مطالعه خواص فيزيكي نخ مغزي با رويه نانو الياف الكتروريسي شده

چكيده انگليسي :

Study on the Physical Properties of Core electrospun Nanofiber Yarn Fateme Bateni f bateni@tx iut ac ir Date of Submission 2011 2 23 Department of Textile Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor s Name and Email address S A Hoseini hoseinir@cc iut ac ir Abstract Producing the yarn from nanofibres is considered as one of the great potentials in electrospinning These yarns can be used in various fields like medical applications and filtration Current Nanofiber yarns have low mechanical properties In the present study first a system was designed and then built for producing core sheath yarn containing the electrospun nanofibers at the sheath This system was used successfully to fabricate core sheath yarn containing the carbon nanotubes CNTs embedded polyacrylonitrile PAN nanofibes at the sheath while a staple acrylic yarn was used as the core yarn The properties of electrospun fibres can be modified using nanosized fillers Carbon nanotubes are widely used as filler in electrospun fibres Carbon nanotubes possess excellent mechanical properties and good electrical and thermal conductivity making CNTs an ideal material for reinforcing polymer materials Typically their function is to serve as a reinforcement component in electrospun polymeric fibres but they are also used to modify the electrical properties of fibres In this study two types of CNTs namely multi wall carbon nanotubes MWCNTs and single wall carbon nanotubes SWCNTs were used To effectively transfer the superior properties of the carbon nanotubes to nanocomposites there are critical challenges innuendo dispersing nanotubes and achieving strong interfacial bonding between the nanotubes and polymer Dispersion of nanotubes is one difficult step in fabricating nanotube composites Because they are present in the form of bundles of nanotubes due to Vander wall s forces both covalent functionalization of the carbon nanotubes and noncovalent attachment were used to form strong interfacial bonding between nanotubes and the polymer matrix In this research ultrasonic process was used to disperse carbon nanotubes in solution Also Nonionic surfactant polyethylene glycol PEG was added to decrease the agglomeration and improve the dispersion In order to achieving interfacial bonding we used SWCNTs modified with carboxylic groups Fillers and additives may interact with solvent with polymer or with both and thus also have an effect on fibre diameter and morphology Addition of CNTs was increased the viscosity and electrical conductivity of the electrospinning solution These caused to increased fiber diameter compared to neat PAN nanofiber In this research coating of nanofibers on the core yarn by using of images of optical microscopy and image processing was investigated coating of nanofibers on the staple acrylic yarn was well done The Mechanical and electrical properties of core sheath yarn was considered too The electrical resistance of the surface of the core sheath yarn containing 15 wt carboxylated single wall carbon nanotubes was decreased by 2 5 orders of magnitude The Mechanical properties of core sheath yarns were affected by mechanical properties of core component because portion of core component is much more than sheath component in yarn The core sheath morphology provides a unique template to develop and improve technology The process designed in this project could potentially lead to large scale production of nanofiber reinforced planar and 3D fibrous structures such as woven fabrics Also confining the CNTs to the sheath of the yarn is advantageous because CNTs are still an expensive material Key Words core sheath yarn nanofibers surface electrical resistivity carbon nanotubes polyacrylonitrile

باطني، فاطمه

مطالعه خواص فيزيكي نخ مغزي با رويه نانو الياف الكتروريسي شده

غلاف , مقاومت الكتريكي سطح , نانو لوله هاي كربني , پلي اكريلونيتريل