Ultrasonic assisted fabrication of dual function surface on PET and preparation of single component ink to attain efficient self-cleaning function via digital printing

Article abstract of DOI:10.1016/j.molliq.2020.114668

The self-cleaning effects of polyethylene terephthalate fabric (PET) through the photocatalytic effects of TiO₂ (T), porphyrin (P) and silane (S) have been explored ultrasonically using bath type (WUC-D22H, Daihan Scientific, Korea). The ultras

Full text of DOI:10.1016/j.molliq.2020.114668

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Ultrasonic assisted fabrication of dual function surface on PET
and preparation of single component ink to attain efficient self-
cleaning function via digital printing
Ramalingam Manivannan, Jiwon Ryu, Young-A Son
PII:
S0167-7322(20)36910-5
DOI:
https://doi.org/10.1016/j.molliq.2020.114668
MOLLIQ 114668
Reference:
To appear in:
Journal of Molecular Liquids
Received date:
Revised date:
Accepted date:
15 September 2020
16 October 2020
26 October 2020
Please cite this article as: R. Manivannan, J. Ryu and Y.-A. Son, Ultrasonic assisted
fabrication of dual function surface on PET and preparation of single component ink to
attain efficient self-cleaning function via digital printing, Journal of Molecular Liquids
(2020), https://doi.org/10.1016/j.molliq.2020.114668
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Ultrasonic Assisted Fabrication of Dual Function Surface on
PET and Preparation of Single Component Ink to Attain
Efficient Self-Cleaning Function via Digital Printing
Ramalingam Manivannan, Jiwon Ryu, Young-A Son*
Department of Advanced Organic Materials Engineering,
Chungnam National University, 220 Gung-dong, Yuseong-gu,
Daejeon 305-764, South Korea
*
Corresponding author. Tel: +82 42 821 6620; Fax: +82 42 821 8870
E-mail address: yason@cnu.ac.kr
Abstract
The self-cleaning effects of polyethylene terephthalate fabric (PET) through the photocatalytic
effects of TiO (T), porphyrin (P) and silane (S) have been explored ultrasonically using bath
2
type (WUC-D22H, Daihan Scientific, Korea). The ultrasonic power and frequency were 100ꢀW
and 30ꢀkHz, respectively. The surface modification in fabric was achieved by the ultrasonic
deposition of anatase TiO (T), porphyrin (P), and further modification by silane (S) was used to
2
achieve dual-function (photocatalytic and superhydrophobic) self-cleaning behavior. The dye-
degrading abilities of the modified fabric surface confirmed by the photo discoloration of various
organic pollutants by visible light treatment. From the tested various dye, methylene blue (MB)
decomposition was monitored using UV-Vis spectroscopy by measuring the changes in
concentrations in the fabric at altered time breaks. The attachment of silane and its stability after
washing the surface of fabric confirmed by measuring the water contact angle (WCA). The self-
cleaning efficacies were in the order PET@TP > PET@TPS. The modifications are done in
fabric surface characterized and confirmed by XRD, XPS, UV-Vis, and FESEM analyses.
Fabric’s self-cleaning effect examined with common daily life pollutants. Easy to make single-

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component ink prepared using silane (S) and used as digital printing ink and printed on fabric,
exclusively attained hydrophobic surface in the printed area.
Keywords: Ultrasonic finished coating; Porphyrin, Stain; Superhydrophobic; Self-Cleaning;
Digital Printing
1
.
Introduction
In current centuries, there is a great attention in research related to functionalizing fibrous
materials to meet specific requirements, such as self-cleaning, protection against pollutants and
microorganisms, and deodorization [1]. In particular, self-cleaning textile materials are of
considerable importance in daily life due to their commercial usages [2]. Self-cleaning surfaces
attained by coating fibrous materials with either hydrophobic or hydrophilic compounds have
undergone rapid advances towards achieving textiles with self-cleaning properties. Apart from
their fundamental properties, these materials should possess properties such as
superhydrophobicity, which leads to excellent liquid repellency and allows various applications
including antisticking, anti-icing, antifogging, antipollution, self-cleaning and water/oil
separation [3-11]. A surface is superhydrophobic if it has a water contact angle greater than 150°
[
12-14]. A surface is water repellent if it has a less than 10°, giving it a self-cleaning effect.
Sufficient roughness with a low surface energy allows dirt to be easily removed by bringing the
material into contact with water, and the fabrication of these surfaces can be inspired by nature,
including by the lotus leaf and water strider [2,12]. However, hydrophilic self-cleaning in fibrous
materials are prepared through photocatalytic modifications involving photoactive materials, and
metal oxide nanoparticles, in particular TiO NPs, are broadly applicable [15,16].
2
In general, TiO is one of the reliable and eco-friendly photocatalyst that possesses high
2
stability, nontoxic, inexpensive and excellent oxidizing ability. These polycrystalline

