Properities And Deposition Of Nanoscale Copper Films Sputtered On Polyester Fabrics

The paper was based on the theory on the growth process and mode of nanoscale metalthin film,clarified the forming mechanism of nanoscale copper films deposited on thedifferent structure of polyester fabrics by magnetron sputtering.Then a variable angledeposition growth model were presented on the basis of above research,revealing therelationship between fabric structures and deposition process of light transmission,electricalconductivity,shielding performance of the polyester fabric sputtered copper films.The peeltest and abrasion experimental methods were used to evaluate the interface bonding strengthbetween copper film and fabrics,then clarified the interface bonding mechanism and analyzedthe impact of environmental conditions on the conductive properties of copper-depositedpolyester fabrics,the effect mechanism of environmental conditions on the conductiveproperties of copper-deposited polyester fabrics were also explained.Firstly, the surface structure,morphology and forming mechanism of polyester fabricssputtered nanoscale copper films were studied.The experimental results showed that thesurfaces of the polyester woven fabrics and knitting fabrics are coated uniformly by a layer ofcopper grain clusters under the same sputtering process, and the number of clusters increasedwith the increasing of the deposition time. With the increasing of sputtering power, theparticle size and the surface roughness of the nanosacle copper film were decreased, thesample translucent is reduced. The copper clusters connect to each other with polymerizedgrow, forming a dense nanoscle copper film. Argon pressure increases the fiber surfaceroughness, nanoscale copper particle size were first decreased and then reduced.The thicknessof the copper film, the copper mass percent, and the atomic percentage were increased as thesputtering time was getting longer. The oxygen plasma etching has more uniform of effect onthe polyester fiber than the argon plasma.The longer sputtering time or the greater sputteringpower resulted in more roughness of the surface of the film, the higher degree of crystallinityof the metal thin film.Sputtering causes the nucleation growth as copper-critical nuclear Volmer-Weber modewith the island shapes. The islands interconnect constitute island, and finally form acontinuous film.RMS roughness of the surface of the copper film first increased and thendecreased, clusters increased in the number and grow up in the three-dimensions, resulting inthe increase in surface roughness.As the deposition proceeds, the roughness of the surface ofthe copper film is increased due to the grain cohesion and merged when the formation of acontinuous dense copper film with certain orientations. The roughness decreases with theincrease of the size of the particles as well as the increased deposition time. The growthpattern remains three-dimensional island based on the variable angle deposition growth model,the mobility of the sputtered atoms on the substrate surface affect the film growthcharacteristics.The sputtering process conditions, substrate structures and substrate plasma pretreatmentprocess affect the properties of polyester coated by the copper film.Then lighttransmission,conductivity,electromagnetic shielding and other properties of polyester fabrics sputtered nanoscale copper films were analyzed.As the sputtering time was increased, the filmon the surface of the fiber gets more uniform and much denser, leading to the sampledecreased translucent while increased electromagnetic shielding effectiveness, but themechanical properties did not change significantly.With the increasing of sputtering power,the particle size of the nanometer copper film and the surface roughness were decreased, thesample translucent is reduced. Argon pressure increased the fiber surface roughness,nano-copper particle size increase after the first decreased the sample translucent conductiveproperties. Nanoscale copper particles on the surface of the fabric matrix forms structuraldifferences of the fabric itself. The increase of porosity causes the deterioration of the samplelight transmitting property and the conductive performance.Under the same sputtering time,the weave density of the fabric increases, the sample conductivity capacity increases. Whenthe electromagnetic wave frequency is the same, the weave density of the electromagneticshielding effectiveness is slightly increased; The oxygen plasma etching has more uniform ofeffect on the polyester fiber than the argon plasma, and after the oxygen plasma treatment, itsignificantly improves the performance of sample conductivity, the electromagnetic shieldingeffectiveness is increased by about5dB, hydrophilic properties and mechanical properties arealso significantly improved with the decrease of the permeability.Following the interface bonding strength between polyester fabrics and copper coatingwere further studied.Scanning electron microscopy, the peel test, the wear experiments canobserve and analyze the interface microstructure of film and substrate, the combinationstrength and performance. The experimental results showed that the nanometer copper filmand polyester fiber combined tightly with good fastness. With longer sputtering time, theplasma pretreatment can improve the adhesion of the film and the substrate.Lastly,The conductivity of polyester fabrics sputtered nanoscale copper films wereevaluated.By changing the temperature, humidity and washing times, the electricityconduction of sample is getting relatively stable. The continuity of the copper thin filmbetween the substrate can be destroyed when it is placed under atmosphere at roomtemperature for90days, meantime the surface composition and chemical state of samples donot change but the conductive performance is decreased to a more stable value.