PROJEKTKATALOG 20100125.pdf - Institut for Matematik og ...

N a t u r v i d e n s k a b e l i g t P r o j e k t 2 0 1 0
Projekt 46: Self-cleaning surfaces – the Lotus effect
Vejleder: Beate Klösgen, kloesgen@ifk.sdu.dk; Per Morgen, per@ifk.sdu.dk
Institut: Institut for Fysik og Kemi (IFK)
Praktisk del: Memphys labs
Gruppeplacering: IFK , MEMPHYS labs
Gruppestørrelse: Mindst 3 og max 3 deltagere. Én gruppe kan arbejde med projektet.
Kommentarer: Teaching language will be a mixture of English and Danish;
reporting / presentation can be chosen to be performed in either language
Keywords:
nanobioscience / physics: Lotus effect / wetting –dewetting / hydrophobic effect
Abstract
The Lotus plant is famous not only for its exotic beauty but as well the self-cleaning properties
of its leaves: rain or water condensed onto the leave surface spontaneously form small droplets
that might grow until the leave bents under the load to spill them off. On
their way, the droplets pick up dirt as dust or bacteria thus keeping the
plants clean, healthy, and well-doing. The origin of the effect – now
called Lotus-effect – is a combination of two properties: hydrophobic
material on the leave surface is organized in a minute surface structure
(“roughness”). This causes excessive water repulsion – the surface is
“super-hydrophobic”. The effect allows to walk on water – in principle
at least, as does a pond skater.
Creating surfaces of designed wetting properties, and especially dewetting
of water by controlled processes has recently created huge scientific interest because of
its fundamental relevance in the context of the “hydrophobic effect” and because of its high
technological impact.
The practical part involves
information gathering (contact interfaces, wetting, contact angles; hydrophobic/hydrophilic
materials; micro-structure triggered super-hydrophobicity; preparation processes),
collecting examples for hydrophobic surfaces from nature; preparing them for the scanning
electron microscope (SEM),
studying selected hydrophobic surfaces using the SEM,
measuring contact angles,
if time allows: preparation of artificial hydrophobic, hydrophilic and super-hydrophobic surfaces,
and characterizing them
building of your own artificial pond-skater.
The project will start with reading assignments and discussions. Students will learn to assemble
the information required using the local library and electronic data bases. They will prepare their
own selection of samples (3-4 types per group) and learn to characterize them by water contact
angles. They will see the SEM, and learn about its function, and how to prepare samples for it.
Minikurser
Obligatorisk: Projektarbejde (Microsoft, Nat)
Litteraturliste over metode artikler, som udleveres til de studerende
Handout material will be offered from week 1. Additional material will be found during a literature
search (university library, internet, data bases )
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