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semiconductor oxides exhibit optical properties, and these photoactive materials can
spontaneously removal of absorbed contaminants through decomposition under light by photo-
oxidation and photoreduction reactions [17-21]. However, attaching TiO to flexible surfaces,
2
such as paper, fabric and plastic, is challenging because of its low thermal and chemical
resistance [22-24]. Based on recent reports integrating nanosized TiO into substrates, various
2
methods have been employed to deposit TiO onto the fibrous materials, including by sol-gel,
2
hydrothermal, impregnation, chemical spacer attachment, and sputtering methods [25-33].
Daoud et al. first invented self-cleaning cotton through the nucleation and growth of anatase
TiO at a low temperature and ambient pressure [34]. The photocatalytic self-cleaning
2
functionalized surface has a hydrophilic self-cleaning coating, which tends to exhibit surprising
photo induced hydrophilicity after irradiation with light [17,35].
Significant research has been made on the production of titanium dioxide nanocrystals on
both natural and synthetic fibers [36] for the fabrication of self-cleaning materials with UV-
active property. But these materials do not show self-cleaning properties under visible light
because of the widespread band gap of TiO (~3.2 eV); thus, TiO absorb approximately 385 nm
2
2
[
37], therefore different approaches were explored to shift its light-absorption region towards the
visible region, such as doping metal and nonmetals [38,39]. Dye sensitization is another method
to bring photocatalytic activity in the observable region [40]. Dye sensitization by incorporating
porphyrin into TiO results in a solid band at 450 nm region (Soret band) and weak Q bands at
2
approximately 500-700 nm [41]. Thus, the modified surfaces attained through this process may
have outstanding self-cleaning properties and may be able to clean themselves when exposed to
visible light.

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Self-cleaning properties achieved by incorporating either hydrophobic and photocatalytic
properties into the fabric have two advantages: 1) water-soluble impurities rolled off due to the
water-repelling nature of fabric and 2) organic dyes and other common stain-causing materials
can be decomposed by photocatalysis.
As a continuation, of our previous work [42], and to improve the self-cleaning effect, we
developed and attached new porphyrin (Scheme 1) and silane derivative to the fabric to increase
its property, in this work we used non-fluorinated silane, which considered being less toxic when
compared with fluorinated silane. The prepared porphyrins contain a carboxylate-substituted
phenyl group in the meso position, and the beta position is occupied by the phenyl ring of the
prepared porphyrin molecule, 4,4',4'',4'''-(2,3,7,8,12,13,17,18-octaphenylporphyrin-5,10,15,20-
tetrayl) tetrabenzoicacid (P) to elucidate the photocatalytic behavior. Additionally, a trimethoxy
alkyl silane with 22-carbon chain, docosyltriethoxysilane (S), synthesized and attached to the
substrate, and determined the hydrophobicity of the modified fabric sample. After successful
modification, the abilities of the material to degrade organic pollutants like nitrophenol (NP),
rhodamine B (RB), eosin Y (EY), indigo (IN), bromophenol blue (BB), methylene blue (MB)
and common stain-causing materials, such as coffee and soy sauce, were studied under visible-
light irradiation, and the hydrophobic properties were assessed by measuring the water contact
angles. As a preliminary attempt, single component hydrophobic ink has been prepared from
docosyltriethoxysilane (S), and printed on polyethylene terephthalate (PET) and examined the
hydrophobic nature in the printed surface.

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Scheme 1. Surface modification process for polyethylene terephthalate fabric to obtain
photocatalytic, superhydrophobic, self-cleaning material.
2
.
Experimental Section
All chemicals procured from Sigma Aldrich and TCI Chemicals and used as received. 600 MHz
NMR spectroscopy (AVANCE spectrometer) to confirm the compounds. ESI mass spectra
measured in 4000 Q TRAP mass spectrometer. Surface characteristics was analyzed using
LYRA3 XMU system (SEM). The absorption spectra were recorded using UV-Vis spectroscopy
(Agilent 8453 instrument). Shimadzu Solid Spec-2700 instrument were used to recorded solid-
state UV-Vis spectra and Multilab 2000 spectrometer for XPS measurements. X-ray
diffractometer (PHILIPS, X’Pert-MPD System (λ=1.54056Å). Decomposition of MB was
examined under visible-light irradiation (300 W lamp). The porphyrin (P) used in the present
study were prepared as shown in Scheme 2.

