10 research outputs found
Highly Stretchable and Conductive Superhydrophobic Coating for Flexible Electronics
Superhydrophobic
materials integrating stretchability with conductivity have huge potential
in the emerging application horizons such as wearable electronic sensors,
flexible power storage apparatus, and corrosion-resistant circuits.
Herein, a facile spraying method is reported to fabricate a durable
superhydrophobic coating with excellent stretchable and electrical
performance by combing 1-octadecanethiol-modified silver nanoparticles
(M-AgNPs) with polystyrene-<i>b</i>-polyÂ(ethylene-<i>co</i>-butylene)-<i>b</i>-polystyrene (SEBS) on a
prestretched natural rubber (NR) substrate. The embedding of M-AgNPs
in elastic SEBS matrix and relaxation of prestretched NR substrate
construct hierarchical rough architecture and endow the coating with
dense charge-transport pathways. The fabricated coating exhibits superhydrophobicity
with water contact angle larger than 160° and a high conductivity
with resistance of about 10 Ω. The coating not only maintains
superhydrophobicity at low/high stretch ratio for the newly generated
small/large protuberances but also responds to stretching and bending
with good sensitivity, broad sensing range, and stable response cycles.
Moreover, the coating exhibits excellent durability to heat and strong
acid/alkali and mechanical forces including droplet impact, kneading,
torsion, and repetitive stretching–relaxation. The findings
conceivably stand out as a new tool to fabricate multifunctional superhydrophobic
materials with excellent stretchability and conductivity for flexible
electronics under wet or corrosive environments
Highly Stretchable and Conductive Superhydrophobic Coating for Flexible Electronics
Superhydrophobic
materials integrating stretchability with conductivity have huge potential
in the emerging application horizons such as wearable electronic sensors,
flexible power storage apparatus, and corrosion-resistant circuits.
Herein, a facile spraying method is reported to fabricate a durable
superhydrophobic coating with excellent stretchable and electrical
performance by combing 1-octadecanethiol-modified silver nanoparticles
(M-AgNPs) with polystyrene-<i>b</i>-polyÂ(ethylene-<i>co</i>-butylene)-<i>b</i>-polystyrene (SEBS) on a
prestretched natural rubber (NR) substrate. The embedding of M-AgNPs
in elastic SEBS matrix and relaxation of prestretched NR substrate
construct hierarchical rough architecture and endow the coating with
dense charge-transport pathways. The fabricated coating exhibits superhydrophobicity
with water contact angle larger than 160° and a high conductivity
with resistance of about 10 Ω. The coating not only maintains
superhydrophobicity at low/high stretch ratio for the newly generated
small/large protuberances but also responds to stretching and bending
with good sensitivity, broad sensing range, and stable response cycles.
Moreover, the coating exhibits excellent durability to heat and strong
acid/alkali and mechanical forces including droplet impact, kneading,
torsion, and repetitive stretching–relaxation. The findings
conceivably stand out as a new tool to fabricate multifunctional superhydrophobic
materials with excellent stretchability and conductivity for flexible
electronics under wet or corrosive environments
Highly Stretchable and Conductive Superhydrophobic Coating for Flexible Electronics
Superhydrophobic
materials integrating stretchability with conductivity have huge potential
in the emerging application horizons such as wearable electronic sensors,
flexible power storage apparatus, and corrosion-resistant circuits.
Herein, a facile spraying method is reported to fabricate a durable
superhydrophobic coating with excellent stretchable and electrical
performance by combing 1-octadecanethiol-modified silver nanoparticles
(M-AgNPs) with polystyrene-<i>b</i>-polyÂ(ethylene-<i>co</i>-butylene)-<i>b</i>-polystyrene (SEBS) on a
prestretched natural rubber (NR) substrate. The embedding of M-AgNPs
in elastic SEBS matrix and relaxation of prestretched NR substrate
construct hierarchical rough architecture and endow the coating with
dense charge-transport pathways. The fabricated coating exhibits superhydrophobicity
with water contact angle larger than 160° and a high conductivity
with resistance of about 10 Ω. The coating not only maintains
superhydrophobicity at low/high stretch ratio for the newly generated
small/large protuberances but also responds to stretching and bending
with good sensitivity, broad sensing range, and stable response cycles.
Moreover, the coating exhibits excellent durability to heat and strong
acid/alkali and mechanical forces including droplet impact, kneading,
torsion, and repetitive stretching–relaxation. The findings
conceivably stand out as a new tool to fabricate multifunctional superhydrophobic
materials with excellent stretchability and conductivity for flexible
electronics under wet or corrosive environments
Suppression Effect and Mechanism of Amine-Containing MQ Silicone Resin on the Tracking and Erosion Resistance of Silicone Rubber
How
to effectively enhance the antitracking performance of silicone
rubber is a huge challenge in the field of high-voltage insulation.
