Design Rules for Fluorocarbon-Free Omniphobic Solvent Barriers in Paper-Based Devices.
The utility of hydrophobic wax barriers in paper-based lateral flow and multiwell devices for containment of aqueous solvents was extended to organic solvents and challenging aqueous surfactant solutions by preparation of a three layer barrier, consisting of internal pullulan impregnated paper barriers surrounded by external wax barriers. When paper impregnated with pullulan solution dries, the polymer forms solvent blocking lenses in the paper structure. Lens formation was illustrated by forming pullulan lenses in glass capillaries. The lens shapes were less curved compared to the predictions of a model based upon minimizing surface area. For barriers on Whatman # 1 filter paper, the pullulan molecular weight must be greater than ∼70 kDa, the mass fraction of pullulan in the barrier zone must be at least 32%, and there are restrictions on the minimum width of the pullulan impregnated zone.
Biointerfaces Institute, McMaster University , 1280 Main St W, Hamilton, Ontario L8S 4L8, Canada.|Department of Chemical Engineering, McMaster University , 1280 Main St W, Hamilton, Ontario L8S 4L7, Canada.
Sana
S
Jahanshahi-Anbuhi
Department of Chemical Engineering, McMaster University , 1280 Main St W, Hamilton, Ontario L8S 4L7, Canada.
Kevin
K
Pennings
Vincent
V
Leung
Biointerfaces Institute, McMaster University , 1280 Main St W, Hamilton, Ontario L8S 4L8, Canada.|Department of Chemistry and Chemical Biology, McMaster University , Hamilton, Ontario L8S 4L7, Canada.
Balamurali
B
Kannan
Biointerfaces Institute, McMaster University , 1280 Main St W, Hamilton, Ontario L8S 4L8, Canada.|Department of Chemistry and Chemical Biology, McMaster University , Hamilton, Ontario L8S 4L7, Canada.
John D
JD
Brennan
Biointerfaces Institute, McMaster University , 1280 Main St W, Hamilton, Ontario L8S 4L8, Canada.|Department of Chemical Engineering, McMaster University , 1280 Main St W, Hamilton, Ontario L8S 4L7, Canada.
Carlos D M
CD
Filipe
Biointerfaces Institute, McMaster University , 1280 Main St W, Hamilton, Ontario L8S 4L8, Canada.|Department of Chemical Engineering, McMaster University , 1280 Main St W, Hamilton, Ontario L8S 4L7, Canada.
Robert H
RH
Pelton
lateral flow devices; microfluidics; paper devices; porous media; pullulan; solvent barriers