Walther Andreas, Matussek Kerstin, Müller Axel H E
Makromolekulare Chemie II and Bayreuther Zentrum fur Kolloide und Grenzflachen, Universitat Bayreuth, D-95440 Bayreuth, Germany.
ACS Nano. 2008 Jun;2(6):1167-78. doi: 10.1021/nn800108y.
Janus particles are used on a multigram scale for the blend compatibilization of two polymers in a twin screw mini-mixer. It is shown that the Janus particles can be located exclusively at the interface of the two polymer phases despite the high temperature and shear conditions. The domain sizes of the dispersed phase decrease with increasing content of Janus particles. The decrease is yet ongoing for high contents of Janus particles. Furthermore, the biphasic particles exhibit an ordered arrangement at the interface. Thus, the approach demonstrates that a nanoscopic structuring of the interface can be achieved under macroscopic processing conditions. The structural order occurs on two levels. The first is the complete adsorption at the interface and the second is the lateral ordering at the interface. The strong adsorption at the interface is explained in terms of the increased desorption energy of Janus particles. Secondly, the compatibilization efficiency is critically compared to state-of-the-art compatibilizers. The efficiency of the Janus particles is found to be superior as compared to block copolymer-based compatibilizers. The efficiency gap between Janus particles and block copolymer compatibilizers widens for larger amounts added.
在双螺杆微型混合器中，以克级规模使用Janus颗粒来实现两种聚合物的共混增容。结果表明，尽管处于高温和剪切条件下，Janus颗粒仍能仅位于两种聚合物相的界面处。随着Janus颗粒含量的增加，分散相的域尺寸减小。对于高含量的Janus颗粒，这种减小仍在持续。此外，双相颗粒在界面处呈现有序排列。因此，该方法表明在宏观加工条件下可以实现界面的纳米级结构化。结构有序性体现在两个层面。第一个是在界面处的完全吸附，第二个是在界面处的横向有序排列。界面处的强吸附是由Janus颗粒解吸能的增加来解释的。其次，将增容效率与现有增容剂进行了严格比较。发现与基于嵌段共聚物的增容剂相比，Janus颗粒的效率更高。随着添加量的增加，Janus颗粒与嵌段共聚物增容剂之间的效率差距扩大。