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Scheme 2. Synthesis of the porphyrin P.
2
5
.1
Procedure for the synthesis of (4,4',4'',4'''-(2,3,7,8,12,13,17,18-octaphenylporphyrin-
,10,15,20- tetrayl) tetra benzoicacid) (P)
Preparation of tetramethyl 4,4',4'',4'''- (porphyrin-5,10,15,20- tetrayl) tetrabenzoate (1)
Methyl 4-formyl benzoate (2.5 g, 15.24 mmol) in 25 mL of propionic acid, added pyrrole (1.02 g,
o
1
5.24 mmol) slowly in drops and it was heated (150 C) for 12 h (dark) and cooled followed by
filtration to obtained purple solid which was purified by column chromatography. Yield (650 mg,
2
0%).
1
H NMR (CDCl , 600 MHz), δ (ppm): -2.88 (s, 2 H), 4.03 (s, 12 H), 8.20 (d, 8 H), 8.36 (d, 8 H),
3
+
8
.73 (s, 8 H) (Fig. S1). ESI-MS: m/z calcd. 846.3, found 847.3 [M+H ] (Fig. S2).
Preparation of tetra methyl 4,4',4'',4'''-(copperporphyrin-5,10,15,20-tetrayl) tetra benzoate (2)

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Tetra methyl 4,4',4'',4'''-(porphyrin-5,10,15,20-tetrayl) tetra benzoate (0.3 g, 0.35 mmol) in
chloroform, to that Cu(OAc) .H O (0.7 g, 3.5 mmol) in methanol was added, and it was heated
2
2
(60 ºC) for about 45 min. Then, it was concentrated for dryness, and it was redissolved using
chloroform and further to remove the excess Cu(OAc) it was washed using water. Yield (300
2
+
mg, 93%). ESI-MS: m/z calcd. 907.2, found 908.3 [M+H ] (Fig. S3).
Preparation of tetramethyl 4,4',4'',4'''-(2,3,7,8,12,13,17,18-octabromoporphyrin-5,10,15,20-
tetrayl)tetrabenzoate (3)
To tetra methyl 4,4',4'',4'''-(copperporphyrin-5,10,15,20-tetrayl) tetra benzoate (0.3 g, 0.33 mmol)
in chloroform, then bromine (0.2 g, 1.32 mmol) in chloroform is added, and was stirred for 12 h.
An excess bromine quenched by adding sodium thiosulfate, and then water added to the reaction
mixture. The mixture then extracted with chloroform, and the organic layer was concentrated to
dryness. Then, the crude reaction mixture was dissolved in chloroform and cooled to 0°C, and to
the cooled solution was added conc. H SO (3 mL), then it was stirred for 20 min and neutralized
2
4
with ammonia, the reaction mixture was extracted with chloroform and the crude product
obtained was purified by column chromatography. Yield (250 mg, 51%).
1
H NMR (CDCl , 300MHz), δ(ppm): 4.03 (s, 12 H), 8.22 (d, 8 H), 8.37 (d, 8 H) (Fig. S4). ESI-
3
+
MS: m/z calcd. 1478.1, found 1478.5 [M+H ] (Fig. S5).
Preparation of tetramethyl-4,4',4'',4'''(2,3,7,8,12,13,17,18-octaphenylporphyrin-5,10,15,20-
tetrayl)tetrabenzoate (4)
A round bottom flask was charged with tetramethyl 4,4',4'',4'''-(2,3,7,8,12,13,17,18-
octabromoporphyrin-5,10,15,20-tetrayl)tetrabenzoate (0.5 g, 0.33 mmol), phenylboronic acid
(0.96 g, 7.92 mmol) and potassium carbonate (2.08 g, 15 mmol) and toluene was added (15 mL).
The mixture degassed under nitrogen, and tetrakis palladium (0.078 g, 0.07 mmol) added. The

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reaction mixture stirred at 100°C for 12 h, toluene removed from reaction mixture under vacuum,
the residue again dissolved in chloroform and washed with water. The desired product obtained
following column chromatography. Yield (230 mg, 46.7 %).
1
H NMR (DMSO-d , 600 MHz), δ (ppm): 3.94 (s, 12H), 6.65 (m, 40H), 7.38 (s, 8 H), 7.61 (s, 8
6
+
H) (Fig. S6). ESI-MS: m/z calcd. 1455.6, found 1456.5 [M+H ] (Fig. S7).
Preparation
tetrayl)tetrabenzoic acid (P)
Tetramethyl 4,4',4'',4'''(2,3,7,8,12,13,17,18-octa
tetrabenzoate (0.2 g, 0.14 mmol) in THF (20 mL) was added 2 M potassium hydroxide in water
10 mL). The reaction mixture was stirred at room temperature for 1 h and then at 80 °C for 48 h.
of
4,4',4'',4'''-(2,3,7,8,12,13,17,18-octaphenylporphyrin-5,10,15,20-
phenyl
porphyrin-5,10,15,20-tetrayl)
(
The THF then evaporated from the reaction mixture, and 2N HCl (25 mL) added to it. The
resulting green precipitate washed by distilled water. Then crystallized from methanol to get the
product. Yield (120 mg, 62.5 %).
1
H NMR (DMSO-d , 600MHz), δ(ppm): 6.64 (m, 40H), 7.61 (s, 8H), 8.12 (s, 8H), 12.83 (s, 4H)
6
+
(
Fig. S8). MALDI-TOF: m/z calcd. 1399.5, found 1400.7 [M+H ] (Fig. S9).
2
.2
Procedure for the synthesis of silane (S) (Scheme S1) and TiO (T).
2
Synthesis of docosyltriethoxysilane (S)
A solution of 1-docosene (0.5 g, 1.6 mmol) in THF 10 mL was reacted with triethoxysilane (1.46
g, 8.9 mmol) and a catalyst solution prepared by dissolving Karstedt’s catalyst [0.1 mL, 15 mol%]
in 1 mL m. xylene, and added to the reaction mixture, stirred at reflux temperature for 36 h in
argon atmosphere. After completion of reaction the crude product obtained purified to get a pure
1
liquid (colorless). Yield: 0.2 g, 26.l %. H NMR (CDCl , 600MHz), δ (ppm): 0.53 (m, 2 H), 0.79
3
1
3
(
t, 3 H, J = 7.2 Hz), 1.14 (m, 47 H), 1.30 (m, 2 H), 3.72 (q, 6 H) (Fig. S10). C NMR (CDCl ,
3

