Premium
A new solventless process to hydrophobize silica powders in fluidized beds
Author(s) -
Lazghab Myriam,
Saleh Khashayar,
Guigon Pierre
Publication year - 2008
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.11436
Subject(s) - fluidization , microporous material , mixing (physics) , materials science , reagent , chemical engineering , fluidized bed , polymerization , octadecyltrichlorosilane , fumed silica , porosity , hydrophobic silica , phase (matter) , composite material , organic chemistry , chemistry , contact angle , polymer , engineering , physics , quantum mechanics
A new hydrophiztaion technique was developed in a fluidized bed reactor to modify the surface of silica‐based powders with n ‐octadecyltrichlorosilane (ODTCS). The reaction was performed at dry phase by mixing two classes of particles during the fluidization: “target‐particles” to be treated (a fine microporous silica powder) and “ODTCS‐carrier” particles consisting of coarser porous alumina beads containing an adequate amount of reagent. The results showed that ODTCS was successfully anchored on silica surface and achieved high surface coverage (1.4 groups/nm 2 ) in only few minutes with an interesting hydrophobic behavior. The energy consumption is reduced if the reaction is carried out at low temperatures, but using humidified air (7% RH). These conditions promote, however, a vertical polymerization of the reagent on solids surface. © 2008 American Institute of Chemical Engineers AIChE J, 2008