Research On The Efficient Preparation Of Highly Ordered Structure Decorated By Janus Particles

Janus particle refer to particle that possesses two or more sides with more sides with different physical or chemical properties.Amphiphilic Janus particles have received extensive attention due to their good interfacial stability.In this paper,the amphiphilic Janus particles were prepared,and employed in the breath figure(BF)method,leading to the highly ordered structures selectively decorated by Janus particle.It has been proven that BF method,being a bottom-up self-assembly process,could be used for directed assembly of components with active interfacial behavior.Based on the established method of particle-assisted BF,the assembly behavior of Janus particles during the BF process is studied.The first part of our work was the preparation of amphiphilic Janus particles based on a masking method.To be specific,the colloidsome of paraffin microspheres embedded with silica particles was prepared based on Pickering emulsion process.The influencing factors in the preparation process were systematically studied,including stirring speed and time of the homogenizer,surfactant concentration,melting point of wax and size of the silica particles.The optimized method overcomes many shortcomings such as the wax sticking,low yield,and high risk failure with small-sized silica particles.An optimized method to make colloidosomes with high efficiency,high yield,regular shape of wax sphere,and nicely embedded layer of silicon particles was established.After the colloidsomes were obtained,the amphiphilic Janus particles are finally produced through selective chemical modification of the colloidsomes.The second part of our work was the employment of the prepared Janus particles as the second component into the surface patterning process of the BF method.We systematically studied the effect of addition amount of the particle,choice of solvents,substrate and Janus balance of the Janus particles on particle assembly behavior.The results show that in the case of high quantity of particle addition,it is easier for the Janus particles to assist in the obtaining of a regular BF array than the case with the isotropic particle.The Janus particle was further evaluated for its behavior in the direct pore-forming BF method.The selective decoration of the particles was achieved along with the pore-formation on the surface of the polymeric surface,and a double-layered pore structure with high density decoration of the particles was prepared.