Expansion of the F127-templated mesostructure in aerosol-generated particles by using polypropylene glycol as a swelling agent

Aerosol Route to Functional Nanostructured Inorganic and Hybrid Porous Materials

“…PPO polymers were used as non volatile alternatives to alkanes or trimethylbenzene (TMB) employed as micelles swelling agents in usual preparations of mesostructured materials obtained by precipitation. [128][129][130] Unsurprisingly, when used without surfactant, PPO-silicate precursors weak attractive interactions promotes uncontrolled phase separation leading to unstructured particles with a broad pore size distribution ranging from 20 to 200 nm and small surface areas ( < 100 m 2 g − 1 ). When added in presence of surfactant (either CTAB or non-ionic PEO surfactant or block copolymers), two parameters were found to control the fi nal material porous structure.…”

“…[ 132 ] Although, one has to point out that the fast incorporation kinetic of PPO of the spray-drying process makes the pore size distribution of such mesocellular particles diffi cult to reproduce. [ 130 ] On the other hand, when hydrophilic PAA is incorporated into a CTAB/silicate precursor solution, both surfactant mesostructuration and phase separation were found coexisting in a large composition range, forming, by this way, hierarchical porous particles with different structures, from hollow mesostructured particles to mesoporous-mesocellular particles. [ 133 ] In this case, the main PAA aggregation factors were found to be the gelation kinetic of silica domains and the radial polarity gradient appearing during droplets drying which drives the hydrophilic PAA to migrate towards the center of the particle.…”

Aerosol-assisted synthesis of mesoporous organosilica microspheres with controlled organic contents

“…We demonstrated the facile preparation of PMO with different organic contents in the frameworks by changing the BTSE/TEOS molar ratios of initial precursor solutions. To the best our knowledge, a systematical study focusing on the control of organic contents has not been reported thus far, though several spray-dried mesoporous materials with different compositions have been designed by adjusting the composition of precursor solutions [23][24][25][26][27][28][29][30][31][32][33][34]. We demonstrated here that ethane and benzene fragments were successfully embedded in the frameworks (up to a BTSE/TEOS molar ratio of 0.50) with the formation of ordered mesoporous structures.…”

“…silica [23][24][25][26][27], organosilica [28][29][30], maghemite-organosilica [31], carbon [32] and metal oxide [33]) have been prepared by spray drying (i.e. aerosol-assisted process) [34].…”

“…clear precursor solution) is sprayed through a nozzle into a hot steam gas, in which the supplied liquid is vaporized and droplets are dried immediately. The system used previously is not suitable for the continuous production of solids, because dried samples are collected using membrane filters [23][24][25][26][27][28][29][30][31][32][33][34]. Recently, we developed a laboratory-made apparatus suitable for rapid mass production and industrial uses [35][36][37][38][39].…”