TS-1 Treatment Research Articles

Reducibility and Adsorbate Interactions of Ti in Titanosilicate Molecular Sieve TS-1

Electron spin resonance (ESR) and electron spin echo modulation (ESEM) spectroscopy are used to study reducibility and adsorbate interaction of Ti in titanosilicate TS-1 molecular sieve. Various reduction methods were used to reduce Ti(IV) in TS-1 to Ti(III) which was then monitored by ESR. When TS-1, after dehydration and oxygen treatment at high temperature followed by evacuation (activation), is γ-irradiated at 77 K; an ESR signal withg‖=1.970 andg⊥=1.906 is observed for isolated Ti(III) centers. Radiation induced defect centers known as V centers are also observed after γ-irradiation. When activated TS-1 is treated with CO or H2at 673 K, an axial ESR signal withg⊥=1.968 andg‖=1.933 is observed which is suggested to be Ti(III)(CO)nand Ti(III)(H2)ncomplexes. When activated TS-1 is exposed to D2O at room temperature and subsequently γ-irradiated at 77 K, a new ESR signal withg=1.924 is observed. This species is identified as Ti(III)-(OD)1from2D ESEM data. Adsorption of CH3OD on activated TS-1 produces a new Ti(III) species withg=1.931. This species is identified as Ti(III)-(CH3OD)1from2D ESEM data. Adsorption of C2D4on activated TS-1 produces a new Ti(III) species withg⊥=1.968 andg‖=1.910. This species is identified as Ti(III)-(C2D4)1from2D ESEM data. Possible coordination geometries of the various Ti(III)-adsorbate complexes are discussed.

Control of product selectivity for the epoxidation of allyl alcohol by variation of the acidity of the catalyst TS-1

The acidity of TS-1 controls the product selectivity for the epoxidation of allyl alcohol with H2O2; base treatment of TS-1 enhances the selectivity to glycidol whereas incorporation of Bronsted acid sites enhances the selectivity to the products of solvolysis ring opening reactions.

Semliki forest virus mutants with temperature-sensitive transport defect of envelope proteins

Seven RNA-positive temperature-sensitive mutants of Semliki Forest virus were studied to find mutants with a defect in the transport of envelope glycoproteins to the host cell plasma membrane. Surface immunofluorescence of infected cells was recorded at the restrictive temperature (39°) and after shift to the permissive temperature (28°) carried out in the presence or absence of protein synthesis inhibitors. Preformed envelope proteins of two mutants, ts-1 and ts-7, were found at the plasma membrane only after shift to the permissive temperature. Staining of intracellular antigens after mild detergent treatment of ts-1 and ts-7 infected cells showed that at 39° the envelope proteins had reached th Golgi apparatus. Electron microscopy of ts-1 and ts-7 infected cells, maintained at 39°, showed that all the nucleocapsids were free in the cytoplasm. In ts-7, but not in ts-1, infected cells binding of nucleocapsids and virus budding started soon after the cultures had been shifted to the permissive temperature. First the budding was observed only at the Golgi and later also at the plasma membrane. Envelope proteins labeled at the restrictive temperature were efficiently incorporated into ts-7 but not into ts-1 virus particles, released after shift to 28°. We suggest that the viral glycoproteins have different “signals” for the transport and for the binding of nucleocapsid. In ts-7 both “signals” become functional after shift to 28°, whereas in ts-1 only the “transport signal” defect is reversible.

Effect of caustic treatment of TS-1 fuel on its lubricity and corrosion properties

Effect of caustic treatment of TS-1 fuel on its lubricity and corrosion properties