Priprava slojeva na bazi nanočestica srebra i TEOS-a

undergraduate thesis

• Title (english): The preparation of coatings based on silver nanoparticles and TEOS
• Author: Marko Plazanić
• Mentor: Stanislav Kurajica (mentor)
• Committee member: Stanislav Kurajica (predsjednik povjerenstva)
• Committee member: Juraj Šipušić (član povjerenstva)
• Committee member: Domagoj Vrsaljko (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2015-09-17, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Basic Technical Sciences; Materials

Abstract

Zahvaljujući dobrim fizikalnim i kemijskim svojstvima te brojnim područjima potencijalne
uporabe nanočestice srebra izazvale su znatan interes u znanstvenoj zajednici i gospodarstvu.
Srebro je od davnina poznato po svome antibakterijskom djelovanju, netoksičnosti i
neškodljivosti za okoliš. Stoga broj različitih primjena nanočestica srebra kontinuirano raste,
posebice u području zaštite površina od rasta mikroorganizama.
U ovom su radu pripravljene nanočestice srebra u svrhu nanošenja na kamenu površinu kao
zaštitnog baktericidnog sloja. Srebrne nanočestice su pripravljene redukcijom srebrovog
nitrata, AgNO3, s natrijevim borhidridom, NaBH4, te su nanešene na umjetni mramor koji je
ranije pripravljen prešanjem i sinteriranjem praha CaCO3 u tablete. Nadalje, kako bi se
smanjila brzina otpuštanje nanočestica srebra te hidrofobirala površina, na površinu je
nanesen TEOS te potom pušten da hidrolizira i gelira.
Pripravljeni uzorci potom su karakterizirani rendgenskom difrakcijskom analizom (XRD),
infracrvenom spektroskopijom s Fourierovim transformacijama (FTIR) i difuznom
refleksijskom spektroskopijom (DRS). Hidrofobnost pripremljenih uzoraka s TEOS-om
ispitana je mjerenjem kontaktnog kuta. Provedeni mikrobiološki testovi s bakterijom
Escherichia coli dali su negativne rezultate što ukazuje da u korištenim koncentracijama
nanočestice srebra nisu učinkovite kao baktericidno sredstvo za zaštitu kamenih površina.

Abstract (english)

Silver nanoparticles have received considerable attention due to their attractive physical and
chemical properties and potential applications with high academic and industrial impacts.
Colloidal silver have been known for a long time to possess antimicrobial properties and also
to be nontoxic and environmental friendly. That is why the aplications of silver nanoparticles
increase continuously, especially for antmicrobial protection of surfaces.
In this study nanoparticles of silver were prepared with the purpose of using them as coatings
for protection of stone surfaces from bacteria growth. Silver nanoparticles were prepared
through chemical reduction of silver nitrate, AgNO3, by sodium borohydride, NaBH4, and
were applied as a coating on artificial marble stone surface, which was previously made by
pressing and sintering CaCO3 powder into tablets. In addition to improve efficiency of silver
nanoparticles by attaining time release of silver as well as hydrophobicity of the stone surface,
TEOS was applied on the surface and allowed to hydrolize and form gel.
Tablets were characterized by means of X-ray diffraction (XRD), Fourier transform infrared
spectroscopy (FTIR) and diffuse reflectance spectroscopy (DRS. Hydrophobicity of the
tablets with gel coating was determined through contact angle measurement.
Conducted microbiological tests of the samples using bacteria Escherichia coli have shown
negative results which points out that in applied concentration silver nanoparticles are not
effective as antimicrobial agent for stone surface protection.

• Keywords: kamena površina; nanočestice srebra; TEOS; antibakterijska zaštita
• Keywords (english): stone surface; silver nanoparticles; TEOS; antimicrobial protection
• Language: croatian
• URN:NBN: urn:nbn:hr:149:482298
• Study programme: Title: Chemical Engineering - Undergraduate study; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka kemijskog inženjerstva (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2016-11-29 16:42:30