[
    {
        "id": 1,
        "chunk": "# Preparation of antifog and antibacterial coatings by photopolymerization  \n\nRuifen Tanga, Atif Muhammadb, Jinliang Yanga and Jun Niea\\*  \n\nThis paper contains a kind of ultraviolet-cured antifogging and antibacterial coating. A quaternary ammonium salt (14QAS), which was synthesized in this paper, has been implemented as a monomer. The chemical structure of 14QAS has been confirmed by Fourier transform infrared spectroscopy and nuclear magnetic resonance. The nitrogen atom on the surface of the coatings with 14QAS was observed by X-ray photoelectron spectroscopy. The Surface wettability of the polymer film was studied by contact angle analysis, which confirmed the hydrophilicity of the coatings with low water contact angle $(\\sim25^{\\circ})$ . The antifog properties were evaluated under different conditions. The antibacterial activity of coatings with 14QAS reached $99.9\\%$ against S. aureus and E. coli. Copyright $\\mathfrak{O}$ 2014 John Wiley & Sons, Ltd.  \n\nKeywords: antifog; antibacterial; coating; photopolymerization; QAS",
        "category": " Results and discussion"
    },
    {
        "id": 2,
        "chunk": "# INTRODUCTION  \n\nNigh to dew point, water vapors condense into microscopic droplets to ensue fogging. Although fog itself is harmless, it can cause serious problems in transparent solid materials (such as optical devices, agricultural transparent plastic films, and translucent panels of solar cells) due to transparency and visibility drop.  \n\nTo avoid fogging phenomenon on transparent materials, several methods have been explored during the past decades. Among them, heating the materials, improving the air velocity, and using antifog coatings are very common. Heating could keep the temperature of materials higher than the dew point, to prevent condensation of water vapor, but it consumes lots of energy that cannot be ignored. Likewise, improving air velocity causes humidity fall at material surface that enhances water evaporation, but this method also consumes too much energy. Thus, antifogging coatings are most interesting due to their lesser energy cost and easily manageable nature.  \n\nAmong these coatings, superhydrophilic or superhydrophobic surfaces[1–5] had attracted a lot of attention, as they can spread water droplets flat or made them roll down from the surface. The disappearance of the droplets made these two kinds of coatings to be excellent antifog surfaces. Otherwise, these surfaces that often contain nanoparticles (such as ${\\mathsf{T i O}}_{2},$ $\\mathsf{S i O}_{2},$ and carbon nanotubes) will cause poor mechanical stability, short lifetimes, and the residual water film on the surface. Moreover, complicated procedure and higher cost are also major restrictions.  \n\nNow, day’s commercial coatings use surfactants, which reduce surface tension of water. So, the droplets wet the surface easily, and the antifog property is obtained. However, this kind of antifog coating cannot maintain its property for a long time due to surfactant discharge with condensed water. Researchers tried to increase lifetime of these coatings, and as a consequence, durable antifog coatings had been reported; e.g. Laura Introzzi[6] presented a new antifog coating made of pullulan for packaging applications. Nurxat Nurraje[7] demonstrated that hydrophilic polysaccharides such as chitosan, alginate, hyaluronic acid, and carboxymethyl cellulose could be used to produce long-lasting antifog coatings via layer-by-layer assembly technique. However, fixing the surfactants in the coatings is another way to produce long-lasting antifog coatings.  \n\nQuaternary ammonium salt (QAS) have been known and widely used for more than half a century to control microbial growth for a variety of applications such as biomedical devices, fabric treatment, hair rinses, and food products.[8] Surfaces coated with QAS-containing polymers have been shown to be very effective in killing a wide range of microorganisms such as Gram-positive and Gram-negative bacteria, yeasts, and molds.[9–11] Furthermore, QAS was also a kind of surfactant, and QAS-containing polymers may also have antifogging behavior.  \n\nIn this paper, a QAS (14QAS), which was synthesized in our lab, was used in the ultraviolet-cured antifog coatings. The results indicated that 14QAS could be preserved in the coatings to create long-time antifog. Moreover, an interesting pheromone was found in this study: the antibacterial property was also found in the cured coating films. Consequently, these coatings have a wide range of applications in daily life, such as bathroom mirrors, vehicle windscreens, room windows, children’s toys, and medical devices.",
