Abstract
In this paper, we report the experimental findings on the phase evolution of mesoporous silica in an evaporation induced self-assembly (EISA) approach by using low molecular weight homopolymer poly(propylene oxide) ( M n = 400, PPO400) as an additive. It is found that the addition of PPO400 can cause hydrotropic curvature-reducing effect on the mesostructures. Upon the increase of PPO400 addition amount, the structures of the obtained mesoporous silicas gradually evolve from three-dimensional (3-D) cubic Im 3 ¯ m to quasi- p6m, to hexagonal p6m, and to mixed structures consisting of lamellar and reversed cylindrical structure. The quasi- p6m mesoporous silica structure has the buckled cylindrical mesopores with intermediate curvature and acts as the metastable structure during the phase evolution from Im 3 ¯ m to p6m structure. We ascribe this curvature-reducing effect to the relatively weak hydrophobicity and good compatibility of PPO400 homopolymer. Moreover, the condition with larger homopolymer PPO4000 ( M n = 4000) as the additive has been also investigated and discussed.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call