LL1, a novel and highly selective STAT3 inhibitor, displays anti-colorectal cancer activities in vitro and in vivo

Article abstract of DOI:10.1111/bph.14863

Background and Purpose: Signal transducer and activator of transcription 3 (STAT3) factor is associated with the development and progression of numerous types of human cancer. STAT3 activation is involved in metastasis. However, no STAT3 inhibitor has bee

Full text of DOI:10.1111/bph.14863

Research Article
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Cite This: ACS Appl. Mater. Interfaces 2019, 11, 16914−16921
Coexistence of Antiadhesion Performance, Intrinsic Stretchability,
and Transparency
Minhuan Liu, Fanghui Liu, Xiubin Xu, Danfeng Yu, Ian Wyman, Hui Yang, Jinben Wang,‡
and Xu Wu*
†
†
‡
†
†
§
‡
,
†
Department of Chemistry and Chemical Engineering, Guangzhou University, Guangzhou 510006, China
‡
Beijing National Laboratory for Molecular Sciences, Key Laboratory of Colloid, Interface and Chemical Thermodynamics, Institute
of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
§
Department of Chemistry, Queen’s University, Kingston K7L 3N6, Canada
S Supporting Information
*
ABSTRACT: Antiadhesion performance, stretchability, and
transparency are highly desirable properties for materials and
devices in numerous applications. However, the existing
strategies for imparting materials with antiadhesion perform-
ance generally induce rigidity and opacity, and principle is yet
to be provided for designing materials that combine these
important parameters. Here, we show that four factors
including a low surface energy, appropriate cross-linking,
availability of a homogeneous and amorphous composite, and
a smooth material surface can be used to design an
intrinsically stretchable and transparent polymer film with
antiadhesion performance against various liquids including water, diiodomethane, hexadecane, cooking oil, and pump oil. The
film can be obtained via simply molding a waterborne polymer network at ambient temperature. Furthermore, the film can
retain its antiadhesion performance and outstanding transparency even when it is subjected to large mechanical deformations
reaching up to 1800%, and its maximal fracture strain exceeds 3000%. These design concepts offer a general platform for
achieving multiple material functionalities, and may open new avenues for the surface functionalization of stretchable materials
and devices.
KEYWORDS: antiadhesion performance, intrinsic stretchability, transparency, polymer film, combined parameters
1
. INTRODUCTION
categories according to their architectures, known as hemi-air,
hemi-liquid, and homogeneous solid materials, respectively.
The lotus-inspired hemi-air surfaces trap air pockets in micro-
and nanoscale textured materials with low surface energies,
thus exhibiting superamphiphobic properties with high contact
angles (exceeding 150°) and low sliding angles (below 10°)
The rapid advancements seen in the fields of information
technology and biotechnology have allowed us to envision the
future, one in which synthetic materials and devices such as
1
,2
3,4
5,6
artificial skin, bionic muscles, and wearable electronics
are widely used for prosthetics and advanced robotics. As
researchers endeavor to achieve these applications to help us
cure diseases and obtain capabilities once thought to be
impossible, stretchability and optical transparency of materials
13−15
toward both water and oil.
The hemi-liquid materials with
slippery liquid-infused porous surfaces (SLIPS) are inspired by
the Nepenthes pitcher plants, containing low-surface-energy
fluids that are locked in place within modified porous
1
−9
and devices have become increasingly sought after.
On the
other hand, controlling the surface wettability of materials is a
classical and key issue, and antiadhesion surfaces with poor
affinity to both water and oil have been designed and prepared
16,17
18
materials
or polymer matrixes, and they yield moderate
contact angles below 120° while remaining clean after exposure
to various liquids. Meanwhile, as the oldest fluorinated
polymer with a low surface energy as well as a homogeneous
solid fluorocarbon-based structure, poly(tetrafluoroethylene)
10−12
extensively in the literature reports.
However, the existing
materials with antiadhesion performance generally have
structural requirements that restrict their stretchability and
transparency. There is still a fundamental lack of a designing
concept considering the coexistence of these highly desirable
properties to achieve the surface functionalization required for
the next generation of stretchable materials and devices.
