Faubel Jessica L, Patel Riddhi P, Wei Wenbin, Curtis Jennifer E, Brettmann Blair K
ACS Macro Lett. 2019 Oct 15;8(10):1323-1327. doi: 10.1021/acsmacrolett.9b00530. Epub 2019 Sep 25.
Polyelectrolyte brushes are important stimuli-responsive materials in a variety of technological applications as well as in biological systems. Their small size, however, introduces characterization challenges, particularly in studying 3D structure and time-dependent behavior. In this Letter, we report on the polyelectrolyte brush behavior of extra-large hyaluronan brushes (∼15 μm) recently developed using an enzyme-mediated growth process. In response to increasing ionic strength, the brush displays the osmotic brush regime and the salted brush regime. We also show a collapse of 96% when the brush is placed in a poor solvent. This collapse is rapid when changing from a good to poor solvent, but re-expansion is slow when changing back to a good solvent. The observed brush behavior described in this Letter is similar to that seen for smaller polyelectrolyte brushes, indicating that these larger brushes may serve as model systems to study more complex phenomena through confocal microscopy.
聚电解质刷是多种技术应用以及生物系统中重要的刺激响应材料。然而，它们的尺寸较小，给表征带来了挑战，尤其是在研究三维结构和随时间变化的行为时。在本信函中，我们报告了最近通过酶介导生长过程开发的超大透明质酸刷（约15μm）的聚电解质刷行为。随着离子强度的增加，刷子呈现出渗透刷状态和盐析刷状态。我们还表明，当刷子置于不良溶剂中时，会发生96%的塌陷。从良溶剂转变为不良溶剂时，这种塌陷很快，但变回良溶剂时重新膨胀则很慢。本信函中观察到的刷子行为与较小聚电解质刷的行为相似，这表明这些较大的刷子可作为模型系统，通过共聚焦显微镜研究更复杂的现象。
