Photochemical surface modification

M.J. Swanson, G.W. Oppermann, Photochemical Surface Modification. Photografting of Polymers for Improved Adhesion, in Part 3 of [90],... 

Ji, J. 1996. Fabrication and photochemical surface modification of photoreactive thin-film composite membranes and model development for thin film formation by interfacial polymerization. Ph.D. Dissertation, McMaster University. 

Versace D-L, Ramier J, Grande D, Andaloussi SA, Dubot P, Hobeika N, Malval J-P, Lalevee J, Renard E, Langlois V. Versatile photochemical surface modification of hiopoly-ester microfibrous scaffolds with photogenerated silver nanoparticles for antibacterial activity. Adv Healthc Mater 2013 2 1008-1018. 

VER 13b] Versace D.-L., Ramier J., Grande D. et al., Versatile Photochemical Surface Modification of Biopolyester Microfibrous Scaffolds with Photogenerated Silver Nanoparticles for Antibacterial Activity , Advanced Healthcare Materials, vol. 2, pp. 1008-1018, 2013. 

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. 

A macromolecular, photochemical surface labeling reagent was developed by Louvard et al. (1976). It comprised a Fab fragment of a human myeloma protein with which 4-fluoro-3-nitrophenylazide (Table 5.1.1c) had been reacted. Used at a concentration of 0.1 mM, this conjugate could be used to label the surfaces of sealed vesicles or it could be trapped inside vesicles and used to label from within. Louvard and colleagues focused their attention on the modification of aminopeptidase in intact brush-border membranes and demonstrated that the enzyme spans the bilayer. From the... 

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... 

Surface modification via chemical reactions is currently a very active field due to potential applications in the development of new materials. In addition to the ene and diene systems, other surface reactions including ionic, radical and photochemical reactions with a variety of functional groups are expected to extend the scope of potentially useful surface techniques. 

Xagas APB, Hugot-Le Goff A, Spyrellis N, Loizos Z, Falaras P. Surface modification and photosensitisation of Ti02 nanocrystalline films with ascorbic acid. J Photochem Photo-biolA Chem 2000 132 115-20. 

This fibre and fabric modification is based on photophysical and photochemical processes induced by exposure to plasma gases. Reactive gases are used to create chemical fibre surface modifications such as repellency of water, oil and soil and higher fibre resistance against aggressive chemicals. These modifications are mainly restricted to the fibre surface to avoid damaging the fibre bulk, for example... 

O.V. Makarova, T. Rajh, M.C. Thumauer, A. Martin, P.A. Kemme, D. Cropek, Surface modification of Ti02 nanoparticles for photochemical reduction of nitrobenzene . Environmental Science and Technology, 34(22), 4797-4803, (2000). 

Rajh, T. Ostafin, A. E. Mieie, O. I. Tiede, D. M. Thumauer, M. C. Surface modification of small particle Ti02 eolloids with cysteine for enhanced photochemical reduction An EPR study. J. Phys. Chem., 1996, 100,4538-4545. 

Other surface modification techniques include the use of free radical-, photochemical-, radiation- redox- and plasma-induced grafting. These are used to covalently attach some useful monomers onto the membrane surface [20]. Gas plasma treatment is also used to induce surface modification water permeabihty is improved by oxygen plasma treatment due to the introduction of hydrophihc carboxylate groups, whereas argon plasma treatment can enhance chlorine resistance by increasing the extent of cross-linking at the nitrogen sites. 

A wide array of surface modification techniques, ranging from simple to sophisticated, wet to dry, and vacuum to nonvacuum, are available for a host of polymeric materials. They include plasma surface treatment laser surface treatment corona, flame, UV, ozone, UV/ozone, photochemical, photografting, chemical grafting, and chemical methods of stuface modification and modification of polyamide surfaces by microorganisms [7]. 

Based on the membrane surface properties and the HA properties, various researchers have attempted to change the membrane surface characteristics by surface modification. Different techniques have been performed, such as ion beam irradiation, plasma treatment, redox-initiated graft polymerization, photochemical grafting, and interfacial polymerization (IP). In this chapter, two surface modification techniques, IP and photochemical grafting, are discussed by means of experimental examples. The surface characteristics of the unmodified membrane and the modified membranes are studied and their relationships with irreversible fouling and NF performance are reported. 

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