scholarly journals Two-Dimensional Nanostrips of Hydrophobic Copper Tetradecanoate for Making Self-Cleaning Glasses

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Subhrangsu Sarkar ◽  
Indrani Mukherjee ◽  
Sriparna Chatterjee ◽  
Smita Gohil ◽  
Bimal P. Singh ◽  
...  
Keyword(s):  
Visible Region ◽  
Contact Angles ◽  
Thin Layers ◽  
The Self ◽  
Surface Microstructure ◽  
Water Contact ◽  
Hydrophobic Nature ◽  
Self Cleaning ◽  
Self Assembled ◽  
Coated Surfaces

We report a simple, solution-based technique for coating arbitrary surfaces with thin layers of self-assembled copper tetradecanoate (CTD) nanostrips, resulting in an optically transparent, superhydrophobic coating. The nanostrip-coated surfaces show water contact angles close to 150° and roll-off angles as small as 2°-3°. Importantly, CTD retains its hydrophobic nature even after annealing the self-assembled nanostrips at 200°C, which does not alter the crystal structure but “melts” the surface microstructure. This clearly indicates that the hydrophobicity in CTD is likely to be intrinsic in nature and not induced by the surface microstructure (as has been suggested earlier). Strong hydrophobicity in CTD over a relatively wide temperature range presumably results from the presence of the long aliphatic (tetradecanoate) chains in its structure. Importantly, the self-assembled copper tetradecanoate nanostrips can be dip-coated on glass to render it hydrophobic and at the same time retain a significant level of transparency over the entire visible region. Such nanostructured thin films may be expected to find applications not only as a self-cleaning glass, but also as a corrosion resistant coating, in gas storage (due to the layered structure), and as an active catalyst because of the visible absorbance.

scholarly journals Self-Cleaning Polyester Fabric Prepared with TiOF2 and Hexadecyltrimethoxysilane

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 387
Author(s):  
Euigyung Jeong ◽  
Heeju Woo ◽  
Yejin Moon ◽  
Dong Yun Lee ◽  
Minjung Jung ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Contact Angle ◽  
Treatment Method ◽  
Polyester Fabric ◽  
Anatase Tio2 ◽  
The Self ◽  
Water Contact ◽  
Direct Fluorination ◽  
Tomato Ketchup ◽  
Self Cleaning

In this study, self-cleaning polyester (PET) fabrics were prepared using TiOF2 and hexadecyltrimethoxysilane(HDS) treatment. TiOF2 was synthesized via direct fluorination of a precursor TiO2 at various reaction temperatures. The prepared PET fabrics had superior photocatalytic self-cleaning properties compared with anatase TiO2/HDS-treated PET fabrics under UV and sunlight with 98% decomposition of methylene blue. TiOF2/HDS-treated PET fabrics also had superior superhydrophobic self-cleaning properties compared with anatase TiO2/HDS-treated PET fabrics with a 161° water contact angle and 6° roll-off angle. After the self-cleaning tests of the non-dyed TiOF2/HDS-treated PET fabrics, we prepared dyed TiOF2/HDS-treated PET fabrics to test practical aspects of the treatment method. These PET fabrics were barely stained by tomato ketchup; even when stained, they could be self-cleaned within 4 h. These results suggest that practical self-cleaning PET fabrics with superhydrophobicity and photocatalytic degradation could be prepared using TiOF2/HDS-treatment.

Controllable magnetic roughness surface with sustainable superhydrophobicity based on magnetorheological colloid

2020 ◽  
pp. 1045389X2094283
Author(s):  
Honghui Zhang ◽  
Zejun Tao ◽  
Yunheng Xiao
Keyword(s):  
Stainless Steel Substrate ◽  
Steel Substrate ◽  
Influential Factors ◽  
The Self ◽  
Surface Microstructure ◽  
Strength Testing ◽  
Structure Model ◽  
Roughness Surface ◽  
Self Cleaning ◽  
Surface Superhydrophobicity

In this article, magnetorheological colloid was adopted to coat a stainless steel substrate, which was cured under magnetic field to form magnetic roughness surface. Superhydrophobicity had been verified in the experiments, and the influential factors on the hydrophobic performance had been explored. A regular sawtooth structure model was proposed to relate the hydrophobicity with the formed surface microstructure. With the self-cleaning and bonding strength testing, the magnetic roughness surface is promising to keep sustainable superhydrophobicity in the self-cleaning or drag reduction applications.