        "category": " Introduction"
    },
    {
        "id": 3,
        "chunk": "# EXPERIMENTAL",
        "category": " Materials and methods"
    },
    {
        "id": 4,
        "chunk": "# Materials  \n\nDimethylaminoethyl methacrylate (DMAEMA), 1-bromotetradecane (BTD), hydroxyethyl acrylate (HEA), and tetrahydrofuran were purchased from Sinopharm Group Chemical Reagent (Beijing, China). Poly (ethylene glycol) diacrylate 600 (PEGDA 600) and polyurethane  \n\n\\* Correspondence to: Jun Nie, State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China. E-mail: niejun@mail.buct.edu.cn   \na R. Tang, J. Yang, J. Nie State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China   \nb A. Muhammad Department of Applied Sciences and Technology, Politecnico di Torino, Corso duca degli Abruzzi-24, Torino-10124, Italy  \n\nacrylate (CN929) were given by Sartomer Company (Warrington, PA, USA) as a gift. 2-hydroxy-2-methylpropiophenone (1173) was obtained from Changzhou Runtec Chemical. The leveling agents were donated by BYK Additives & Instruments (Wesel, Germany).",
        "category": " Materials and methods"
    },
    {
        "id": 5,
        "chunk": "# Synthesis  \n\nThe synthesis route of 14QAS was list in Scheme 1.",
        "category": " Materials and methods"
    },
    {
        "id": 6,
        "chunk": "# Synthesis of 14QAS  \n\nDimethylaminoethyl methacrylate $\\beta1.49,\\ 0.25\\$ , BTD $(55.49,$ $0.2\\mathsf{m o l}.$ ), and tetrahydrofuran $(30\\mathsf{m}\\mathsf{l})$ were added into a $250\\mathrm{ml}$ three-neck round-bottomed flask equipped with condensator, desiccator, and mechanical stirrer. The mixture was stirred at $37^{\\circ}\\mathsf{C}$ for $24\\mathsf{h r}$ .  \n\nAfter the reaction, unreacted BTD and DMAEMA were removed by repeated washing for $1{-}2\\mathsf{m i n}$ with $5\\mathrm{-}7\\mathsf{m}|$ ether aliquots, discarding the ether supernatant after each wash. Residual ether was removed via gentle nitrogen stream, and the final product was dried for $24\\mathsf{h r}$ under vacuum in the dark. The yield of 14QAS under $37^{\\circ}\\mathsf{C}$ could be $33.7\\%$ .",
        "category": " Materials and methods"
    },
    {
        "id": 7,
        "chunk": "# Preparation of the antifog coatings  \n\nFirstly, 14QAS and 1173 were dissolved in HEA and then mixed with PEGDA 600, CN929, and leveling agent. Secondly, the wire bar coater $(20\\upmu\\mathsf{m})$ was used to prepare the film on glass slides and irradiated for 3 min with a medium-pressure mercury lamp. The light intensity was detected by an ultraviolet light radiometer (Beijing Normal University, China), and the value was $20\\mathsf{m w/c m}^{2}$ .",
        "category": " Materials and methods"
    },
    {
        "id": 8,
        "chunk": "# Characterization  \n\nThe $^1\\mathsf{H}$ nuclear magnetic resonance (NMR) spectra were carried out on a 400 MHz NMR instrument (Bruker Corporation, Germany) at $298\\mathsf{K}$ with $C D C\\mathsf{I}_{3}$ as solvent and TMS as internal standard.  \n\nThe IR spectra were measure on a Fourier transform infrared spectroscopy 5700 (Thermo Electro Corporation, Waltham, MA).  \n\nThe XPS spectra of the coatings were obtained by using a VG ESCALAB MKII X-ray photoelectron spectrometer (VG Scientific Ltd., UK) with Al $\\mathsf{K}a$ radiation to find out if there was any nitrogen atom on the surface of them. Survey spectra were recorded for $0{\\mathrm{-}}1350{\\mathrm{eV}}$ binding energy range.  \n\nContact angle (CA) was obtained with a VCA Optima CA measuring instrument (AST products, Inc.) with a drop size $1.0\\upmu\\up L$ of deionized water. Four samples of each formulation were prepared for this test. Four measurements were made on each sample. The final CA of each coating according to its own formulation was the average of its own data.",