In general, the materials with adhesion resistance to both
water- and solvent-based liquids can be classified into three
(
PTFE, Teflon) can also repel a wide range of liquids at
moderate contact angles, and has been successfully employed
Received: January 30, 2019
Accepted: April 16, 2019
Published: April 16, 2019
©
2019 American Chemical Society
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in many demanding applications where antiadhesion perform-
ance is required.
use. Acetone was used after it had been dehydrated for 48 h with 4.0
Å molecular sieves.
́
1
9−21
2
.2. Synthesis of FSCPN, FPN-P, and FPN-C. In a typical
Unfortunately, the inherent structures of superamphiphobic,
SLIPS, and PTFE-based materials inhibit their stretchability,
thus restricting their applications in wearable, implanted, or
epidermal materials and devices. To the best of our knowledge,
no intrinsically stretchable superamphiphobic materials have
been reported, as the hierarchical textured structures that hold
air pockets in place are often intricate and prone to damage via
mechanical deformation. By regulating the roughness of the
surfaces that are damaged by deformation, a limited variety of
elongated surfaces that can only repel water have been
achieved. These materials were prepared by spraying hydro-
phobic nanoparticles onto stretchable substrates such as
synthesis procedure for the fluorine-terminated synergistic cross-
linked polyurethane network (denoted as FSCPN), calculated
amounts of PTMG (15.0 g, 15.0 mmol), DMBA (1.48 g, 10.0
mmol), and TMP (0.67 g, 5.00 mmol) were charged into a 250 mL
flask, and the mixture was purged with nitrogen for 30 min at room
temperature. IPDI (11.1 g, 50.0 mmol), DBTDL (0.0100 g, 0.0160
mmol), and acetone (5.00 mL) were added to the flask, and the
reaction proceeded for 2 h at 80 °C. TFO (3.64 g, 10.0 mmol) was
subsequently added into the above mixture, and the reaction was
allowed to continue for 2 h. This reaction mixture was cooled to 40
°
C, and TEA (1.01 g, 10.0 mmol) was used to neutralize the DMBA
units. Finally, an aqueous solution (78.6 g) comprising EDA (0.75 g,
12.5 mmol) was added dropwise under vigorous stirring to obtain a
2
2
23
rubber and resin, or by creating micro/nanotextured
3
0.00 wt % FSCPN aqueous solution. The fluorine-terminated
polyurethane networks with either physical or chemical cross-linking
denoted as FPN-P and FPN-C, respectively) were prepared via
24
roughness on monoliths with a maximum strain of ∼100%.
In the case of a SLIPS material, the slight stretching by less
than 10% would severely degrade its liquid repellency and
transparency due to the disruption of the lubricant surface
(
similar procedures, except that ED (0.47 g, 7.50 mmol) was used
instead of TMP for the preparation of FPN-P, and ED (0.78 g, 12.5
mmol) was added and allowed to react for 2 h prior to the cooling of
the reaction mixture, although the addition of EDA was not
performed during the preparation of FPN-C.
25
layer by newly formed gaps resulting from this deformation.
Monolayers
2
6,27
28−31
or polymer-based coatings
bearing
lubricant surfaces formed by the low-surface-energy fluids
can provide similar antiadhesion performance as obtained with
SLIPS materials. These surfaces can also exhibit transparency,
although there has been a lack of studies regarding their
stretchability. Lastly, it is difficult to impart PTFE-based
materials with stretchability because of their poor solubility in
most solvents and high melting points (∼330 °C), whereas
their high melting viscosities further impede the molding of
2
.3. Preparation of the Films. The FSCPN/FPN-P/FPN-C
aqueous solutions were poured into a culture dish at 50 °C for 24 h to
form the films. The films were then peeled from the culture dish and
cut into rectangle pieces for further testing.
2
.4. Characterization Methods. The energy-dispersive X-ray
spectroscopy (EDX) elemental mapping of the films was conducted
using a scanning electron microscope (SEM, Hitachi, SU8010), which
was operated at an accelerating voltage of 20 kV. The elemental
analysis of both sides of the film was performed by X-ray
photoelectron spectroscopy (XPS, Thermo Scientific, ESCALAB
32−34
these materials into films.
