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Klik hier om die volledige joernaal in PDF-formaat af te laai - LitNet

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<strong>LitNet</strong> Akademies Jaargang 9(2), Augustus 2012<br />

Due to the larger prevalence of silver nanoparticles <strong>in</strong> PAN nanofibres, a grea<strong>te</strong>r<br />

antimicrobial effect could be expec<strong>te</strong>d. In all three pathogens <strong>te</strong>s<strong>te</strong>d, there was a decrease <strong>in</strong><br />

biolum<strong>in</strong>escence of between 98% and 100% <strong>in</strong> cells that were <strong>in</strong> contact with PAN<br />

nanofibres conta<strong>in</strong><strong>in</strong>g silver nanoparticles, as opposed to cells <strong>in</strong> contact with pla<strong>in</strong> PAN<br />

nanofibres.<br />

Similar to pla<strong>in</strong> PVA fibres, filtration through membranes with pla<strong>in</strong> PAN nanofibres on the<br />

surface led to roughly a 100-fold <strong>in</strong>crease <strong>in</strong> viable cell numbers as opposed to the number of<br />

CFUs before filtration. When fil<strong>te</strong>red through a fil<strong>te</strong>r with PAN nanofibres conta<strong>in</strong><strong>in</strong>g silver<br />

nanoparticles on the surface, there was a 100% reduction <strong>in</strong> CFUs <strong>in</strong> all three pathogens<br />

<strong>te</strong>s<strong>te</strong>d, as opposed to the number of CFUs before filtration. This showed that PAN nanofibres<br />

conta<strong>in</strong><strong>in</strong>g 5% (wt/v) AgNO3 not only had higher silver nanoparticle con<strong>te</strong>nt, but also had a<br />

higher antimicrobial efficacy than PVA nanofibres conta<strong>in</strong><strong>in</strong>g 5% (wt/v) AgNO3.<br />

When consider<strong>in</strong>g that PVA nanofibres with silver nanoparticles are fabrica<strong>te</strong>d fr<strong>om</strong> a wa<strong>te</strong>rsoluble,<br />

non-toxic and biodegradable polymer, and have excellent antimicrobial activity, such<br />

fibers can be highly applicable <strong>in</strong> wa<strong>te</strong>r sanitation, especially <strong>in</strong> an environment-conscious<br />

milieu. On the other hand, the fabrication process of PAN nanofibres is more conducive to<br />

the formation of silver nanoparticles, lead<strong>in</strong>g to a higher silver nanoparticle con<strong>te</strong>nt, allow<strong>in</strong>g<br />

the c<strong>om</strong>ple<strong>te</strong> sanitation of pathogenically contam<strong>in</strong>a<strong>te</strong>d wa<strong>te</strong>r samples. Furthermore, these<br />

fibres are strong and very durable <strong>in</strong> wa<strong>te</strong>r, mak<strong>in</strong>g them ideal for use <strong>in</strong> high-throughput<br />

sys<strong>te</strong>ms. The mechanism of antimicrobial action here and <strong>in</strong> other stu<strong>die</strong>s has, however not<br />

been elucida<strong>te</strong>d to <strong>in</strong>dica<strong>te</strong> specifically whether it is direct contact of bac<strong>te</strong>rial cells with<br />

silver <strong>in</strong> its immobilised sta<strong>te</strong> that is responsible for the antimicrobial activity, or ions that<br />

leach out.<br />

The methods used to <strong>te</strong>st the antimicrobial activity of these fibres <strong>in</strong> this study were easily<br />

executable, accura<strong>te</strong> and quick to perform.<br />

1. Inleid<strong>in</strong>g<br />

Wêreldwyd het ongeveer een miljard mense nie toegang tot veilige dr<strong>in</strong>kwa<strong>te</strong>r nie. Die<br />

bevolk<strong>in</strong>gs van ontwikkelende lande en <strong>af</strong>geleë gebiede word <strong>die</strong> swaars<strong>te</strong> getref (WHO<br />

2004). Daar bestaan dus ’n groot behoef<strong>te</strong> aan wa<strong>te</strong>rsuiwer<strong>in</strong>gsmetodes wat kos<strong>te</strong>-effektief,<br />

maklik bek<strong>om</strong>baar en effektief is (Theron et al. 2008). Konvensionele<br />

wa<strong>te</strong>rsuiwer<strong>in</strong>gsmetodes sluit <strong>die</strong> gebruik van chemiese biosiede <strong>in</strong>, soos vrye chloor,<br />

chlooramiene en osoon. Neweproduk<strong>te</strong> wat deur chemiese ontsmett<strong>in</strong>gsmiddels gevorm<br />

word, het kankerwekkende eienskappe (Krasner et al. 2006). Verder is daar ook ’n toename<br />

<strong>in</strong> <strong>die</strong> voork<strong>om</strong>s van patogene wat weerstandbiedend is <strong>te</strong>enoor antibiotika en biosiede, en<br />

daar<strong>om</strong> is dit belangrik dat al<strong>te</strong>rnatiewe ontsmett<strong>in</strong>gsmetodes nagevors word (Sondi en<br />

Salopek-Sondi 2004).<br />

Nano<strong>te</strong>gnologie is geïdentifiseer as ’n hulpbron met verskeie moontlike toepass<strong>in</strong>gs <strong>in</strong> <strong>die</strong><br />

wa<strong>te</strong>rbedryf (Bot<strong>te</strong>ro et al. 2006; Cloe<strong>te</strong> et al. 2010). Een moontlike toepass<strong>in</strong>g is <strong>die</strong> gebruik<br />

van nanovesels <strong>in</strong> wa<strong>te</strong>rfiltrasie (Cloe<strong>te</strong> et al. 2010).<br />

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