Microfluidic synthesis of multiscale polymer composite particles

在下一个项目阶段，计划利用已开发的微流体辅助生成具有二级和三级组织水平的复合颗粒的步骤，合成具有多达五个空间组织水平的多尺度微颗粒。连续微流过程将用于有机和无机纳米颗粒以及具有明确尺寸，组成和几何形状的复合纳米颗粒集成到聚合物微颗粒中。液滴微流体和光诱导聚合和聚合物基体交联将被应用于复合组成微粒的生成。采用交叉流、共流和流动聚焦等方法制备粒径分布较窄的单体/纳米颗粒混合物液滴。控制静电斥力的原理将用于确保在纳米颗粒水平上胶体状态的高稳定性。表面电荷的控制将通过表面功能化来实现，这在第一个项目阶段已经成功地使用了。此外，表面电荷的控制也将用于减少排斥力效应的时间和有限的纳米颗粒聚集。我们计划研究这种策略，通过组装较小的纳米颗粒来逐步形成更大的纳米颗粒，以便在更高的纳米和更低的微米水平上获得嵌套的内部子结构。尺寸范围在2到20纳米之间的粒子组合将被整合到亚微米范围（150到500纳米）的粒子中，这些粒子可以进一步集成到组成微粒的域中。该项目的目标是表明，可以通过涉及微流体步骤的一般策略生成不同成分的分层结构粒子。新的合成也应该证明微反应技术非常适合于生成新型复合颗粒。因此，该项目将通过连接纳米材料和微粒的世界，为纳米技术自下而上的总体战略做出贡献。同时，预计该项目将展示一种解决纳米和微米范围内组合粒子的大组合变化的一般方法。

In the next project phase, it is planned to use the developed steps of the microfluidically assisted generation of composite particles with two and three organization levels for the synthesis of multiscale microparticles with up to five levels of spatial organization. Continuous micro flow processes will be used for the integration of organic and inorganic nanoparticles and composed nanoparticles with well-defined sizes, composition and geometries into polymer micro particles. Droplet microfluidics and light-induced polymerization and cross-linking of the polymer matrix will be applied for generation of the complex composed microparticles. Cross-flow, Co-flow and flow focusing are applied for the generation of droplets of monomer/nanoparticle mixtures with narrow size distribution.The principle of controlled electrostatic repulsion will be used for ensuring a high stability of the colloidal state at the nanoparticle level. The control of electrical surface charges will be achieved by surface functionalization which has been already successful used in the first project phase. In addition, the control of surface charge will also be used for temporal reduction of repulsion effects and for limited nanoparticle aggregation. It is planned to investigate this strategy for step-wise formation of larger nanoparticles by assembling smaller ones in order to obtain nested internal substructures at the higher nanometer and lower micrometer level. Assemblies of particles in the size range between about 2 and 20 nm will be incorporated into particles in the submicron range (150 to 500 nm) which can be further integrated in domains of composed microparticles. The goal of the project is to show that hierarchically constructed particles of different components can be generated by a general strategy involving microfluidic steps. The new syntheses should also demonstrate that micro reaction technology is well suited for generation of new types of composite particles. Thus, the project will contribute to the general bottom-up strategy of nanotechnology by bridging the world of nanomaterials and microparticles. At the same time, it is expected that the project will show a general approach for addressing the large combinatorial variety of composed particles in the nanometer and micrometer range.