Borosilicate Glass Bottles-media/reagent bottles

Special Offer pricing available until the end of March 2020 for Fisherbrand borosilicate reagent/media bottles.

Re-usable borosilicate glass with pouring ring and polypropylene cap.  Autoclavable.

Standard GL45 thread.

Example price – 250ml capacity, pack of 10 – Only £19.95

Example price – 1000ml capacity, pack of 10 – Only £30.50

The flyer gives the full range available.  Offer is valid until 31st March 2020 only.  Quote REA20 to qualify.

Click here to download the flyer.

Visit http://www.totallabsupplies.co.uk/?cat=33

What is a Soxhlet Extractor?

A Soxhlet extractor is a piece of laboratory apparatus invented in 1879 by Franz von Soxhlet. It was originally designed for the extraction of a lipid from a solid material. However, a Soxhlet extractor is not limited to the extraction of lipids. Typically, a Soxhlet extraction is only required where the desired compound has a limited solubility in a solvent, and the impurity is insoluble in that solvent. If the desired compound has a significant solubility in a solvent then a simple filtration can be used to separate the compound from the insoluble substance.

Normally a solid material containing some of the desired compound is placed inside a thimble made from thick filter paper, which is loaded into the main chamber of the Soxhlet extractor. The Soxhlet extractor is placed onto a flask containing the extraction solvent. The Soxhlet is then equipped with a condenser.

The solvent is heated to reflux. The solvent vapour travels up a distillation arm, and floods into the chamber housing the thimble of solid. The condenser ensures that any solvent vapour cools, and drips back down into the chamber housing the solid material.

The chamber containing the solid material slowly fills with warm solvent. Some of the desired compound will then dissolve in the warm solvent. When the Soxhlet chamber is almost full, the chamber is automatically emptied by a siphon side arm, with the solvent running back down to the distillation flask. The thimble ensures that the rapid motion of the solvent does not transport any solid material to the still pot. This cycle may be allowed to repeat many times, over hours or days.

During each cycle, a portion of the non-volatile compound dissolves in the solvent. After many cycles the desired compound is concentrated in the distillation flask. The advantage of this system is that instead of many portions of warm solvent being passed through the sample, just one batch of solvent is recycled.

After extraction the solvent is removed, typically by means of a rotary evaporator, yielding the extracted compound. The non-soluble portion of the extracted solid remains in the thimble, and is usually discarded.

For more information:-
http://en.wikipedia.org/wiki/Soxhlet_extractor
http://www.scilabware.com/Extraction-&-Fractionation/Soxhlet--Extraction/Soxhlet-complete-assemblies/p-51-52-208/
(Scilabware, Pyrex, Quickfit glassware available from P&R Labpak)

The amazing properties of Borosilicate Glass

Borosilicate glass is a type of glass with the main glass-forming constituents silica and boron oxide. Borosilicate glasses are known for having very low coefficients of thermal expansion (~3 × 10⁻⁶ /°C at 20°C), making them resistant to thermal shock, more so than any other common glass. Such glass is less subject to thermal stress and is commonly used for the construction of reagent bottles, flasks, beakers and many other laboratory glassware items. Borosilicate glass is sold under such trade names as Pyrex, Schott & Simax.

 

Borosilicate glass was first developed by German glassmaker Otto Schott in the late 19th century and sold under the brand name "Duran" in 1893. After Corning Glass Works introduced Pyrex in 1915, the name became a synonym for borosilicate glass in the English-speaking world.

Chemical Properties
Borosilicate glass has a very high resistance to attack from water, acids, salt solutions, halogens and organic solvents. Only hydrofluoric acid, hot concentrated phosphoric acid and strong alkaline solutions cause appreciable corrosion of the glass.

Hydrolytic resistance For many applications, it is important that laboratory glassware has excellent hydrolytic resistance; e.g. during steam sterilisation procedures, where repeated exposure to water vapour at high temperature can leach out alkali (Na+) ions. Pyrex borosilicate glass for example has a relatively low alkali metal oxide content and consequently a high resistance to attack from water. Pyrex fits into Class 1 of glasses for hydrolytic resistance according to ISO 719 (98°C) and ISO 720 (121°C).

Acid resistance
Glasses with a high percentage weight of silica (SiO2) are less likely to be attacked by acids. Pyrex borosilicate glass is over 80% silica and therefore remarkably resistant to acids (with the exception of hot concentrated phosphoric acid and hydrofluoric acid). Glass is separated into 4 acid resistance classes and Pyrex corresponds to Class 1 in accordance with DIN 12116 and meets the requirements of ISO 1776.

Alkali resistance
Alkaline solutions attack all glasses and Pyrex can be classified as moderately resistant. The alkali resistance of Pyrex borosilicate glass meets Class 2 requirements as defined by ISO 695 and DIN 52322.

High usage temperature

           

The maximum permissible operating temperature for DURAN® borosilicate glass is 500 °C. Above a temperature of 525 °C the glass begins to soften and above a temperature of 860 °C it changes to the liquid state.

DURAN® can be cooled down to the maximum possible negative temperature and is therefore suitable for use with liquid nitrogen (approx. – 196 °C). During such use/ freezing. In general DURAN® products are recommended for use down to – 70 °C. During thawing ensure that the temperature difference does not exceed 100 K.

 

The link below shows how Duran glass is made
http://www.duran-group.com/en/about-duran/how-duran-is-made.html

For more information visit
http://www.scilabware.com/Glass_technical/
http://www.duran-group.com/en/about-duran/duran-properties.html
http://en.wikipedia.org/wiki/Borosilicate_glass