DC glow discharge air plasma. Appl. Surf. Sci. 255, 3965-3971 (2009)... 

B. E. Koel, R. G. Nindhaum "Chemical Modification of Surface Properties" Proceedings, Ind. Univ. Advanced Materials Conference, Denver (Ed J. G. Morse), 1987... 

Svoreik V, Kolafova K, Slepicka P, Mackova A, Novotna M, Hnatowicz V (2006) Modification of Surface Properties of High and Low Density Polyethylene by Ar Plasma Discharge. Pol3rm. degr. stab. 91 1219-1225. 

Modification of surface properties Antiblock, lubricating silica, CaCOj, PTFE, M0S2, and graphite Radiation absorption Metal particles, lead oxide, and leaded glass... 

Arce, F. T. Avd, R. Beech, I. B. Cooksey, K. E. Cooksey, B. W., Modification of Surface Properties of Poly(dimethylsiloxane)-Based Elastomer, RTVll, upon Exposure to Seawater. Langmuir 2006,22, 7217-7225. 

Leboda, R. 1974. Modification of surface properties of silica gels from the point of view of their application in chromatography. PhD thesis. Lublin Maria Curie-Sklodowska University. 

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