        "category": " Materials and methods"
    },
    {
        "id": 9,
        "chunk": "# Antifog tests  \n\nAntifog properties were evaluated by simulating real conditions of fogged materials: (a) hot-fog test, (b) cold-fog test, and (c) aspiration test.[7] In hot-fog test, the coated side of glass was exposed to steam of beaker containing $80^{\\circ}C$ water as compared with the cleaning glass. Then, two glass slides were placed on the top of written letters. The visibility of the letter at the bottom of the glass slide was evaluated for the degree of antifog. In coldfog test (b), the coated glasses were placed in a refrigerator $(4^{\\circ}\\mathsf{C})$ for 6 hr and then placed on the top of an Erlenmeyer flask containing steaming water. For comparison, the cleaning glass was also placed in the refrigerator $(4^{\\circ}\\mathsf{C})$ . In test (c), for quick evaluation of the antifog performance of the coatings, a simple aspirating / breathing test was conducted on the sample.  \n\n![](images/00fb2ff62fa90b7ea57d3eea710699783675150548f47d3d3e9568d0b40468e0.jpg)  \nScheme 1. Synthesis route of 14QAS.",
        "category": " Materials and methods"
    },
    {
        "id": 10,
        "chunk": "# Mechanical property  \n\nSeveral methods were used to evaluate the mechanical properties of the films, including the following: (a) ISO15184 pencil hardness test and (b) pendulum hardness test.  \n\nIn the pencil hardness test, first, placed the coated substrate under the tip of a pencil, and then moved the pencil holder in one direction. The force applied to the pencil tip came from a 1 Kg static load. The scratched regions were evaluated by optical microscopy. The pencil hardness scale extends from 9H (good) to 6B (poor).  \n\nIn the pendulum hardness test, the pendulum hardness tester (BGD 508) supplied by BIUGED which follows ISO 1522. The pendulum angles were sat from $5^{\\circ}$ to $2^{\\circ},$ and the time of empty swing was $440\\pm6$ sec. The hardness was calculated with the following expression where $t$ is the time of swing on sample and $\\mathfrak{t}_{0}$ is the time of empty swing.  \n\n$$\n\\mathsf{X}=\\frac{\\mathsf{t}}{\\mathsf{t}_{0}}\n$$",
        "category": " Materials and methods"
    },
    {
        "id": 11,
        "chunk": "# Antibacterial tests  \n\nAntibacterial properties of antifog coatings were quantitatively evaluated on E. coli (gram-negative) and S. aureus (grampositive) by using the experimental protocols as described by Tiller.[12] A $100\\mathrm{-\\upmuL}$ suspension of E. coli or S. aureus in $0.1\\mathsf{M}$ aqueous PBS buffer $\\mathsf{(p H7.0,~10~^{11}~c e l l s/m l)}$ was added to $50\\mathrm{ml}$ of yeast/dextrose broth in a sterile Erlenmeyer flask. With shaking at 200 rpm, the suspension was incubated for $8\\mathsf{h r}$ at $37^{\\circ}C$ Bacterial cells were separated by centrifugation (2700 rpm, $10\\mathrm{{min}})$ , washed, and suspended in distilled water.[13] This bacterial suspension had a concentration of ${10}^{6}/\\mathrm{ml}$ . The inoculated specimens were prepared following ISO22196-2007. Before preparing, every coating was soaked in water for $2\\mathsf{h r}$ to remove unreactive 14QAS. An uncoated slide was used as standard, and the number of viable colonies grown was used as reference. The coating that did not contain QAS was used as a sample to compare. The bacterial colonies were allowed to grow on the surface of the coatings. The antibacterial activity was then evaluated according to their antibacterial rates.",
        "category": " Materials and methods"
    },
    {
        "id": 12,
        "chunk": "# RESULTS AND DISCUSSION",
        "category": " Results and discussion"
    },
    {
        "id": 13,
