HF dissolve glass bottles. However I need to perform a reaction in which HF participates as reactant in a glass reactor for few hours. How can I perform this reaction without dissolving the glass bottle?
Thank you very much
I dont know the chemistry of what you are doing, but i am sure the dissolution start at the moment HF will come in contact with glass. Your system will be contaminated from the word go and whatever result you would not be clean data.
Hope some chemist who works using HF will be able to help you in finding an alternate to glass
Should work.
The easy thing to do would be to heat some paraffin wax in a glass bottle, and swish it around to cover the entire inner surface, drain the excess, and leave it to cool. The acid only comes into contact with the wax, but the container has the strength of glass. But never stick anything hard inside, like a pipette, that could scratch the wax.
Fully refined paraffin wax of high temperature melt point (say ~67 ºC) may indeed provide a fairly good option for coating the inner glass surface, which becomes protected from HF etching as long as the layer can not dissolve or melt with the intended use. This type of coating is easily applied by melting the wax.
Polyethylene coating can alternatively be considered, particularly if use at higher temperatures is required. Low- and high-density polyethylene lining can withstand up to ~80 °C or ~110 °C, respectively. Powdered polyethylene can be dissolved in some convenient solvent (e.g. xylene ~80 ºC) to obtain a viscous solution used to coat the glass inside surface. Drying can be assisted by moderate heat and/or vacuum.
Can use Bee Wax ( mpt range=61-66C; depending upon the quality)
And I reproduce the contents from the following book[page- 396; where the first paragraph ends.]
Elements of Chemistry; including the applications of the science in the arts
By Thomas GRAHAM (Master of the Mint.)
It reads as:
The dilute acid[HF] may be preserved without much contamination in a glass bottle which has been previously heated and coated internally with melted bee wax.
How to search it from google?
Fill/ Click:
hf in a glass bottles coated with bee wax
Reach/ Click:
Elements of Chemistry; including the applications of the ...
books.google.co.in/books?id=0K1cAAAAcAAJ
Thomas GRAHAM (Master of the Mint.) - 1842
This vapor is received in a flask or bottle, likewise of lead, kept cold by ice, in which it condenses without the presence of water. ... in vessels of lead formed without tin solder, tin being rapidly acted upon by hydrofluoric acid. ... in a glass bottle, which has been previously heated and coated internally with melted bees-wax.
I am going to conclude that coating with Wax seems to be a good choice.
Since this old man has to spend his retirement with the young scholars[ in the process gets both brickbats/ bouquets; got brickbats only today ], pls. find below another way to store HF in glass .
[A]Gutta percha can store HF.
[B] Cones made of gutta percha are available commercially. Just fit one cone well in the glass vessel and you can pour HF safely in the gutta percha cone. The glass will provide the required strength and one can hold it in hands.
[C] There can be an indiect way as:
Gutta percha be coated over glass indirectly and is done even commercially in some parts of the world.
(i)First of all an epoxy resin is coated over glass. This resin ,then, binds with the gutta percha which, in turn, can store HF very safely. Working range of gutta percha= 42-60C
Fill/ Click:
Epoxy - Wikipedia, the free encyclopedia
Just note the following two lines
Epoxy resin is employed to bind gutta percha
The epoxy resins can be used as adhesives for wood, metal, glass, stone, and some plastics.
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