Research On Preparation Of Single-Base Spherical Propellants Based On Capillary Microfluidic Technology

Microfluidic technology refers to the technology to explore the law of fluid flow and transportation in the micron-scale channel.Taking microfluidic chip as the carrier,it can realize a variety of fluid manipulation processes that cannot be completed at macro scale with the help of micro hydrodynamics theory and micro/nano manufacturing technology.As an important branch of microfluidic technology,droplet microfluidic technology has attracted more and more attention,and capillary microfluidic chips have been widely applied and studied for their characteristics of low preparation difficulty,low material cost,excellent chemical properties,flexible design and unique advantages in droplet preparation.The traditional preparation technology of single-base spherical propellant mainly relies on mechanical agitation to complete the pellet formation.However,the force of each microsphere is uneven in the process of agitation.This will lead to the poor mono dispersity of microspheres,low yield and high danger coefficient.So,a new preparation method of single-base spherical propellant was explored based on the capillary microfluidic technology.The main research contents are as follows:(1)Numerical simulation of propellant droplet formation in single channel.Firstly,the capillary model was simplified into a two-dimensional symmetric model.Then,the droplet formation process was simulated by using the phase field method.By exploring the influence of two phases flow rate and viscosity on droplet formation,the results of simulation provides the theoretical reference for the preparation process of single-base spherical propellant.(2)Numerical simulation of propellant droplet formation in multi-channel.Based on the simulation of the single channel,the multi-capillary microchannel structure was designed.Then,the droplet formation process of the multicapillary microchannel was simulated by using the phase field method,which provides the theoretical reference for the subsequent high-throughput preparation process of the single-base spherical propellant.(3)Study on surface modification technology in glass capillary channel.Considering the properties of the materials used in this study and the influence of contact angle on the droplet preparation process,it is necessary to modify the channel surface of the glass capillary.After using four surface modification methods,it is finally determined that the surface treatment method soaked by Na OH solution is most suitable for this research.(4)Preparation of single-base spherical propellant using capillary microfluidic chips.Firstly,the capillary microfluidic chip was prepared by adhesive method.Then,preparing two phase solution,setting up the experimental system,preparing the propellant micro-drops and exploring the solidification method.Finally,the CV value of single-base spherical propellant particle size is less than 4%.In addition,the particle size of spherical propellant was regulated by changing the two-phase flow ratio,microchannel size and solvent mass ratio in the capillary microfluidic chip,and the influence of different parameters on the particle size of single-base spherical propellant was explored.(5)High-throughput preparation of single-base spherical propellant.In order to improve the preparation efficiency of single-base spherical propellant,two kinds of high flux devices for single-base spherical propellant based on capillary microfluidic technology were designed,namely vertical array type and horizontal radiation type high flux microfluidic device.The single-base spherical propellant can be successfully prepared by them,and the preparation efficiency increased about 50 times and 27 times.