High pressure in organic chemistry on the way to miniaturization

Selected Examples of High‐Pressure Reactions in Glass Microreactors

“…However, the order changes at pressures of >50 bar being 5c > 5b > 5a, having 14, 2.8, and 2.0 times larger rate constants, respectively, at 150 bar compared to batch conditions (see Fig. 4) [14].…”

“…In the same setup, the known reaction [9] of Danishefsky's diene 8 with imine 9 in methanol to give 1,2-diphenyl-2,3-dihydropyridin-4(1H)-one 10 was studied at different pressures (see Scheme 3) [10]. The product formation was monitored by the increase of the absorption at 335 nm in the UV/Vis spectrum; k obs -values of 1.5·10 -4 , 1.8·10 …”

“…Application of (high) pressure is a well-known methodology to enhance the reaction rate of different types of organic reactions [1]. In general, reactions accompanied by a decrease in molar activation volume (DV ≠ ) are accelerated by pressure.…”

Modular microfluidic valve structures based on reversible thermoresponsive ionogel actuators

“…This pressure is considered to be sufficient for most of the microfluidic applications. [28] After valve failure, the thermoactuation process and associated swelling enabled the channel to be once again blocked, and the most of these valves could be reused, four out of five of the tested valves. Failure tests were repeated with these valves and the failure pressure values decreased substantially to 300 ± 100 mbar (n = 5) and their reproducibility was very low.…”

From Nanotechnology to Nanoengineering

“…Consequently, micro-reactors are supreme for conducting operations even with highly exothermic reactions or under supercritical conditions (Nauman 2008;Benito-Lopez et al 2008;Marre et al 2012). Besides all processing benefits for micro-reactor, the axial dispersion effects associated with the parabolic flow profile of typical micro-channel contribute to a broader RTD (Chang 2013).…”