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1
5
50MHz), δ (ppm): 9.36, 13.09, 17.27, 21.68, 21.74, 28.26, 28.35, 28.55, 28.69, 30.92, 32.19,
+
7.26 (Fig. S11). ESI-MS: m/z calcd. 472.4, found 473.4 [M+H ] (Fig. S12).
Preparation and characterization of TiO (T)
2
In a typical synthesis, 30 wt %, 0.5 mL of NH OH solution and 1.0 mL of H O were added into a
4
2
combination of ethanol (150 mL) and acetonitrile (100 mL) under strong stirring. Then, 5 mL of
titanium isopropoxide was quickly injected, and a milky suspension was formed within a few
seconds, pH of the reaction mixture found to be in the range of around 7-8. After continuous
stirring for 6 h at 200°C, the precipitate formed collected by centrifugation, washed with ethanol
twice and dried at 60°C. The as-prepared TiO confirmed further by XRD, and the material
2
showed individual diffraction peaks at 2 = 25.3, 37.9, 47.7 and 54.4° (Fig. S13).
2
.3
Deposition process of TiO in PET
2
A solution of TiO (T) was used to generate a transparent coating on the F by an ultrasonic
2
assisted method (ultrasonic power and frequency were 100ꢀW and 30ꢀkHz). Then, the obtained
sample exposed in ammonia vapor to neutralize the surface.
2
.4
Deposition of porphyrin and silane in TiO attached PET
2
Porphyrin is ultrasonically deposited (ultrasonic power and frequency were 100ꢀW and 30ꢀkHz)
-5
on the TiO -coated fabric by preparing a solution (1x10 M) in DMF. The process carried out by
2
soaking the TiO -coated fabric and ultrasonicating for 30 minutes, washing with DMF and water
2
-5
to take out excess unbound porphyrin and dried. Finally, silane (1x10 M) in ethanol deposited
o
to porphyrin/TiO coated fabric by ultrasonicated for 30 minutes, dried at 100 C for about 1
2
hour and then washed the fabric in excess ethanol to remove unbounded silane.
2
.5
Photocatalytic self-cleaning function of organic pollutants

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-3
NP, RB, EY, IN, BB and MB in chloroform or water (1.5x10 M), and this was then drop cast on
surface modified fabric (TP and TPS) and dried for an hour in the dark to reach the adsorption-
desorption equilibrium. The self-cleaning abilities of the modified fabric samples were
determined by measuring the change in the intensity under visible light irradiation and confirmed
by recording the UV-Vis absorption spectra at altered time intervals.
3
3
.
Results and discussion
UV-Vis spectroscopy
.1
Attachment of TiO , silane and porphyrin to the fabric was confirmed by recorded the UV-
2
Visible spectra of the samples. The surface modifications resulting in the TP, TPS fabrics are
shown in Fig. 1B. No peaks were observed in the visible region of the spectra of pristine fabric,
which are shown in Fig. 1B (curve a). As shown in Fig. 1B (curve b), after attaching the
porphyrin P, strong absorption peaks were observed at 505 nm, and these can be attributed to the
Soret bands of porphyrin, and they are similar to the peaks of P observed at approximately 486
nm in DMF solutions. Two weaker bands observed at 656 and 764 nm for P and these
correspond to the Q-band of porphyrin (Fig. 1A). These results clearly indicate the successful
decoration of P on the surface of the fabric. The absorbance peaks of the soret bands of P
showed a clear redshift by 19 nm after attachment to the fabric, shift caused due to the
interactions of carboxylic acid group of the porphyrin and the TiO . In addition, in the absorption
2
spectra of Si-bound fabric, no new absorption peaks were observed beyond those of porphyrin P,
but the intensities of the peaks from P were lower, as shown in Fig. 1B (curve c), which is due to
the silane molecules screening or shielding the surface of TiO and porphyrin coated in fabric.
2

