Chemical surface modification method

Chemical surface modification methods of gas-separation membranes include treatment with fluorine, chlorine, bromine, or ozone. These treatments result in an increase in membrane selectivity with a decrease in flux. Cross-linking of polymers is often applied to improve the chemical stability and selectivity of membranes for reverse osmosis, pervaporation, and gas-separation applications (41). Mosqueda-Jimenez and co-workers studied the addition of surface modifying macromolecules, and the use of the additive... 

TABLE 40.7 Physical and Chemical Surface Modification Methods for Polymeric Biomaterials... 

TaMe 1. Physical and chemical surface modification methods [61] Covalently attached coatings... 

Yang, Y., Zhu, Z.K., Yin, J., Wang, X.Y., Qi, Z.E., 1999. Preparation and properties of hybrids of organo-soluble polyimide and montmoriUonite with various chemical surface modification methods. Polymer 40, 4407—4414. 

Amylose brushes (a layer consisting of polymer chains dangling in a solvent with one end attached to a surface is frequently referred to as a polymer brush) on spherical and planar surfaces can have several advantageous uses, such as detoxification of surfaces etc. The modification of surfaces with thin polymer films is widely used to tailor surface properties such as wettability, biocompatibility, corrosion resistance, and friction [142-144]. The advantage of polymer brushes over other surface modification methods like self-assembled monolayers is their mechanical and chemical robustness, coupled with a high degree of synthetic flexibility towards the introduction of a variety of functional groups. 

Cell adhesion on a nonfunctional scaffold is mediated dominantly by nonspecific, entropically favored adsorption of a layer of cell adhesion proteins, excreted by the cell itself [61]. In order to obtain and retain the native function of these proteins, attempts are being made to tune the hydrophilicity or hydrophobicity of the scaffold surfaces [62], Different methods of surface activation are commonly applied, e.g., blending, copolymerization, plasma treatment, etching, radiation, chemical surface modification, coatings, and combinations of those. 

Kitamori s group has proposed selective chemical surface modification utilizing capillarity (called the capillarity restricted modification or CARM method) (Hibara et al., 2005). In the CARM method, a microchannel structure combining shallow and deep microchannels and the principle of capillarity are utilized. The procedures are shown in Figure 19. A portion of an ODS/toluene solution (lwt%) is dropped onto the inlet hole of the shallow channel, and the solution is spontaneously drawn into this channel by capillary action. The solution is stopped at the boundary between the shallow and deep channels by the balance between the solid-liquid and gas-liquid interfacial energies. Therefore, the solution does not enter the deep channel. It remains at the boundary for several minutes and is then pushed from the deep channel side by air pressure. 

Karl C. Vrancken is presently a researcher at the Laboratory of Inorganic Chemistry (University of Antwerp). In this position he substantiated the development of the Chemical Surface Coating method. In his young career as a Doctor in Sciences, he gained full expertise in organosilane chemistry. His current work is concerned with surface modifications and advanced materials preparation. 

All electrodes react with their environment via the surfaces in ways which will determine their electrochemical performance. Properly selected surface modification can effectively enhance the electrode heterogeneous catalysis property, especially selectivity and activity. The bulk materials can be chosen to provide mechanical, chemical, electrical, and structural integrity. In this part, several surface modification methods will be introduced in terms of metal film deposition, metal ion implantation, electrochemical activation, organic surface coating, nanoparticle deposition, glucose oxidase (GOx) enzyme-modified electrode, and DNA-modified electrode. 

There is a very limited selection of commercially available materials due to higher inertness of the metal oxide surface, and there are almost no reproducible methods of chemical surface modification [37]. Most of the surface chemistry alteration is achieved by coating and not bonding. Control of the surface area and porosity is also limited. 

We have prepared nanoneedles of mixed Co oxide using the sonochemical method for decomposing metal complexes. Resulted nanoparticles are rather well-ordered structures with the average size of 23 nm in length and 5 nm in diameter. Magnetic measurements revealed the ferromagnetic transition at 25 K, which can be explained by the chemical surface modification of the particles. 

Effective methods of chemical surface modification of mesoporous materials, to create robust surface structures with high catalytic activities in liquid phase reactions, are essential for the future development of environmentally friendly heterogeneous processes. In this paper we demonstrate the value of this methodology in different areas of organic chemistry and catalysis. 

The materials used for the fabrication of most microfluidic chips include glass, silicon, quartz, and plastics ( Materials Used in Microfluidic Devices) In addition to cost and optical, electric, and physical properties, careful consideration must be given to the surface chemistry of the material ( Surface Modification, Methods). In fact, surface chemistry plays a major role in chemical cytometry, as protein adsorption to the channel walls can degrade the separation performance and make the electroosmotic flow unreproducible. 

Fig. 5.4 Scheme illustrating some of the methods for chemical surface modification of QDs (Reprinted from Jorge et al. 2007, Published by MDPI)... 

Several surface modification methods for synthetic polymers have been described, for example, the use of chemical finishers based on carboxyl-containing polymers [100]. Alkaline and acid hydrolysis treatments are unspecific and result in strength and weight losses [97, 108]. Ionized gas treatment of PET materials using plasma has also been investigated to introduce hydrophilic groups at the surface of the polymer [80]. However, the application of this method is limited because it is complicated to use, and it can be difficult to control the extent of the material modification [16]. 

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