Study On The Mechanism Of Short Chain Alkane Additive On Curing Process Of Polymer Microspheres

The application prospect of hollow polymer microspheres is very broad,and higher requirements on the quality of the microspheres and the preparation method of the microspheres arise.In the energy field,hollow polymer microspheres can wrap phase change materials to prepare phase change microcapsules.Phase change microcapsules can effectively solve the problem of weak flow capacity,poor compatibility and corrosion resistance of phase change materials,and have a large heat transfer area,fast heat transfer speed,easy dispersion,and strong application.In addition,hollow polymer microsphere shell can be used for paint coatings in construction and leather,as well as cosmetics and paper,because of the strong light-shielding ability which results from the high refractive index difference between the hollow polymer microsphere shell and the air.The wide application of hollow polymer microspheres also requires some technical breakthroughs.In the hollow polymer microspheres preparation process by emulsion microencapsulation,alkane additives can prolong the curing time of the double emulsion,which is beneficial to inhibit the deformation of the double emulsion.In addition,shortening the chain length of the alkane can suppress the deformation of the double emulsion and increase the sphericity of the shell.Combined with the above conclusions,the influence mechanism of alkane additives on the mass transfer process of double emulsion oil phase solidification from the micro level was discussed.Oil phase systems containing different concentrations and different chain lengths of alkane additives was constructed to explore the influence of alkane additives on the oil phase diffusion with the droplet evaporation theory and Widom insertion method,and the drying and solidification process of the emulsion was numerically simulated.In this paper,a double emulsion oil/water interface system was constructed to explore the influence of adding alkane additives on the microevolution of the double emulsion oil phase.In general,the main conclusions of this paper are as follows:(1)The latest development of chemical potential calculation methods for several dense solution systems is reviewed,including detection volume bias,simulation system-bias,particle insertion offset three biasing methods.An ODVO method for calculating the chemical potential of double emulsions is developed,and the chemical potential of aqueous solution of sodium chloride and aqueous 1,3 butanediol were predicted after the correct calculation of the chemical potential of liquid water,liquid argon.The ODVO method improves the calculation accuracy of a single molecular position,reducing the number of molecular shaped numbers required to obtain accurate chemical growth,thereby improving the calculation efficiency of the chemical potential.In addition,OVDO method is an effective method for the study of the chemical study of hollow polymer microsphere evaporation process.(2)Double emulsion is studied by the microscopic simulation,and the comparison of the diffusion coefficient of fluorobenzene in fluorobenzene and in alkane-containing fluorobenzene solution shows that the effect of alkanes on the diffusion ability of fluorobenzene is very weak.According to the double emulsion interface analysis,there is no significant interaction between alkanes and polystyrene.In addition,there are trace water clusters in the oil phase during the double emulsion curing process,which will affect the internal structure of the oil phase droplets and ultimately affect the inhomogeneity of the quality of the whole batch of microspheres.(3)Combined with the chemical potential calculation of fluorobenzene and the numerical simulation in the early stage of curing,it is known that the fugacity of fluorobenzene is the main factor affecting evaporation,and the increase of chain length of alkane additives will increase the activity coefficient,fugacity and evaporation capacity of fluorobenzene.