In this contribution, amine-containing MQ silicone resin (A-MQ) was
prepared to enhance the tracking and erosion resistance of addition-cure
liquid silicone rubber (ALSR). The results showed that A-MQ imparted
ALSR with excellent tracking and erosion resistance. When A-MQ content
was 4 phr, all test samples passed the inclined plane test at 4.5
kV, and the erosion mass decreased by 67.8%. In addition, the tensile
strength and tear strength increased by 13.2 and 13.6%, respectively,
compared with that of ALSR without A-MQ. The suppression mechanism
was further investigated in the aspects of heat attack and plasma
bombardment by laser Raman spectroscopy, thermogravimetry, thermogravimetry-Fourier
transform infrared spectrometry, scanning electron microscopy, attenuated
total reflection-Fourier transform infrared spectrometry, and X-ray
photoelectron spectroscopy. This revealed that at the elevated temperature
caused by arc discharge, A-MQ promoted crosslinking of the polysiloxane
molecules and suppressed the generation of cyclic oligomers, which
reduced the intensity of the electrical arc. Moreover, when suffering
from plasma bombardment, which was also produced by arc discharge,
A-MQ protected the silicone chains from degradation and eliminated
the carbon deposited on the surface
Synthesis of phenyl silicone resin with epoxy and acrylate group and its adhesion enhancement for addition-cure silicone encapsulant with high refractive index
<p>A novel phenyl silicone resin with epoxy and acrylate group (PSREA) was successfully synthesized via the non-hydrolytic sol-gel condensation reaction of 3-glycidoxypropyltrimethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane, and diphenylsilanediol, and was employed as the adhesion promoter for addition-cure silicone encapsulant (ASE) with high refractive index. The structure of PSREA was confirmed by Fourier transform infrared spectroscopy, <sup>1</sup>H nuclear magnetic resonance spectroscopy, and <sup>29</sup>Si nuclear magnetic resonance spectroscopy. The influence of PSREA on the properties of ASE was studied. It was found that PSREA could markedly enhance the adhesion strength of ASE to aluminum (Al) and poly(p-phenylene terephthamide) (PPA) substrate. When the content of PSREA was 1.5 phr, the shear strength of ASE was 4.43 and 2.27 MPa for Al and PPA substrate, which was about 71 and 266% higher than that of ASE without the adhesion promoter, respectively. In addition, PSREA had little effect on the mechanical properties, refractive index, and viscosity of ASE.</p
Suppression Effect and Mechanism of Platinum and Nitrogen-Containing Silane on the Tracking and Erosion of Silicone Rubber for High-Voltage Insulation
How
to effectively improve the tracking and erosion resistance
of silicone rubber (SR) was an urgent topic in the field of high-voltage
insulation. In this work, the tracking and erosion resistance of SR
was significantly improved by incorporating platinum (Pt) catalyst
and nitrogen-containing silane (NS). The suppression effect and mechanism
of Pt/NS on tracking and erosion were studied by inclined plane (IP)
test, thermogravimetry (TG), thermogravimetry-Fourier transform infrared
spectrometry, laser Raman spectroscopy, and scanning electron microscopy.
It revealed that when 1.4 phr of NS and 6.7 ppm of Pt were added,
the tracking resistance of SR was improved from 2.5 to 4.5 kV level
in the IP test, and the eroded mass was significantly reduced. This
might be attributed to the synergistic effect of Pt/NS on silicone
chains. At a high temperature produced by arc discharge, Pt/NS would
catalyze radical cross-linking, meanwhile suppressing oxidation and
depolymerization of silicone chains. Hence, a tightly cross-linked
network was formed and protected inner materials from arc ablation.
Moreover, carbon deposit during pyrolysis was suppressed by Pt/NS,
which served as the secondary mechanism of tracking suppression
Vapor–Liquid Sol–Gel Approach to Fabricating Highly Durable and Robust Superhydrophobic Polydimethylsiloxane@Silica Surface on Polyester Textile for Oil–Water Separation
Large-scale fabrication
of superhydrophobic surfaces with excellent durability by simple techniques
has been of considerable interest for its urgent practical application
in oil–water separation in recent years. Herein, we proposed
a facile vapor–liquid sol–gel approach to fabricating
highly durable and robust superhydrophobic polydimethylsiloxane@silica
surfaces on the cross-structure polyester textiles. Scanning electron
microscopy and Fourier transform infrared spectroscopy demonstrated
that the silica generated from the hydrolysis–condensation
of tetraethyl orthosilicate (TEOS) gradually aggregated at microscale
driven by the extreme nonpolar dihydroxyl-terminated polydimethylsiloxane
(PDMSÂ(OH)). This led to construction of hierarchical roughness and
micronano structures of the superhydrophobic textile surface. The
as-fabricated superhydrophobic textile possessed outstanding durability
in deionized water, various solvents, strong acid/base solutions,
and boiling/ice water. Remarkably, the polyester textile still retained
great water repellency and even after ultrasonic treatment for 18
h, 96 laundering cycles, and 600 abrasion cycles, exhibiting excellent
mechanical robustness. Importantly, the superhydrophobic polyester
textile was further applied for oil–water separation as absorption
materials and/or filter pipes, presenting high separation efficiency
and great reusability. Our method to construct superhydrophobic textiles
is simple but highly efficient; no special equipment, chemicals, or
atmosphere is required. Additionally, no fluorinated slianes and organic
solvents are involved, which is very beneficial for environment safety
and protection. Our findings conceivably stand out as a new tool to
fabricate organic–inorganic superhydrophobic surfaces with
strong durability and robustness for practical applications in oil
spill accidents and industrial sewage emission
Polydimethylsiloxane-Based Superhydrophobic Surfaces on Steel Substrate: Fabrication, Reversibly Extreme Wettability and Oil–Water Separation
Functional
surfaces for reversibly switchable wettability and oil–water
separation have attracted much interest with pushing forward an immense
influence on fundamental research and industrial application in recent
years. This article proposed a facile method to fabricate superhydrophobic
surfaces on steel substrates via electroless replacement deposition
of copper sulfate (CuSO<sub>4</sub>) and UV curing of vinyl-terminated
polydimethylsiloxane (PDMS). PDMS-based superhydrophobic surfaces
exhibited water contact angle (WCA) close to 160° and water sliding
angle (WSA) lower than 5°, preserving outstanding chemical stability
that maintained superhydrophobicity immersing in different aqueous
solutions with pH values from 1 to 13 for 12 h. Interestingly, the
superhydrophobic surface could dramatically switch to the superhydrophilic
state under UV irradiation and then gradually recover to the highly
hydrophobic state with WCA at 140° after dark storage. The underlying
mechanism was also investigated by scanning electron microscopy, Fourier
transform infrared spectroscopy, and X-ray photoelectron spectroscopy.
