Dissertation > Excellent graduate degree dissertation topics show

Preparation and Properties of Nanostructured Silver Films Deposited on Nonwovens

Author: WangHongBo
Tutor: ZhuZhiFeng；WeiQuFu
School: Jiangnan University
Course: Textile Engineering
Keywords: Silver Non-woven fabric Magnetron sputtering Antibacterial Optical and electrical Electromagnetic shielding
CLC: TB383.1
Type: PhD thesis
Year: 2007
Downloads: 685
Quote: 3
Read: Download Dissertation

Abstract

Many unique properties of nano-silver particles due to the quantum size effect, surface effect and macroscopic quantum tunneling effect, the photoelectric properties of silver materials do not have the performance of the photocatalytic activity, anti-bacterial, electromagnetic shielding and absorption and emission spectra. Building nano-silver particles into a film by the test to an important part of the application changes. In this paper, the low temperature magnetron sputtering deposition of functional nano-silver films deposited on the surface of non-woven material, surface functionalization of textile materials. Overcome the one hand, the use of nano particles material as filler nanoparticles reunion process flow reduction and pollution; the other hand, can reduce processing costs and implementation of online processing. Focused on the formation of the surface of the nonwoven material silver functional nanostructures principle, preparation technique and its performance, to meet the market demand on the function of the nonwoven material. Therefore, the subject has both forward-looking and feasible, and has the important academic value and commercial applications; non-woven material widely used in research of this subject will function to provide a theoretical and experimental basis. Paper non-woven polypropylene (PP) and polylactic acid (PLA) as the base material, the preparation of nano-silver antibacterial film; non-woven polyester (PET) substrate prepared with good electrical conductivity, electromagnetic shielding and anti-UV transmission function Nano Silver feature film. Explore the sputtering process parameters as well as argon plasma pretreatment performance. The use of scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray spectroscopy analyzer (EDX) study the silver film surface morphology and composition; using X-ray diffraction (XRD) analysis of nano silver film micro The structure; to four probe tester Determination of silver film box resistance value; non-woven fabric according to the ASTM D4935-99 Standard Test silvered electromagnetic shielding effectiveness; shake flask testing the antimicrobial properties of the silver thin film of the nonwoven SUBSTRATE. The results show that the sputtering time and the argon plasma pretreatment is two of the key factors that affect the antimicrobial properties, the antimicrobial properties of the sputtering power, sputtering pressure, the gas flow was less affected. PP and PLA nonwovens, antibacterial rate reached 100 percent of E. coli and Staphylococcus aureus, the silver film thickness of 3nm and 2nm; nano silver under the same conditions, the argon plasma pretreatment The film antibacterial properties significantly improved antibacterial activity against E. coli and Staphylococcus aureus rate of up to 100% of the silver film thickness is 2nm and 0.5nm. The sputtering process parameters influence the membrane conductivity, electromagnetic shielding, and transmittance. Conductive performance increases as film thickness; on a thin film of the same thickness, as the sputtering power increases, the conductive performance degradation; improve with increasing argon pressure, after the first decline in conductive properties; electromagnetic shielding effectiveness (SE ) With the increase in the thickness of the film increases, the film thickness of 100 nm when the shielding effectiveness (SE value) reaches more than 26dB (shielding rate of greater than 99.7%); nonwoven the SUBSTRATE silver film performance in the wavelength range of 250 ~ 600nm, for the extreme ultraviolet and visible light shielding function, the film thickness of 50 nm or more, and its transmittance rate is below 6%. The paper was first proposed nonwoven nano silver thin film composite antibacterial mechanism inhibiting antimicrobial, i.e., the eluted silver ions antibacterial and the surface of the silver film. The one hand, due to dissolution and active action of the silver ions, on the other hand, a substrate by the argon plasma pretreatment and sputtering silver film, the adhesion of the bacteria to the surface of the silver film of PP (or PLA) yl sputtering freedom from negative to positive, indicates that the adhesion process is difficult to occur, even if the adhesion is also reversible, preferably from the perspective of energy explains the sputtered silver film surface to inhibit bacterial. The paper discusses the mechanism of interfacial bonding between the metal and polymer substrates, substrate pretreatment on the interface fastness, better characterization of the bond between the film and substrate wear law and stripped fastness. First proposed in view of non-woven base surface sputtering silver film had a fractal, fractal dimension can better describe the film surface morphology; fractal dimension greater the higher the quality of the film surface, the fractal dimension of the smaller, the surface quality of the more poor. Fractal dimension of the conductive film surface, the particle diameter, the shielding performance has a corresponding relationship. Thesis nonwoven nano silver thin film growth mechanism and micro-structure, the Ag film thickness is less than 5nm in the nano silver antimicrobial film, can be considered a layer growth type, because no significant changes of the roughness of the film after the sputtering ; on the thickness of the silver film in the more than 30-40nm, nuclear growth mode or layers of plus island mode, which is related to the state with the surface of the substrate, substrate temperature, sputtering process conditions. The micro-structure analysis showed that: using magnetron sputtering deposition on the non-woven fabric substrate of a different thickness of the Ag film remains face-centered cubic crystal structure of the Ag film was a polycrystalline state, with the increase in the thickness of the silver film, The average grain size of the films gradually becomes larger.

Related Dissertations

CLC: > Industrial Technology > General industrial technology > Materials science and engineering > Special structural materials
© 2012 www.DissertationTopic.Net Mobile