(64c) Microreactors for the Basic Organic Teaching Lab Course

Microreactor technology currently finds its way to applications in chemical industry and research. The method offers significant opportunities and advantages: Chemical syntheses may proceed more efficient with increased selectivity and the small volumes used in the technology make it inherent safe. However, the application of microreactors in production, development and research calls for trained personnel. Only skilled scientists, who are aware of opportunities and limitation of the technology, will gain its potential. Therefore, microreactor technology should become part of the educational curriculum at universities, in particular in chemistry and chemical engineering. To meet the needs of university education, microreactors to be used in a basic teaching laboratory must be affordable, reliable and robust, and allow a direct monitoring of the chemistry. We develop such systems based on glass microstructured components produced by a sand blasting method by the industrial project partner Little Things Factory GmbH (Ilmenau, Germany). The microreactors are made from borosilicate glass which is inert to most chemicals. To connect the microreactor a set of easy to use fittings and tubing was developed. The flow of the reactants is either realized by gravity using reservoirs placed at different height or by the use of a syringe pump. A flow rate without pulses up to 10 mL/min is feasible. To control the reaction temperature the whole microreactor is simply emerged into a cooling or heating bath. If a precise or liquid-free control of the temperature is desired, thermoelectric modules are used which allow a temperature range between -10 to +60 oC. On-line reaction monitoring is envisaged by the use of a UV flow cell based on LED technique and conductivity measurements inside the device. The teaching laboratory experiments developed for the microreactor devices span the full range of the organic chemistry at the Bachelor level. To be instructive and easy to monitor, reactions with visible colour change are selected. So far aldol condensations, redox reactions and the synthesis of an azo compound have been realized. Overall, a set of 15 reactions will be developed with full instructions for students and supervisors. All experimental set-ups, lab manuals, background material and instructions for syntheses will become part of the internet teaching material database NOP at www.oc-praktikum.de. The documents are available in several languages, e.g. in German and English. All material is available free of charge and supports docents and lab supervisors developing state of the art laboratory classes.