Polimerni nanokompoziti na osnovu grafena

undergraduate thesis

• Title (english): Polymer nanocomposites based on graphene
• Author: Vanessa Delač
• Mentor: Sanja Lučić Blagojević (mentor)
• Committee member: Sanja Lučić Blagojević (predsjednik povjerenstva)
• Committee member: Mirela Leskovac (član povjerenstva)
• Committee member: Iva Movre Šapić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2021-09-24, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Polimerni nanokompoziti hibridni su organsko-anorganski materijali kojima je najmanje jedna dimenzija punila manja od 100 nm. Postoje različite vrste punila, a jedno od njih je i grafen, dvodimenzionalan atomski kristal koji zahvaljujući svojim izvanrednim svojstvima sve češće pronalazi svoje mjesto u naprednim materijalima i tehnologijama. U ovome su radu iznesena dosadašnja saznanja o utjecaju grafena na svojstva polimernih materijala. Proučavao se utjecaj grafena na mehanička svojstva, električnu i toplinsku vodljivost, toplinsku stabilnost, gorivost te propusnost polimernih materijala. Dodatkom grafena dolazi do porasta Youngovog modula elastičnosti i vlačne čvrstoće, porasta električne vodljivosti zbog stvaranja vodljive mreže te porasta toplinske vodljivosti. Najveći naglasak u istraživanju toplinske vodljivosti nanokompozita na bazi grafena ili s ugljikovim nanočesticama je na kompozitima s epoksidnom matricom zbog postignutih značajnih poboljšanja toplinske vodljivosti. Dodatak grafena u polimernu matricu utječe i na toplinsku stabilnost te gorivost. Smanjenje gorivost je vrlo poželjno svojstvo za mnoge primjene, a do njega dolazi zbog stvaranja barijernog učinka na površini polimera što smanjuje razmjenu topline i mase između plina i kondenzirane faze te štite materijal od daljnjeg izgaranja. Nadalje, dodatak grafena utječe i na propusnost polimernih materijala. Do smanjenje propusnosti dolazi zbog nastajanja mreže slojeva grafena te posljedično molekula koja difundira mora preći duži put u odnosu na put koji bi morala proći ukoliko nanopunilo ne bi bilo prisutno. Tijekom posljednjeg desetljeća, interes za nanokompozite je porastao kako u znanosti tako i u industriji zbog niže cijene te značajnog poboljšanja svojstva konvencionalnih polimera dodatkom male količine nanoaditiva.

Abstract (english)

Polymer nanocomposites are hybrid organic-inorganic materials with at least one dimension of the filler phase less than 100 nm. There are many different types of fillers, and one of them is graphene, a two dimensional atomic crystal which, thanks to its extra ordinary properties, is increasingly finding its place in modern technologies. To date findings of graphene influence on polymer properties have been presented in this thesis. The influence of graphene on mechanical properties, electric and heat conductivity, heat stability, burning properties and permeability has been studied. By adding graphene, an increase of Young's modulus of elasticity and tensile strength is obtained, increase in electrical conductivity due to creation of conductive net as well as increase in heat conductivity. The biggest emphasis in heat conductivity researchof graphene based nanocomposite is on epoxy matrix composites due to significant heat conductivity increase achieved. Adding graphene to polymer matrix affects also heat stability and flammability properties. Decrease of flammability is a very desirable property in many applications and is achieved by creating barrier effect on polymer surface which reduces heat exchange between gas and condensed phase thus protecting the material from further burning. In addition, adding graphene affects also the permeability of polymers. Decrease of permeability is caused by the creation of net of graphene layers causing the diffusing molecule to pass a longer path compared to a path with no nanofiller present. Over the last decade, interest in nanocomposites has increased in both science and industry due to lower cost and significant improvement in the properties of conventional polymers by the addition of a small amount of nanoadditives.

• Keywords: polimerni nanokompoziti; grafen; električna vodljivost; toplinska vodljvost; propusnost; gorivost; mehanička svojstva; toplinska stabilnost
• Keywords (english): polymer nanocomposites; graphene; electrical conductivity; thermal conductivity; permeability; flammability; mechanical properties; thermal stability
• Language: croatian
• URN:NBN: urn:nbn:hr:149:833932
• Study programme: Title: Applied Chemistry - Undergraduate study; specializations in: Environmental chemistry and green technologies, Advanced materials and technologies, Applied organic chemistry; Course: Advanced materials and technologies; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) primijenjene kemije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) primijenjene kemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2023-03-27 11:51:34