Torres-Rodriguez Jorge, E Bedolla Diana, D'Amico Francesco, Koopmann Ann-Kathrin, Vaccari Lisa, Saccomano Giulia, Kohns Richard, Huesing Nicola
Chemistry and Physics of Materials, Paris-Lodron-University of Salzburg, Jakob Haringer-Str. 2A, 5020 Salzburg, Austria.
Salzburg Center for Smart Materials, Jakob Haringer-Str. 2A, 5020 Salzburg, Austria.
Gels. 2022 Nov 9;8(11):727. doi: 10.3390/gels8110727.
In this work, polyvinylidene fluoride (PVDF) aerogels with a tailorable phase composition were prepared by following the crystallization-induced gelation principle. A series of PVDF wet gels (5 to 12 wt.%) were prepared from either PVDF−DMF solutions or a mixture of DMF and ethanol as non-solvent. The effects of the non-solvent concentration on the crystalline composition of the PVDF aerogels were thoroughly investigated. It was found that the nucleating role of ethanol can be adjusted to produce low-density PVDF aerogels, whereas the changes in composition by the addition of small amounts of water to the solution promote the stabilization of the valuable β and γ phases. These phases of the aerogels were monitored by FTIR and Raman spectroscopies. Furthermore, the crystallization process was followed by in-time and in situ ATR−FTIR spectroscopy. The obtained aerogels displayed specific surface areas > 150 m2 g−1, with variable particle morphologies that are dependent on the non-solvent composition, as observed by using SEM and Synchrotron Radiation Computed micro-Tomography (SR-μCT).
在本工作中，遵循结晶诱导凝胶化原理制备了具有可定制相组成的聚偏氟乙烯（PVDF）气凝胶。由PVDF - DMF溶液或DMF与乙醇的混合物作为非溶剂制备了一系列PVDF湿凝胶（5至12 wt.%）。深入研究了非溶剂浓度对PVDF气凝胶结晶组成的影响。发现乙醇的成核作用可进行调节以制备低密度PVDF气凝胶，而向溶液中添加少量水导致的组成变化促进了有价值的β相和γ相的稳定。通过傅里叶变换红外光谱（FTIR）和拉曼光谱对气凝胶的这些相进行了监测。此外，通过实时原位衰减全反射傅里叶变换红外光谱（ATR - FTIR）对结晶过程进行了跟踪。如使用扫描电子显微镜（SEM）和同步辐射计算机断层扫描（SR - μCT）所观察到的，所得气凝胶的比表面积> 150 m² g⁻¹，具有取决于非溶剂组成的可变颗粒形态。
