Polymer Surfaces modification methods,

Ozdemir M., C.U. Yurteri, and H. Sadikoglu. 1999. Physical polymer surface modification methods and applications in food packaging polymers. Critical Reviews in Food Science and Nutrition 39 457-77. 

In a previous section, the effect of plasma on PVA surface for pervaporation processes was also mentioned. In fact, plasma treatment is a surface-modification method to control the hydrophilicity-hydrophobicity balance of polymer materials in order to optimize their properties in various domains, such as adhesion, biocompatibility and membrane-separation techniques. Non-porous PVA membranes were prepared by the cast-evaporating method and covered with an allyl alcohol or acrylic acid plasma-polymerized layer the effect of plasma treatment on the increase of PVA membrane surface hydrophobicity was checked [37].The allyl alcohol plasma layer was weakly crosslinked, in contrast to the acrylic acid layer. The best results for the dehydration of ethanol were obtained using allyl alcohol treatment. The selectivity of treated membrane (H20 wt% in the pervaporate in the range 83-92 and a water selectivity, aH2o, of 250 at 25 °C) is higher than that of the non-treated one (aH2o = 19) as well as that of the acrylic acid treated membrane (aH2o = 22). 

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. 

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... 

J. Yang, et al.. Enhancing the cell affinity of macroporous poly(L-lactide) cell scaffold by a convenient surface modification method. Polym. Int. 52 (2003) 1892-1899, doi 10.1002/pi.l272. 

Surface modification of iPP in vapwurs of halogen compounds (Novak Chodak, 2001 Novak Chodak, 2001 Kharitonov, 2000 Novak Chodak, 2001 Hruska Lepot, 2000 Carstens et al., 2000) under UV irradiation represents an efficient method for the increase of the adhesive properties. The ptresented method is based on the influence of the UV radiation and vapours of phosphoiyl chloride on the iPP surface. UV-irradiation results in a faster decomposition of the halogen compwimd and leads to the UV-oxidation of the surface of polymer. Surface modification of iPP vapours of phosphoryl chloride imder UV irradiation... 

Surface modification is a valuable tool for the design of appropriate membrane, as the interfacial characteristics required can rarely be achieved by bulk modification of the membrane-forming polymer without complications during membrane fabrication (He et al. 2009). Surface modification methods have been employed by the membrane manufacturers to produce hydrophilic, low-binding membranes (Peinemann and Nunes 2008) with improved membrane performances and properties (Pandey and Chauhan 2001 Robeson 1999). These methods include UV... 

M. Strobel, M. J. Walzak, J. M. Hill, A. Lin, E. Karbashewski and C. S. Lyons, A comparison of sas-phase methods of modifying polymer surfaces, in Polymer Surface Modification, K. L. Mittal, Ed., VSP, Utrecht, 1995, Part 3. 

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]. 

Interest in natural fibers obtained from different resources to reinforce polymer so as to get the novel composites is growing rapidly because they are renewable, cheap, recyclable, and biodegradable. Research in this field has prompted surface modification of natural fibers in order to improve the compatibility between hydrophilic fibers and hydrophobic matrix [1], Major challenges for polymer scientists in the development of structural natural fiber-reinforced composites are to increase the moisture resistance, dimensional stability with minimized matrix material, and to decrease the manufacture costs of the composite materials. Different researchers have used different surface modification methods, that is, mercerization [2], benzoylation [3], silanation [4], acetylation [5], graft... 

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