Research On The Mechanism And Control Of The Particles Self-Assembly Based On The Droplet Evaporation

In order to improve the utilization rate of the pesticide, it is very necessary to predict and control the pesticide deposition on the leaves where it pinned, and uniform deposition is really wanted. So, exploring and understanding the fluid flow and the solute particles deposition mechanism inside the evaporating droplet is very important and useful. This research is not only useful to improve the utilization rate of the pesticide, but can offer the instruction of the process control of the micro-nano particles self-assembly. Which will improve the quality and reliability of particles self-assembly, thus has broad application prospects and significant economic value. And it has important scientific significance and academic value of establishing micro-nano self-assembly theory, clarifying particles deposition mechanism inside evaporating droplet and revealing new mechanism and new laws in micro-nano manufacturing.This paper will use the fluorescent particles as tracer particles, combined with the particle imaging velocimetry technology, developing the experimental observation on the building microfluidic observation system. According to research needs, design and manufacture the experiment device, and optimize and improve it by using. This paper through experiment observation and theoretical derivation, verifying there are liquid convection flow and outward flow exist in the evaporating pinned droplet under the open environment, exploring the height-average velocity change rules. Experiment observed the droplet state under the saturated vapor pressure environment, and analyze the law of its existence and changes. Design the humidity controlling system by using the stable related humidity of the saturated salt solution. Experimental comparison and analysis the influence of the environmental related humidity, concentration of pesticide ingredients and droplet size on the pesticide droplet pesticide deposition. The research in this paper will provide theoretical basis and application value to control the particles self-assembly configuration inside the evaporating droplet.