scholarly journals Fabrication of Robust Superhydrophobic Surfaces with Dual-Curing Siloxane Resin and Controlled Dispersion of Nanoparticles

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1420
Author(s):  
Hyeran Kim ◽  
Kibeom Nam ◽  
Dong Yun Lee

We developed a simple method for the fabrication of superhydrophobic surfaces on various substrates using spray coating. The fabrication method started with the blending of a modified hydrophobic siloxane binder, silica nanoparticles, and a volatile solvent by sonication. The mixture was spray-coated on various surfaces such as slide glass, paper, metal and fabric, forming a rough surface comprising silica particles dispersed in a hydrophobic binder. Surface hydrophobicity was affected by the surface energy of the binder and the degree of roughness. Therefore, we realized a superhydrophobic surface by controlling these two factors. The hydrophobicity of the siloxane binder was determined by the treatment of fluorine silane; the roughness was controlled by the amount of coated materials and sonication time. Thus, using the spray coating method, we obtained a superhydrophobic surface that was mechanically durable, thermally stable, and chemically resistant.

2012 ◽  
Vol 706-709 ◽  
pp. 2874-2879 ◽  
Author(s):  
R. Jafari ◽  
Masoud Farzaneh

Superhydrophobic surfaces were prepared using a very simple and low-cost method by spray coating. A high static water contact angle of about 154° was obtained by deposition of stearic acid on an aluminium alloy. However, this coating demonstrated a high contact angle hysteresis (~ 30º). On the other hand, superhydrophobic surfaces with a static contact angle of about 162º and 158º, and a low contact angle hysteresis of about 3º and 5º were respectively obtained by incorporating nanoparticles of SiO2and CaCO3in stearic acid. The excellent resulting hydrophobicity is attributed to the synergistic effects of micro/nanoroughness and low surface energy. A study of the wettability of these surfaces at temperatures ranging from 20 to-10 °C showed that the superhydrophobic surface becomes rather hydrophobic at supercooled temperatures.


Coatings ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 472 ◽  
Author(s):  
Doeun Kim ◽  
Arun Sasidharanpillai ◽  
Ki Hoon Yun ◽  
Younki Lee ◽  
Dong-Jin Yun ◽  
...  

Robust superhydrophobic surfaces are fabricated on different substrates by a scalable spray coating process. The developed superhydrophobic surface consists of thin layers of surface functionalized silica nanoparticle (SiO2) bound to the substrate by acrylate-polyurethane (PU) binder. The influence of the SiO2/PU ratio on the superhydrophobicity, and the robustness of the developed surface, is systematically analyzed. The optimized SiO2/PU ratio for prepared superhydrophobic surfaces is obtained between 0.9 and 1.2. The mechanism which yields superhydrophobicity to the surface is deduced for the first time with the help of scanning electron microscopy and profilometer. The effect of mechanical abrasion on the surface roughness and superhydrophobicity are analyzed by using profilometer and contact angle measurement, respectively. Finally, it is concluded that the binder plays a key role in controlling the surface roughness and superhydrophobicity through the capillary mechanism. Additionally, the reason for the reduction in performance is also discussed with respect to the morphology variation.


2013 ◽  
Vol 133 (5) ◽  
pp. 170-176 ◽  
Author(s):  
Mikio Akamatsu ◽  
Kyohei Terao ◽  
Hidekuni Takao ◽  
Fusao Simokawa ◽  
Fumikazu Oohira ◽  
...  

Soft Matter ◽  
2021 ◽  
Author(s):  
Jianchen Zhu ◽  
Tian ren Zhang ◽  
Yajie Liu ◽  
Daoyi Lu ◽  
Peng Zhang ◽  
...  

A kind of low-molecular weight organic gelator (LMOG) bearing hydrazine linkage and end-capped by alkoxy-substituted phenyl, namely 1, 4-bis[(3, 4-bisoctyloxyphenyl)hydrozide]phenylene (BPH-8), was used to facilely fabricate superhydrophobic surfaces by drop-casting...