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Fig. 1. UV-Vis spectra of (A) P in DMF and (B) solid-state UV-Vis spectra of (a) PET, (b)
PET@TP and (c) PET@TPS.
3
.2
XRD analysis
The crystallinities of PET, PET@TP and PET@TPS fabrics measured by XRD, and the
patterns shown in Fig. 2. Pristine fabric showed no characteristic peaks (Fig. 2 curve a). The
fabric coated with TiO showed diffraction peaks at 2θ=25.7, 38.0 47.9, 54.5 and 62.8 (Fig. 2
2

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curve b) correspond to the lattice planes of (1 0 1), (0 0 4), (2 0 0), (2 1 1) and (2 0 4),
respectively, which is in good agreement with (JCPDS) data [no. 04-0783]. These results,
indicates anatase TiO nanoparticles form on the fabric surface. The XRD patterns of PET@TP
2
was not significantly different from that of fabric coated with TiO which clearly indicates that
2
,
after modification with P, the anatase TiO reserved its crystallinity. Finally, the samples altered
2
with silane attachment, PET@TPS retained the peak intensities of the TiO on the fabric surface.
2
Fig. 2. XRD spectra of (a) PET, (b) PET@T, (c) PET@TP and (d) PET@TPS.
3
.3
SEM and EDX analysis
SEM to investigate the structures and morphologies of the pristine and surface modified fabrics.
As shown in Fig. 3(a), pristine fabric possesses a braided structure and has a thin, sheet-like
morphology. After decoration with TiO nanoparticles, we observed that TiO particles with an
2
2
average size of 200 nm uniformly and densely dispersed on the surface of the fabric, as shown in
Fig. 3(b). For the TP samples, the size of the TiO particles increased, and some layered
2

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structures were deposited on the surface of fabric. In addition, after the installation of Si on the
surface of TP fabric, the TiO nanoparticles aggregated, which is similar to previous reports by
2
our research group. Mapping study for PET@TPS has been done to confirm the presence of C,
N, O, Si and Ti (Fig. 4). Furthermore, the EDX profiles confirm the presence of Ti and Si on the
modified fabrics, as shown in Fig. S14.
Fig. 3. SEM images of (A) PET, (B) PET@T, (C) PET@TP and (D) PET@TPS.

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Fig. 4. Mapping analysis of PET@TPS.
.4 XPS measurement
3
To investigate the chemical state of surface modifications on fabric, XPS measurement done.
The survey spectrum (Fig. 5) shows that the materials was composed of C, O, N, Si and Ti,
which supports the successful decoration of TiO , porphyrin and Silane on the surface of fabric.
2
The C1s peaks in the XPS spectra of PET@TPS (Fig. S15A) appear as two deconvoluted peaks
at 285.4 and 286.3, which indicate more sp -hybridized (C-O-C & C=O) linkages. The
2
deconvoluted O1s peaks at 533.3, 532.6 and 531.7 were ascribed to the existence of C=O, C-O
and Si-O, respectively (Fig. S15C) [42,43], in the skeleton. Moreover, the peak at 530.1 eV was
from the presence of TiO on the fabric. The N1s peaks of PET@TPS (Fig. S15B) appearing at
2
3
1
99.2 eV corresponded to the porphyrin ring of pyrrole-like nitrogen. The additional peak at
03.5 eV was attributed to the Si2p peak from the silicate (Si-O) network. The Ti2p signals

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appeared as two peaks at 458.8 (Ti2p3/2) and 464.2 eV (Ti2p1/2), and the O1s peak at 530.0 eV
was characteristic of TiO2.
Fig. 5. XPS survey spectra of PET@TPS.
3
.5
Water repelling measurement of modified fabric surface
The superhydrophobicity of the surface modified fabric has been investigated by WCA (water
contact angle) measurements. Fig. 6 shows that the pure and clean pristine polyethylene

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terephthalate surface has a WCA of 134°. Generally, surface of PET is intrinsically hydrophobic,
but the water droplet was not simply roll off when the surface was sloped. To achieve this, the
surface of fabric was modified with TiO , and the WCA increased (138°), corresponding to
2
greater hydrophobicity. For comparison, after modification with porphyrin, the WCA of the
fabric surface was 0° (surface of fabric becomes hydrophilic) but showed superior photocatalytic
activity due to the porphyrin attachment to the fabric surface. On the other hand, further
modification with Silane on the surface of the PET@TP resulted in superhydrophobic or water-
repelling properties, and the WCA values were found to be 152°, respectively, which are higher
than that of the pristine polyethylene terephthalate surface, as shown in Fig. 6.
Fig. 6. Water contact angles of (A) PET, (B) PET@T, (C) PET@TP and (D) PET@TPS.
3
.6
Photo decomposition of organic pollutant
The discoloration of organic pollutant and dye molecules such as EY, NP, BB, RB and IN were
examined by attaching each chemical separately to fabric and surface modified fabric PET@TP
and irradiated in visible-light about 3 h and the results are shown as Fig. 7 indicating almost most
of the pollutant undergoes discoloration except IN.

