Andrieux Sébastien, Drenckhan Wiebke, Stubenrauch Cosima
Institute of Physical Chemistry, University of Stuttgart , Pfaffenwaldring 55, 70569 Stuttgart, Germany.
Institut Charles Sadron, CNRS, 23 Rue du Loess, 67200 Strasbourg, France.
Langmuir. 2018 Jan 30;34(4):1581-1590. doi: 10.1021/acs.langmuir.7b03602. Epub 2018 Jan 8.
Many properties of solid foams depend on the distribution of the pore sizes and their organization in space. However, these two parameters are very difficult to control with most traditional foaming techniques. Here we show how microfluidics can be used to tune the polydispersity of the foams (mono- vs different polydispersities) and the spatial organization of the pores (ordered vs disordered). For this purpose, the microfluidic flow-focusing technique was modified such that the gas pressure oscillates periodically, which translates into periodically oscillating bubble sizes in the liquid foam template. The liquid foams were generated from chitosan solutions and then gelled via cross-linking with genipin before we freeze-dried them to obtain a solid foam with a specific structure. The study at hand fills two existing scientific gaps. On the one hand, we present a novel approach for the generation of foams with controlled polydispersity. On the other hand, we obtained a solid foam with a new structure for foam templating consisting of rhombic dodecahedra. The controlled variation of the foam's structure will allow studying systematically structure-property relations. Moreover, being fully biobased, this type of solid foam is a suitable candidate for applications in tissue engineering.
固体泡沫的许多特性取决于孔径分布及其在空间中的排列方式。然而，使用大多数传统发泡技术很难控制这两个参数。在此，我们展示了如何利用微流控技术来调节泡沫的多分散性（单分散与不同的多分散性）以及孔隙的空间排列（有序与无序）。为此，对微流控流动聚焦技术进行了改进，使气压周期性振荡，这导致液体泡沫模板中的气泡尺寸周期性振荡。液体泡沫由壳聚糖溶液生成，然后在与京尼平交联后凝胶化，接着进行冷冻干燥以获得具有特定结构的固体泡沫。手头的这项研究填补了两个现有的科学空白。一方面，我们提出了一种生成具有可控多分散性泡沫的新方法。另一方面，我们获得了一种具有由菱形十二面体组成的新型泡沫模板结构的固体泡沫。泡沫结构的可控变化将有助于系统地研究结构 - 性能关系。此外，这种完全基于生物基的固体泡沫是组织工程应用的合适候选材料。
