Fabrication, mechanical testing and application of high-pressure glass microreactor chips

Abstract

The design, fabrication and high-pressure performance of several in-plane fiber-based interface geometries to microreactor chips for highpressure chemistry are discussed, and an application is presented. The main investigated design parameters are the geometry of the inlet/outlet structure, the manner in which top and bottom wafer are bonded and the way the inlets/outlets turn over into the microfluidic channels.Destructive pressure experiments with H 2 O and liquid CO 2 showed that the maximum pressure that the proposed inlet/outlet structures can withstand is in the range of 180-690 bar. The optimal geometry for high-pressure microreactor chips is a tubular structure that is etched with hydrofluoric acid (HF) and suitable for fibers with a diameter of 110 m. These inlets/outlets can withstand pressures up to 690 bar. On the other hand, small powderblasted inlets/outlets that are smoothened with HF and with a sharp transition towards the flow channels are adequate for working pressures up to 300 bar.Microreactor chips with tubular inlet/outlet geometries were used for studying the formation of the carbamic acid of N-benzylmethylamine and CO 2 . These chips could be used for pressures up to 400 bar without problems/failure, thereby showing that these micromachined microreactor chips are attractive tools for performing high-pressure chemistry in a fast and safe way.

Alkane Activation at Ambient Temperatures: Unusual Selectivities, CC, CH Bond Scission versus CC Bond Coupling

“…[18] In this study, we report oxidative conversion of light alkanes, C 1 -C 3 range, in the presence of cold plasma in a microreactor. [19] The use of a microreactor for plasma processing [20] helps to work at higher pressures instead of the vacuum required in conventional systems. [13] Generation of a DBD at atmospheric pressure in a small and confined reactor space may imply a 1) stronger electric field, 2) more uniform and dense plasma and 3) better control of the residence time.…”

“…[21] Sandwich thermal bonding of three Pyrex plates (one with and, respectively, the bottom and top plate without a channel) allowed fabrication of the microreactor (Figure 4, right). [19] Gas in-and out-lets were created by powder blasting using alumina particles. Two copper ribbon electrodes were attached, externally, on the top and bottom side of the chip.…”

Microchip technology in mass spectrometry

“…In addition to etching, through-holes in glass wafers can be made by drilling and powder blasting (Belloy, Sayah, & Gijs, 2000). In general, glass-glass bonding is considered easier than silicon-silicon or polymer-polymer bonding because of the wide variety of methods available for glass (Chiem et al, 2000;Daridon et al, 2001;Jia, Fang, & Fang, 2004;Easley, Humphrey, & Landers, 2007;Tiggelaar et al, 2007). Silicon-glass anodic bonding is also a routine task (Despont et al, 1996;Berthold et al, 2000;Lee et al, 2000).…”

Flow Chemistry of the Kolbe‐Schmitt Synthesis from Resorcinol: Process Intensification by Alternative Solvents, New Reagents and Advanced Reactor Engineering

“…High-p,T micro processing studies from other research groups with new application examples revealed similar effects. Gardenier et al [29] studied the formation of carbamic acid from N-benzylmethylamine and CO 2 using a high-pressure glass microreactor chip. Only by high-pressure operation at 200 bar can the product be formed, whereas at 10 bar no product formation was observed.…”