In addition to their rigidity and
lengthy preparation, superamphiphobic, SLIPS, and PTFE-
based materials tend to scatter light due to their micro/
250Xi). Size-exclusion chromatography (SEC) analysis was performed
2
2−24
25
32−34
using a Waters 515 system equipped with a guard column. The
molecular weight of FSCPN was determined using polystyrene
standards, and tetrahydrofuran was used as the mobile phase at a flow
rate of 1.0 mL/min. The aggregates that formed in aqueous FSCPN
solutions were observed with a transmission electron microscope
nanoscaled roughness,
pores, and crystallinity,
which can affect their transparency and render them unsuitable
for applications as wearable electronics, such as displays,
35−37
sensors, and actuators.
Herein, we were able to develop a transparent polymer film
that exhibits both antiadhesion performance against various
liquids and high intrinsic stretchability. As will be described
below and referred to later in this report, four essential
structural elements were incorporated into the design of this
material with a combination of desirable properties. These
features included (1) a low-surface-energy component
necessary for antiadhesion performance, (2) an appropriate
(
TEM, JEOL, JEM-2100F). The solution was added dropwise onto a
400-mesh carbon-coated copper grid, frozen using liquid nitrogen,
and then dried under vacuum to prepare the TEM samples. Fourier-
transform infrared (FTIR, Bruker Optics, Spectrum 100) spectra
recorded with a Tensor-27 spectrometer were employed to monitor
the consumption of the isocyanate groups, and KBr was used as the
sample matrix. The contact angle (CA), sliding angle (SA), advancing
contact angle (θ ), and receding contact angle (θ ) were measured
using a contact angle measuring instrument (Shengding, JC2000A).
The θA and θR were, respectively, measured by injecting the test
liquids into or withdrawing them from a droplet resting on the film
until it advanced or receded. Each reported contact angle or sliding
angle corresponded to the average of five measurements. Thermal
stability measurements were conducted via thermogravimetric analysis
(TGA, Perkin Elmer, TGA4000) using dry nitrogen as the purge gas.
Differential scanning calorimetry (DSC, Perkin Elmer, DSC8000) was
performed under a nitrogen atmosphere with the heating and cooling
rates of 10 °C/min. Mechanical tensile-stress tests were performed
using a universal testing machine (SUNS, UT4304) with a load cell of
100 kN. The microphotographs were recorded using an optical
microscope (Mshot, MD30). The recovery ratio was calculated by the
A
R
(
including both chemical and physical) cross-linking of
polymers to also provide the antiadhesion performance and
stretchability, (3) a homogeneous and amorphous nature to
offer transparency, and (4) a smooth material surface that
reliably retained its curvature during stretching, so that it was
immune to deformation-induced changes of roughness and
wettability that typically plague textured surfaces.
2
. EXPERIMENTAL SECTION
2
.1. Materials. Isophorone diisocyanate (IPDI, >99.0%), poly-
tetramethylene glycol) (PTMG, with an average equivalent weight of
000 g/mol), and dimethylolbutanoic acid (DMBA) were supplied by
(
1
equation: R = 1 − ε(t)/εmax, where εmax is the strain measured at the
r
Hengtai Chemical Co., Ltd. Trimethylolpropane (TMP), triethyl-
beginning of the recovery process and ε(t) is the time-dependent
strain. An atomic force microscope (AFM, Bruker, Dimension) was
used to analyze the surface roughness of the film. Dynamic
thermomechanical analysis (DMA) was conducted using a dynamic
mechanical analyzer (TA instrument, Q800). Meanwhile, the optical
transmittance of the film was measured using a UV−vis spectropho-
tometer (Perkin Elmer, Lambda 950).
amine (TEA, ≥99%), ethanediol (ED), and ethylene diamine (EDA,
≥99%) were provided by Damao Chemical Reagent Co., Ltd. IPDI,
dibutyltin dilaurate (DBTDL, Aladdin, 95%), EDA, and TEA were
used as received. PTMG, TMP, EG, and DMBA were purified under
vacuum prior to use. 1H,1H,2H,2H-Tridecafluoro-1-octanol (TFO)
was purchased from XEOGIA and distilled under vacuum prior to
1
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Research Article
Figure 1. Design and synthesis of the FSCPN film, as well as the SEM and EDX mapping of the film’s cross section.
