Preparation And Properties Of Acrylic-styrene Copolymer Janus Microspheres

With their unique features,Janus particles were named for the two-faced Roman god Janus,and have been attracted attention in a wide range of applications such as in optics,catalysis,micromotors,biosensors,and biomedicine.Now,the technique bottleneck is synthesis technologies.Although many synthetic strategies have been found and great progress has been made in the preparation of various Janus particles,such as:electrospray,microfluidics,self-assembly,emulsion polymerization,etc.,it is still a challenge to use inexpensive raw materials and simple path to synthesize morphology accurately controllable polymer Janus particles through control the experimental conditions.Based on the characteristics of Janus particle synthesis is flexible and easily functionalized,combined with its unique spatial structure will become the best choice for basic research and application development.In this paper,cheap and functional styrene-acrylic monomers are used as raw materials,an appropriate mixed solvent is selected to design and synthesize a series of styrene-acrylic polymers Janus microspheres with different morphologies,and loaded with inorganic materials to make it functional and broaden application range.The main research contents and results are as follows:1.Firstly,the morphology,preparation method and application fields of the polymer Janus are summarized.Secondly,the preparation method and application of the styrene-acrylic copolymer are introduced.2.Using methacrylic acid?MAA?,methyl methacrylate?MMA?,butyl acrylate?BA?and styrene?St?as comonomers,ethanol/water solution as the solvent,and azobisisobutyronitrile?AIBN?as the initiator,the puff-like acrylic-styrene copolymer Janus microspheres?MAStP-PJ?were successfully synthesized through the solvent-mediated self-assembly method.MAStP-PJ was characterized and analyzed by SEM,FT-IR,XRD,nano-particle size analyzer,and fluorescence microscope.Then,nano-Ag particles and Fe₃O₄ were loaded on it to synthesize Ag@MAStP-PJ particles and Fe₃O₄@MAStP-PJ particles,and studied their antibacterial properties and magnetic properties.The results revealed that the puff-like acrylic styrene copolymer Janus microspheres were successfully synthesized under the conditions of the monomer ratio of the first/second step was 2:1.5.It could be used as emulsifiers and have obvious pH responsiveness.In addition,it is also considered as a carrier to load inorganic materials such as Ag nanoparticles and magnetic Fe₃O₄ to synthesize composite materials with antibacterial activity and magnetic responsiveness.3.Using ethanol/water or isopropanol/water as the solvent and AIBN as the initiator,the propylene copolymerization was successfully synthesized through step-by-step polymerization-thermal assembly method,which used MAA,MMA,BA,and St,BA to synthesized polymer chains L₁ and L₂ respectively,and then a certain proportion of the two polymer chains were self-assembled by evaporation of the solvent.Their structure,composition and performance were characterized and analyzed by a series of test methods.Then,amoxicillin was encapsulated in Janus microspheres?MAStS-PJ?and evaluated its antibacterial properties.The results showed that When L₁:L₂=1:1 and the solvent was ethanol/water,the acrylic-styrene copolymer stean-like Janus microspheres were successfully synthesized.In addition,the acrylic-styrene copolymer stean-like Janus microspheres?MAStS-PJ?could be used as emulsifiers and have pH responsiveness.At the same time,it also could be used as microcontainers to encapsulate amoxicillin with antibacterial activity.4.A mixture of ethanol and water was used as the solvent,and AIBN was used as the initiator,MAA and MMA were first copolymerized,and then St and BA were added,using a one-pot two-step solvent-induced phase separation method,the acrylic-styrene copolymer bowl-shaped Janus microspheres?MAStB-PJ?were successfully synthesized by controlling the proportion of polymerized monomers and the solvent.And their structure,composition and properties were analyzed.Then,nano-Ag particles and Fe₃O₄ were loaded on Janus microspheres?MAStB-PJ?to synthesize Ag@MAStB-PJ particles and Fe₃O₄@MAStB-PJ particles,and their antibacterial properties and magnetic properties were investigated.The results indicated that the acrylic-styrene copolymer bowl-shaped Janus microspheres were successfully synthesized,when the monomer ratio of the first/second step was 4:3.In addition,the acrylic-styrene copolymer bowl-like Janus microspheres could be used as emulsifiers and have obvious pH responsiveness.In addition,it is also considered as a carrier to load inorganic materials such as Ag nanoparticles and magnetic Fe₃O₄to synthesize composite materials with antibacterial activity and magnetic responsiveness.In summary,three types of polymer Janus microspheres with different morphologies were prepared using cheap styrene-acrylic monomers,which could be used as emulsifiers and carriers to support inorganic nanoparticles.It is expected to be applied in the field of biomedicine and provide new strategies and methods for preparing functional and intelligent polymer Janus microspheres.