Additionally, the PDMS-based steel mesh possessed high separation
efficiency and excellent reusability in oil–water separation.
Our studies provide a simple, fast, and economical fabrication method
for wettability-transformable superhydrophobic surfaces and have the
potential applications in microfluidics, the biomedical field, and
oil spill cleanup
Polydimethylsiloxane-Based Superhydrophobic Surfaces on Steel Substrate: Fabrication, Reversibly Extreme Wettability and Oil–Water Separation
Functional
surfaces for reversibly switchable wettability and oil–water
separation have attracted much interest with pushing forward an immense
influence on fundamental research and industrial application in recent
years. This article proposed a facile method to fabricate superhydrophobic
surfaces on steel substrates via electroless replacement deposition
of copper sulfate (CuSO<sub>4</sub>) and UV curing of vinyl-terminated
polydimethylsiloxane (PDMS). PDMS-based superhydrophobic surfaces
exhibited water contact angle (WCA) close to 160° and water sliding
angle (WSA) lower than 5°, preserving outstanding chemical stability
that maintained superhydrophobicity immersing in different aqueous
solutions with pH values from 1 to 13 for 12 h. Interestingly, the
superhydrophobic surface could dramatically switch to the superhydrophilic
state under UV irradiation and then gradually recover to the highly
hydrophobic state with WCA at 140° after dark storage. The underlying
mechanism was also investigated by scanning electron microscopy, Fourier
transform infrared spectroscopy, and X-ray photoelectron spectroscopy.
Additionally, the PDMS-based steel mesh possessed high separation
efficiency and excellent reusability in oil–water separation.
Our studies provide a simple, fast, and economical fabrication method
for wettability-transformable superhydrophobic surfaces and have the
potential applications in microfluidics, the biomedical field, and
oil spill cleanup
Dual-Functional Superhydrophobic Textiles with Asymmetric Roll-Down/Pinned States for Water Droplet Transportation and Oil–Water Separation
Superhydrophobic
surfaces with tunable adhesion from lotus-leaf to rose-petal states
have generated much attention for their potential applications in
self-cleaning, anti-icing, oil–water separation, microdroplet
transportation, and microfluidic devices. Herein we report a facile
magnetic-field-manipulation strategy to fabricate dual-functional
superhydrophobic textiles with asymmetric roll-down/pinned states
on the two surfaces of the textile simultaneously. Upon exposure to
a static magnetic field, fluoroalkylsilane-modified iron oxide (F-Fe<sub>3</sub>O<sub>4</sub>) nanoparticles in polydimethylsiloxane (PDMS)
moved along the magnetic field to construct discrepant hierarchical
structures and roughnesses on the two sides of the textile. The positive
surface (closer to the magnet, or P-surface) showed a water contact
angle up to 165°, and the opposite surface (or O-surface) had
a water contact angle of 152.5°. The P-surface where water droplets
easily slid off with a sliding angle of 7.5° appeared in the
“roll-down” state as Cassie mode, while the O-surface
was in the “pinned” state as Wenzel mode, where water
droplets firmly adhered even at vertical (90°) and inverted (180°)
angles. The surface morphology and wetting mode were adjustable by
varying the ratios of F-Fe<sub>3</sub>O<sub>4</sub> nanoparticles
and PDMS. By taking advantage of the asymmetric adhesion behaviors,
the as-fabricated superhydrophobic textile was successfully applied
in no-loss microdroplet transportation and oil–water separation.
Our method is simple and cost-effective. The fabricated textile has
the characteristics of superhydrophobicity, magnetic responsiveness,
excellent chemical stability, adjustable surface morphology, and controllable
adhesion. Our findings conceivably stand out as a new tool to fabricate
functional superhydrophobic materials with asymmetric surface properties
for various potential applications