Preparation And Research Of Peptidomimetic Polymer Covalent Antifouling Coating

Research of antifouling materials was important in the fields of biomaterials, medical apparatus, and marine anti-fouling materials. and the antifouling polymer coatings were always used to resovle the issue.Although PEG and its derivatives have been widely used as antifouling coatings due to their hydrophilicity and electric neutrality, PEG coatings have been reported to lose their function when placed in vivo, lead to the limitation for clinical applications. Nevertheless, PEG molecules are not recommended to be exposed to oxygen during long-term storage because PEG is subject to autoxidative degradation and chain cleavage. Thus, in recent years, some researches have focus on bioinert polymers to substitute for PEG. Poly(2-methyl-2-oxazoline)(PMOXA) has been proved to be a kind of potential antifouling coating material. The water-soluble PMOXA resembles the poly (ethylene glycol)(PEG) in structure and shows similar or better properties to PEG (e.g. hydrophilicity, biocompatibility), while it might be less prone to degradation than PEG. Additionally, PMOXA can be readily synthesized by living cationic ring-opening polymerization (CROP) with less labor demanding. Moreover, this allows for designing and constructing polymers with multifunctional, well-defined architectures by incorporation of functional initiators, terminal groups, and particularly functional groups.On this account, PMOXA appears to be a promising candidate as antifouling coating material. In order to meet the challenge to develop a method which enables the polymer to be robustly anchored. Covalent attachment of polymer offers better stability compared to physisorption methods. So we have immobilized PMOXA brush covalently onto various material surfaces (including silica, glass) through a more efficient and simple approach.Working was on the following aspects:1. Poly (2-methyl-2-oxazoline)(PMOXA) with controlled terminal groups, reactive ionic cyclic functional groups-terminated PMOXA (PMOXA-NPP) were synthesized by living cationic ring-opening polymerization of2-methyl-2-oxazoline (MOXA). PMOXA coating was prepared through a novel method "Electrostatic Self-Assembly-Covalent Fixation", which is highly efficient and leads to permanent surface modification. And then, the chemical composition and hydrophilicity of the PMOXA coating were studied by using X-ray photoelectron spectroscopy (XPS), and contact angel (CA) test. But it was showed that the coating procedure was not effective.2. A series of comb copolymers, poly[(2-methyl-2-oxazoline)-random-glycidyl methacrylate](PMOXA-r-GMA) with a variety of compositions were synthesized by free radical polymerization of oligo(2-methyl-2-oxazoline)methacrylate macromonomer and glycidyl methacrylate, then characterized and used to coat silicon/glass surfaces. A one-step coating procedure by simple annealing protocol was used to yield covalent and cross-linked PMOXA-based antifouling coating. The coatings were rigorously characterized in terms of the surface chemical composition, hydrophilicity, thickness and morphology using X-ray photoelectron spectroscopy (XPS), water contact angel (WCA) test, ellipsometry and atomic force microscopy. The results demonstrated that the PMOXA-r-GMA brushes could successfully be bonded onto the silicon/glass surfaces.3.The fouling resistance ability of the modified surface was evaluated by analyzing the adsorption of bovine serum albumin protein, bacterial cell attachment and platelet adhesion, which indicated that the modified silicon/glass surfaces had superior resistance to protein, bacterial cell and platelet adsorption, and the performance of fouling resistance was enhanced with the content of PMOXA segments in the copolymers.