以环己烷为油相、淀粉乳液为水相、Span60和Tween60为乳化剂,对淀粉微球的形成过程进行了耗散粒子动力学(DPD)模拟及实验研究.模拟结果表明,淀粉微球的形成过程存在四个阶段,即淀粉与乳化剂分子无规则分散阶段、小聚集体形成阶段、球状聚集体形成阶段和稳定平衡阶段,并且发现油水比是影响聚集体是否能形成球状的关键因素.油水比小于7的条件下,油水两相分离较难,水相呈现片状、十字型状、柱状及椭球状等形状;当油水比增加到8,水相能形成微球且微球粒径随油水比增加而减小.同时实验结果表明,油水比为8时,微球粘连,几乎看不清球状形貌,油水比为10～20时,微球的粒径随油水比的增大而减小.实验结果很好地吻合了模拟结果.%Dissipative particle dynamics (DPD) simulation method and experimental study were used to study the formation of starch microspheres (SM).Cyclohexane was selected as oil phase, amylose as aqueous phase, meanwhile Span60 and Tween60 as emulsifiers, respectively.It is shown from DPD simulations that the forming process of SM is consisted of four steps: (1) irregular dispersion of amylose and emulsifiers,(2) the formation of small aggregates, (3) the formation of microspheres aggregates, (4) stabilization of microspheres.The simulation results represent that the oil-aqueous volume ratio is the key influencing factor to the formation of microspheres aggregates.When the oil-aqueous volume ratio is smaller than 7, aggregate morphologies of the aqueous phase as lamellar, columnar, crisscross and ellipsoidal structures are observed.Microspheres are formed only when oil-aqueous volume ratio is 8, and the panicle sizes are decreased with the increase of oil-aqueous volume ratio.And the experiments show that the microspheres can not get good sphericity when oil-aqueous volume ratio is 8, and the particle sizes are decreased with the increase of oil-aqueous volume ratio when the ratio is 10 to 20.The experimental results could be interpreted with the simulation results.DPD simulation provides an insight into the microstructure of SM and help to analyze the experimental results, which is helpful in synthesis of SM.
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