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Fig. 7. Photocatalytic discoloration of organic pollutant by pristine and surface modified fabric.
.7 Photocatalytic activity
3
The detoxification of organic pollutants is of great importance in the environment and beyond. In
this regard, the self-cleaning function through photodiscoloration activities of fabric surface
modified with T, TP and TPS investigated with surface-adsorbed harmful MB. Under visible-
light irradiation, MB decomposition occurred in pristine fabric and modified fabric surfaces
easily monitored visually, as shown in Fig. S16. In the absence of surface modifications, the
fabric surface caused no obvious color changes. On the other hand, the intense color of the MB
slowly faded in the surface modified fabric. These color changes and UV-DRS spectra
simultaneously monitored as a function of time (Fig. 8). The decomposition efficiency was in the

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order PET@TP > TPS > T. The C/C vs time plot displayed in Figure 9. A good linear
0
correlation between ln(C/C ) and the reaction time t (99.9%) was obtained (Fig. S17). The rate
0
constant, k, of the MB discoloration was derived from the following equation [44-46]:
-ln C/C0 = kt (1)
Where k is the rate constant and t is the reaction time. C and C are the initial MB concentration
0
and the concentration at time t, respectively. In comparing, the results obtained from the above
study it is noted that PET@TP caused a significant enhancement in the photocatalytic
performance, which can be attributed to the increased photosensitization of the porphyrin. In
addition, after decoration with the silane molecules, the photocatalytic activity decreased because
the silane-modified surface masks the surface of the TiO , porphyrin-coated in fabric, and the
2
surface becomes superhydrophobic. Therefore, the silane molecules functionalized fabric
PET@TPS have dual self-cleaning effects.

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Fig. 8. Solid-state UV-Vis spectra of the decomposition of MB under visible-light irradiation by
A) PET, (B) PET@T, (C) PET@TP and (D) PET@TPS.
(

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Fig. 9. Plot of C/Co Vs Time for the decomposition of MB under visible-light irradiation before
and after fabric surface-modification.
3
.8
TiO /porphyrin stability study
2
To check the stability and reusability of TiO /porphyrin-modified fabric. In this case, TiO has
2
2
good adhesive properties, allowing to easily binding with both fabric and the porphyrin
derivatives. Therefore, to evaluate the stability of TiO and porphyrin-modified fabric before and
2
after irradiation with visible light (Fig. S18), exposure to water, petroleum ether and washing
with detergent, the UV-Vis spectra of the samples were acquired and are shown in Fig. S19. No
obvious changes in the UV-Vis spectra of the Soret and the Q-bands of the porphyrin were
observed. This result indicates that the fabric surface modified with TiO and porphyrin retained
2
its stability and reusability, which can be attributed to the strong interactions between the
carboxylate groups of the porphyrin and TiO2.

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3
.9
Stability of the silane coating
To assess the stability of the superhydrophobic surfaces, we measured the WCA. Previously, we
determined that the stability of PET@TP was due to the strong affinity of TiO towards the
2
carboxylate groups on the porphyrin. As shown in Fig. S20, the permanence of the silane on the
surface evaluated by washing samples in three different media: detergent, petroleum ether and
water. Even after five washing cycles, the WCAs decreased slightly from 152° to 150° for
PET@TPS fabric sample. Furthermore, the photostability of the surface also measured before
and after 24 h of irradiation with visible-light. No drastic decrease in the WCAs observed, as
shown in Fig. S20. This result indicates that the water repelling properties and photo stability
retained in silane-modified fabric.
3
.10 Photo reduction mechanism

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A possible mechanism for the decomposition of MB on the surface of fabric in visible-light
radiation shown in figure 10. When the fabric irradiated by visible-light, the surface modified
sample can be excited to generate holes and electrons. After the absorption of light by the
porphyrin, the excited electrons migrate out of the ground state (HOMO orbital) over and done
with inter system crossing. These excited level electrons (in LUMO orbital) are readily
transferred to the CB of the TiO [47,48]. The modified surface then reacts with oxygen to yield
2
active superoxide radicals and subsequent protonation provides HOO• radicals, which are
competing through back electron transfer towards the dye+• [42]. In the meantime, the surface
modified with silane retained superhydrophobic even after irradiation, which is due to the
destruction of OH• on the surface of the TiO through dye sensitization, allowing it to retain its
2
hydrophobicity.
Fig. 10. Plausible charge separation mechanism and its process for the self-cleaning function in
modified fabric.
3
.11 Analysis of real samples

