Lu Yan, Wittemann Alexander, Ballauff Matthias
Physikalische Chemie I, University of Bayreuth, 95440 Bayreuth, Germany.
Macromol Rapid Commun. 2009 May 19;30(9-10):806-15. doi: 10.1002/marc.200800789. Epub 2009 Apr 21.
We survey recent studies on composite particles made from spherical polyelectrolyte brushes (SPB) and catalytically active nanoparticles or enzymes. SPB consist of a solid core (diameter: ca. 100 nm) onto which long chains of anionic or cationic polyelectrolyte (PE) are densely grafted ("PE brush"). Immersed in water the PE layer affixed to the colloidal core will swell due to the enormous osmotic pressure of the confined counterions ("osmotic brush"). This confinement of the counterions can be used to generate metal nanoparticles on the surface of the SPB. Moreover, enzymes can be immobilized within the PE layer. In both cases, the resulting composite particles are stable against coagulation and can be easily handled and filtered off. The catalytic activity of both systems is largely preserved in case of the enzymes, in case of the metal nanoparticles it is even enhanced. Thus, the SPB present an excellent carrier system for applications in catalysis.
我们综述了近期关于由球形聚电解质刷（SPB）与催化活性纳米颗粒或酶制成的复合粒子的研究。SPB由一个固体核心（直径约100纳米）组成，阴离子或阳离子聚电解质（PE）的长链密集地接枝在该核心上（“PE刷”）。浸入水中时，附着在胶体核心上的PE层会由于受限反离子的巨大渗透压而膨胀（“渗透刷”）。这种反离子的限制可用于在SPB表面生成金属纳米颗粒。此外，酶可以固定在PE层内。在这两种情况下，所得的复合粒子都能抗凝聚，并且易于处理和过滤。对于酶而言，两种体系的催化活性在很大程度上得以保留；对于金属纳米颗粒，其催化活性甚至得到增强。因此，SPB是用于催化应用的优异载体体系。
