Supporting Information Design Rules for Fluorocarbon-Free Omniphobic Solvent Barriers in Paper-Based Devices

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1 Supporting Information Design Rules for Fluorocarbon-Free Omniphobic Solvent Barriers in Paper-Based Devices Sana Jahanshahi-Anbuhi, a,b Kevin Pennings, b Vincent Leung, a,b Balamurali Kannan, a,c John D. Brennan a,c, Carlos D. M Filipe, a,b and Robert H. Pelton, a,b,* a Biointerfaces Institute, McMaster University, 1280 Main St W, Hamilton, ON, L8S 4L8, Canada b Department of Chemical Engineering, McMaster University, 1280 Main St W, Hamilton, ON L8S 4L7, Canada c Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Ontario L8S 4L7, Canada * Corresponding Author: peltonrh@mcmaster.ca S-1

2 Figure S1. Illustrating the visual inspection and air leak testing of pullulan lenses. Table S1. The influence of 9.09 %w/w 200 kda pullulan solution coverage on barrier performance when challenged with absolute methanol, acetone or 5% aqueous sodium dodecyl sulfate. Volume/Surface Area (ml/m 2 ) Barrier Performance S-2

3 Figure S2. (A) SEM surface images of plain filter paper (left hand side), and pullulan treated paper (right hand side). (B) Micrograph of the cross-section of an unmodified plain filter paper sample (left hand side) and a and pullulan treated paper sample (right hand side). The polymeric coating on the paper sample as well as blocked channels due to formation of lens like structures across the paper fiber is evidenced in comparison to the unmodified paper. S-

4 Table S2. Experimental results of varying the width of the printed pullulan barrier. The width refers to the gap between the double-lined wax borders after the heat treatment. The pullulan solution (10 %w/v) coverage on filter paper was 0.75 μl/mm 2 for each case. In each case, the barrier performance was examined by three different solvents of absolute ethanol, acetone and 5% SDS. Gap Width (mm) Barrier Performance S-4

5 Figure S. Graphical representation of barrier results on different Whatman paper grades. Success rate is calculated based on the fractional value obtained from triplicate trials where 1 is assigned to each success, and 0 to each failed barrier. Alternatively, we could use the Figure S4 below, which corrects by allowing for the thickness of the paper (1, 2 or ) into account. Thereby, on a volume basis, all three paper samples have nearly identical critical pullulan coverages to allow for a successful barrier. S-5

6 Success Rate Whatman #1 Whatman #2 Whatman # Normalized Pullulan Coverage (ul/mm 2 /mm) Figure S4. Different Whatman paper grades and barrier performance. Pullulan Molecular Weight. GPC traces and molecular weight for a series of lower molecular weight pullulan polymers were prepared by acid hydrolysis are given below, in Figure S5, and Table S. Figure S5. GPC traces S-6

7 Table S. Data extracted from GPC curves. Acid Hydrolysis Reaction Time Mn Mw MP PDI Start (min) End (min) 0 min min min min min min min min d d d d d S-7

8 Influence of Pullulan MW on Lens Formation. Lens formation was tested by slowly pipetting pullulan solution into an Adelphi and capillary tubes while the tube was held horizontally and rotated. This approach prevented the formation of bubbles. After allowing the lenses to dry under a fume hood in ambient conditions, they were tested with methanol. If the lenses had formed successfully, the solvent would not pass through to the bottom of the tube when added. From the above table, the cut-off time-point revealed to be between 240 minutes and 00 minutes, which are corresponded to 68 and 79 kda based on Table S. Table S4. Methanol blocking tests as functions of pullulan hydrolysis time (i.e. MW). Reaction Time Adelphi tube Capillary tube 0 min 15 min 0 min 60 min 120 min 180 min 240 min 00 min 1d 4d 5d 6d S-8

9 Figure S6. Contract angles as functions of drying time for 10% wt/wt, 200 kda pullulan drying on clean glass or cellulose S-9

10 Table of Variables for Calculation Part Symbol t n bw n ρ c ρ w ρ pn φ n Γ s m c D c Ɵ c p δ c ρ pull,dry k 1 k 2 ρ pull (c p ) R c V cap h L crit χ e Definition Thickness of paper (t 1 = Whatman #1, t 2 = Whatman #2, ) Basis weight of paper (bw 1 = Whatman #1, bw 2 = Whatman #2, ) Density of cellulose Density of water Density of paper (ρ p1 = Whatman #1, ρ p2 = Whatman #2, ) Pore volume of paper (φ 1 = Whatman #1, φ 2 = Whatman #2, ) Coverage required to fill pores. How much you have to print to fill pores with water. Total mass of cellulose in 1 m of paper. Diameter of smallest capturable particle Contact angle Concentration of pullulan Lens thickness Density of dry pullulan First Langmuir isotherm parameter for density of pullulan solution equation. Second Langmuir isotherm parameter for density of pullulan solution equation. Pullulan solution density as a function of pullulan concentration. Radius of curvature of spherical cap of pullulan lens. Volume of spherical cap of pullulan lens. Height of spherical cap of pullulan lens. Minimum length of plug in capillary to get lens formation. Mass fraction of pullulan in paper. S-10

