Why Should You Use Micro-Reactors?
Micro flow reactors are an exciting technology and dynamic approach which is very helpful for industrial processes and is in the light of the scientific community. Continuous flow micro-reactors have many practical, economical and environmental advantages. There are many advantages over batch reactors such as continuous flow operation, easy separation, sampling without contamination, and high reproducibility due to the facilitated condition control 1.
The Importance of Flow Micro-Reactors
Perhaps you want to produce an exciting polymer like Poly Butyl-Acrylate 2 or energetical molecules like ethanol or bio-diesel 6, where you need to define conditions for chemical and biochemical reactions. This is not an easy task since several variables like flow rate, agitation, and substrate concentration should be optimized. To achieve this goal the use of micro-reactors is a step forward, which allows testing several variables at the same time, minimizing reactive consumption and improving the mass transport phenomena. In this way, new straightforward studies can be performed properly using micro-reactors.
Micro flow reactors have found applications at least in three areas of science. In this brief review, the principal contributions on polymer synthesis, chemical reaction, enzymatic reaction and cell culture evaluation will be presented.
Polymer Science: A Step Forward By the Micro-Reactor Implementation
Polymer synthesis is a high control required process. Recently, the use of a cobalt catalyst allowed the polymerization of vinyl acetate with high polymerization control in conjugation with reactive ratio improvement thanks to the implementation of continuous flow micro-reactors. Also, poly(phosphoester)s were produced in glass-chip micro-reactors in just 20 min of reaction 2. In a couple of papers Vanderberg et al., demonstrate the feasibility of micro-reactors in the synthesis of well-defined block copolymers and the multiblock-copolymerization is successfully achieved. Reaction times in this new configurations can be as fast as 10 minutes 9. The results of this and other studies are far superior to the batch processes at the same reaction conditions.
What About Chemical Organic Synthesis?
Fine tune modifications can be reached by the micro-reactor implementation for end group modification in the case of atom transfer radical polymerization with precursor polymers into azide end-capped materials and the subsequent click chemistry (click chemistry is the copper-catalyzed reaction with azide and alkyne to produce a cycloaddition)10. As a micro-reactor operates under very stable operating conditions, reactions become more selective, and higher quality products with less byproduct formation can be obtained. For this kind of reactions, five micro-reactors can be optimized by the easy screening of residence times and reaction temperatures. The total reaction time was around 40 minutes which is fast compared to the several hours usually needed to reach completion. Micro flow reactors can accelerate these reactions from hours to seconds.
High-Performance Enzymatic Synthesis with Micro-Reactors Technology
The implementation of micro flow reactors in enzymatic processes allow the control of mass transport and can help in enzyme stabilization. New exciting technologies to accomplished enzyme immobilization can be used in this new setups. In which heavy metals determination could be achieved, for example, copper detection 7. Nevertheless, the development of prototypes for multi enzymatic reactions are implemented to achieve synthetic biology designs. The outcome of these technologies is an increase in the specific conversion, and the design is further improved by computational optimization 3.
Processes involving gas reactants require high mass control, for example, tube-in-tube reactors are another type of micro-reactors used in the production of 3-phenylcatechol in a coupled enzymatic system. This type of micro flow reactor improves oxygen transfer to the point of not having oxygen depletion. Micro-reactors in this configurations achieves high conversion rates in low total reaction time by the improvement of mass oxygen transfer 8. Also, new micro-reactors allow long-term operation with high substrate concentration (1 mol/L) with the Calb enzyme which can be performed complex transesterification reaction. The mass transfer improvement and efficient mixing conditions allow no just high conversion rate but also favors enzymatic stability of the packed-bed micro-reactor 4.
Understanding the Dynamics of Oxygen in Cell Culture
The dissolved oxygen dynamics have a critical role in the understanding of liver on-chip applications. Different studies like the vasculature microenvironment of stem cells help to gain new insight on the role of molecules like acetaminophen in the embryonic development. The implementation of micro-reactor approach provides fine-tune control and high oxygen control which is relevant to understand molecule toxicity 5.
Syringe Pumps for Micro-Reactors Applications
With any microfluidic device, proper flow control for micro-reactors applications is needed; for that matter, smart syringe pumps are highly reliable and stable systems. Chemyx syringe pump systems allow a wide range of operational modes that allowed the elaboration of the above-discussed studies. Chemyx technology is preferred by many scientists in the micro-reactor field due to the high performance and proved quality.
- Alobaiti, M.T., Taylor, M.J., Liu, D., Beaumont, S.K., Kyriakou, G., 2016. Selective oxidation of cyclohexene through gold functionalized silica monolith microreactors. Surface Science. 646, 179-185. http://dx.doi.org/10.1016/j.susc.2015.10.039
- Baeten, E., Vanslambrouck, S., Jérôme, C., Lecomte, P., Junkers, T., 2016. Anionic flow polymerizations toward functional polyphosphoesters in microreactors: Polymerization and UV-modification. Eur. Polym. J. 80, 208–218. https://doi.org/10.1016/j.eurpolymj.2016.02.012
- Boehm, C.R., Freemont, P.S., Ces, O., 2013. Design of a prototype flow microreactor for synthetic biology in vitro. Lab Chip 13, 3426. https://doi.org/10.1039/c3lc50231g
- Denčić, I., De Vaan, S., Noël, T., Meuldijk, J., De Croon, M., Hessel, V., 2013. Lipase-based biocatalytic flow process in a packed-bed microreactor. Ind. Eng. Chem. Res. 52, 10951–10960. https://doi.org/10.1021/ie400348f
- Kermagoret, A., Wenn, B., Debuigne, A., Jérôme, C., Junkers, T., Detrembleur, C., 2015. Improved photo-induced cobalt-mediated radical polymerization in continuous flow photoreactors. Polym. Chem. 6, 3847–3857. https://doi.org/10.1039/C5PY00299K
- Kim, H.S., Weiss, T.L., Thapa, H.R., Devarenne, T.P., Han, A., 2014. A microfluidic photobioreactor array demonstrating high-throughput screening for microalgal oil production. Lab Chip 14, 1415. https://doi.org/10.1039/c3lc51396c
- Rattanakit, P., Liawruangrath, S., 2014. Performance Evaluation of Monolith Based Immobilized Acetylcholinesterase Flow-Through Reactor for Copper(II) Determination with Spectrophotometric Detection. J. Chem., 1-7. http://dx.doi.org/10.1155/2014/757069.
- Tomaszewski, B., Schmid, A., Buehler, K., 2014. Biocatalytic production of catechols using a high pressure tube-in-tube segmented flow microreactor. Org. Process Res. Dev. 18, 1516–1526. https://doi.org/10.1021/op5002116
- Vandenbergh, J., De Moraes Ogawa, T., Junkers, T., 2013. Precision synthesis of acrylate multiblock copolymers from consecutive microreactor RAFT polymerizations. J. Polym. Sci. Part A Polym. Chem. 51, 2366–2374. https://doi.org/10.1002/pola.26593
- Vandenbergh, J., Tura, T., Baeten, E., Junkers, T., 2014. Polymer end group modifications and polymer conjugations via “click” chemistry employing microreactor technology. J. Polym. Sci. Part A Polym. Chem. 52, 1263–1274. https://doi.org/10.1002/pola.27112