Pyrex glass composition

The possibility that a third osmium(VII) oxide fluoride exists remains, since a dimorphic crystalline material of unknown composition, but thought to be either 0s02F2 or Os03F, was produced during the reaction of OsF6 with Pyrex glass (185). 

Reaction vessels are reused in many instruments (e.g., SYNCHRON CX Series, Abbott Architect cSOOO series, MODULAR, and the AU 400, AU 640, and AU 5400). The tune before reusable cuvet and/or reaction vessels must be replaced depends on their composition (e.g., 1 month for plastic and 2 years for standard glass vessels). Pyrex glass vessels are not replaced unless physically damaged. 

Catalytic activity data for both CO and propane oxidation were obtained using a conventional continuous flow microreactor. The catalyst sample (0.5g) is situated in a pyrex glass tube located within a stainless steel heated block. Catalyst samples were activated by in situ preheating in the reactor for 2 hours under a flow of air. The catalysts were then allowed to cool to ambient temperature still under the air flow before acquiring %conversion versus temperature data. Input gas mixture compositions, which were controlled by mass flow controllers, and flow rates are shown in Table 10. 

For the physical-chemical analysis volumes between lOOmL and 3L are collected using manual or automatic devices. The water samples are collected in colorless glasses, chemically resistant (pyrex glass with fixed composition) but lately, because of their fragility polyethylene vessels with the following advantages replaced these ... 

Countless variations in glass composition and properties are possible. If part of the silica is replaced by boron oxide, the glass has less tendency to crack with changes in temperature. Pyrex, the trademarked glass common in kitchens and laboratories, is a borosilicate glass. Many beautiful colors can be produced by adding the substances listed in Table 18.5. The composition and properties of some other types of glasses are listed in Table 18.6. 

Figure 4.3. The borax-silica phase diagram showing the compositions of Vycor and Pyrex glass.

Samples should be kept in closed Pyrex glass bottles to reduce the change in composition of the sample from evaporation and absorption. 

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