Central spot formed in dried coffee-water-mixture droplets: Inverse coffee-ring effect
- 자연과학대학
- Hit2582
- 2018-03-05
Central spot formed in dried coffee-water-mixture droplets: Inverse coffee-ring effect
A research paper 'Central Spot Formed in Dried coffee-Water-Mixture Droplets: Inverse Coffee-Ring Effect', in which the first author, Sungkyunkwan University physicis student, Baek Ji Min, and a correspondent author, Jooyull Rhee, participated, was finally approved in the 'Current Applied Physics' (Impact Factor: 1.971) on the 10th.
Baek identified the cause of the reverse phenomenon in the coffee-ring effect that is commonly found in everyday life. A coffee-ring effect is a phenomenon in which when a coffee droplet falls on a smooth surface such as a table, the coffee powder drifts to the edge of the coffee droplet and dries up, leaving only a ring-shaped trail on the edge.
This phenomenon occurs when most of the colloidal solution is dry. Especially, it is an important phenomenon to be solved in the field of display industry utilizing inkjet printing technology.
In this study, Baek discovered that coffee powder was collected in the middle of the coffee drop as opposed to the coffee-ring effect, resulting in spots in the center of the coffee drop. In other words, the cause of the phenomenon opposite to the coffee-ring effect is identified.
This article is a translation of dhnews.
(Source 1: https://www.sciencedirect.com/science/article/pii/S1567173918300075
Source 2: http://www.dhnews.co.kr/news/articleView.html?idxno=78037)