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To evaluate the modified fabric surfaces for the photocatalytic self-cleaning activity and
superhydrophobicity, real samples (coffee and oil stains) were tested, and the obtained results
shown in Fig. 11. Coffee drops added to the surface of pristine sample and surface modified
sample, and the reliability and practicality of the system verified. Under visible-light radiation,
PET@TP surface reaches maximum decomposition at a different time than the other surfaces,
which indicates that the surface has excellent photocatalytic activity, whereas the coffee droplets
moved off from the silane attached fabrics PET@TPS, as shown in fig. 11A. On the other hand,
these fabrics also tested for the decomposition of oil stains such as soy sauce. The oil present in
the sauce easily adsorbed onto the surface of the fabrics, and the stains adsorbed on the modified
fabrics generally degraded the stain in 6h (fig. 11B). The result obtained clearly indicates that
before and after modification with silane, the fabric surface has excellent photodecomposition
ability and superhydrophobicity owing to an excellent self-cleaning material.
Fig. 11. Photocatalytic decomposition and superhydrophobicity of before and after surface-
modified fabric (A) coffee stain and (B) soy sauce.
3
.12 Printing Application

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As a preliminary study, in the present work, we developed a single-component ink consisting of
silane (0.5 g) in ethanol (10 mL) solution that is highly suitable for use as a digital printing ink,
-3
and the ink was injected into a cartridge [to facilitate visualization, dye (2.5x10 M) was added
to the Silane ink]. A Canon (MG2590) printer and cartridge (CL-946) used, and an image was
printed on the TiO /porphyrin-modified fabric, which is shown in fig. 12. The hydrophobicity of
2
the printed image on the fabrics confirmed by water droplet testing, which involved placing
water droplets on the image as well as on the non-printed area of the fabric. As predicted, the
printed area is superhydrophobic with a WCA of 150°, and the rest of the fabric area is
hydrophilic, shown in figure 12. Thus, the prepared ink can be utilized as a highly efficient
printing material to make fabric surface superhydrophobic.

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Fig. 12. Digital printing process on surface modified fabric to attain superhydrophobic image.
4
.
Conclusions
A visible light active, superhydrophobic, self-cleaning fabric effectively established through
surface modification by incorporating TiO , porphyrin and silane by ultrasonic method. The
2
visible-light photocatalytic activity of the modified surface, the stability of the porphyrin and

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silane on the surface and the overall self-cleaning efficiency discussed in detail. Self-cleaning
abilities, based on the reproducible photodiscoloration of approximately 90% of MB, observed
for the modified surface, a WCA of approximately 152° obtained for PET@TPS-coated surface,
and the stability of the porphyrin and silane on TiO -bearing fabric confirmed by washing the
2
sample with aqueous and organic solvents and irradiating the sample under visible light. As a
preliminary attempt, a single-component ink prepared using silane and used in digital printing,
and the superhydrophobicity of the printed image on the fabric confirmed by water droplet
testing. Thus, surface modification on fabric makes the material dual-functioning self-cleaning
effect.
Acknowledgements
This work was supported by the industrial Fundamental Technology Development Program
(10076350) funded by the Ministry of Trade, Industry and Energy (MOTIE) of Korea. This study
was supported by the Basic Science Research Program through the National Research
Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning (Grant
No. NRF-2017R1E1A1A01074266).
References
[
1] P. Chauhan, A. Kumar, B. Bhushan, Self-cleaning, stain-resistant and anti-bacterial
superhydrophobic cotton fabric prepared by simple immersion technique, J. Colloid
Interface Sci. 535 (2019) 66-74.
[
[
2] S. Wang, K. Liu, Y. Xi, J. Lei, Bioinspired surfaces with super wettability: new insight
on theory, design, and applications, Chem. Rev. 115 (2015) 8230-8293.
3] H. Zhao, K.Y. Law, Directional Self-Cleaning Superoleophobic Surface, Langmuir 28
(2012) 11812-11818.

Journal Pre-proof
27
[
[
[
[
4] Z.H. Yang, C.Y. Chiu, J.T. Yang, J.A. Yeh, Investigation and application of an
ultrahydrophobic hybrid-structured surface with anti-sticking character, J. Micromech.
Microeng. 19 (2009) 085022-085032.
5] Y. Lai, Y. Tang, J. Gong, D. Gong, L. Chi, C. Lin, Z. Chen, Transparent
superhydrophobic/superhydrophilic TiO -based coatings for self-cleaning and anti-
2
fogging, J. Mater. Chem. 22 (2012) 7420-7426.
6] L. Mishchenko, B. Hatton, V. Bahadur, J.A. Taylor, T. Krupenkin, J. Aizenberg, Design
of ice-free nanostructured surfaces based on repulsion of impacting water droplets. ACS
Nano 4 (2010) 7699-7707.
7] Y. Zhao, Y. Tang, X. Wang, T. Lin, Superhydrophobic cotton fabric fabricated by
electrostatic assembly of silica nanoparticles and its remarkable buoyancy, Appl. Surf.
Sci. 256 (2010) 6736-6742.
[
[
8] A. Marmur, Super-hydrophobicity fundamentals: implications to biofouling prevention,
Biofouling J. Bioadhes. Biofilm Res. 22 (2006) 107-115.
9] Z. Ming, L. Jian, W. Chunxia, Z. Xiaokang, C. Lan, Fluid drag reduction on
superhydrophobic surfaces coated with carbon nanotube forests (CNTs), Soft Matter 7
(2011) 4391-4396.
[
[
10] F. Zhang, L. Zhao, H. Chen, S. Xu, D.G. Evans, X. Duan, Corrosion resistance of
superhydrophobic layered double hydroxide films on aluminum, Angew. Chem. Int. Ed.
4
7 (2008) 2466-2469.
11] G. Hayase, K. Kanamori, M. Fukuchi, H. Kaji, K. Nakanishi, Facile synthesis of
marshmallow‐like macroporous gels usable under harsh conditions for the separation of
oil and water, Angew. Chem. Int. Ed. 52 (2013) 1986-1989.

