| 摘要 |
THE PRESENT INVENTION IS HYDROPHOBIC SILICA GELS AND A METHOD FOR THEIR PREPARATION UNDER NEUTRAL CONDITIONS. THE METHOD COMPRISES TWO STEPS, WHERE IN THE FIRST STEP THE PH OF A SILICA HYDROSOL IS ADJUSTED WITH A BASE TO WITHIN A RANGE OF PH 3 TO PH 7 TO FACILITATE FORMATION OF A SILICA HYDROGEL. IN THE SECOND STEP, THE SILICA HYDROGEL IS CONTACTED WITH AN ORGANOSILICON COMPOUND IN THE PRESENCE OF A CATALYTIC AMOUNT OF A STRONG ACID TO EFFECT HYDROPHOBING OF THE SILICA HYDROGEL. IN A PREFERRED METHOD, IN A THIRD STEP THE HYDROPHOBIC SILICA GEL IS CONTACTED WITH A SUFFICIENT QUANTITY OF A WATER-IMMISCIBLE ORGANIC SOLVENT TO CONVERT THE HYDROPHOBIC SILICA HYDROGEL INTO A HYDROPHOBIC SILICA ORGANOGEL. |
