Beating the teapot effect
(Submitted on 17 Oct 2009)
Cyrill Duez’s team show that superhydrophobic surfaces stop the tea from wetting the inner surface of the spout and pretty much stop the dripping.
Richard Alleyne, science correspondent for the UK Telegraph newspaper, says this backs up the old adage that putting butter inside the spout stops the drip.
But no-one is saying what we should do with the buttery taste – maybe get used to it like the Tibetans have with tsampa (toasted barley flour, green tea, and yak butter) – see picture on the last page of the linked PDF file
Of course all this leads to some interesting side trips on the internet, this time to the web page of Lydéric Bocquet an the Liquids @ interfaces’ group at the Laboratoire de Physique de la Matière Condensée et Nanostructures, Université Lyon 1, and a link to a paper of his from The American Journal of Physics from 2007 called “Tasting edge effects“. The paper backs a hypothesis that, to quote him, “the baking of potato wedges constitutes a crunchy example of edge effects” . He goes on to say in the abstract- “A simple model of the diffusive transport of water vapor around the potato wedges shows that the water vapor flux diverges at the sharp edges… This increased evaporation at the edges leads to the crispy taste of these parts of the potatoes“.
All I can say is, thank goodness this happens and that baked potatoes have extra tasty edges, all a function of increased drying rates that speed Maillard browning.
FotoosVanRobin via Flickr
Coffee stains explained
“Capillary flow as the cause of ring stains from dried liquid drops“ Robert D. Deegan et al
Nature 389, 827-829 (23 October 1997) | doi:10.1038/39827 – even folks without a full text subscription should be able to access the abstract via this link .
Who’da thought Nature would be interested in coffee stains – still, the journos and editors, they probably live on coffee.