TY - JOUR
T1 - Microfluidics with
T2 - In situ Raman spectroscopy for the characterization of non-polar/aqueous interfaces
AU - Pinho, Bruno
AU - Hartman, Ryan L.
N1 - Funding Information:
This material is based upon work supported by the National Science Foundation under Grant Number CBET-1550483. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation. The authors also gratefully acknowledge Dr. Chuntian Hu for his help early in the project by drawing masks of the semi-flow microsystems with AutoCAD.
PY - 2017/4
Y1 - 2017/4
N2 - The design of microfluidics with in situ Raman spectroscopy is reported in the present work for the investigation of immiscible non-polar/aqueous interactions. A dynamic aqueous phase in contact with a static hydrophobic phase (semi-flow) was engineered on-chip by performing a force balance, and it was validated using high-resolution in situ Raman spectroscopy. The semi-flow microfluidic device isolated non-polar solvents in a series of micro-reservoirs that communicated with aqueous laminar flows via molecular diffusion. As a consequence, the inspection of concentration and density profiles from the bulk-to-bulk of toluene-, diethyl ether-, and xylenes-water were made possible. The Schlieren pattern was observed for all solvent pairs, and the bulk-to-bulk region was characterized by water rarefaction (17.5 to 23.2 μm), mixing (3.4 to 6.4 μm), and hydrophobic shockwaves (34.9 to 38.8 μm). Understanding the position, thickness, and profiles of each zone revealed new insight on the chemistry at the interface, which could someday be used to validate molecular simulations, reduce the quantities of solvents wasted during separations/purifications of compounds, and improve kinetic models for mixed mass-transfer-reaction-rate-limited and mass-transfer-limited scenarios in continuous-flow processes.
AB - The design of microfluidics with in situ Raman spectroscopy is reported in the present work for the investigation of immiscible non-polar/aqueous interactions. A dynamic aqueous phase in contact with a static hydrophobic phase (semi-flow) was engineered on-chip by performing a force balance, and it was validated using high-resolution in situ Raman spectroscopy. The semi-flow microfluidic device isolated non-polar solvents in a series of micro-reservoirs that communicated with aqueous laminar flows via molecular diffusion. As a consequence, the inspection of concentration and density profiles from the bulk-to-bulk of toluene-, diethyl ether-, and xylenes-water were made possible. The Schlieren pattern was observed for all solvent pairs, and the bulk-to-bulk region was characterized by water rarefaction (17.5 to 23.2 μm), mixing (3.4 to 6.4 μm), and hydrophobic shockwaves (34.9 to 38.8 μm). Understanding the position, thickness, and profiles of each zone revealed new insight on the chemistry at the interface, which could someday be used to validate molecular simulations, reduce the quantities of solvents wasted during separations/purifications of compounds, and improve kinetic models for mixed mass-transfer-reaction-rate-limited and mass-transfer-limited scenarios in continuous-flow processes.
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U2 - 10.1039/c6re00177g
DO - 10.1039/c6re00177g
M3 - Article
AN - SCOPUS:85029373572
VL - 2
SP - 189
EP - 200
JO - Reaction Chemistry and Engineering
JF - Reaction Chemistry and Engineering
SN - 2058-9883
IS - 2
ER -