Thesis (MSc)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: Polymeric nanofibrous membranes that act as surfaces offer two compelling properties; they have
extremely large surface areas that can be modified and they can offer multiple reactive sites depending
on which polymer they were electrospun from. Combining nanofibrous surfaces such as these with
photochromic dyes can give remarkable, light responsive materials.
In this study, a terpolymer was electrospun and crosslinked (to impart insolubility to the material) to
produce a nanofibrous mat that contained surface secondary-hydroxyl units and benzyl chloride units,
from which monomers could grow using surface-initiated atom transfer polymerization (SI-ATRP).
The surface was further fluorinated though the secondary-hydroxyl moieties to produce a hydrophobic
crosslinked nanofibrous surface.
n-Butyl acrylate and a photochromic spiropyran dye were copolymerized from the surface using SIATRP,
in order to produce a surface that exhibited reversible adhesion towards a water droplet using
ultraviolet and visible light as a stimulus to change between the two states. This in principle would
allow the droplet to roll off and stick to the surface respectively. Although the surface displayed a
colour change when switched, proving that the SI-ATRP had taken place, the droplet of water remained
attached to the surface in both states. / AFRIKAANSE OPSOMMING: Polimeriese nanovesel membrane wat dien as oppervlaktes bied twee aantreklike eienskappe; hulle het
baie groot oppervlakareas wat gemodifiseer kan word en hulle bied veelvuldige reaktiewe punte,
afhangende van die polimeer waarvan hulle ge-elektrospin is. Deur sulke nanovesel oppervlaktes met
fotochromiese kleurstowwe te kombineer, kan uitstekende lig reagerende materiale verkry word.
In hierdie studie is ‘n terpolimeer ge-elektrospin en daarna gekruisbind (om die materiaal onoplosbaar
te maak) om ‘n nanovesel web te kry wat oppervlak sekondêre-hidroksiel en benzielchloried eenhede
bevat. Monomere kan dan vanaf hierdie eenhede groei deur middel van oppervlak-geïnisieerde atoomoordrag
polimerisasie (OI-AOPR). Die oppervlak was verder gefluorineer via die sekondêre-hidroksiel
eenhede om ‘n hidrofobiese, gekruisbinde nanovesel oppervlak te vorm.
n-Butielakrilaat en ‘n fotochromiese spiropiraan kleurstof is gekopolimeriseer vanaf die oppervlak deur
middel van OI-AORP om sodoende ‘n oppervlak te skep wat omkeerbare adhesie van ‘n water druppel
gee as ultraviolet en sigbare lig as stimulus gebruik word om tussen die twee toestande te wissel. In
beginsel sal die water druppel vanaf die oppervlak kan afrol én daaraan vassit, afhangende van die
toestand van die oppervlak. Alhoewel die oppervlak van kleur verander het met die wisseling tussen
die twee toestande, wat as bewys dien dat OI-AORP wel plaasgevind het, het die druppel water bly
vassit aan die oppervlak in beide toestande.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/17959 |
| Date | 12 1900 |
| Creators | Reader, Paul |
| Contributors | Klumperman, Bert, Arnott, Gareth, Stellenbosch University. Faculty of Science. Dept. of Chemistry and Polymer Science. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | Unknown |
| Type | Thesis |
| Rights | Stellenbosch University |
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