No abstract

Biofouling of all structures immersed in seawater constitutes an important problem, and many strategies are currently being developed to tackle it. In this context, our previous work shows that poly(ethylene glycol) monoacrylate (PEGA) macromonomer grafted on preoxidized poly(methyl methacrylate) (PMMAox) films exhibits an excellent repellency against the bovine serum albumin used as a model protein. This study aims to evaluate the following: (1) the prevention of a marine extract material adsorption by the modified surfaces and (2) the antifouling property of the PEGA-g-PMMAox substrates when immersed in natural seawater during two seasons (season 1: end of April-beginning of May 2007, and season 2: end of October-beginning of November 2007). The antifouling performances of the PEGA-g-PMMAox films are investigated for different PEG chain lengths and macromonomer concentrations into the PEGA-based coatings. These two parameters are followed as a function of the immersion time, which evolves up to 14 days. The influence of the PEGA layer on marine compounds (proteins and phospholipids) adsorption is evidenced by time-of-flight secondary ion mass spectrometry (ToF-SIMS) and X-ray photoelectron spectroscopy (XPS). It was found that the antifouling efficiency of the PEGA-grafted surfaces increases with both PEGA concentration and PEG chain length.

Surface modification of high-density-polyethylene (HDPE) and linear-low-density polyethylene (LL-DPE) films is promoted by sodium hypochlorite solutions using two different processes (I and II). Such an oxidation system introduces limited amounts of carbonyl-carboxyl and hydroxyl groups onto the surface of hydrocarbon polymers. FTIR, XPS, and SEM were used to assess the efficiency of the oxidation. The hydrophilicity of the studied surfaces was investigated by the sessile drop technique and the Wilhelmy plate and a plausible oxidation mechanism is proposed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100:

BACKGROUND: The surface properties of high-density polyethylene and linear low-density polyethylene were modified by grafting urethane monoacrylate monomer under UV irradiation. This graft polymerization was carried out on native substrates and on substrates pre-treated by wet oxidation, for different oxidation times. RESULTS:As the urethane monacrylate layer is crosslinked, its grafting efficiency was checked by dissolving the polyethylene substrates in hot toluene. Grafting was evidenced by Fourier transform infrared spectroscopy of the obtained residues, which showed that both the characteristic urethane acrylate (3350 cm −1 ) and polyethylene (2920, 730 and 720 cm −1 ) bands were observable for any polyethylene oxidation time. For an oxidation time longer than 10 hours, acrylate grafting was homogeneous and the grafted surface was smooth with a roughness of less than 10 nm. In addition, X-ray photoelectron spectroscopy analysis of the residues revealed that O/C had an average value of 0.19, which is lower than the value corresponding to pure acrylate (0.42), whereas N/C had an average value of 0.068, also lower than that of pure acrylate (0.09), thus confirming the grafting. CONCLUSION: A urethane monoacrylate layer was grafted on native and oxidized polyethylene films. For highly oxidized films, the grafted surfaces are smooth and homogeneous.

No abstract