Nanoparticles in a Commercial Floor Coating The Efficacy and Environmental … · 2017-08-30 ·...
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1 The Efficacy and Environmental Implications of Engineered TiO 2 Nanoparticles in a Commercial Floor Coating Yuqiang Bi † , Tatiana Zaikova ⁋ , Jared Schoepf † , Pierre Herckes § , James E. Hutchison ⁋& and Paul Westerhoff † * * Corresponding Author: [email protected]; 480-965-2885; †School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ 85287-3005 ⁋ Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR 97403 & Materials Science Institute, University of Oregon, Eugene, OR 97403 § School of Molecular Sciences, Arizona State University, Tempe, AZ 85287-1604 In preparation for Submission to: Environmental Science: Nano Date of Last Revision: August 15 th , 2017 Electronic Supplementary Material (ESI) for Environmental Science: Nano. This journal is © The Royal Society of Chemistry 2017
Transcript of Nanoparticles in a Commercial Floor Coating The Efficacy and Environmental … · 2017-08-30 ·...
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The Efficacy and Environmental Implications of Engineered TiO2
Nanoparticles in a Commercial Floor Coating
Yuqiang Bi†, Tatiana Zaikova⁋, Jared Schoepf†, Pierre Herckes§, James E. Hutchison⁋& and Paul
Westerhoff†*
* Corresponding Author: [email protected]; 480-965-2885;
†School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ 85287-3005⁋Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR 97403
&Materials Science Institute, University of Oregon, Eugene, OR 97403
§School of Molecular Sciences, Arizona State University, Tempe, AZ 85287-1604
In preparation for Submission to: Environmental Science: Nano
Date of Last Revision: August 15th, 2017
Electronic Supplementary Material (ESI) for Environmental Science: Nano.This journal is © The Royal Society of Chemistry 2017
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Table of contents Table SI1. Standard conditions used for the Taber abrasion test on floor tiles, including the material of the abrasion wheels, the normal force, and the number of abrasive cycles (number of turntable revolutions).
Table SI2. Chemical composition of the commercial floor coating product determined by ICP-MS after HNO3/HF microwave digestion.
Figure SI1. Fluorescent lamp irradiance spectrum from 300 to 800 nm for the antimicrobial efficacy test. UV light was found insignificant for this study.
Figure SI2. Transmission electron microscopy (TEM) micrographs of particles separated from the coating product with corresponding EDX results. (a) aggregates of TiO2 nanoparticles; (b) amorphous potassium silicate; (c) histogram of TiO2 particle size distribution.
Figure SI3. Wide-scan XPS spectrum collected from extracted solids from the commercial floor coating product.
Figure SI4. Scanning electron micrograph (SEM) of surface coated tile with the commercial product containing TiO2 nanoparticles. The corresponding EDX result shows the dominance of silicon and potassium on the tile surfaces.
Figure SI5. SEM image of surface coated tile with the product containing additional food-grade TiO2 nanoparticles for a surface coverage of ~10 mg/m2. The corresponding EDX result shows clusters of TiO2 nanoparticles on the tile surface after coating application.
Figure SI6. Optical profiler data showing the topography of coated tile surfaces with the original product (sample A) after the abrasion test using H-18 (coarse) abrasive. Surface roughness significantly increased after the abrasion, resulting in ~5 µm loss of surface thickness. The left side of the white bar shows the unabraded surface, and the right side shows the abraded surface.
Figure SI7. Water contact angle of coated floor samples with varied TiO2 content. The inserted images above the bars illustrate the relative difference in contact angle during the measurement.
Figure SI8. Comparison of the first-order photocatalytic degradation of methyl orange (MO) in the presence of coating TiO2, NIST SRM 1898, and food-grade TiO2 under UV light irradiation at 312 nm. MO concentration was 10 mg/L, TiO2 concentration was 60 mg/L, pH = 8.0.
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Table SI1. Standard conditions used for the Taber abrasion test on floor tiles, including the material of the abrasion wheels, the normal force, and the number of abrasive cycles (number of turntable revolutions).
Abrasion Wheel Type
Wheel Composition Relative Abrasive Action
Wheel Weight
Number of cycles
Number of runs (replicates)
Wheel CS10 Rubber and aluminum oxide particles
Soft 1000 g 2500 5
Wheel H-18 Vitrified silica and aluminum oxide
Hard 500 g 100 5
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Table SI2. Chemical composition of the commercial floor coating product determined by ICP-MS after HNO3/HF microwave digestion.
