Applying grease for an airtight seal that also reduces chances of seized joints. скачать в хорошем качестве

Applying grease for an airtight seal that also reduces chances of seized joints.

Use grease made for high vacuum and its inert qualities, e.g., Krytox (PFPE/PTFE), Dow Corning high vacuum grease (dimethyl siloxane, hydroxy terminated). My joints are 24/40 and I use very little at the top of the joint. (Less chance of contaminating your rxn). PTFE joint sleeves suck (tried them) and using thin PTFE tape also sucks, comparatively, to using lab grade grease as shown. This not only puts stress on your joints (due to the tolerances involved between how the stopper fits the joint), but also is a less reliable way to prevent leaking joints - whether under vacuum or just preventing any harsh chemicals from releasing. You know the joint is properly greased when there is a 'solid' coverage around the circumference with a less opaque clear coating. You will observe a better light transfer or clarity inbetween the joints if using grease. Yes, putting silicone grease on a clean joint with a bare finger will not hurt you. Silicone can even be found in products people put on their face (lotions, skin care products...etc. It usually is called dimethicone). It is mostly inert. Non-reactive. By removing the polymeric siloxane hydroxyl groups, (H(OSiH2)nOH) to (OSiH2), Dow rendered it even more inert. Hydroxyl functional groups are easily oxidized, protonated and have partial polarity giving it these reactive characteristics. (electronegativity of the oxygen holds more electron density than the hydrogen.) Utilizing solvents, reagents and synthesis is another story. PPE, fume hood with proper ventilation, low static pressure (less bends in ducting), short duct runs, proper airflow utilizing externally protected centrifugal blower motors and proper "insert airflow number here"3/h for the size of the fume hood is all required for proper safe synthesis. Disclaimer: Non chemists, do not attempt.