Capillary driven flow in wettability altered microchannel

Abstract

The capillary driven flow of water inside a microchannel with altered wettabilities is experimentally investigated and modeled theoretically. The surfaces of the PDMS made microchannel are exposed to oxygen plasma, rendering the surfaces increasingly hydrophilic, which provides the driving force for the flow. The plasma treated surfaces are characterized using topography and phase imaging of AFM scanning, as well as nano‐indentation, to correlate the distinct structural changes to the hydrodynamic profiles of the advancing meniscus. The experimental results are further analyzed using a newly proposed slip velocity model. The aim is to obtain a qualitative relationship between the surface properties and the flow parameters, namely the advancing meniscus velocity and pressure drop inside the channel. The insights are of fundamental importance in diverse fields, such as enhanced oil recovery, microfluidic devices, cell separation, and pathology. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4616–4627, 2017

Inner Surface Design of Functional Microchannels for Microscale Flow Control

“…Gogolides and co‐workers reported the preparation of microchannels with capillary filling performance by oxygen plasma etching, and further provided the microchannel with hydrophobic valving performance by C 4 F 8 plasma treatment . DasGupta and co‐workers functionalized the PDMS microchannels by oxygen plasma treatment . The functional microchannels were prepared by irreversible bonding of oxygen plasma treated PDMS mold and PDMS‐coated glass substrate.…”

Assessment of extended Derjaguin–Landau–Verwey–Overbeek‐based water film on multiphase transport behavior in shale microfractures

“…Understanding the multiphase transport process in microfractures or microchannels is crucial to predict production performance in shale gas reservoirs [1][2][3] as well as control fluid transport in microfluidic devices. 4,5 Gas shale is a complex sedimentary system that is considered to exhibit different storage space types 6,7 and complex fluid transport properties. 8,9 It is widely observed that not only confined nanopores but also microfractures extensively exist as shown in Figure 1, [10][11][12] which are often regarded as preferential transport pathways in shale gas reservoirs.…”

“…Understanding the multiphase transport process in microfractures or microchannels is crucial to predict production performance in shale gas reservoirs 1‐3 as well as control fluid transport in microfluidic devices 4,5 . Gas shale is a complex sedimentary system that is considered to exhibit different storage space types 6,7 and complex fluid transport properties 8,9 .…”