Abstract This study examined the effects of adding iron to rice hulls samples (RHs) on thermal degradation prepare nano silica and oxide-silica mixtures. Iron is precipitated in different amounts within RH fibers (as hydroxide) by dipping them a solution concentrations acidic ferrous sulfate then immersing it dilute ammonia solution. The dry RHs were fired at temperatures between 400 °C 700 sta...

To evaluate the influence of convergence angle tooth preparations and abutments height several surface treatments for zirconia copings through tensile retention test. 120 crown were made in Nema G10 with maxillary first molar anatomy. In total, 60 5 mm divided into two groups 6° 20° angles preparations, a 12° 4 6 heights. Three used MDP-primer (10-Methacryloyloxydecyl dihydrogen phosphate), gla...

A 0.46 cm x 10.0 cm silica monolith column was modified through the in situ covalent attachment of lysine (2,6-diaminohexanoic acid) groups. Due to the zwitterionic nature of the resultant stationary phase, the modified monolithic column contained both cation and anion exchange capacity. In the case of cation exchange, the capacity was found to be relatively low at between 5 and 6.5 micromoles ...

Um catalisador baseado em sílica quimicamente modificada com tetrametilguanidina (TMG) foi sintetizado pela co-condensação de tetraetilortossilicato (TEOS) com um novo agente sililante, preparado pela reação entre a molécula TMG e (3-cloropropil)trimetoxisilano. O direcionador n-dodecilamina foi utilizado para organizar a polimerização do catalisador inorgânico-orgânico. A termogravimetria most...

In this study, 6-azido-2,3-di(p-chlorophenylcarbamoylated) cellulose was synthesized and bonded onto aminized silica gel to obtain a new chiral stationary phase. Enantioselectivity of the chiral stationary phase and Chiralcel OF suggested promising chiral separation ability of the new cellulose chiral stationary phase. In addition, the effect of trifluoroacetic acid, diethylamine on enantiosele...