Surface modification acrylic acid treatment

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). 

Control of fiber friction is essential to the processing of fibers, and it is sometimes desirable to modify fiber surfaces for particular end-uses. Most fiber friction modifications are accomplished by coating the fibers with lubricants or finishes. In most cases, these are temporary treatments that are removed in final processing steps before sale of the finished good. In some cases, a more permanent treatment is desired, and chemical reactions are performed to attach different species to the fiber surface, e.g. siliconized slick finishes or rubber adhesion promoters. Polyester s lack of chemical bonding sites can be modified by surface treatments that generate free radicals, such as with corrosive chemicals (e.g. acrylic acid) or by ionic bombardment with plasma treatments. The broken molecular bonds produce more polar sites, thus providing increased surface wettability and reactivity. 

Plasma treatment of microchannels can be useful for improving the functionality of microdevices. For example, previous studies have shown that PDMS microchannels can be made hydrophilic by the addition of silane molecules with polar head groups [6]. In this process (3-mercaptopropyl)trimethoxysilane (3-MPS) was absorbed to PDMS to increase the hydrophilic properties of microchannels. Additionally, plasma polymerization has been used to induce in the long-term hydrophilic surface modification by covalently bonding a polymer layer to the surface. Barbier et al. [7] describe a method based on plasma polymerization modification with acrylic acid coatings. First, argon plasma pretreatment was used to activate trace oxygen molecules in the chamber, which partially oxidize the top layer of the substrate. This step cross-linked the surface to reduce ablation of silicon... 

Chen JP and Chiang YP, Surface modification of non-woven fabric by DC pulsed plasma treatment and graft polymerization with acrylic acid, Journal of Membrane Science, 270 (1), 2006, pp 212-220. 

To achieve enhanced cell adhesion and proliferation in vitro which probably leads to a better integration of the prosthesis into the surrounding tissue the cell adhesion mediator fibronectin was coupled to the surface of silicone. Figure 40 shows the two principal steps of the appHed surface modification procedure. Argon plasma treatment and subsequent exposure to air of the silicone samples leads to the formation of hydroperoxide groups on its surface which are used to initiate polymerization of acrylic acid (AAc), methacrylic acid (MAAc) and gly-cidyl methacrylate (GMA) generating carboxylic and epoxy groups, respectively. 

If monomeric acrylic acid, in the vapor phase, is used for glow discharge modification, both, an increase in surface hydrophilicity and a decrease in bacterial adhesion is seen. It is likely that the treatment with the gases leads to an etching effect of the polymer surface. The increase in surface roughness might be the reason for the enhancement of bacterial adhesion, although from thermodynamical considerations adhesion to the more hydrophilic surface should be reduced. Treatment with acrylic acid leads to a smoother surface modification, and bacterial adhesion is... 

Kalapat N, Amomsakchai T. Surface modification of biaxially miented polypropylene (BOPP) film using acrylic acid-corona treatment Part 1. Properties and characterization of treated films. Surf Coat Technol 2012 207 594-601. 

The present paper is specially focused on the surface mechanieal properties of polypropylene films heterogeneous modified by using acrylic acid as grafting agent in solution. Surface mechanical properties have been measured by nano-indentation techniques and the chemical treatment induced variation of the mean image roughness, reduced modulus and surface hardness have been assessed. Whetha- beneficial bulk mechanical properties remained actually unaffected by surface chemical modification was checked by determining the tensile deformation behavior, static fracture behavior and dart impact response. 

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