Institute of Physical Chemistry , Justus-Liebig University , Heinrich-Buff-Ring 17 , D-35392 Giessen , Germany.
Physical Chemistry III , University of Bayreuth , D-95447 Bayreuth , Germany.
Inorg Chem. 2019 Feb 18;58(4):2599-2609. doi: 10.1021/acs.inorgchem.8b03203. Epub 2019 Jan 25.
TiO monoliths were synthesized by a partially hindered sol-gel process. Various synthesis parameters like precursor concentrations and gelation temperature were varied to investigate changes in the macroporosity (being in the range of micrometers) and to determine influences on the macropore formation mechanism. Ionic liquids (ILs) were used as templates to vary the mesopore size independently from the macropore size. Depending on the synthesis parameters, TiO monoliths with exclusive mesoporosity or with hierarchical meso-/macropore structure were received, and the range of macropores can be shifted between 100 nm and 10 μm without influencing the mesopore diameter. Pore volumes up to 880 mm/g were achieved, as determined by mercury intrusion porosimetry. The mesopores' diameter can be adjusted between 6 and 25 nm by adding different amounts of IL, and surface areas up to 260 m/g and mesopore volumes of 0.5 cm/g were obtained, based on N-physisorption measurements. The monoliths were cladded by polymer, allowing for studying the flow-through properties depending on the macropore size. This precise control for tailored macropores enables the design of optimized TiO monoliths with respect to the desired application requirements.
TiO 整体式材料是通过部分受阻的溶胶-凝胶工艺合成的。改变了各种合成参数，如前体浓度和凝胶化温度，以研究大孔率（在微米范围内）的变化，并确定对大孔形成机制的影响。离子液体（ILs）被用作模板，以独立于大孔尺寸来改变中孔尺寸。根据合成参数，可以得到仅具有中孔或具有分级中孔/大孔结构的 TiO 整体式材料，并且大孔的范围可以在 100nm 到 10μm 之间变化，而不会影响中孔直径。通过汞侵入孔隙率测定法确定，可达 880mm³/g 的孔体积。通过添加不同量的 IL，可以将中孔的直径调整在 6nm 到 25nm 之间，根据 N2 物理吸附测量，获得高达 260m²/g 的比表面积和 0.5cm³/g 的中孔体积。聚合物对整体式材料进行了包覆，这允许根据大孔尺寸研究其流动特性。这种对大孔的精确控制可以设计出针对特定应用要求优化的 TiO 整体式材料。