Journal Pre-proof
28
[
[
[
12] B. Bhushan, Biomimetics: Bioinspired hierarchical-structured surfaces for green science
rd
and technology, 3 ed. Springer, Switzerland (2018).
13] L. Wen, Y. Tian, L. Jiang, Bioinspired super-wettability from fundamental research to
practical applications, Angew. Chem. Int. Ed. 54 (2015) 3387-3399.
14] S.S. Latthe, R.S. Sutar, V.S. Kodag, A.K. Bhosale, A.M. Kumar, K.K. Sadasivuni, R.
Xing, S. Liu, Self-cleaning superhydrophobic coatings: Potential industrial applications,
Prog. Org. Coat. 128 (2019) 52-58.
[
15] S. Banerjee, D.D. Dionysiou, S.C. Pillai, Self-cleaning applications of TiO by photo-
2
induced hydrophilicity and photocatalysis, Appl. Catal. B Environ. 176-177 (2015) 396-
4
28.
[
[
16] D. Pasqui, R. Barbucci, Synthesis, characterization and self cleaning properties of titania
nanoparticles grafted on polyester fabrics, J. Photochem. Photobiol. A 274 (2014) 1-6.
17] C.S.U. Demirel, N.C. Birben, M. Bekbolet, A comprehensive review on the use of second
generation TiO photocatalysts: microorganism inactivation, Chemosphere 211 (2018)
2
4
20-448.
[
[
18] A. Fujishima, X. Zhang, Titanium dioxide photocatalysis: present situation and future
approaches, C.R. Chim. 9 (2006) 750-760.
19] G. Heo, R. Manivannan, H. Kim, J.W. Ryu, Y.A. Son, Visible light photo-sensitized
metallo-porphyrin/TiO photocatalyst and its related self-cleaning effects in poly ethylene
2
terephthalate, J. Nanosci. Nanotechnol. 19 (2019) 8004-8012.
[
20] H. Kim, R. Manivannan, G. Heo, J.W. Ryu, Y.A. Son, Porphyrin dye/TiO entrenched in
2
PET to attain self-cleaning property through visible light photocatalytic activity, Res.
Chem. Intermed. 45 (2019) 3655-3671.

Journal Pre-proof
29
[
[
21] R. Manivannan, J.W. Ryu, Y.A. Son, Photo discoloration of eosin yellow dye under
visible light using TiO @TPPS nanocomposite synthesized via ultrasonic assisted
2
method, Colloid. Surface. A 608 (2021) 125601.
22] M. Dhananjeyan, E. Mielczarski, K. Thampi, P. Buffat, M. Bensimon, A. Kulik, J.
Mielczarski, J. Kiwi, Photodynamics and surface characterization of TiO and Fe O
2
2
3
photocatalysts immobilized on modified polyethylene films, J. Phy. Chem. B 105 (2001)
2046-12055.
1
[
[
[
23] L. Xiao-e, A.N.M. Green, S.A. Haque, A. Mills, J.R. Durrant. Light-driven oxygen
scavenging by titania/polymer nanocomposite films, J. Photochem. Photobiol. A 162
(2004) 253-259.
24] H. Ichiura, T. Kitaoka, H. Tanaka, Removal of indoor pollutants under UV irradiation by
a composite TiO -zeolite sheet prepared using a papermaking technique, Chemosphere
2
5
0 (2003) 79-83.
25] P. Wang, Y. Dong, B. Li, Z. Li, L. Bian, A sustainable and cost effective surface
functionalization of cotton fabric using TiO hydrosol produced in a pilot scale: condition
2
optimization, sunlight-driven photocatalytic activity and practical applications, Ind. Crop
Prod. 123 (2018) 197-207.
[
[
26] H. Zhang, X. Li, B. Han, H. Wu, N. Mao, Simultaneous reactive dyeing and surface
modification of polyamide fabric with TiO2 precursor finish using a one-step
hydrothermal process, Text. Res. J. 88 (2018) 2611-2623.
27] K. Qi, W.A. Daoud, J.H. Xin, C.L. Mak, W.S. Tang, W.P. Cheung, Self-cleaning cotton,
J. Mater. Chem. 16 (2006) 4567-4574.