        "chunk": "# Synthesis  \n\n14QAS was prepared by the reaction of tertiary amine and bromoalkane. As shown in Table 1, the yield was first increased and then decreased with rising temperature, and the maximum yield was obtained at $35^{\\circ}\\mathsf{C}$ To get the optimal one for synthesis of 14QAS, the temperatures between $35^{\\circ}C$ and $40^{\\circ}\\mathsf{C}$ were also used. Finally, $37^{\\circ}\\mathsf{C}$ was found to be the temperature having the maximum yield $(35.4~\\%)$ .  \n\nAs shown in Figure 1, compared with the spectrum of DMAEMA, peaks of C–N $1299\\mathsf{c m}^{-1}$ and $1034(c m^{-1})$ and $C=C$ $(1635\\mathsf{c m}^{-1})$ are preserved in the spectrum of 14QAS after reaction while a new peak of $(C H_{2})_{n}$ $(\\mathsf{n}\\geq2)$ ) rocking vibration appears at $728{\\mathsf{c m}}^{-1}$ . Disappearance of C–Br $(1043\\mathsf{c m}^{-1})$ peak in 14QAS spectrum had backed up the reaction between DMAEMA and BTD.[14]  \n\n<html><body><table><tr><td colspan=\"6\">Table 1. The yield of 14QAS under different temperature</td></tr><tr><td rowspan=\"3\">Product</td><td colspan=\"4\">Yield under different temperature (%)</td></tr><tr><td>25℃</td><td>30℃ 35℃</td><td>40℃</td><td>45°℃</td></tr><tr><td>25.8</td><td>30.3</td><td>33.4 31.7</td><td>28.7</td></tr></table></body></html>  \n\n![](images/8db9fad7721a9ad0292a6da503293c0b17768e73e76e7970c2d445e780d4ed54.jpg)  \nFigure 1. Fourier transform infrared spectroscopy spectra of 14QAS, dimethylaminoethyl methacrylate, and bromotetradecane. This figure is available in colour online at wileyonlinelibrary.com/journal/pat  \n\n![](images/36a2a926f1656e41e773c3da6878908bb47f633af013d56cc835e8d1265f6b5c.jpg)  \nFigure 2. Nuclear magnetic resonance spectra of 14QAS and dimethylaminoethyl methacrylate. This figure is available in colour online at wileyonlinelibrary.com/journal/pat  \n\n$\\mathsf{\\Omega}^{1}\\mathsf{H}$ NMR was used as another method to identify the chemical structure of 14QAS. As shown in Fig. 2, peaks in the $^1\\mathsf{H}$ NMR spectrum of 14QAS $C D C\\mathsf{I}_{3}$ was used as the lock solvent) at  \n\n3.5 ppm $(-N^{+}\\mathrm{-}C H_{2}-)$ and 3.3 ppm $[(-N^{+}-(C\\Hat{1}_{3})_{2}]$ appeared with a complete disappearance of the dimethylamino protons at 2.2 ppm.[9]  \n\n$^1\\mathsf{H}$ (DMAEMA): 1.88[3H, s, $-C H_{3}];$ 2.2[6H, s, $(-N-(C H_{3})_{2}];$ 2.5 [2H, $ S,-C H_{2}-N-1];$ 4.18[2H, $S,\\mathrm{-CH}_{2}$ –COO–)]; 5.5–6.05[2H, s, $\\scriptstyle(=\\mathsf{C H}_{2})],$ $^1\\mathsf{H}$ (14QAS): 0.88[3H, $\\mathsf{t},(-\\mathsf{C}\\mathsf{H}_{3})],$ 1.25–1.34 [26H,m, $(-{\\mathsf{C H}}_{2})_{13}];$ 1.96[3H, s, $-C H_{3}];$ 3.3[6H, s, $(-N^{+}-(C H_{3})_{2}];$ 3.5[2H, s, $(-N^{+}-C H_{2}-)I;$ 4.17[2H,s,– $C H_{2}$ –COO–)]; $4.69[2mathsf{H},\\mathsf{S},-\\mathsf{C H}_{2}-\\mathsf{N}^{+}-)];$ 5.55–6.15[2H, s, $(=C H_{2})];$",
        "category": " Materials and methods"
    },
    {
        "id": 14,
        "chunk": "# Contact angle analysis  \n\nIn Table 2 first set of experiments shows increase in CA that could be due to increase of HEA and decrease of PEGDA600 in coatings. Although there was no regularity in this change, yet results indicated that PEGDA600 was more hydrophilic than HEA. It must be the long chain of ethylene oxide in PEGDA 600 that led to those results. Second group of experiments displays association between CA and weight ratio between HEA and CN929. As observed clearly, CA increases with the increase of HEA and the decrease of CN929 in coatings, which could confirm that CN929 was more hydrophilic than HEA. Upon comparison of two sets of experiments for same content of HEA, the CAs in first group was always higher than the second. For this reason, PEGDA600 also confirmed to have higher hydrophilic property than CN929.  \n\nThus, it can be concluded that these three materials had different effects on hydrophilic property of the coating. Their hydrophilicity can be arranged as: $\\mathsf{P E G D A600>C N929>H E A}$ .  \n\nAfter examining the hydrophilic properties of the coatings without QAS, the QAS-contained coatings were explored. Thus, data of Table 3 were created. A significant decrease in CA was observed with 14QAS increase and HEA decrease. Hence, it could be concluded that 14QAS improves hydrophilicity of coatings. So, more 14QAS dissolved in HEA, more hydrophilic coatings will be.  \n\nTable 2. Average contact angles of coatings having different ratios of HEA and PEGDA600 or CN929 $(3\\%$ 1173)   \n\n\n<html><body><table><tr><td rowspan=\"2\">Code</td><td colspan=\"4\">The content of each component in coatings (wt. %)</td><td rowspan=\"2\">CA</td></tr><tr><td>14QAS</td><td>HEA</td><td>CN929</td><td>PEGDA600</td></tr><tr><td rowspan=\"6\">1 2 3 4 5</td><td>0</td><td>5</td><td>47</td><td>45</td><td>39.7</td></tr><tr><td></td><td>10</td><td></td><td>40</td><td>43.0</td></tr><tr><td></td><td>15</td><td></td><td>35</td><td>46.5</td></tr><tr><td></td><td>20</td><td></td><td>30</td><td>49.3</td></tr><tr><td>0</td><td>25</td><td></td><td>25</td><td>54.0</td></tr><tr><td>6</td><td>5</td><td>47</td><td>45</td><td>39.7</td></tr><tr><td>7</td><td></td><td>10</td><td>42</td><td></td><td>42.0</td></tr><tr><td>8</td><td></td><td>15</td><td>37</td><td></td><td>43.5</td></tr><tr><td>9</td><td></td><td>20</td><td>32</td><td></td><td>46.1</td></tr><tr><td>10</td><td></td><td>25</td><td>27</td><td></td><td>49.0</td></tr></table></body></html>  \n\nTable 3. Average contact angles of coatings having different ratios of 14QAS and HEA $(3\\%$ 1173)   \n\n\n<html><body><table><tr><td rowspan=\"2\">Code</td><td colspan=\"4\">The content of each component in coatings (wt%)</td><td rowspan=\"2\">CA</td></tr><tr><td>14QAS</td><td>HEA</td><td>CN929</td><td>PEGDA600</td></tr><tr><td>11</td><td>2.5</td><td>22.5</td><td>47</td><td>25</td><td>46.0</td></tr><tr><td>12</td><td>5</td><td>20</td><td></td><td></td><td>37.1</td></tr><tr><td>13</td><td>7.5</td><td>17.5</td><td></td><td></td><td>27.4</td></tr><tr><td>14</td><td>10</td><td>15</td><td></td><td></td><td>21.3</td></tr><tr><td>15</td><td>12.5</td><td>12.5</td><td></td><td></td><td>17.4</td></tr><tr><td>16</td><td>2.5</td><td>22.5</td><td>27</td><td>45</td><td>38.7</td></tr><tr><td>17</td><td>5</td><td>20</td><td></td><td></td><td>29.3</td></tr><tr><td>18</td><td>7.5</td><td>17.5</td><td></td><td></td><td>21.3</td></tr><tr><td>19</td><td>10</td><td>15</td><td></td><td></td><td>16.5</td></tr><tr><td>20</td><td>12.5</td><td>12.5</td><td></td><td></td><td>12.4</td></tr></table></body></html>  \n\nTable 4. Average contact angles of coatings with different HEA-14QAS $(3\\%$ 1173)   \n\n\n<html><body><table><tr><td rowspan=\"2\">Code</td><td colspan=\"4\">The content of each component in coatings (wt%)</td><td rowspan=\"2\">CA</td></tr><tr><td>14QAS</td><td>HEA</td><td>CN929</td><td>PEGDA600</td></tr><tr><td>21</td><td>2.5</td><td>2.5</td><td>47</td><td>45</td><td>31.3</td></tr><tr><td>22</td><td>5</td><td>5</td><td>42</td><td></td><td>24.1</td></tr><tr><td>23</td><td>7.5</td><td>7.5</td><td>37</td><td></td><td>19.3</td></tr><tr><td>24</td><td>10</td><td>10</td><td>32</td><td></td><td>15.4</td></tr><tr><td>25</td><td>12.5</td><td>12.5</td><td>27</td><td></td><td>12.4</td></tr><tr><td>26</td><td>2.5</td><td>2.5</td><td>47</td><td>45</td><td>31.3</td></tr><tr><td>27</td><td>5</td><td>5</td><td></td><td>40</td><td>27.4</td></tr><tr><td>28</td><td>7.5</td><td>7.5</td><td></td><td>35</td><td>24.3</td></tr><tr><td>29</td><td>10</td><td>10</td><td></td><td>30</td><td>21.6</td></tr><tr><td>30</td><td>12.5</td><td>12.5</td><td></td><td>25</td><td>19.4</td></tr></table></body></html>  \n\nAs described earlier that 14QAS, due to poor compatibility with PEGDA600 and CN929, should be dissolved in HEA first. Different mass contents of HEA-14QAS 1:1 solution were investigated in coatings, as shown in Table 4. Data shows that, by increasing mass content of HEA-14QAS solution, CA of water decreases.  \n\nUpon comparison of two sets of experiments, CA decreasing rates were different to each other. Evidently, the rate in first group was higher than in second group.  \n\nThe other side of the story is excellent hydrophilic properties also had disadvantages like defect of leveling properties. Hence, the desire to reduce the surface tension at the liquid/vapor interface, as low as possible, was created. In that regard, leveling agent was needed to obtain smooth surface. At the meantime, the leveling agent should have the least influence on the hydrophilic properties of the coatings. Keeping in mind all these factors, BYK 348 was chosen. The results from Table 5 indicated that the CA increased on average by almost $4{-}5^{\\circ}$ because of the participants of BYK 348.",
        "category": " Results and discussion"
    },
    {
        "id": 15,
