Titania and copper based Polystyrene Nanocomposite Materials and Investigation of their Antibacterial Properties
Author
Jeppesen, Cesarino Mario
Term
4. term
Education
Publication year
2017
Submitted on
2017-06-10
Pages
145
Abstract
Dette speciale undersøger metal‑polymer‑nanokompositter – blandinger af meget små metalpartikler i en plastmatrix – som en mulig måde at modvirke bakterielle infektioner. Vi fremstillede kobberklynger med et magnetron‑sputter‑klyngesystem (MaSCA) og titandioxid (titania) nanopartikler med en gas‑aggregeringskilde i Prag. Begge typer partikler blev aflejret på stive underlag af kvarts og silicium, som var belagt med tynde film af polystyren (PS), en almindelig plast. Ved kontrolleret efteropvarmning (termisk annealing) efter aflejring styrede vi, hvor dybt partiklerne sank ned i PS‑filmen, og dermed hvor meget af dem der var eksponeret ved overfladen. For at forstå strukturen og overfladen karakteriserede vi prøverne med atomkraftmikroskopi (AFM) og scanning‑elektronmikroskopi (SEM), samt optiske målinger. Derefter blev de antibakterielle egenskaber testet. Vi målte antimikrobiel effekt med CFU‑pladetælling (Colony Forming Units), som kvantificerer overlevende bakterier, og med fluorescensmikroskopi, hvor molekylære farvestoffer bruges til at visualisere morfologiske skader på bakterieceller. I den sidste del undersøgte vi, hvordan forskellige bakteriedræbende mekanismer påvirker effektiviteten af de forberedte overflader. Vi vurderede også, i hvilket omfang disse overflader kan genbruges, for at få indblik i, hvordan dræbeevnen udvikler sig over tid.
This thesis explores metal–polymer nanocomposites—mixtures of very small metal particles embedded in a plastic matrix—as a possible way to reduce bacterial infections. We produced copper clusters using a magnetron sputtering cluster apparatus (MaSCA) and prepared titanium dioxide (titania) nanoparticles with a gas aggregation source in Prague. Both types of particles were deposited onto rigid quartz and silicon substrates coated with thin films of polystyrene (PS), a common plastic. By applying controlled heating (thermal annealing) after deposition, we adjusted how deeply the particles sank into the PS film, and thus how much of them was exposed at the surface. To understand the structure and surface, we characterized the samples using Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM), along with optical measurements. We then evaluated their antimicrobial performance. Antibacterial activity was assessed by CFU plate counting (Colony Forming Units), which quantifies surviving bacteria, and by fluorescence microscopy using molecular probes to visualize morphological damage to bacterial cells. Finally, we examined how different bactericidal mechanisms influence the efficiency of the prepared surfaces. We also investigated how well these surfaces can be reused to gain insight into how their killing performance changes over time.
[This abstract was generated with the help of AI]
Documents