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An Inexpensive Device for Stirring Sealed Tube Reactions
On a number of occasions we have found i t necessary to agitate asealed tube rePERFORATED action in order to keep a solid reagent suspended in the reaction mixture or to provide mixing for a reaction containing two liquid phases. We have found that shaking stirrers, ALUMINUM PLATE which are relatively expensive, were unsatisfactory because they tended to provide a reciprocating stirring action which does not effectively mix reactions in narrow bore tubes. On the other hand, a vortex stirrer provided effective mixing but required that the worker hold the sealed tube by hand to the mixing cupduring the mixingprocess. This was considered unsatisfactory for reactions requiring continuous mixing. We have r".Oo MOTOR found the following device to be inexpensive and very handy for agitating reaction mixtures in sealed tubes. 2 \. A small electric motor (usually & rpm) was extracted from an inexpensive electric alarm clock. The motor was then glued to the vertical part of a metal bookend with epoxy cement. A light-weight, perforated aluminum plate (-2 X 100 X 200 mm) was then glued t o the motor's gear axle with epoxy cement. Such a plate may be purchased from mwt hardware stores or obtained from an old Erector Set. After allowing the epoxy to cure thoroughly, the sealed tubes can then be attached to the aluminum plate by means of rubber bands or wire. When the motor is turned on, the tubes are turned over BOOKEND and aver a t the rate of 4-6 times per minute. This type of stirring is very effective for keeping solids suspended or mixing two liquid phases. The total cost of this device can be as little as $4-5, including the price of the alarm clock. University of Illinois a t Urbana-Champaign
486 / Journal of Chemical Education
George F. Luteri