Major Elements
Concentration in Original Product Sample A (mg/L)
wt.% in Original Product
Sample A*
Concentration in Sample B Suspension
(mg/L)
Potassium (K) 104,258 ± 3505 9.36 498.9 ± 28.1
Calcium (Ca) 31.1 ± 1.2 0.0028 175.7 ± 14.1
Sodium (Na) 285.4 ± 2.5 0.026 7.0 ± 1.8
Aluminum (Al) 41.8 ± 0.3 0.0038 10.9 ± 0.7
Iron (Fe) 35.5 ± 0.6 0.0032 21.1 ±1.4
Titanium (Ti) 18.2 ± 0.8 0.0016 144.0 ± 10.5
Silicon (Si) 49,412 ± 513 4.44 2634.8 ± 210.8
Nickel (Ni) 0.2 ± 0.06 <0.001 < 0.3
Phosphorous (P) 30.7 ± 0.8 0.0028 3.5 ± 0.4
TiO2 solids 30.3 ± 1.3 0.003 242.4 ± 14.1 * The liquid coating product (sample A) has a density of ~1.11 kg/L.
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Figure SI1. Fluorescent lamp irradiance spectrum from 300 to 800 nm for the antimicrobial efficacy test. UV light was found insignificant for this study.
300 350 400 450 500 550 600 650 700 750 8000.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
Wavelength (nm)
Inte
nsity
(µW
/cm
2)
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Figure SI2. Transmission electron microscopy (TEM) micrographs of particles separated from the coating product with corresponding EDX results. (a) aggregates of TiO2 nanoparticles; (b) amorphous potassium silicate; (c) histogram of TiO2 particle size distribution.
0
2
4
6
8
10
12
25 40 55 70 85 100 115 130 145 160 175 190 205 220 235
Freq
uenc
y
Diameter (nm)
a. b.
c.
c.
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Figure SI3. Wide-scan XPS spectrum collected from extracted solids from the commercial floor coating product.
CasaXPS (T his string can be edited in CasaXPS.DEF/Print FootNot e.t xt )
wide
NameO 1sC 1sCa 2pK 2pSi 2pT i 2p
Pos.526.6280295.6280346.6280295.6280110.6280453.6280
FWHM4.76595.56345.44485.56344.66853.8240
Area1033527.065148558.48964274.729
148558.489175082.491
6644.636
At%46.0219.381.654.88
27.960.11
O 1
s
C 1
s
Ca
2p
K 2
p
Si 2
p
Ti 2
p
x 104
5
10
15
20
25
CPS
1200 900 600 300 0Binding Energy (eV)
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Figure SI4. Scanning electron micrograph (SEM) of surface coated tile with the commercial product containing TiO2 nanoparticles. The corresponding EDX result shows the dominance of silicon and potassium on the tile surfaces.
2 µm
K
10
Figure SI5. SEM image of surface coated tile with the product containing additional food-grade TiO2 nanoparticles for a surface coverage of ~10 mg/m2. The corresponding EDX result shows clusters of TiO2 nanoparticles on the tile surface after coating application.
2 µm
K
11
Figure SI6. Optical profiler data showing the topography of coated tile surfaces with the original product (sample A) after the abrasion test using H-18 (coarse) abrasive. Surface roughness significantly increased after the abrasion, resulting in ~5 µm loss of surface thickness. The left side of the white bar shows the unabraded surface, and the right side shows the abraded surface.
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Figure SI7. Water contact angle of coated floor samples with varied TiO2 content. The inserted images above the bars illustrate the relative difference in contact angle during the measurement.
0
10
20
30
40
50
60
70
80
90
No coating Coating w/o TiO2 Coating w/ 0.1%TiO2
Coating w/ 1%TiO2
Con
tact
ang
le (°
)
coating w/o TiO2
original coating coating w/ added FG-TiO2
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Figure SI8. Comparison of the first-order photocatalytic degradation of methyl orange (MO) in the presence of coating TiO2, NIST SRM 1898, and food-grade TiO2 under UV light irradiation at 312 nm. MO concentration was 10 mg/L, TiO2 concentration was 60 mg/L, pH = 8.0.
-1.8
-1.6
-1.4
-1.2
-1
-0.8
-0.6
-0.4
-0.2
0
0 20 40 60 80 100
Ln(C
/C0)
Reaction time (min)
Coating TiO2
NIST SRM 1898
Food-grade TiO2
Methyl orange control
TiO2
TiO2
