Surface modifications effects

Zhang Y., Hanayama K., and Tsubaki N. 2006. The surface modification effects of silica support by organic solvents for Fischer-Tropsch synthesis catalysts. Catal. Commun. 7 251-54. 

Fukai, T. and K. Matsumoto, Surface modification effects on hydrogen permeation in high-temperature, high-pressure, hydrogen-hydrogen sulfide environments. Corrosion (Houston), 50, 522 (1994). 

The introduced hydrophilic moieties tend to migrate into the deeper section of the surface state while the surface is kept dry. Such a migration occurs in the direction to minimize the interfacial tension of polymer/air interface. This process has been recognized as the decay of the surface modification effect. 

Figure 3.9 shows a schemalic representation of the chemical filing process. The first step of the process involves the chlorination of the surface of the pyrochlore-based ceria-zirconia sample. The extent of the chlorination can be controlled by the concentration of the chlorine gas and/or chlorination time and the cerium and zirconium chlorides partially formed on the surface are vaporized and transported by the formation of gaseous complexes with aluminum chloride. This chemical filing process is carried out at 1273 K to stabilize the surface modification effects at high temperatures. A similar effect can also be achieved by chlorination with ammonium chloride followed by dominant vaporization of formed zirconium chloride. ... 

C) Plasma-treatment variables In all of the above comparisons, the various mica samples had been exposed to plasmas under arbitrarily selected, constant conditions of monomer pressure, plasma duration and applied power. It is very probable (2, that these variables and possibly others, such as reactor geometry and post-treatment history, may influence strongly the magnitude of surface modification effects attained by the present route. For this reason the performance modifications of polymer composites will also depend on the exact selection of treatment variables. 

With a particular focus on polymers, two important properties of a low-pressure plasma treatment should be emphasized (i) A low-pressure plasma provides high activation energies of several electron volts without elevated temperatures of ions and neutrals (cold plasma). For that reason, there is no thermal load to sensitive polymer materials, while most chemical bonds can be broken and surface radical sites can be formed, (ii) When a polymer is exposed to a low-pressure plasma, the surface modification effect is limited to the uppermost few nanometers (i.e., the range of impinging ions and vacuum ultraviolet photons). Hence, favorable bulk properties of the material remain unchanged. 

ABSTRACT. The paper examines the influence of interactions at polymer surfaces and interfaces on the properties of polymer systems, with emphasis on acid/base interactions. The method of inverse gas chromatography is used to evaluate the donor-acceptor interaction potential of components in polymer systems. The usefulness of the interaction parameters is established by their ability to rationalize diverse properties of polymer systems, including the adsorption of polymers on pigments, and the effectiveness of thermal stabilizers in pigmented polymers. Various strategies for controlling surface and interfacial interactions in polymer systems are reviewed, with emphasis placed on the ability of polymers to adopt various surface orientations and compositions. TTiese inherent surface modification effects are attributed to thermodynamic driving forces, and are shown to influence polymer adhesion, barrier and other properties dependent on surface and interfacial forces. 

Arbelaiz A, Cantero G, Fernandez B, Ganan P, Kenny JM, Mondragon I (2005) Flax fiber surface modifications. Effect on fibre physico mechanical and flax/polypropylene interface properties. Polym Compos 26 324—332... 

Silicone polymers that exhibit good surface modification effects are classified as surfactants. Silicone polymers are derived from a polysiloxane backbone, wherein the reactive sites could be attached to this backbone. The reactive sites are typically reacted to organic moieties forming organomodified siloxane polymers. Such derivatives form a different class of surfactants providing unique properties and applications that differ significantly from traditional surfactants. A Surfactant Science Series volume was published in 1999 that covers a wide spectrum of topics related to the chemistry. 

In the indirect method, surface-modified whiskers are filled into polymers to prepare composite materials and the surface modification effects of whiskers can be evaluated by studying characteristics of composites, such as mechanical, thermal, and electrical properties. This method is the most often used. 

To optimize the surface modification effect of free radicals and ionic bombardment, high-energy, enhanced discharge devices are particularly effective in optimizing surface modification effects. Critical air and gas plasma device design and operational features should include the following ... 

Vourdas, N.,Tserepi, A., Boudouvis, A.G., Gogohdes, E., 2008. Plasma processing for polymeric microfluidics fabrication and surface modification effect of super-hydrophobic walls on electroosmotic flow. Microelectron. Eng. 85, 1124. 

---