تاثير ساختار بافت بر فوق آبگريزي پارچه پلي استر حلقوي پودي پوشش داده شده با نانو ذرات سيليكا

چكيده انگليسي :

105 Effect of Fabric Structure on the Superhydrophobicity of Polyester Weft Knitted Goods Coated with Silica Nano Particles Sanaz Ghapanvari s ghapanvari@tx iut ac ir Date of Submission 22 2 2012 Department of Textile Engineering Isfahan University of Technology Isfahan Iran Degree M Sc Language FarsiSupervisor A Prof A Kodami khoddami@cc iut ac ir A Prof H Hasani h hasani@cc iut ac irAbstract Non wettable surfaces with high water contact angles WCAs and low sliding angles ofdrops which are called superhydrophobic or ultrahydrophobic have received tremendous attention in recentyears A water droplet easily rolls off a superhydrophobic surface washing dirt off in the process andeffectively cleaning the surface This unusual wetting behavior is called the Lotus effect or self cleaning Forth t th tu ty u a combination of two major requirements low surface energy andthe magnified of the degree of roughness should be utilized The problem of waterproofing surfaces specifically for fabrics was first critically examined by Wenzel For a superhydrophobic textiles the originalCassie Baxter model better describes the wetting of rough surfaces Superhydrophobic surfaces can beproduced simply by making woven or non woven cloth hydrophobic without altering its roughness As theroughness of the cloth is usually on a relatively large scale some efforts have been made to generate smallerscale structures to increase the superhydrophobicity and pressure resistance of the structures Fractalstructures have been reported to effectively enhance the hydrophobicity of a solid surface but so far there hasbeen only limited research on how surface shapes and dimensions enhance surface hydrophobicity and watersliding behavior Various weft knitted structures can be produced using different knitting techniques These structure result indifferent surface roughness In this paper research the effect of structural parameters of weft knitted fabricson the superhydrophobicity Different single and double jersey weft knitted fabrics were produced using 20 Ne polyester spun yarn In order to minimize the surface energy of knitted fabrics fluorocarbon compoundwas used Sliding angle of droplet on the fabric was measure in technical back and face as well as wale andcourse directions Comparision the smooth polyester film Melinex and the knitted fabrics showed that fabricstructures remarkably have changed the surface roughness and sliding angles Also the findings showed thatstructural parameter has a great effect on superhydrophobicity Also the findings show that various knittedstructure and stitch density has a great effect on superhydrophobicity In addition the correlation between roughness factor and sliding angle of these surfaces was examined Theresults indicated that roughness have no significant influence on the sliding angle In order to create surfaceroughness on the polyester fibers alkaline hydrolysis was used and the results from it were compared withnano particles Polyester weight reduction process alkaline hydrolysis by creating pits which mainly resultfrom the presence of TiO2 particles efficiently roughened the surface in order that after the fluorocarboncoating remarkable improvement in fabric repellent properties was observed so that there was no necessityto use nanoparticles Moreover deformation and movement of a droplet sitting on a surface in differentsituations was simulated Keywords Superhydrophobic surface Knitting structure Nano particles Surfaceroughness Alkaline hydrolysis simulation

قپانوري، ساناز

تاثير ساختار بافت بر فوق آبگريزي پارچه پلي استر حلقوي پودي پوشش داده شده با نانو ذرات سيليكا

زبري سطح , هيدروليز قليايي , شبيه سازي