scholarly journals Superhydrophobicity/Superhydrophilicity Transformation of Transparent PS-PMMA-SiO2 Nanocomposite Films

2018 ◽  
Vol 63 (3) ◽  
pp. 226 ◽  
Author(s):  
A. Sriboonruang ◽  
T. Kumpika ◽  
W. Sroila ◽  
E. Kantarak ◽  
P. Singjai ◽  
...  

A transparent superhydrophobic nanocoating with high water contact angle (>150∘ ) was successfully prepared by a simple dip coating method. The coating solutions were prepared by the dissolution of polystyrene (PS) and poly(methyl methacrylate) (PMMA) in toluene. Fumed silica (SiO2) was then added to increase the roughness of the coating. The annealing treatment conditions were investigated to optimize the water contact angle. The heat treatment conditions and other factors were studied systematically to optimize the transmission and the contact angle of water on the films. The results have shown that the films increase with the annealing temperature. The superhydrophobicity of films is observed only in PS-consisted films after the annealing at 200 ∘C. The superhydrophobic/superhydrophilic transformation was achieved at the annealing temperature higher than 200 ∘C due to the decay of the polymer into hydrophilic monomers.

2020 ◽  
Vol 12 (2) ◽  
pp. 49-56
Author(s):  
Roihatur Rohmah ◽  
Mochamad Zainuri

The hydrophobic surface can be self-cleaning. The hierarchy of surface roughness affects the hydrophobic surface. In this research, the hydrophobic surface was fabricated by modification of surface roughness from the composite filler. Natural silica was used as a filler and was done a variation of calcination temperature to modify the hierarchy of roughness formed. The variation of calcination temperature was 800°C, 1000°C, 1200°C, and 1400°C. The coating method was a dip-coating method by 30-second long immersion. A glass as coating media was coated by PVDF/SiO2 composite. The hydrophobic surface could be known from the value of the water contact angle (WCA) formed. If a water contact angle more than 90°, the surface could be called the hydrophobic surface. In this research, the hydrophobicity aspect cause of variation of calcination temperature was known from the value of water contact angle formed on the surface of PVDF/SiO2 composite coating 800°C, 1000°C, 1200°C, and 1400°C was 117,12° ± 0,98°, 107,80° ± 0,91°, 121,31° ± 1,45°, and 111,75° ± 1,47°, respectively.


Soft Matter ◽  
2021 ◽  
Author(s):  
Jixi Zhang ◽  
Ligui Zhang ◽  
Xiao Gong

In this work, we prepare a PDMS-SiO2-PDA@fabric with high water contact angle (WCA=155o). Combining dopamine self-polymerization and sol-gel method, SiO2 is in situ grown on a PDA-modified fabric surface to...


2009 ◽  
Vol 620-622 ◽  
pp. 741-744 ◽  
Author(s):  
Rui Weng ◽  
Chong Rui Wang ◽  
Lian Meng Zhang ◽  
Shui Ping Wang

Fluoralkylpolysiloxane modified Polyurethane (FSPU) films with high water contact angle (CA) were prepared. fluoralkylpolysiloxane was obtained using perfluoro octyl sulfuryl fluoride and terminal amino-silicone oil as reactants. Then, the isocyanate end capped PU prepolymer was synthesized by reacting isocyanate with a soft segment mixed by active amino-end-capping fluoralkylpolysiloxane and polyether glycol. The fluoralkylpolysiloxane modified PU films were obtained after the PU prepolymer was cured by 3,3 '- dichloro -4,4' – amino - diphenyl methane (MOCA). The results showed that the modified polyurethane with 10% (mass fraction) PFATPS had a good compatibility, low surface energy, surface water contact angle and surface oil contact angle was improved by 49° and 37° respectively, and heat resistance, water resistance was apparently improved.


Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2474 ◽  
Author(s):  
Hao Wu ◽  
Hao Li ◽  
Ahmad Umar ◽  
Yao Wang ◽  
Guofu Zhou

Fluoropolymers play an essential role in electrowetting (EW) systems. However, no fluoropolymer possesses the desirable properties of both hydrophobicity and dielectric strength. In this study, for the first time, we report the integration of two representative fluoropolymers—namely, Teflon AF (AF 1600X) and Cytop (Cytop 809A)—into one bifunctionalized dielectric nanolayer. Within this nanolayer, both the superior hydrophobicity of Teflon AF and the excellent dielectric strength of Cytop were able to be retained. Each composed of a 0.5 μm Cytop bottom layer and a 0.06 μm Teflon AF top layer, the fabricated composite nanolayers showed a high withstand voltage of ~70 V (a dielectric strength of 125 V/μm) and a high water contact angle of ~120°. The electrowetting and dielectric properties of various film thicknesses were also systemically investigated. Through detailed study, it was observed that the thicker Teflon AF top layers produced no obvious enhancement of the Cytop/Teflon AF stack.


2008 ◽  
Vol 1132 ◽  
Author(s):  
Mehdi Shafiei ◽  
Ahmet T. Alpas

ABSTRACTA new method to fabricate superhydrophobic hard films is described. Surface texture of lotus leaf was replicated on an acetate film, on which a nanocrystalline (NC) Ni coating with a grain size of 30 ± 4 nm and a hardness of 4.42 GPa was electrodeposited. The surface texture consisted of conical protuberances with a height of 10.0 ± 2.0 0m and a tip radius of 2.5 ± 0.5 0m. An additional electrodeposition for 120 s and 300 s was used to locally modify the surface structure by depositing ‘Ni crowns' on the protuberances that increased their height to 14.0 ± 2.0 0m and their tip radius to 6.0 ± 0.5 0m. The modified structures were then treated with a perfluoropolyether (PFPE) solution, which provided a high water contact angle of 156°, i.e., comparable to the naturally superhydrophobic lotus leaf. The increased hydrophobicity as a result of surface structure and chemistry modifications was evident compared to a smooth NC Ni sample, which had a contact angle of 64°.


2011 ◽  
Vol 130-134 ◽  
pp. 1049-1053
Author(s):  
Qi Wang ◽  
Cheng Pu Lin ◽  
Peng Cui

Mesoporous TiO2 films was prepared by evaporation-induced self-assembly and dip-coating method. And the pore size of the TiO2 films is adjusted by controlling the molar ratio of H2O/TiO2 (H value). Water contact angle was chosen to represent the hydrophilic property, and XRD and AFM were carried out to characterize the films. With the increase of H value, the pore size increased firstly then decreased. And when H is 15, the pore size is the biggest, which hydrophilicity in dark is the best too. With the extention of the non-irridation time, the hydrophilicity is worse. And the reason may be ascribed to the adsorption of organic matter in air.


2013 ◽  
Vol 537 ◽  
pp. 234-237
Author(s):  
Di Fa Xu ◽  
Hai Bo Wang ◽  
Xiang Chao Zhang ◽  
Shi Ying Zhang

The S+Ce co-doped TiO2 nanocomposite films deposited on glass substrate had been synthesized by the sol–gel dip-coating method. The as-synthesized samples were characterized using X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and ultraviolet-visible (UV-vis) absorption spectra analysis technologies. The surface morphology and surface chemical composition of the S+Ce co-doped TiO2 nanocomposite film had been primarily investigated. The results shows that the properties of doped TiO2 thin films with different ions have close relations with the intrinsical properties of S and Ce doped ions, the absorption edge shifted towards visible light region and the water contact angle of the surface of the nanocomposite films with the water droplet was only 6°, indicating that the S+Ce co-doped TiO2 nanocomposite film showed promising applications in the self-cleaning and other potential fields.


2017 ◽  
Vol 9 (27) ◽  
pp. 23246-23254 ◽  
Author(s):  
Mei Chen ◽  
Wei Hu ◽  
Xiao Liang ◽  
Cheng Zou ◽  
Fasheng Li ◽  
...  

RSC Advances ◽  
2016 ◽  
Vol 6 (82) ◽  
pp. 78791-78794 ◽  
Author(s):  
Thamodaran Partheeban ◽  
Marappan Sathish

Super-hydrophobic fullerene octahedron and flower-like microcrystals with a high water contact angle of 158.8° were prepared using anisole and IPA in a liquid–liquid interfacial precipitation method.


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