        "chunk": "# Antifog tests  \n\nTable 5 contains data for antifog tests of samples. As observed, only sample 35 has shown antifog properties (the bold and underlined words) where the other samples were all fogging during tests. These results were consistent with the hypothesis that the 14QAS could create a coating with antifogging capability.  \n\nAfter hot-fog test sample, 35 were dried at $40^{\\circ}C$ for $24\\mathsf{h r}$ under vacuum. Then, its antifog property was investigated again, through the hot-fog test. These two steps were repeated three times. Photos of these tests are shown in Fig. 3, demonstrating that these coatings still have excellent antifog property.",
        "category": " Results and discussion"
    },
    {
        "id": 16,
        "chunk": "# Antibacterial properties  \n\nThe antibacterial activity of coatings with 14QAS against S. aureus and E. coli is shown in Table 5. For comparison, coatings without 14QAS are shown in Table 6 as reference. Coatings with 14QAS showed a sharp decrease in the count for viable colonies of both bacteria after $24\\mathsf{h r}$ . Furthermore, the antibacterial rate of coatings with 14QAS (not lower than $12.5\\mathrm{wt\\%}$ could reach $99.9\\%$ against S. aureus and $99.9\\%$ against E. coli (the bold and underlined numbers). Although coatings having 14QAS lower than $12.5~\\mathrm{wt\\%}$ did not show complete inhibition of gram-negative and grampositive, yet antibacterial activity rates were still higher than coatings without 14QAS. These results indicate that introduction of 14QAS endows coatings with excellent antibacterial properties.  \n\nTable 5. Average contact angles, antifog tests and antibacterial rates of the coatings contained $0.5\\%$ BYK348 $2.5\\%$ 1173)   \n\n\n<html><body><table><tr><td rowspan=\"2\">Sample</td><td colspan=\"4\"> The content of each component in coatings</td><td rowspan=\"2\">CA</td><td colspan=\"3\"></td><td colspan=\"2\">Antibacterial</td></tr><tr><td></td><td>(wt%)</td><td>PUA(CN929)</td><td>PEGDA600</td><td colspan=\"3\">Antifog tests</td><td>rate</td><td></td></tr><tr><td></td><td>14QAS</td><td>HEA</td><td></td><td></td><td></td><td>Hot-fog test </td><td>Cold-fog test</td><td>Aspiration test</td><td>S.aureus</td><td>E. coli</td></tr><tr><td>31 32</td><td>2.5</td><td>2.5</td><td>47</td><td>45</td><td>36.5</td><td>Fogging</td><td>Fogging</td><td>Fogging</td><td>97.4</td><td>97.2</td></tr><tr><td>33</td><td>5</td><td>5</td><td>42</td><td></td><td>28.1</td><td>Fogging</td><td>Fogging</td><td>Fogging</td><td>97.9</td><td>97.5</td></tr><tr><td>34</td><td>7.5 10</td><td>7.5</td><td>37</td><td></td><td>25.3</td><td>Fogging</td><td>Fogging</td><td>Fogging Fogging</td><td>98.1 98.5</td><td>97.9 98.4</td></tr><tr><td></td><td>12.5</td><td>10</td><td>32 27</td><td></td><td>22.3</td><td>Fogging Antifog</td><td>Fogging Antifog</td><td>Antifog</td><td>99.9</td><td>99.9</td></tr><tr><td>35</td><td>2.5</td><td>12.5</td><td>47</td><td>45</td><td>18.7</td><td>Fogging</td><td>Fogging</td><td>Fogging</td><td>97.5</td><td>97.2</td></tr><tr><td>36 37</td><td>5</td><td>2.5 5</td><td></td><td>40</td><td>36.5 31.7</td><td>Fogging</td><td>Fogging</td><td>Fogging</td><td>97.5</td><td>97.4</td></tr><tr><td>38</td><td>7.5</td><td>7.5</td><td></td><td>35</td><td>28.7</td><td>Fogging</td><td>Fogging</td><td>Fogging</td><td>97.9</td><td>98.1</td></tr><tr><td>39</td><td>10</td><td>10</td><td></td><td>30</td><td>26.3</td><td>Fogging</td><td>Fogging</td><td>Fogging</td><td>98.3</td><td>98.2</td></tr><tr><td>40</td><td>12.5</td><td>12.5</td><td></td><td>25</td><td>23.1</td><td>Fogging</td><td>Fogging</td><td>Fogging</td><td>98.4</td><td>98.4</td></tr></table></body></html>  \n\n![](images/480d94caf33c92249386b2c4ddb7b956193e85302267bf274545b06133863fc2.jpg)  \nFigure 3. Antifog photos of repeated hot-fog tests taken after being dried (a. once, b. twice, and c. triple). This figure is available in colour online at wileyonlinelibrary.com/journal/pat  \n\n<html><body><table><tr><td colspan=\"4\">Table 6. Antibacterial properties of coatings contained BYK348without14QAS</td></tr><tr><td rowspan=\"3\">Sample</td><td colspan=\"3\">The content of each component in</td><td rowspan=\"2\">S. E. aureus coli</td></tr><tr><td>14QAS</td><td>coatings (wt%) HEAPUA(CN929)PEGDA600</td></tr><tr><td>0 5 47</td><td></td><td></td><td>42.7</td></tr><tr><td>41 42</td><td>10</td><td></td><td>45 40</td><td>40.5 51.6 47.8</td></tr><tr><td>43</td><td>15</td><td></td><td>35</td><td>57.6 52.6</td></tr><tr><td>44</td><td>20</td><td></td><td>30</td><td>60.5</td></tr><tr><td></td><td></td><td></td><td></td><td>58.4</td></tr><tr><td>45</td><td>25</td><td></td><td>25</td><td>62.3 61.3</td></tr><tr><td>46</td><td>0 5</td><td>47</td><td>45</td><td>43.3 42.3</td></tr><tr><td>47</td><td>10</td><td>42</td><td>52.3</td><td>46.4</td></tr><tr><td>48</td><td>15</td><td>37</td><td>56.8</td><td>53.4</td></tr><tr><td>49</td><td>20</td><td>32</td><td>62.6</td><td>57.2</td></tr><tr><td>50</td><td>25</td><td>27</td><td></td><td>66.3 63.4</td></tr></table></body></html>",
        "category": " Results and discussion"
    },
    {
        "id": 17,
        "chunk": "# Surface properties  \n\nThe migratory aptitude was further supported by XPS analysis of the coatings. As shown, the integrated spectra Fig. 4A peak at $403\\mathrm{eV}$ represents nitrogen which conformed that surface of sample 35 contained N, while no signal for nitrogen element could be detected when running XPS to the other four samples, as shown in Fig. 4B. And because the only source of N in the coatings is 14QAS, it could be concluded that there were some quaternary ammonium groups on the surface of sample 35. The results of N element through those samples indicated that quaternary ammonium group had a good migratory ability in this system leading the aggregation of the 14QAS to the surface and only the 14QAS in sample 35 had migrated successfully.  \n\nThis phenomenon attributed to the high-surface tension of 14QAS. As an amphipathic molecule, 14QAS has a long carbon chain which is hydrophobic and the quaternary ammonium group which is hydrophilic. Thus, when 14QAS acted as a part of the coatings, the quaternary ammonium groups were rejected by other components. After that, they got their rudimentary energy to migrate to the surface. Otherwise, the viscosity of the coating system resisted this kind of migration. That is may be the reason that the N element only appeared on the surface of sample 35.",
        "category": " Results and discussion"
    },
    {
        "id": 18,
        "chunk": "# Mechanical properties  \n\nThe results from the conventional coating characterization analyses are shown in Table 7. According to the pencil hardness test, CN929 and PEGDA600 all had pronounced positive effects on the scratch resistance because of their ability to form a network. On the contrary, the more HEA-14QAS in coatings, the worse pencil hardness of the coatings. Still, it can be found that the antifog coating (Sample 35) had pencil hardness approaching 3H, at which hardness the coatings had the ability to exhibit some damage and delamination.  \n\n![](images/8ef1a0c7b558bf52e7e470881a098c8e2b43035d666002dccc5d6e713ceb7755.jpg)  \nFigure 4. XPS spectra of Sample 31–35 (A, Sample 35; B, Sample 31-34). This figure is available in colour online at wileyonlinelibrary.com/journal/pa  \n\nTable 7. Mechanical Properties of coatings with changed components   \n\n\n<html><body><table><tr><td rowspan=\"2\">Code</td><td colspan=\"4\">The content of each component in coatings (wt%)</td><td rowspan=\"2\">Pencil</td><td rowspan=\"2\">Pendulum</td></tr><tr><td>14QAS</td><td>HEA</td><td>CN929</td><td>PEGDA600</td></tr><tr><td>1</td><td>0</td><td>5</td><td>47</td><td>45</td><td>4H</td><td>0.82</td></tr><tr><td>2</td><td></td><td>10</td><td></td><td>40</td><td>4H</td><td>0.78</td></tr><tr><td>3</td><td></td><td>15</td><td></td><td>35</td><td>4H</td><td>0.76</td></tr><tr><td>4</td><td></td><td>20</td><td></td><td>30</td><td>3H</td><td>0.74</td></tr><tr><td>5</td><td></td><td>25</td><td></td><td>25</td><td>3H</td><td>0.72</td></tr><tr><td>6</td><td>0</td><td>5</td><td>47</td><td>45</td><td>4H</td><td>0.82</td></tr><tr><td>7</td><td></td><td>10</td><td>42</td><td></td><td>4H</td><td>0.76</td></tr><tr><td>8</td><td></td><td>15</td><td>37</td><td></td><td>3H</td><td>0.72</td></tr><tr><td>9</td><td></td><td>20</td><td>32</td><td></td><td>3H</td><td>0.69</td></tr><tr><td>10</td><td></td><td>25</td><td>27</td><td></td