Figure 2. Transparency, antiadhesion performance, and flexibility of the films. (a) G′, G″, and tan δ (G″/G′) curves of the film obtained via DMA.
b) Optical transmission measurements of the film, including an inset AFM image of the film surface. (c) Photograph of a smartphone screen
(
covered by the film in the top region that is outlined by red dashed lines. The remaining region at the lower sections of the screen was left uncoated
for comparison. (d) Photographs of various liquids sliding off the film. (e) Photograph taken during the measurement of the film’s minimum
bending radius. (f) Photograph of a film sample that had been folded into a crane shape.
3
. RESULTS AND DISCUSSION
water dispersibility, and PTMG was introduced as a flexible
hydrophobic macrodiol. TMP was selected as a cross-linking
agent to form branching bonds and thus undergo internal
chemical (covalent) cross-linking. Meanwhile, a noncovalent
physical cross-linking phenomenon was achieved via the
macrocyclic urea hydrogen bonding that resulted from the
reactions between EDA and IPDI. The chemical and physical
synergistic cross-linking phenomena satisfied the second
requirement outlined earlier. The average molecular weight
The film developed in this work was simply molded in a
culture dish at 50 °C for 24 h from a fluorine-terminated
synergistic cross-linked polyurethane network (FSCPN, Figure
1
) that was dispersed in water. The FSCPN was synthesized
via the polycondensation of IPDI with multifunctional polyols
and a diamine, which were selected for various reasons. For
example, TFO was chosen to provide a low surface energy as
the first required factor, and the applied content accounted for
3
.60 wt % of the aqueous solution and represented 10.8 wt %
between cross-links (M ) could be calculated by dividing the
c
of the resultant film. DMBA was employed to provide the
total amount of materials by the molar number of cross-links,
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and the chemical and urea physical cross-linking densities (ν =
this surface (Movie S3, Supporting Information). The CA, SA,
−5
1
3
/2M ) thus determined for FSCPN were 7.66 × 10 and
θ , and θ of these test liquids are given in Table 1, with a
c
A
R
−
4
38
.83 × 10 mol/g, respectively. Furthermore, we envisioned
that the FSCPN composite with suitable compatibility could
form a homogeneous and amorphous material with a smooth
surface, thus meeting the third and fourth required factors.
As we had anticipated, the SEM and EDX elemental
mapping revealed that a smooth surface was obtained, and the
fluorinated moieties were distributed uniformly both on the
surface and throughout the matrix of the FSCPN film (Figure
Table 1. CA, SA, θ , and θ of the Film toward Various Test
A R
Liquids
water
deg)
diiodomethane hexadecane cooking oil pump oil
(
(deg)
(deg)
(deg)
(deg)
CA
SA
θA
92 ± 2
49 ± 1
96 ± 2
75 ± 3
65 ± 2
12 ± 1
69 ± 2
52 ± 1
33 ± 2
13 ± 1
41 ± 1
28 ± 2
57 ± 2
18 ± 1
64 ± 2
35 ± 2
56 ± 3
18 ± 1
32 ± 2
43 ± 2
1
); thus, the first, third, and fourth required factors (low
θR
surface energy, homogeneous composition, and smoothness,
respectively) were achieved. The EDX mappings of both sides
of the film, and the surface elementary analysis via XPS
provided in Figures S1 and S2 (Supporting Information)
further demonstrated the homogeneous composition of the
FSCPN film. The characterizations confirming the structure of
FSCPN, including SEC analysis, TEM images, and FTIR
spectra, are given in Figures S3−S5 (Supporting Information).
The TGA indicated that the film withstood temperatures of
up to 200 °C without encountering mass loss (Figure S6,
Supporting Information). The storage modulus (G′), loss
modulus (G″), and tan δ (G″/G′) curves obtained via DMA
over the temperature range from −70 to 200 °C are given in
liquid droplet volume of 2 μL employed for the CA tests and a
0 μL volume used for the SA tests. The CAs recorded at
2
various times after the application of these liquids onto the film
are provided in Figure S8 (Supporting Information). A
minimum bending radius of less than 1 mm was reached,
thus demonstrating that the film had a high degree of flexibility
44
and foldability (Figure 2e). The flexibility of the film was
further illustrated by folding it into a crane shape without
inducing damage (Figure 2f).
