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Mussel-Inspired Biomimetic Surface Functionalization and Metallization

Author: LiaoYuan
Tutor: WangWenCai
School: Beijing University of Chemical Technology
Course: Materials Science and Engineering
Keywords: Silver Chemical reduction UV irradiation Polyimide Glass microspheres Dopamine
CLC: TB30
Type: Master's thesis
Year: 2010
Downloads: 290
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Abstract

Material surface modification method of the material are of great significance in research and industrial applications. Existing material surface modification method has advantages and disadvantages. Which has excellent bonding properties and other properties of the molecule and polymer self-assembly the function layer formed in the surface of the material by all the attention. This method has a low-cost, applied to a large area of ??the shape of the complex three-dimensional structure of the matrix, the advantage of micron-and nano-level functional layer can be formed on the surface. Inspired by the structure of the adhesion protein secretion by shellfish, scholars reported Polydopamine adhesion mechanism and performance. The results indicate that dopamine (3,4 - dihydroxy - phenylalanine) and other compounds having similar catechol structure can be deposited on the surface of the substrate of the different materials, including organic, inorganic and metallic material. By the dopamine oxidative polymerization Polydopamine deposition substrate surface of different materials can be modified material surface functionalization. Using polyethylene dopamine layer surface groups for further reaction other functional layer is formed on the material surface, including use of self-assembled to form a single molecule layer, the polymer layer is formed by long-chain molecules reaction, the metal layer is formed by electrodeposition as well as by large the bioactive layer formed by molecular grafting. In the present study, we have functional Modification dopamine polymerization on the surface of the polyimide membrane (PI) and the glass microspheres (Glass beads), and then by UV irradiation or a chemical plating the surface of the base material after the functional plating the silver layer. Specific work includes the following three aspects: (1) the first study of dopamine functionalization and chemical reduction of silver high reflectivity of the preparation of highly conductive polyimide (PI) film of the new method. In this method, first, the polyimide (PI) film is immersed in dopamine in aqueous solution, in the presence of oxygen of dopamine in the PI surface polymerization and deposition, and then deposited with a the polyimide film Polydopamine (PI-DOPA) surface by chemical reduction (electroless plating) The method of depositing a layer of metallic silver. Changes in the composition and structure of the surface of the PI film by X-ray photoelectron spectroscopy (XPS) test results show that the surface of the PI film successfully deposited on Polydopamine layer. In the silver reduction process, since the polyethylene has a certain dopamine redox ability, Polydopamine functional layer, not only in the silver plating process as the silver ion adsorption points, while improving the bonding force between the silver layer and the substrate. The surface silvered obtained by the preparation of the Institute PI film (PI / Ag) having excellent electrical conductivity and reflective, a surface resistance of 1.5Ω, the reflection rate of 95%. (2) In this paper, the silver particles by UV irradiation restore dopamine function PI film surface preparation of antibacterial film. The solution pH, dopamine concentration and reaction time on the dopamine polymerization reaction. As Polydopamine hydrophilic, is compared with the PI film of dopamine function of a water contact angle of the surface of the PI film and before the modification significantly reduced. PI film using X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) for Polydopamine modified PI film and ultraviolet irradiation, reducible silver surface chemical composition analyzed. By scanning electron microscopy (SEM), the the PI surface morphology changes. By antimicrobial experimental tests, this composite film having excellent antibacterial properties. (3) also studied the surface coated silver particles of glass microspheres (Glass beads / Ag) core-shell composite microspheres prepared through dopamine functionalization and electroless deposition method. By dopamine polymerizable functional modification of the surface of the glass microspheres, the introduction of the phenolic hydroxyl group and a nitrogen-containing group. By changing the concentration of the silver nitrate solution, and the corresponding glucose concentration of the solution obtained in the process of electroless deposition of silver, the surface is covered with a silver layer of different thickness and densification of the glass microspheres. X-ray photoelectron spectroscopy (XPS) and X-ray diffractometer (XRD) analysis of chemical composition on the surface of the glass microspheres / silver composite microspheres. Use of scanning electron microscopy (SEM) and energy dispersive x-ray spectrometer (EDX) characterization of glass microspheres changes in surface morphology and elemental composition of the silver-plated front and rear. Adsorption of silver ions can play a role in the same time can promote silver restore dopamine layer formed in the surface of the glass microspheres. Because of Polydopamine the role of a \In this paper, based on bionic technology dopamine self-polymerization method for different substrate surface functionalization provides a new platform for films, fibers, micro / nanoparticles such as size and shape can be achieved on this basis by electroless plating surface metallization of materials for functional modification of the material surface provides a new way of thinking.

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