><td>3H</td><td>0.65</td></tr><tr><td>31</td><td>2.5</td><td>2.5</td><td>47</td><td>45</td><td>4H</td><td>0.70</td></tr><tr><td>32</td><td>5</td><td>5</td><td>42</td><td></td><td>4H</td><td>0.64</td></tr><tr><td>33</td><td>7.5</td><td>7.5</td><td>37</td><td></td><td>3H</td><td>0.62</td></tr><tr><td>34</td><td>10</td><td>10</td><td>32</td><td></td><td>3H</td><td>0.60</td></tr><tr><td>35</td><td>12.5</td><td>12.5</td><td>27</td><td></td><td>3H</td><td>0.42</td></tr><tr><td>36</td><td>2.5</td><td>2.5</td><td>47</td><td>45</td><td>4H</td><td>0.70</td></tr><tr><td>37</td><td>5</td><td>5</td><td></td><td>40</td><td>4H</td><td>0.65</td></tr><tr><td>38</td><td>7.5</td><td>7.5</td><td></td><td>35</td><td>4H</td><td>0.62</td></tr><tr><td>39</td><td>10</td><td>10</td><td></td><td>30</td><td>3H</td><td>0.59</td></tr><tr><td>40</td><td>12.5</td><td>12.5</td><td></td><td>25</td><td>3H</td><td>0.55</td></tr></table></body></html>  \n\nThe results from the pendulum hardness test, which measured the surface hardness in combination with the surface friction, indicated that the coatings with lower content of HEA-14QAS gave rise to a higher number of pendulum swings which mean a harder surface. Especially, Sample 35 had the lowest data pendulum hardness. And the difference between Samples 35 and 34 was higher than anyone else. This phenomenon could also be explained by the migration of 14QAS in the systems. Because the long carbon chain was supported to the surface according to the movement of 14QAS, the surface could be more flexible than before.  \n\nThus, although HEA-14QAS gave rise to the antifog and antibacterial properties, it could decrease the hardness of the final coatings, which was necessary in practical application.",
        "category": " Results and discussion"
    },
    {
        "id": 19,
        "chunk": "# CONCLUSION  \n\nThis work demonstrates that coatings contained enough QAS could exhibit excellent antifog and antibacterial properties under a variety of environmental challenges. With photopolymerized QAS, these antifog and antibacterial coatings can be used for a long time. CA studies also provided that the excellent hydrophilic capabilities of the coatings were associated with the mass content of QAS in HEA (HEMA)-QAS and the mass content of PEGDA in coatings.  \n\nThe persistent antifog and antibacterial property of this coating open up new possibilities for a wide range of applications, especially used in people’s daily life, such as on the mirrors of bathroom, the windscreens of car, the windows in baby room, and so on.",
        "category": " Conclusions"
    },
    {
        "id": 20,
        "chunk": "# REFERENCES  \n\n[1] C. Xiong, K. J. Balkus, Chem. Mater. 2005, 17, 5136–5140.   \n[2] I. Badge, S. Sethi, A. Dhinojwala, Langmuir 2011, 27, 14726–14731. [3] X. Gao, X. Yan, X. Yao, L. Xu, K. Zhang, J. Zhang, B. Yang, L. Jiang, Adv. Mater. 2007, 19, 2213 2217. [4] P. Chevallier, S. Turgeon, C. Sarra-Bournet, R. Turcotte, G. Laroche, ACS Appl. Mater. Interfaces 2011, 3, 750 758. [5] J. Seo, S. Lee, J. Lee, T. Lee, Mater. Interfaces 2011, 3, 4722 4729. [6] L. Introzzi, J. M. Fuentes-Alventosa, C. A. Cozzolino, S. Trabattoni, S. Tavazzi, C. L. Bianchi, A. Schiraldi, L. Piergiovanni, S. Farris, Appl. Mater. Interfaces 2012, 4, 3692–3700.   \n[7] N. Nuraje, R. Asmatulu, R. E. Cohen, M. F. Rubner, Langmuir 2011, 27(2), 782–791.   \n[8] P. Majumdar, E. Lee, N. Gubbins, D. A. Christianson, S. J. Stafslien, J. Daniels, L. VanderWal, J. Bahr, B. J. Chisholm, J. Comb. Chem. 2009, 11, 1115–1127.   \n[9] R. R. Pant, J. L. Buckley, P. A. Fulmer, J. H. Wynne, D. M. McCluskey, J. P. Phillips, J. Appl. Polym. Sci. 2008, 110, 3080–3086.   \n[10] G. Sauvet, W. Fortuniak, K. Kazmierski, J. J. Chojnowski, Polym. Sci., Part A: Polym. Chem. 2003, 41(19), 2939–2948.   \n[11] B. Gottenbos, H. C. van der Mei, F. Klatter, P. Nieuwenhuis, H. J. Busscher, Biomaterials 2002, 23(6), 1417–1423.   \n[12] J. C. Tiller, C. J. Liao, K. Lewis, A. M. Klibanov, Proc. Natl. Acad. Sci. 2001, 98(11), 5981–5985.   \n[13] M. J. Saif, J. Anwar, M. A. Munawar, Langmuir 2009, 25, 377–379.   \n[14] G. Lu, D. Wu, R. Fu. React. Funct. Polym. 2007, 67, 355–366.",
        "category": " References"
    }
]