Strikingly, a maximal fracture strain of up to 3100 ± 150%
was achieved for a FSCPN film sample with a thickness, gauge
length, and width of 0.5, 5, and 10 mm, respectively, at the
stretching rates of 2−15 mm/min (Figure 3a and Movie S4,
Supporting Information). In addition, the samples retained
their transparency when they were elongated by 1900 ± 100%.
Considering the maximum elongation of only 100−1100% that
is achieved with typical silicon rubbers, it is apparent that the
synergistic cross-linking in this work provided an impressive
Figure 2a. The glass transition temperature (T ) as determined
g
according to the tan δ (G″/G′) curve was 58 °C, which was
consistent with the value corresponding to the broad peak at
∼
55 °C in the DSC curve (Figure S7, Supporting
39
Information). The film with this Tg will not undergo
temperature-induced transitions if it is used at ambient
temperatures, thus ensuring that the film will have suitable
40
45
stability for various room-temperature applications. Further-
more, the DSC curve did not exhibit any sharp peaks
corresponding to crystallization over the range from −70 to
degree of stretchability.
The film stretchability at various stretching rates is provided
in Figure 3b, and the increased fracture tolerance observed as
the stretching rate was decreased, which could be attributed to
the greater amount of time available for the reformation of the
2
00 °C, confirming the amorphous nature of the FSCPN
composite and thus fulfilling the third required factor.
46
Film samples with a thickness of 0.5 ± 0.1 mm exhibited an
optical transmission exceeding 98% at 500 nm as seen in
Figure 2b. The inset AFM image indicates that the roughness
of the film surface was only in the range of several nanometers,
which was close to the physical roughness limits and further
cleaved physical bonds. It was noteworthy that the tensile
strength reached up to 44 MPa, and this excellent mechanical
performance surpassed those achieved in many previously
47
reported examples. The excellent strength and toughness of
the film was further demonstrated when it was employed to lift
a 10 kg barbell (Figure 3c). To the best of our knowledge, only
a few elastomers with much less tensile strength (<0.4 MPa)
have exhibited higher stretchabilities, such as those based on
41,42
demonstrated that a smooth surface was achieved.
The
film was subsequently applied onto the screen of a mobile
phone to demonstrate its possible application for electronic
displays. As shown in the top region of the screen enclosed by
the red dashed lines in Figure 2c, this transparent film did not
obscure the screen. Moreover, the portion of the screen that
was covered by the film retained its responsiveness to finger
touch commands, further indicating its potential applicability
for mobile electronic displays or devices (Movie S1,
Supporting Information).
48
49
metal−ligand complexes or nanocomposite hydrogels.
When the stretched film was released, the initial recovery
proceeded rapidly and the transparency also exhibited self-
healing behavior (Figure 3d and Movie S5, Supporting
Information). The recovery ratios exhibited by the film that
had been subjected to strain values of both 3000 and 1800%
exceeded 80% after 5 min of recovery, over 90% after 30 min
of recovery, and reached 95% after 24 h of recovery, as
indicated by the free recovery processes of the films in Figure
3e. The stress−strain curves for each of the 10 stretch-and-
recover cycles with elongations of 1800, 1000, 500, and 200%,
respectively, demonstrated the sustained reversible stretch-
ability of the film, although the tensile strength diminished as
the number of cycles increased (Figure S9, Supporting
Information).
The FSCPN film exhibited free adhesion after it had been
exposed to test liquids with various surface tensions including
water, diiodomethane, and hexadecane (72.8, 50.8, and 27.5
43
mN/m, respectively, at 20 °C), and oils with different
viscosities such as cooking oil and pump oil (∼80 and 200 cP,
respectively, at 20 °C). All of these liquids cleanly glided down
the surface of the film without leaving any residue along their
paths (Figure 2d and Movie S2, Supporting Information).
Notably, these liquids were still able to slide off our film after
an hour of contact. In addition, after the immersion of films in
these liquids, the stained water (blue) did not wet the film, and
all the other liquids had contracted and gradually flowed off
More strikingly, all of the test liquids were found to cleanly
slide off the stretched films, and the films retained their
antiadhesion properties when they were elongated by up to
1800% (Figure 4a and Movie S6, Supporting Information).
