[
    {
        "id": 1,
        "chunk": "# Supporting Information for  \n\nDesign of Abrasion Resistant, Long-lasting Anti-Fog Coatings  \n\nBrian Macdonald1, Fan-Wei Wang2, Brian Tobelmann1, Jing Wang3, Jason Landini1, Nipuli   \nGunaratne2, Joseph Kovac4, Todd Miller5, Ravi Mosurkal5, Anish Tuteja1,2,6,7,\\*   \n1 Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI   \n48109, USA   \n2 Department of Chemical Engineering, University of Michigan, Ann Arbor 48109, MI, USA   \n3 Department of Mechanical Engineering University of Michigan, Ann Arbor, MI 48109, USA   \n4 Department of Aerospace Engineering, University of Michigan, Ann   \nArbor 48109, MI, USA   \n5Protection Materials Division, Soldier Protection Directorate, US Army DEVCOM Soldier   \nCenter, 15 General Greene Avenue, Natick, MA 01760   \n6 Department of Macromolecular Science and Engineering, University of Michigan, Ann   \nArbor, MI 48109, USA   \n7 Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, USA   \n\\*Corresponding author. Email: atuteja $@$ umich.edu  \n\nFourier Transform Infrared Spectroscopy (FTIR)  \n\nInfrared spectrum measurement was conducted by a Nicolet 6700 FTIR spectrometer (Thermo Scientific) with an ATR (diamond crystal) and a frequency range of $400{-}4{,}000\\ \\mathrm{cm^{-1}}$ . Antifog samples were coated on polycarbonate and analyzed as a function of UV time. To confirm the crosslinking of adjacent pyrrolidone groups within PVP and within the presence of $\\mathrm{H}_{2}\\mathrm{O}_{2}$ , the $\\scriptstyle{\\mathrm{C=O}}$ group was tracked for samples with varying UV time. Figure 1A demonstrates that a 10-minute UV time – the UV time utilized for our experiments – was sufficient to produce crosslinking of adjacent PVP. To investigate the self-reacting nature of the toughening agent, PETRA solutions were made to analyze the curing properties with a concentration of $0.090\\mathrm{g/ml}$ in a 0.091:0.900 mixture of $30\\%$ hydrogen peroxide and 1-Propanol. The PETRA solution was sprayed onto small polycarbonate strips ( $1/2\\mathrm{~x~}1$ inch) and cured under UV at varying times. Figure S1B displays a segment of an FTIR spectrum for pure PETRA on polycarbonate. The peak at $820\\mathrm{cm}^{-1}$ pertaining to acrylate functional groups shows a decrease with increasing UV time 1. This indicates that PETRA oligomers self-crosslink in the presence of hydrogen peroxide and UV irradiation. After 10 minutes, there is a notable decrease in the acrylate peak which indicates crosslinking, and the formation of a partial S-IPN.  \n\n![](images/77968d1458d4135fdc4ad8813e763c3be7bd120a20f9a5466c764a373fad9b13.jpg)  \nFigure S1. A) Change in $\\scriptstyle{\\mathrm{C=O}}$ bond for a PVP antifog coated polycarbonate as a function of UVC exposure time. B) Change in acrylate peak of pure PETRA coated polycarbonate with increasing UVC exposure  \n\nThe thin polymer strips were fabricated by developing a $0.053\\mathrm{g/ml}$ solution of PVP in 1-propanol, water, and $30\\%$ $\\mathrm{H}_{2}\\mathrm{O}_{2}$ with volume ratios of 0.931:0.029:0.040 respectively. PETRA/1-Propanol solutions were also developed and added to the PVP solution with a volume of 2ml. The PETRA/1- Propanol solutions varied depending on the desired mass ratio of PETRA/PVP. 5mL of the final PVP-based solutions was dispensed into a silicone mold with dimensions of $76.2\\mathrm{x}50.8\\mathrm{x}1.2\\mathrm{mm}$ and allowed to dry for 2 days. The dried film and mold were then placed under UVC for 30 minutes (to ensure that the strip was cured sufficiently). Once cured, the polymer sheet was cut to ${\\sim}7.5-$ 8mm widths and lengths of $\\sim76\\mathrm{mm}$ . The cut samples were immediately sandwiched between two glass plates and allowed to uniformly dry completely for ${>}10$ hours in relative humidity $<20\\%$ .",
