Hierarchical silica particles by dynamic multicomponent assembly

✍ Scribed by Zhiwang Wu; Qingyuan Hu; Jiebin Pang; Hans P. Jakobsen; Donghong Yu; Yunfeng Lu

• Publisher: Elsevier Science
• Year: 2005
• Tongue: English
• Weight: 546 KB
• Volume: 85
• Category: Article
• ISSN: 1387-1811
• DOI: 10.1016/j.micromeso.2005.06.034

✦ Synopsis

Aerosol-assisted assembly of mesoporous silica particles with hierarchically controllable pore structure has been prepared using cetyltrimethylammonium bromide (CTAB) and poly(propylene oxide) (PPO, H[OCH(CH 3 )CH 2 ] n OH) as co-templates. Addition of the hydrophobic PPO significantly influences the delicate hydrophilic-hydrophobic balance in the well-studied CTAB-silicate coassembling system, resulting in various mesostructures (such as hexagonal, lamellar, and hierarchical structure). The co-assembly of CTAB, silicate clusters, and a low-molecular-weight PPO (average M n 425) results in a uniform lamellar structure; while the use of a high-molecular-weight PPO (average M n 2000), which is more hydrophobic, leads to the formation of hierarchical pore structure that contains meso-meso or meso-macro pore structure. The role of PPO additives on the mesostructure evolution in the CTAB-silicate assembling system was discussed. The mesostructure of these particles was characterized by transmission electron microscope (TEM), scanning electron microscope (SEM), X-ray diffraction (XRD), and N 2 sorption.