1
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Figure 3. Stretchability, robustness, and recovery of the films. (a) Photographs of the film before and after stretching by up to 3000% at the
stretching rate of 15 mm/min. Transparency was retained after stretching by up to 1800%. (b) The stress−strain curves of the films stretched at
various rates. (c) Photograph demonstrating the excellent strength and toughness of the film. (d) The rapid initial recovery of the film after it had
been stretched by 3000% at 15 mm/min and subsequently released. (e) The recovery of the film after it had been stretched by 3000 and 1800% at
15 mm/min. The inset photographs show the recovered film after its elongation by 3000% and the original film prior to stretching.
The CAs and SAs of these liquids on the films that had been
stretched to different degrees are provided in Figure 4b,c.
Although all of the test liquids could slide cleanly off these
films, the contact angles became smaller, whereas the sliding
angles grew larger when the film was subjected to greater
elongation. When the films were stretched by more than
linking (FPN-P) film that lacked chemical cross-linking and
another fluorine-terminated polyurethane network with
chemical-cross-linking (FPN-C) film that lacked urea-based
physical cross-linking. With regard to the structural designs,
the TMP units were replaced by ethanediol with an equal
quantity of hydroxyl groups for the preparation of FPN-P to
thus eliminate the branching bonds. Meanwhile, an equimolar
quantity of ethanediol was used instead of EDA during the
preparation of FPN-C to remove the urea-based hydrogen
bonds.
Notably, in the absence of the cooperatively enhanced
effects of the chemical and physical cross-linking, test liquids
were found to adhere to both the FPN-P and FPN-C films
(Figure S10, Supporting Information). Furthermore, the
maximum stretchabilities of the FPN-P and FPN-C films
were both significantly decreased to 1050 ± 100% strain, and
the tensile strengths were also dramatically reduced to 12 and
5 MPa, respectively, as indicated by the stress−strain images
and curves of the films (Figure 4f,g). The recovery capabilities
of these films had also significantly diminished (Figures 4h and
S11, Supporting Information). After they were elongated by
1000%, the FPN-P and FPN-C films, respectively, exhibited
recovery ratios of 68 and 55% after 5 min of recovery, 77 and
64% after 30 min of recovery, and 88 and 75% after 24 h of
recovery.
1
800%, the liquids slid off the surfaces but left residue along
their pathways.
As the loss of both antiadhesion properties and transparency
was observed when the film elongation exceeded 1800%, we
suspect that the film may have undergone a strain-induced
structural change, which likely disrupted the four previously
mentioned factors and thus degraded these properties. This
consideration inspired us to investigate the structural changes
that may have occurred during stretching, whereas the extreme
tensile strength and strain performance as well as the rapid
reversibility impeded most of these characterizations. Optical
microscopy images of the film with 2500% strain (Figure 4d)
and those obtained under various stretching states during a full
stretching and 24 h recovery process are shown in Figure 4e.
When the deformation exceeded 1800%, a lamellar structure
that was aligned in an orthogonal direction toward the
stretching direction was observed, and the amorphous nature
as well as the smoothness were lost, so that the third and
fourth required factors were thus unsatisfied. Although seldom
directly observed, this structure was commonly considered as a
local ordered structure that arose due to stretching-induced
polymer chain alignment and packing, and structures formed in
the perpendicular direction were attributed to the mechanical
The chemical and physical cross-linking phenomena
combined as the second required factor were thus found to
enhance both the antiadhesion properties and the stretchability
of the film. Although chemical cross-linking has been used
previously to enhance liquid repellency, the effect of physical
cross-linking was for the first time presented and exper-
5
0,51
torque required to prevent excessive local stress.
During
the recovery process, the ordered structure disappeared in a
reversible manner, thus facilitating the recovery of the
antiadhesion properties and transparency. This reversible
behavior also provides the film with potential applications as
a self-healing and strain-responsive smart material.
To better demonstrate the synergistic effect of cross-linking
as the second required factor, we compared the properties of
the FSCPN film with those of two other films, including a
fluorine-terminated polyurethane network with physical-cross-
52,53
imentally confirmed in this work.
