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چكيده انگليسي :

An Investigation into Creating Self cleaning Effect on Architectural Fabrics Shabnam Joneidy s joneidy@tx iut ac ir 2011 Department of Textile Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor s Name and Email address Dr Akbar khoddami khoddami@cc iut ac ir Dr Ali zadhoudh zadhoush@cc iut ac ir Abstract Poly vinylchloride coated polyester fabrics are the most commonly used material in construction of structural fabric Among different properties of these fabrics which are used as awning and canopies resistance against dirt pick up and surface degradations weathering are the most important characteristics to ensure long life aesthetic properties Preparation of self cleaning effect on surface of Poly vinylchloride is an effective technique to improve performance Superhydrophobic surfaces cause droplets to roll off easily and wash off dirt and other particles completely even by small amount of rain Therefore combination of a low surface energy material and nano particles was used to create effective roughness on the top of Poly vinylchloride surface Air pockets which entrapped between roughness decrease adhesion of dirt particles and water droplets to surface Adhesion decrease of dirt particles and water droplets to surface is obtained by decreasing the contact area First Poly vinylchloride plastisols with different amount of additives were prepared and coated on Polyster fabrics Then mechanical properties of the fabrics like tensile and tear strength were tested The sample which had optimum properties was selected as base fabric for the next experiments Second different percentages of nano Titanium Dioxide and nano Zinc Oxide were dispersed in mixture of Perfluoroalkylacrylates and 2 isopropanol These topcoating solutions were sprayed on the selected Poly vinylchloride coated fabric After dry cure process the effects of finishing on the topcoated sample properties were evaluated by measuring contact angle sliding angle and 3M water repellency test Then the pictures of each sample before and after rolling a water droplet on surface were compared by image processing program So quantitative self cleaning property of the samples was studied Because of low abrasion fastness of topcoating Improvement in topcoating adhesion to the substrate was improved using surface functionalization by UV Ozone treatment The effect of different conditions of surface modification on the samples performance was studied by ATR FTIR spectroscopy and Martindale wear abrasion tester Finally weathering resistance of samples was tested for 96 hours Results obtained indicate that optimum percentage of Perfluoro alkylacrylates topcoating can increase water repellent properties of Poly vinylchloride Furthermore existence of 3 nano Titanium Dioxide created a superhydrophobic surface on Poly vinylchloride with high contact angle 150 and very low sliding angle 2 These data was the characterestics of superhydrophobic surfaces Super hydrophobicity which causes self cleaning effect occurred due to low surface energy of Perfluoroalkylacrylates and multi scale structured roughness on the surface So surface cleanability by water droplet was increased three times Abrasion fastness of top coating was improved by surface oxidation via UV Ozone surface treatments ATR FTIR analysis demonstrated that formation of oxygenated functional groups such as C O C O and O C O improves Poly vinylchloride wettability and adhesion of topcoating to it The longer time of exposure the more oxygenated functional groups were created Weathering test showed that superhydrophobic property of samples which had Titanium Dioxide topcoating was not changed after 96 hours At last a superhydrophobic surface with self cleaning property was produced which had not only good resistance to weathering like ultraviolet beam and rain but also a good washing and abrasion fastness Key Words Fabric structures Poly vinylchloride coated fabric Nano Titan

جنيدي، شبنم

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