11 Calculations for Design Rules for Fluorocarbon-Free Solvent Barriers in PaperBased Devices by Sana Jahanshahi-Anbuhi et-al Whatman 1 Properties: τ1 180 µm Thickness gm bw m Basis Weight kg ρc 1540 m Cellulose Density gm ρw ml Derived Properties bw1 kg = 48. ρp1 τ1 m Dry Paper Density ρp1 ϕ1 1 = ρc Pore volume 2 τ1 m ϕ1 µl Γs = Coverage required to fill pores. This is how much 2 2 m mm you have to print to fill pores with water kg total mass of cellulose in m paper mc ρc 1 ϕ1 = 48. m Matrices giving properties of Whatman µl Γe mm τe µm Whatman thickness of 1, 2,, and 4 filter paper 1 Experimental minimum coverage of pullulan solution at a concentration of cp, to block methanol flow bwe τe ϕe 1 = ρc Calculated total pore volume S-11 Non-Commercial Use Only gm bwe 187 m Dc µm 6 2 Diameters of smallest capturable particles

12 gm cp 1 11 gm Contact angle on glass (measured) θ 25 deg Pullulan Properties Assumed minimum thickness of lens δc 1 µm pullulan conc Modeling density vs pullulan mass fraction as a Langmuir adsorption isotherm shape. The inital slope comes from Nishinari Fig 1 and Table 1 Nishinari, et al. Macromolecules 1991, 24 Specific volume (20), 5590 gm ρpuldry 1.2 ml The density of dry films comes from our measurements slope of density vs mass 1 kg fraction in limit of c =0 k1 = ml m gm k1 ρpuldry ρw + density at cp =1 1 + k2 k1 k2 1 = ρpuldry ρw cp k1 ρpul cp ρw k2 cp gm ρpul (1) = 1.2 ml kg ρpul cp = m gm ρpul (0) = ml cc 0, Density of pullulan solutions g/ml gm ρpul (cc) ml cc Mass Fraction of Pullan in water 2 S-12 Non-Commercial Use Only

13 Pullulan Lens Formation in a capillary tube The goal of this model is estimate the volume of pullulan in a lens r Rc (r, θ) cos (θ) Radius of curvature of spherical cap Volume of cap Wolfram 1 Vcap (r, θ) π Rc (r, θ) 2 sin (θ) + sin (θ) h (r, θ) Rc (r, θ) (1 sin (θ)) height of cap 2 Vlens (r, θ, δ) π r (2 h (r, θ) + δ) 2 Vcap (r, θ) Vlens r, θ, δc 1 Lcrit r, θ, cp, δc 2 cp π r Volume of dry lens - divide by cp to get inital polymer solution volume Minimum length of plug in capillary to get lens Modeling our glass capillary experiments 1.2 Vlens mm, θ, δc 2 = µl cp δc = 1 µm cp = Lcrit mm, θ, cp, δc =.6468 mm 2 θ = 25 deg rr 0.1 µm, 0.2 µm 15 µm ⁵ ⁵ ⁵ ⁵ Lcrit rr, θ, cp, δc (m) ⁵ ⁵ This shows that Lcrit is a linear function of r ⁵ ⁵ ⁵ Lcrit is called Lmin in the paper ⁵ ⁶ 10 ⁶ ⁶ 6 10 ⁶ ⁶ 9 10 ⁶ ⁵ ⁵ ⁵ ⁵ rr (m) S-1 Non-Commercial Use Only

14 Experimental Pullulan Content for Blocking The goal is to convert experimental pullulan coverages to mass fractions in paper gm Γe ρpul cp cp = m Γe ρpul cp cp χe = Γe ρpul cp cp + bwe Converting lig vol/ area to pullulan mass/arear Corresponding mass fraction of pullulan in paper Calculating the minimum capillary length to for a lens in paper using the capture diameter given by Whatman as a measure of pore radius Γe cpe cp = τe ϕe calculating the effective polymer concentration. In fact we slowly added more polymer solution than needed to saturate the paper. Here we take the total mass of polymer and divide it by the pore volume to get an effective concentration 22.9 Dc µm Lcrit, 0 deg, cpe, δc = capillary lengths for experimental polymer concentrations using capture diameters S-14 Non-Commercial Use Only