2021 ◽  
Vol 13 (15) ◽  
pp. 8244
Author(s):  
Francesca Cirisano ◽  
Michele Ferrari

Highly hydrophobic and superhydrophobic materials obtained from recycled polymers represent an interesting challenge to recycle and reuse advanced performance materials after their first life. In this article, we present a simple and low-cost method to fabricate a superhydrophobic surface by employing polytetrafluoroethylene (PTFE) powder in polystyrene (PS) dispersion. With respect to the literature, the superhydrophobic surface (SHS) was prepared by utilizing a spray- coating technique at room temperature, a glass substrate without any further modification or thermal treatment, and which can be applied onto a large area and on to any type of material with some degree of fine control over the wettability properties. The prepared surface showed superhydrophobic behavior with a water contact angle (CA) of 170°; furthermore, the coating was characterized with different techniques, such as a 3D confocal profilometer, to measure the average roughness of the coating, and scanning electron microscopy (SEM) to characterize the surface morphology. In addition, the durability of SH coating was investigated by a long-water impact test (raining test), thermal treatment at high temperature, an abrasion test, and in acidic and alkaline environments. The present study may suggest an easy and scalable method to produce SHS PS/PTFE films that may find implementation in various fields.


Soft Matter ◽  
2021 ◽  
Author(s):  
Yuxing Shan ◽  
shuai liang ◽  
Xiangkai Mao ◽  
Jie Lu ◽  
Lili Liu ◽  
...  

Abstract. Stretchable elastomers with superhydrophobic surfaces have potential applications in wearable electronics. However, various types of damage inevitably occur on these elastomers in actual application, resulting in deterioration of the...


2008 ◽  
Vol 22 (31n32) ◽  
pp. 5887-5894 ◽  
Author(s):  
HONG GUE SHIN ◽  
JONG TAE KWON ◽  
YOUNG HO SEO ◽  
BYEONG HEE KIM

A simple method for the fabrication of polymer master for antireflective surface is presented. In conventional fabrication methods for antireflective surface, coating method with low refractive index have usually been used. However, it is required to have a high cost and a long processing time for mass production. In this paper, antireflective surface was fabricated by using hot embossing process with porous anodized aluminum oxide. Through multi-AAO and etching processes, nano patterned master with high aspect ratio was fabricated at the large area. Size and aspect ratio of nano patterned master are about 175 ± 25 nm and 2 ~ 3, respectively. In order to replicate nano patterned master, hot embossing process was performed by varying the processing parameters such as temperature, pressure and embossing time etc. Finally, antireflective surface can be successfully obtained after etching process to remove selectively silicon layer of AAO master. Optical and rheological characteristics of antireflective surface were analyzed by using SEM, EDX and spectrometer inspection. Antireflective structure by replicating hot embossing process can be applied to various displays and automobile components.


2018 ◽  
Vol 195 ◽  
pp. 295-304 ◽  
Author(s):  
N.H. Ismail ◽  
W.N.W. Salleh ◽  
N. Sazali ◽  
A.F. Ismail ◽  
N. Yusof ◽  
...  

Sensors ◽  
2022 ◽  
Vol 22 (2) ◽  
pp. 445
Author(s):  
Kai-Uwe Zirk ◽  
Manuel Olze ◽  
Harald Pötzschke

This article presents a novel method for the detection of biofilms based on a heatable, capacitive sensor structure (CSS). Biofilms are capable of strongly binding large amounts of water to their extracellular biopolymer matrix, which is detectable via its dielectric properties. A main challenge is to determine the difference between the inherent occurring presence of moisture in the ecosystem, which is necessary to form a biofilm and an actual formed biofilm. Therefore, the CSS is carefully heated to evaporate unbound surface moisture and determine whether there is a remaining residual alternation of the capacitance in comparison to the dry state. As a reproduceable substitute for complex, real biofilms, a hygroscopic, medical hydrogel-based on polysaccharides was used and applied by spray coating. Printed circuit boards (PCB) in different geometries and materials were used as CSS and compared in terms of their performance. A layer-thickness of 20 µm for the hydrogel coating to be sufficiently detected was defined as a realistic condition based on known values for real biofilms cited in literature. For this thickness a double-meander structure proves to be preferable over interdigitating and spiral geometries. It does offer a 30% lower, yet sufficient sensitivity, but shows advantages in manufacturing (one layer instead of two) and conductive heating capability. In the experiments, free water showed virtually no residual change, while the hydrogel-coated CSS still shows an approx. 300% higher value compared to a dry capacity. Yet, the overall small capacities of about 6–30 pF in dry state are difficult to measure and therefore sensitive to interferences and noise, which results in a high deviation. The principle of measurement can be evaluated as proofed by the carried out experiments, though offering room for improvement in the design of the study. The new method might be especially useful for pipes (e.g., hydrodynamically ineffective sensors installed in a pipe wall) if they at least are not permanently flooded with an aqueous medium, but can occasionally dry. If the internal surface is still only moist, it can be dried by initial heating.


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