Guerrero Gabriel, Hägg May-Britt, Simon Christian, Peters Thijs, Rival Nicolas, Denonville Christelle
Department of Chemical Engineering, Norwegian University of Science and Technology, 7491 Trondheim, Norway.
SINTEF Industry, 0314 Oslo, Norway.
Membranes (Basel). 2018 Jun 8;8(2):28. doi: 10.3390/membranes8020028.
In this article, we studied two different types of polyhedral oligomeric silsesquioxanes (POSS) functionalized nanoparticles as additives for nanocomposite membranes for CO₂ separation. One with amidine functionalization (Amidino POSS) and the second with amine and lactamide groups functionalization (Lactamide POSS). Composite membranes were produced by casting a polyvinyl alcohol (PVA) layer, containing either amidine or lactamide functionalized POSS nanoparticles, on a polysulfone (PSf) porous support. FTIR characterization shows a good compatibility between the nanoparticles and the polymer. Differential scanning calorimetry (DSC) and the dynamic mechanical analysis (DMA) show an increment of the crystalline regions. Both the degree of crystallinity (Xc) and the alpha star transition, associated with the slippage between crystallites, increase with the content of nanoparticles in the PVA selective layer. These crystalline regions were affected by the conformation of the polymer chains, decreasing the gas separation performance. Moreover, lactamide POSS shows a higher interaction with PVA, inducing lower values in the CO₂ flux. We have concluded that the interaction of the POSS nanoparticles increased the crystallinity of the composite membranes, thereby playing an important role in the gas separation performance. Moreover, these nanocomposite membranes did not show separation according to a facilitated transport mechanism as expected, based on their functionalized amino-groups, thus, solution-diffusion was the main mechanism responsible for the transport phenomena.
在本文中，我们研究了两种不同类型的多面体低聚倍半硅氧烷（POSS）功能化纳米颗粒，作为用于CO₂分离的纳米复合膜的添加剂。一种是脒基功能化（脒基POSS），另一种是胺基和乳酰胺基功能化（乳酰胺基POSS）。通过在聚砜（PSf）多孔支撑体上浇铸含有脒基或乳酰胺基功能化POSS纳米颗粒的聚乙烯醇（PVA）层来制备复合膜。傅里叶变换红外光谱（FTIR）表征显示纳米颗粒与聚合物之间具有良好的相容性。差示扫描量热法（DSC）和动态力学分析（DMA）表明结晶区域增加。与微晶之间的滑移相关的结晶度（Xc）和α*转变均随PVA选择层中纳米颗粒的含量增加而增加。这些结晶区域受聚合物链构象的影响，降低了气体分离性能。此外，乳酰胺基POSS与PVA的相互作用更强，导致CO₂通量值更低。我们得出结论，POSS纳米颗粒的相互作用增加了复合膜的结晶度，从而在气体分离性能中发挥了重要作用。此外，这些纳米复合膜并未如预期那样基于其功能化氨基按照促进传输机制进行分离，因此，溶解扩散是负责传输现象的主要机制。
