Controlled manipulation of TiO.sub.2 nanoclusters inside mesochannels of core-shell silica particles as stationary phase for HPLC separation

• Published in: Mikrochimica acta (1966) 2020-06, Vol.187 (6)
• Main Authors: Li, Wanying, Qian, Hui, Liu, Rui, Zhao, Xiaoli, Tang, Zhi, Huang, Xianhuai, Li, Weihua
• Format: Article
• Language: English
• Subjects: Density functionals; High performance liquid chromatography; Hydrolysis; Silica
• ISSN: 0026-3672
• DOI: 10.1007/s00604-020-04268-w

Based on a detailed study of the hydrolysis process of tetrabutyl orthotitanate (TBOT), TiO.sub.2 nanoclusters were modified inside the pores of SiO.sub.2 core-shell particles instead of the outside. The pore size distribution of SiO.sub.2 core-shell spheres modified with TiO.sub.2 ([e-mail][e-mail].2) was analyzed by Barrett-Joyner-Halenda (BJH) method and density functional theory (DFT) method, respectively. The results of the DFT calculations demonstrate that the TiO.sub.2 nanoclusters are always first formed in bulk solution and then enter the pores. By regulating the rate of hydrolysis of TBOT, almost all of the TiO.sub.2 nanoclusters are modified into the pores and the structure of the original SiO.sub.2 core-shell sphere is hardly affected. The morphology of the particles was characterized by scanning electron microscopy and transmission electron microscopy. The crystal phase of TiO.sub.2 was measured by XRD. [e-mail][e-mail].2 spheres functionalized with C18 were packed into a stainless steel column. The chemical stability of [e-mail][e-mail].2 spheres under alkaline was tested by flushing of a mobile phase at pH 13 for 7 days. The efficiency of the column after the alkali solution treatment still reaches 98,430 plates m.sup.-1, which is only about 1.6% lower than that before the alkali solution treatment. A series of basic and acidic analytes were also separated on the column.