        "category": " Materials and methods"
    },
    {
        "id": 2,
        "chunk": "# Dynamic Mechanical Analysis (DMA)  \n\nAn RSA-G2 DMA (TA Instruments) was utilized to conduct tensile tests on PVP and PVP/PETRA thin strips. Each sample was secured with untextured flat grips, with a spacing of $35\\mathrm{mm}$ . A strain rate of $0.035\\upmu\\mathrm{m}/\\mathrm{s}$ was used for each sample. The relative humidity of the testing room was maintained at $20\\text{\\textperthousand}$ .",
        "category": " Materials and methods"
    },
    {
        "id": 3,
        "chunk": "# Hansen Solubility Parameters:  \n\nHansen solubility parameters were measured by dissolving a small amount (3-5 drops) of surfactant into $10\\mathrm{ml}$ of solvent. The solvents consisted of DI water, Methanol (Fisher Scientific), Ethanol (Fisher Scientific), 1-Propanol (Fisher Scientific), 2-Propanol (Fisher Scientific), Dimethyl Formamide (Fisher Scientific), 1-Hexanol (Sigma-Aldrich), Dimethyl Sulfoxide (Fisher Scientific), Ethyl Acetate (Sigma-Aldrich), Toluene (Fisher Scientific), Benzene (Fisher Scientific), Cyclohexane (Acros Organics), Decane (Sigma-Aldrich), Pentane (Fisher Scientific), n-Heptane (Acros Organics), O-Xylene (Acros Organics), Perfluorohexane (Alfa Aesar), Formamide (Sigma-Aldrich), Acetonitrile (Fisher Scientific), Acetic Acid, (Fisher Scientific) Propylene Carbonate (Alfa Aesar), Methyl Acetate (Acros Organics), Chloroform (Fisher Scientific), and $30\\%$ Hydrogen Peroxide (Fisher Scientific). Once added to the solvent, the solutions were mixed briefly in a vortexer (Vortex-Genie 2 - Scientific Industries, Inc). The solutions were visually inspected to determine their solubility within each solvent and noted. The data (either miscible or immiscible) was plugged into the HSPiP version 5.3.09 and Hansen solubility parameters and sphere radii were generated. The results are listed in Table S1.  \n\nTable S1. Hansen solubility parameters calculated by HSPiP software. \\*PVP parameters were taken from the HSPiP database.   \n\n\n<html><body><table><tr><td></td><td>8D</td><td>8P</td><td>8H</td><td>R</td></tr><tr><td>PS20</td><td>17.06 ±1.4</td><td>7.93 ±1.2</td><td>19.3 ±0.7</td><td>18.9</td></tr><tr><td>PS80</td><td>16.76 ±0.65</td><td>7.81 ±1.25</td><td>19.22 ±0.65</td><td>18.9</td></tr><tr><td>PS85</td><td>13.57 ±0.65</td><td>3.64 ±1.25</td><td>14.17 ±0.95</td><td>15.7</td></tr><tr><td>SPAN20</td><td>13.15 ±2.6</td><td>0.10 ±1.35</td><td>12.6 ±1.35</td><td>14.6</td></tr><tr><td>SPAN80</td><td>13.67 ±1.8</td><td>0.09 ±2.35</td><td>9.64 ±1.2</td><td>11.7</td></tr><tr><td>PVP*</td><td>18.1</td><td>10</td><td>18</td><td>8</td></tr></table></body></html>  \n\nTable S2. Select Surfactants and corresponding HLB values and $\\mathbf{S}^{*}$ values.   \n\n\n<html><body><table><tr><td>Slip Additive</td><td>Hydrophilic- Lipophilic Balance (HLB)</td><td>Miscibility Parameter (S*)</td></tr><tr><td>PS20</td><td>16.7</td><td>-0.515</td></tr><tr><td>PS80</td><td>15.0</td><td>-0.504</td></tr><tr><td>PS85</td><td>11.0</td><td>0.062</td></tr><tr><td>SPAN20</td><td>8.6</td><td>0.357</td></tr><tr><td>SPAN80</td><td>4.3</td><td>0.506</td></tr></table></body></html>",
        "category": " Materials and methods"
    },
    {
        "id": 4,
