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Abstract Under-oil open microfluidic system, utilizing liquid-liquid boundaries for confinements, offers inherent advantages including clogging-free flow channels, flexible access to samples, and adjustable gas permeation, making it well-suited for studying multi-phase chemical reactions that are challenging for closed microfluidics. However, reports on the novel system have primarily focused on device fabrication and functionality demonstrations within biology, leaving their application in broader chemical analysis underexplored. Here, we present a visualization-enhanced under-oil open microfluidic system for in situ characterization of multi-phase chemical reactions with Raman spectroscopy. The enhanced system utilizes a semi-transparent silicon (Si) nanolayer over the substrate to enhance visualization in both inverted and upright microscope setups while reducing Raman noise from the substrate. We validated the system’s chemical stability and capability to monitor gas evolution and gas-liquid reactions in situ. The enhanced under-oil open microfluidic system, integrating Raman spectroscopy, offers a robust open-microfluidic platform for label-free molecular sensing and real-time chemical/biochemical process monitoring in multi-phase systems. 

In-situ characterization techniques, although complex, can provide a wealth of insight into material chemistry and evolution dynamics. Grasping the fundamental kinetics of material synthesis is essential to enhance and streamline these processes and facilitate easier scaleup. Metal–organic frameworks (MOFs), a class of porous crystalline materials discovered three decades ago, have been developed and implemented in various applications at the laboratory scale. However, only a few studies have explored the fundamental mechanisms of their formation that determine their physical structure and chemical properties. Independent experimental and theoretical investigations focusing on chemical kinetics have provided some understanding of the mechanisms governing MOF formation. However, more effort is needed to fully control their formation pathways and properties to enhance stability, optimize performance, and design strategies for scalable production. This Perspective highlights current techniques for studying MOF kinetics, discusses their limitations, and proposes multimodal experimental and theoretical protocols, emphasizing how improved data acquisition and multiscale approaches can advance scalable applications. 

This study reports the cradle-to-wheel life cycle greenhouse gas (GHG) emissions resulting from enhanced oil recovery (EOR) using CO2 sourced from direct air capture (DAC). A Monte Carlo simulation model representing variability in technology, location, and supply chain is used to model the possible range of carbon intensities (CI) of oil produced through DAC-EOR. Crude oil produced through DAC-EOR is expected to have a CI of 449 tCO2/ mbbl. With 95% confidence, the CI is between 345 tCO2/mbbl to 553 tCO2/mbbl. Producing net-zero GHG emission oil through DAC-EOR is thus highly improbable. An example case of DAC-EOR in the U.S. Permian Basin shows that only in the unlikely instance of the most storage efficient sites using 100% renewable energy does DAC-EOR result in “carbon-negative” oil production. 

This review explores designing highly ion-conductive COFs for advanced electrochemical devices, merging theory and practice.