Interestingly, only the FPN-P film exhibited a reversible
strain-induced opaqueness and microscopic lamellar structure,
which was similar to that of the FSCPN film. This
demonstrated the crucial effect of urea-based hydrogen
bonds in enabling the exchange of hydrogen-bonded pairs
when the polymer chains became interpenetrated during the
polymer chain alignment and packing process (Figure S12,
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Figure 4. Antiadhesion performance and transparency of the films under significant deformations. (a) The test liquids cleanly slid off films that
were stretched by 1800%. CA (b) and SA (c) on the FSCPN films with different strains. (d) The enlarged morphologies of the film that had been
elongated by 2500%. (e) Optical microscopy images depicting the morphologies of the film at different elongation degrees recorded during an
entire stretching and 24 h recovery cycle. (f) Photographs of the FPN-P and FPN-C films when they were stretched at 15 mm/min and fractured.
(
g) The stress−strain curves of the FSCPN, FPN-P, and FPN-C at 15 mm/min. (h) The 24 h recovery of the FPN-P and FPN-C films after they
have been stretched by 1000% at 15 mm/min.
Supporting Information). In addition to the slower recovery in
comparison with the FSCPN film, the time-dependence of the
structural development for the FPN-P film was also observed
during the recovery process. The disappearance of these
lamellar structures as well as the self-healing of transparency
required extra time (∼6 h) after the release of the film from a
facile and scalable preparation ensure that this material will
have a wide range of potential applications.
ASSOCIATED CONTENT
■
*
S
Supporting Information
The Supporting Information is available free of charge on the
ACS Publications website at DOI: 10.1021/acsami.9b01971.
1
000% strain to a smaller 500% strain.
EDX mapping of the top and opposite surfaces of the
FSCPN film; XPS analysis of the top and opposite
surfaces of the FSCPN film; SEC trace of FSCPN; TEM
image of FSCPN aqueous solution; FTIR spectrum of
the FSCPN film; TGA thermograms of the FSCPN film;
DSC thermograms of the FSCPN film; contact angles of
water, diiodomethane, hexadecane, cooking oil, and
pump oil recorded at various times after their application
onto the FSCPN film; stress−strain curves of the films
stretched at 15 mm/min for each of the 10 stretching
and recovery cycles with the elongation of 1800, 1000,
500, and 200%, respectively; various liquids strongly
adhere to the FPN-P and FPN-C films; time-lapsed
recovery of the FPN-P and FPN-C films after 1000%
4
. CONCLUSIONS
In summary, the present work demonstrates that four essential
criteria including the use of a low-surface-energy component, a
chemical and physical synergistic cross-linking, a homogeneous
and amorphous composite, and a smooth material surface can
be successfully employed to achieve a FSCPN polymer film
exhibiting antiadhesion performance and transparency even
under significant deformations. The combination of desirable
properties such as the adhesion-resistance to various liquids
under large deformations, reversible elongation by up to
3
000% with a tensile strength of over 44 MPa, optical
transmission in excess of 98% at a thickness of 0.5 mm, and its
1
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ACS Applied Materials & Interfaces
Research Article
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Portion of the screen covered by the film retained its
responsiveness to finger touch commands (AVI)
Liquids gliding down the surface of the film (AVI)
Immersion of films in liquids (AVI)
Maximal fracture strain for FSCPN film sample (AVI)
Release of stretched film (AVI)
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AUTHOR INFORMATION
Corresponding Author
E-mail: xuwu@gzhu.edu.cn.
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Jinben Wang: 0000-0002-6360-9572
Xu Wu: 0000-0002-8907-6073
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X.W. conceived the experiments and wrote the manuscript.
M.L., F.L., X.X., and D.Y. participated in the materials
preparation and characterization. H.Y. and J.W. performed
the AFM and XPS measurements. All authors were involved in
analyzing the results and revising the manuscript.
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The authors declare no competing financial interest.
Dynamic Polymer Systems with Self-Regulated Secretion for the
Control of Surface Properties and Material Healing. Nat. Mater. 2015,
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ACKNOWLEDGMENTS
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We gratefully thank the Important National Science and
Technology Specific Project of China (2017ZX05013003004),
the National Natural Science Foundations of China (21878059
and 21603240), the Science and Technology Project of
Guangdong Province (2017A050501040), and the Science
and Technology Project of Guangzhou City (201610010018)
for sponsoring this research.
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