Portable, Droplet-Based Microfluidic Device for Aqueous-Two-Phaseextractions and Colorimetric Detection of Cadmium
Loading...
Authors
Hermann, Matthias
Date
Type
thesis
Language
eng
Keyword
Digital Microfluidics , Microfluidics , Superhydrophobic , Droplet Array , 3D-Printing , Droplet Splitting , Aqueous-Two-Phase-System , Aqueous-Two-Phase-Extraction , ATPS , ATPE , Cadmium , Extraction , Colorimetry , Smartphone , Surface Energy Trap , Spin Coating , Air Plasma , Laser Micromachining , Memory Foam
Alternative Title
Abstract
A portable, digital-microfluidic device for aqueous-two-phase-based extractions is presented. Droplets (50 µL) consist of an aqueous-two-phase-system (sodium sulfate and polyethylene glycol) and an extractant (potassium iodide) to move Cd2+ ions selectively from a mixture of metal ions into the polyethylene glycol top phase.
The droplets are confined by hydrophilic surface energy traps on a superhydrophobic substrate that is made of a commercially available coating (Ultra-EverDry™). Surface energy traps are generated by exposing specific regions of the surface to air plasma or by laser micro-machining, where a portion of the superhydrophobic coating is ablated and the hydrophilic glass underneath is exposed. A 3D-printed holder applies another surface energy trap on top of the droplet and
lifts it. This allows one to precisely separate different volumes (0.19-14.91 µL) of the polyethylene glycol top phase depending on the surface energy trap size.
Subsequent addition of an indicator dye to a separated aliquot of the top phase allows interference free, colorimetric detection of Cd2+ ions with a smartphone camera.
Description
Citation
Publisher
License
Queen's University's Thesis/Dissertation Non-Exclusive License for Deposit to QSpace and Library and Archives Canada
ProQuest PhD and Master's Theses International Dissemination Agreement
Intellectual Property Guidelines at Queen's University
Copying and Preserving Your Thesis
This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.
ProQuest PhD and Master's Theses International Dissemination Agreement
Intellectual Property Guidelines at Queen's University
Copying and Preserving Your Thesis
This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.