        "chunk": "# Friction Coefficient  \n\nThe steady-state dynamic friction coefficient was measured with a Shimpo model FG-7005 force gauge. The force gauge was attached horizontally to a motorized stage which traveled at a controlled velocity of $74~{\\upmu\\mathrm{m/s}}$ . An aluminum block with dimensions of $44\\mathrm{x}50\\mathrm{x}24\\mathrm{mm}$ and with a standard nonwoven cleanroom wipe (Texwipe TX606) adhered to the $44\\mathrm{x}24\\mathrm{mm}$ face was pushed across each surface with the force gauge. The substrates were secured onto a level adjacent stage statically with double-sided tape. Force data was taken every 0.2 seconds and was pushed for 60 seconds. Table S3 displays the average dynamic friction coefficients for the plateaued regions.  \n\nTable S3. Average steady-state friction coefficients of polycarbonate and antifog coated polycarbonate.   \n\n\n<html><body><table><tr><td>Surface</td><td>Average Coefficient</td><td>Friction</td></tr><tr><td>Polycarbonate</td><td>0.522</td><td></td></tr><tr><td>PVP</td><td>0.598</td><td></td></tr><tr><td>PVP/20%PETRA</td><td>0.599</td><td></td></tr><tr><td>15% SPAN80</td><td>0.139</td><td></td></tr><tr><td>15% SPAN20</td><td>0.152</td><td></td></tr><tr><td>15% PS85</td><td>0.171</td><td></td></tr><tr><td>15% PS80</td><td>0.196</td><td></td></tr><tr><td>15% PS20</td><td>0.167</td><td></td></tr></table></body></html>",
        "category": " Materials and methods"
    },
    {
        "id": 5,
        "chunk": "# Abrasion Testing  \n\nWe utilized the Taber abrader to conduct the ASTM D4060 tests which evaluates the durability and wear resistance of organic coatings. This test has been shown to correlate very well with the long-term durability of organic coatings and paints, and has been widely utilized to be able to predict the long-term performance of different organic coatings since the 1930s. Additionally, the wearing action of the abrader typically pulls the coating away from the surface during the abrasion cycles. Thus, the adhesion to the substrate can be a significant contributor (and therefore an indirect measure) to the overall wear resistance of a given coating. All substrates were abrasion tested with a Taber Linear abrader Model 5750 with a stroke length of 1 inch and frequency of 60 cycles/minute. $32\\mathrm{x}32\\ \\mathrm{mm}$ samples were abraded with a stroke length of 0.5 inches. A CS-5 abrasion tip was used for each test and was purchased from the Taber manufacturer. Between each test, the CS-5 was washed with IPA to remove potential debris or surfactant. The number of cycles varied between ${\\sim}10$ and 8000 depending on the tests. The weight varied between $300\\mathrm{g}$ and $1050\\mathrm{g}$ .  \n\n![](images/aa569f36877a849aef522f81c2b069dcd4c2b4535440324828149a5f562f1053.jpg)  \nFigure S2. Linear Tabor abrasion setup for antifog coated polycarbonate and the SEM image of the microstructure of the CS-5 felt tip abrasion tip.",
        "category": " Materials and methods"
    },
    {
        "id": 6,
        "chunk": "# Controlled Wiping Simulation  \n\nTo be able to uniformly abrade a large sample surface, and thereby evaluate the impact of normal, everyday wiping on the developed coatings antifog performance, we modified the Taber abrader to include a common microfiber lens wipe which was attached to a 1” x 1” block of soft foam and mounted to the raster arm of the abrader. The samples were mounted to the apparatus in the same fashion as prior and wiped with the custom lens wipe fixture with a stroke length of 1 inch and frequency of 60 cycles/min. For 32x32 mm samples, 1-inch polycarbonate spacers were placed on either side of the sample to allow full range of motion of the raster arm.  \n\nTable S4. List of experiments demonstrating material and additive effects on sequential abrasion resistance to CS-5 Tabor Abrasion under increasing mass. A $\\checkmark$ indicates the absence of visible abrasion after abrasion cycles and $\\cdot$ indicates the presence of obvious abrasion. Each cycle was done in succession per sample.   \n\n\n<html><body><table><tr><td>PVP</td><td>Composition Coating</td><td colspan=\"7\">Abrasion Cycle and Qualitative Result</td></tr><tr><td>%PETRA</td><td>Slip Additive</td><td>5000 (300g)</td><td>Cycles</td><td>1000 (550g)</td><td>Cycles</td><td>1000 (800g)</td><td>Cycles</td><td>1000 (1050g)</td><td>Cycles</td></tr><tr><td></td><td>10% PS80</td><td>×</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>0%</td><td>15% PS80</td><td>√</td><td></td><td></td><td></td><td>X</td><td></td><td>×</td><td></td></tr><tr><td></td><td>20% PS80</td><td>√</td><td></td><td>√</td><td></td><td></td><td></td><td>×</td><td></td></tr><tr><td></td><td>10% PS80</td><td>×</td><td></td><td></td><td></td><td>X</td><td></td><td></td><td></td></tr><tr><td>10%</td><td>15% PS80</td><td></td><td></td><td>√</td><td></td><td></td><td></td><td></td><td></td></tr><tr><td></td><td>20% PS80</td><td>?</td><td></td><td>√</td><td></td><td></td><td></td><td>√</td><td></td></tr><tr><td></td><td>10% PS80</td><td></td><td></td><td></td><td></td><td>X</td><td></td><td></td><td></td></tr><tr><td>15%</td><td>15% PS80</td><td></td><td></td><td>√</td><td></td><td>√</td><td></td><td>√</td><td></td></tr><tr><td></td><td>20% PS80</td><td></td><td></td><td>√</td><td></td><td>√</td><td></td><td>√</td><td></td></tr><tr><td></td><td>10% PS80</td><td>√</td><td></td><td>√</td><td></td><td>√</td><td></td><td>√</td><td></td></tr><tr><td>20%</td><td>15% PS80</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td></td><td>20% PS80</td><td>√</td><td></td><td>√</td><td></td><td>√</td><td></td><td>√</td><td></td></tr><tr><td></td><td>10% PS20</td><td>?</td><td></td><td>√</td><td></td><td>√</td><td></td><td>√</td><td></td></tr><tr><td>20%</td><td>15% PS20</td><td>√</td><td></td><td>√</td><td></td><td>√</td><td></td><td></td><td></td></tr><tr><td></td><td>20% PS20</td><td>√</td><td></td><td>√</td><td></td><td>√</td><td></td><td>√</td><td></td></tr><tr><td></td><td>10% SPAN80</td><td>√</td><td></td><td>√</td><td></td><td>√</td><td></td><td>√</td><td></td></tr><tr><td>20%</td><td>15% SPAN80</td><td></td><td></td><td>√</td><td></td><td>√</td><td></td><td>√</td><td></td></tr><tr><td></td><td>20% SPAN80</td><td>√</td><td></td><td>√</td><td></td><td>√</td><td></td><td>√</td><td></td></tr><tr><td>20%</td><td>15% SPAN20</td><td>√</td><td></td><td>√</td><td></td><td>√</td><td></td><td>√</td><td></td></tr><tr><td>20%</td><td>15% PS85</td><td>√</td><td></td><td>√</td><td></td><td>√</td><td></td><td></td><td></td></tr></table></body></html>  \n\n![](images/c3a0874f2083309e18e8a04aadf5f8ed3a0af86f89a6b75da7d27093413908c4.jpg)",
        "category": " Materials and methods"
    },
    {
        "id": 7,
        "chunk": "# Scanning Electron Microscopy  \n\nScanning electron micrographs were obtained with a Tescan MIRA3 FEGSEM. A beam intensity of 7, an accelerating voltage of $7\\mathrm{kV}$ , and a working distance between 9-11mm were used for each micrograph.",
        "category": " Materials and methods"
    },
    {
        "id": 8,
        "chunk": "# Linear Stylus Profilometry  \n\nSurface roughness was measured via a Dektak 6M stylus profilometer. A 5mg stylus force, a segment length of $2000\\upmu\\mathrm{m}$ , and a raster time of 120 seconds were used for each measurement. At least 4 spatially separated segments were measured for each sample (abraded and unabraded).",
        "category": " Materials and methods"
    },
    {
        "id": 9,
        "chunk": "# Homemade Fog Tester  \n\nExperimental structure for fogging tests  \n\nExperiments were conducted in a stainless-steel chamber (Figure S3A) with an observation window (the outer diameter of 6 inches and the inner diameter of 4 inches) (Figure S3B). The coated polycarbonate plates $35\\mathrm{mm}\\times35\\mathrm{mm}\\times1\\mathrm{mm}$ ) (Figure S3C) were held with a cylindrical glass (a diameter of 1.5 inches and a height of 0.5 inches) (Figure S3D) and an aluminum plate $(32\\mathrm{mm}\\mathrm{x}32\\mathrm{mm}$ , with text design) (Figure S3E) by a holder (Figure S3F) with a square Teflon window (the inner dimension of $25~\\mathrm{mm}$ and outer dimension of $47~\\mathrm{mm}$ ) fixed on the cooling platform with screws. The aluminum plates were mounted onto a copper pillar $20\\mathrm{mm}\\times20\\mathrm{mm}$ ) (Figure S3G) using fast-drying silver paint (Ted Pella, Inc., USA). Liquid cooling channels (Figure S3H) were built into the opposite end of the copper pillar with ethylene glycol (Arcos Organics, USA) pumped through by an MS immersion thermostat (Lauda, Germany) and cooled by $1/2\\mathrm{HP}$ glycol chiller (Penguin Chillers, USA). The temperature is controlled by the circulator in a precision of $\\pm0.1^{\\circ}\\mathrm{C}$ . The entire portion of copper was insulated from the environment with a Teflon enclosure (a diameter of $11.5~\\mathrm{cm}$ ) (Figure S3I) and was mounted to the test chamber. A type-T thermocouple (OMEGATM, USA) was used to measure the temperature of the sample surface. A temperature/humidity gauge iTHX-W3-2 (OMEGATM, USA) (Figure S3J) was mounted on the top of the chamber to obtain the humidity/temperature readings. A self-made humidity-controlled box (Figure S3K) was linked to the top of the chamber to blow humid air into the chamber. The other side of the box was connected to an air supply with an adjustable valve. The dry air from the air supply was blown to the box which stores water to gain humidity and then to the chamber to control the humidity. The air went out of the chamber through the air outlet (Figure S3L) at the bottom of the chamber.  \n\n![](images/11d93e9ac33e71a93c555fe246ef6e7fb38c7add1f0146dd2f4b40711288aa09.jpg)  \nFigure S3. A schematic diagram of the test chamber.  \n\nExperimental setup for fogging test  \n\nThe circulator was first held at the temperature of $40.0{\\pm}0.1\\ ^{\\circ}\\mathrm{C}$ to control the surface temperature of the sample at $28{\\pm}1~^{\\circ}\\mathrm{C}$ to prevent any fogging before the test. After the humidity was controlled at $65\\pm1\\ \\%$ relative humidity and the temperature was $22{\\pm}2\\ ^{\\circ}\\mathrm{C}$ , the target value of the circulator was changed to $5.0{\\pm}0.1~^{\\circ}\\mathrm{C}$ (surface temperature of the sample would be $14{\\pm}0.5\\ ^{\\circ}\\mathrm{C}$ ) and the experiment started. The fogging evolution on the sample was captured by a single-lens camera D3200 (Nikon, Japan) with a $150\\ \\mathrm{mm}\\ \\mathrm{f}/2.8$ Macro 1:1 lens (Irix, Switzerland) and a $28~\\mathrm{mm}$ long spacer (Photo Plus, USA) at the rate of 1 frame per minute controlled by RC-N2II ShutterBoss II timer remote switch (Vello, USA) with a light source VM-160 LED macro ring light (Bolt, USA). The experiment duration was 45 min for normal fogging tests and 20 min for the cyclic fogging test (15 cycles in total).  The detailed humidity and temperature changes during the experiment are listed in the supplemental materials. A reference image was placed behind the substrate, and between them, a 1-inch glass spacer to enhance the effect of image distortion from a fog. Images were captured every minute, for 40 minutes. The reference image provides the ability to visually display fogging properties over time and is used to measure image distortion caused by fogging. Image distortion was analyzed with an open-source ImageJ plugin utilized and developed by Lee et al 2.  \n\nHumidity and temperature change during the experiments  \n\nThe humidity and temperature change are shown in Figure S4. The humidity changed from $65{\\pm}1$ $\\%$ to $54\\pm1\\%$ and stayed stable from about 10 minutes after the experiments began. The sampleto-sample variation of different test samples and different coatings is within $1\\%$ , showing the consistency of the experimental manipulation. On the other hand, the temperature changed from  \n\n$29^{\\circ}\\mathrm{C}$ to $14~^{\\circ}\\mathrm{C}$ and maintained stable from about 10 minutes, which is similar to the trend of the humidity. Near 10 minutes, the temperature became lower than $15^{\\circ}\\mathrm{C}$ which is estimated to be near the dew point of the system (estimated under the condition of $65\\%$ relative humidity and $22^{\\circ}\\mathrm{C}$ temperature), leading to the beginning of the fogging which can be observed from the experiments.  \n\n![](images/19f63477a5e98f0ae2000f63c71b1e0ac8a51e7b9a8daf3236058ffc23daddc2.jpg)  \nFigure S4.  The humidity and temperature evolution during the experiments. The red cross denotes the temperature corresponding to the secondary y-axis. The hollow orange triangle, the hollow grey diamond, and the hollow yellow circle respectively denote the humidity records during the fogging tests of PS 85 coating, SPAN 20 coating, and PVP coating. All the error bars are obtained from the standard deviations from triplet trials.",
        "category": " Materials and methods"
    },
    {
        "id": 10,
        "chunk": "# Fog Tester developed at the US Army Soldier Center, Natick, MA  \n\nThe fog tester consisted of an environmentally controlled chamber, a head form and a radiator disposed within the chamber.  The radiator was connected to a liquid cooling system.  A humidifier device was configured to deliver a flow of warm moist air towards the frontal portion of the head form, and the surface of the eyewear. A camera within the head form aligned with an eye position opening was configured to detect a target image within the chamber while the flow of warm moist air is delivered. A processor was configured to calculate a contrast difference between the background of the target image detected by the camera and the resolution bars of the target image detected by the camera. The final pass/fail criteria for anti-fog substrates or eyewear were determined based on the contrast ratio data equal to less than $7\\%$ Haze.  \n\nIn a typical fog testing experiment, the sample glass plate or eyewear was inserted into the enclosure via iris ports or open top of the environmental chamber as required. The humidifier system was turned on for 15 minutes or until the eyewear equilibrated to the humid conditions. The sample plate was placed in front of the eye of the head form with a clamp and the angle. The tilt angle was adjusted until the full field view of the camera image readout was obtained. The test time was fixed to 60 seconds (at 2 frames per second record rate) and the data was collected.  The measurement was repeated two more times, waiting for 5 minutes in between the tests.",
        "category": " Materials and methods"
    },
    {
        "id": 11,
        "chunk": "# UV-Vis Optical Properties  \n\nTransmittance and transmission haze were measured with a Shimadzu UV-2600. Transmittance haze is the fraction of light scattered when the incident light passes through a transparent material and describes the optical clarity of a material 3. Experimentally, haze was measured by the total transmittance of the sample $\\mathrm{(T_{s})}$ and the diffusion rate of both the sample $\\mathrm{(DT_{s})}$ ) as well as the instrument $(\\mathrm{DT_{ins}})$ ) using a UV-vis spectrophotometer equipped with an integrating sphere. The haze percentage was calculated by the following equation:  \n\n$$\n\\%\\mathrm{{Haze}=(}D T_{\\mathrm{{s}}}-D T_{\\mathrm{{ins}}})/T_{\\mathrm{{s}}}\\times100\\%\n$$  \n\nComparison to Commercial Antifog Solutions Optix 55 (Purchased from Amazon), Revision Military Anti-Fog Cloth (Purchased from Amazon), and Gear Aid McNett Tactical OP Drops (Purchased from Amazon) temporary antifog solutions were all applied to the substrates using the directions indicated by the manufacturers. The Exxene HCF-100 Anti-Fog Coating formulation (Donated by Exxene Corporation) was applied to the substrates via flow coating method and cured on a $110^{\\circ}\\mathrm{C}$ hotplate for 1 hour.  \n\n![](images/2b38d29a19bb2c91ec86a6ce31828c2ec147b2e23c12b275f53e58bdc6683258.jpg)  \nFigure S5. Static water contact angles for different commercial antifog coatings, as well as the optimal PS20 coating developed in our work.  \n\nFigure S5 shows the static water contact angle for the different commercial coatings and treatments tested in our work, as well as the optimal PS 20 coating. The temporary antifog solutions (Optix and Ops Drops) yielded low contact angles due to their hydrophilic properties and high degrees of freedom when compared to crosslinked coatings. Exxene yielded relatively high contact angles but offered time-dependent absorbing capabilities over the course of 5 minutes. Unlike  \n\nExxeene, the contact angle of our PS20 durable antifog coating yielded comparatively low contact angle values.  \n\n![](images/c9acf01f6f5934a2a1a2d50bf9d528757ebcfad20a0fd9422261fbe50684ea50.jpg)  \nFigure S6. Change in roughness of commercial antifog formulations and, polycarbonate (PC), and the PS20 antifog coating after 8000 CS-5 abrasion cycles.  \n\nFigure S6 demonstrates that the temporary coatings did not yield significant wear resistance, but did perform better than bare polycarbonate. This finding agrees well with the durability data of surfactant additive antifog coatings. Since the temporary agents exist as free antifogging macromolecules on the surface, they impart a lubricating or slip effect and therefore a degree of wear resistance. However, unlike our coating which contains embedded surfactant within the film network, these ephemeral antifog solutions can only offer wear resistance for a short duration and can be easily removed mechanically. Exxene does not contain any additive, but is characteristically durable as polyurethane and therefore proved to be highly wear-resistant. However, the wear resistance inherently compromised the performance of antifogging.  \n\nA.  \n\n![](images/64d6de6de3f497ea784408c1c49e44136bcdab2f0a68210b0855aa404f510902.jpg)  \n\nC.  \n\n![](images/0b0b305e1eea8215590d59397c0c749bdcd35035a4ed6e06854ab3871c6683c4.jpg)  \nFigure S7. Longevity of static water contact angle performance with extended exposure time to normal environmental conditions. Contact angle at A) time $=0$ min, B) time $=1~\\mathrm{min}$ , and C) time $=5\\mathrm{min}$ .  \n\nThe comparative performance longevity of each antifog formulation was assessed by monitoring the contact angle of each week. The samples were kept in open-air normal laboratory conditions between sampling and like previous contact angle measurements, time-series contact angle data were taken to observe the absorbency of the coatings. As shown in Figures 5 and 7, the contact angle for the crosslinked polymer coatings (PVP, PS20, Exxene) decreases notably with time, indicating the absorption of water. Plasma-treated polycarbonate and Optix do not show considerable contact angle change over the course of 5 minutes (contact angle change here is due to evaporation and pinning of the contact line). Over the course of 5 weeks, increases in contact angles due to ambient air contamination increase the contact angle for all coating except the PS20 durable antifog coating. This is particularly true for the Optix antifog coating being that it exists as a thin layer of hydrophilic molecules. The crosslinked PVP and Exxene coatings also yield increases in contact angle, owing to contamination. The PS20 coating being both crosslinked and imbibed with hydrophilic slip additive allows for significant enhancements in hydrophilic longevity.",
        "category": " Results and discussion"
    },
    {
        "id": 12,
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        "category": " References"
    }
]