Taming the Coffee-Ring Effect on Solid Surface by Localized Heating Upon the Suspension Droplet
International Journal of Heat and Mass Transfer/International journal of heat and mass transfer(2024)
Abstract
Coffee-ring effect is a very common phenomenon in our daily life, especially in the evaporation process of colloidal solutions on solid surfaces. However, in processes such as inkjet printing, this effect can change the uniformity of the deposited film, thus affecting the quality of the printed products. In this paper, a facile and convenient method of localized heating of liquid droplets by using a tiny steel wire is proposed. The results indicated that this method can effectively suppress the generation of coffee-ring effect, and the deposition morphology of the suspended particles can be adjusted by controlling the applied temperature, wire diameter and the distance from the wire to the droplet. And it was found that the heated wire-induced inward flows caused by the temperature gradient of the droplet are the main reason for adjusting the deposition morphology. The coffee-ring effect is mainly controlled by the free convection from the edge to the center caused by the evaporation loss of the solution, so as to adjust the distribution of suspended particles in the evaporating droplet and thus achieve the goal of suppressing the coffee-ring effect. This method has no special requirements for the substrate and droplet solution, and it is expected to be universally applicable to uniform deposition of colloidal solutions.
MoreTranslated text
Key words
Coffee-ring effect,Localized heating,Droplet evaporation,Colloidal solution,Uniform deposition
AI Read Science
Must-Reading Tree
Example
![](https://originalfileserver.aminer.cn/sys/aminer/pubs/mrt_preview.jpeg)
Generate MRT to find the research sequence of this paper
Chat Paper
Summary is being generated by the instructions you defined