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On the preparation, characterization, and application of Janus spheres.

机译：关于Janus球的制备，表征和应用。

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Surface-anisotropic Janus particles are a new class of materials with interesting properties that have attracted great attention recently. There have been many reports on the manufacture of Janus particles. However, most of them employ the traditional high-cost vapor phase deposition to obtain an asymmetric surface modification of particles.;In this thesis, a novel templating process is developed for the manufacturing of Janus spheres via the economic and mild electroless deposition (ELD) method. Templated micron- and submicron-sized polystyrene (PS) spheres are modified with a silver cap composed of 50-200 nm nanoparticles (NPs) through the ELD process. The deposits are found to be stable over time and under physical treatment. Further, the study determines that the substrate sphere curvature influences the ELD modification due to the functional group coverage and distribution as well as the size ratio of the substrate sphere to the NPs deposit. Gold, palladium and titanium oxide particles are successfully deposited onto PS spheres using the same templating process and nanoparticle synthesis methods from literatures in the electroless/wet chemical deposition.;Modifications obtained with the ELD conditions studied exhibit a rough surface compared to the vapor-phase modified surfaces. The surface roughness is controlled by varying the ELD reaction conditions to adjust the amount of deposit and the size distribution of the NPs deposited. The assembly of Janus spheres with smooth caps produces planar 2-D structures while spheres with rougher caps tend to form 3-D cluster structures, implying that the surface morphology has an effect on the sphere-sphere interactions. The assembly of new dual-cap/mono-belt Janus particles prepared by combining the vapor phase and ELD processes confirms that the surface roughness influences the orientation of the Janus spheres during assembly.;Janus spheres are then incorporated into electroactive polymers as fillers to enhance the electromechanical performance of acrylate polymer matrixes employing the fact that Janus spheres carry large dipole moments and orient themselves in an electric field. Incorporation of the electric-field aligned Au-caped sPS spheres increase the deformation strain of the tested acylate polymer dramatically from less than 10% to 80% and decreases the electric field required to below 20 V/mum.
机译：表面各向异性的Janus粒子是一类具有令人感兴趣的特性的新型材料，最近引起了极大的关注。关于Janus颗粒的制造已有许多报道。然而，它们中的大多数都采用传统的高成本气相沉积法来获得颗粒的不对称表面改性。;本论文中，开发了一种通过经济且温和的化学沉积（ELD）制造Janus球的新型模板工艺。方法。模板化的微米级和亚微米级的聚苯乙烯（PS）球通过ELD工艺用由50-200 nm纳米颗粒（NP）组成的银盖修饰。发现这些沉积物在一段时间内和经过物理处理后是稳定的。此外，研究确定，由于官能团的覆盖和分布以及基质球与NPs沉积物的尺寸比，基质球曲率会影响ELD修饰。在化学/湿化学沉积中，使用相同的模板工艺和文献中的纳米颗粒合成方法，将金，钯和二氧化钛颗粒成功沉积到PS球上；与气相相比，在研究的ELD条件下获得的改性显示出粗糙的表面修改过的表面。通过改变ELD反应条件来控制表面粗糙度，以调节沉积量和所沉积NP的尺寸分布。具有光滑帽盖的Janus球体的组装会产生平面2-D结构，而带有较粗糙帽盖的球体往往会形成3-D簇结构，这意味着表面形态会影响球体-球体的相互作用。通过结合气相和ELD工艺制备的新型双帽/单带Janus颗粒的组装证实了表面粗糙度会影响组装过程中Janus球的取向。然后将Janus球掺入电活性聚合物中作为填充剂以增强通过利用Janus球携带大偶极矩并使自己在电场中定向这一事实，来控制丙烯酸酯聚合物基体的机电性能。结合电场取向的Au帽sPS球形球体，可将测试的酰化物聚合物的变形应变从小于10％显着提高至80％，并将所需的电场降低至低于20 V / mum。

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