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The optional second step (for bare silicon wafers) is a short immersion in a 1:100 or 1:50 solution of aqueous HF (hydrofluoric acid) at 25 °C for about fifteen seconds, in order to remove the thin oxide layer and some fraction of ionic contaminants. If this step is performed without ultra high purity materials and ultra clean containers, it ...
Dealkalizing glass containers is accomplished by exposing the glass surface to reactive sulfur- or fluorine-containing compounds during the manufacturing process. A rapid ion-exchange reaction proceeds that depletes the inside surface of alkali, and is performed when the glass is at high temperature, usually on the order of 500–650 °C or ...
The intent of vacuum packing is usually to remove oxygen from the container to extend the shelf life of foods and, with flexible package forms, to reduce the volume of the contents and package. [2] Vacuum packing reduces atmospheric oxygen, limiting the growth of aerobic bacteria or fungi, and preventing the evaporation of volatile components.
A hermetic seal is any type of sealing that makes a given object airtight (preventing the passage of air, oxygen, or other gases).The term originally applied to airtight glass containers but, as technology advanced, it applied to a larger category of materials, including metals, rubber, and plastics.
Silicone-based defoamers are polymers with silicon backbones. These might be delivered as an oil or a water-based emulsion. The silicone compound consists of a hydrophobic silica dispersed in a silicone oil. Emulsifiers are added to ensure that the silicone spreads fast and well in the foaming medium.
In ancient Mesoamerican cultures, rubber was used to make balls, sandal soles, elastic bands, and waterproof containers. [4] It was cured using sulfur-rich plant juices, an early form of vulcanization. [5] In the 1830s, Charles Goodyear worked to devise a process for strengthening rubber tires. Tires of the time would become soft and sticky ...
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Silicone caulk can be used as a basic sealant against water and air penetration. In organosilicon and polymer chemistry, a silicone or polysiloxane is a polymer composed of repeating units of siloxane (−O−R 2 Si−O−SiR 2 −, where R = organic group). They are typically colorless oils or rubber-like substances. Silicones are used in ...