scholarly journals Facile approach to develop anti-corrosive superhydrophobic aluminium with high mechanical, chemical and thermal durability

2018 ◽  
Vol 377 (2138) ◽  
pp. 20180272 ◽  
Author(s):  
Balraj Krishnan Tudu ◽  
Aditya Kumar ◽  
Bharat Bhushan
Keyword(s):  
Tilt Angle ◽  
Corrosion Current ◽  
Industrial Applications ◽  
Corrosion Properties ◽  
Water Contact ◽  
Droplet Dynamics ◽  
Electrochemical Tests ◽  
High Corrosion ◽  
Self Cleaning ◽  
Coated Surfaces

Durable, superhydrophobic and self-cleaning aluminium surfaces with high corrosion resistance are desirable in many industrial applications. In this study, a facile approach is used to produce aluminium surfaces with superhydrophobicity with a low tilt angle by creating desired roughness structure by immersing in NaOH solution followed by lowering the surface energy by immersing in hexadecyltrimethoxysilane solution. The coated samples show water contact angle of 164 ± 7° and tilt angle of 5 ± 1°. Droplet dynamics of the coated surfaces was investigated. Surfaces exhibited self-cleaning properties. In addition, mechanical, chemical and thermal stability tests were performed. Electrochemical tests of coated surfaces demonstrated anti-corrosion properties with low corrosion current density and high corrosion potential. This article is part of the theme issue ‘Bioinspired materials and surfaces for green science and technology’.

Effect of Annealing Temperature on the Photocatalytic Activity and Hydrophobic Property of TiO2 Nanorod Arrays Prepared by Hydrothermal Method

2018 ◽  
Vol 928 ◽  
pp. 71-76 ◽  
Author(s):  
Peerawas Kongsong ◽  
Nuan La Ong Srakaew ◽  
Phatcharee Phoempoon ◽  
Mahamasuhaimi Masae ◽  
Lek Sikong
Keyword(s):  
Photocatalytic Activity ◽  
Annealing Temperature ◽  
Rutile Phase ◽  
Contact Angles ◽  
Water Molecules ◽  
Nanorod Arrays ◽  
Hydrophobic Property ◽  
Water Contact ◽  
Photocatalytic Activities ◽  
Hydrophobic Nature

TiO2nanorod arrays (TNRs) films were fabricated on the polished Ti substrates using hydrothermal and then annealed for 2 h in air at 300°-500°C. The films were characterized by XRD and FESEM. The photocatalytic activities to degrade methylene blue (MB) in solution were determined, expecting these activities to correlate with the hydrophobic property. The experiment showed that rutile peaks recrystallized at the annealing temperature, with the crystallinity increase with increasing annealing temperatures. The TNRs films annealed at 500 oC had a comparatively high crystallinity of rutile phase as well as the highest photocatalytic activity of the films prepared. Surface wettability was studied by measuring the contact angle of the liquid interface which showed hydrophobic nature as water contact angles were greater than 120°. The results can be concluded that as-prepared TNRs film was annealed at 500 oC exhibits excellent hydrophobicity for water molecules and the highest photocatalytic activity on the degradation of MB under UV irradiation.

scholarly journals Synthesis and photocatalytic activity for TiO2 nanoparticles as air purification

2018 ◽  
Vol 162 ◽  
pp. 05006 ◽  
Author(s):  
Adawiya Haider ◽  
Riyad Al-Anbari ◽  
Ghadah Kadhim ◽  
Zainab Jameel
Keyword(s):  
Contact Angle ◽  
Titanium Dioxide ◽  
Tio2 Nanoparticles ◽  
Sol Gel ◽  
Xrd Analysis ◽  
The Self ◽  
Root Mean Square Roughness ◽  
Bacterial Inactivation ◽  
Water Contact ◽  
Self Cleaning

In the present work, titanium dioxide (TiO2) nanoparticles (NP’s) were prepared using sol-gel process from Titanium Tetrachloride (TiCl4) as a precursor with calcinations at two temperatures (500 and 900) °C. The effect of calcinations temperatures on the structural, optical, morphological and Root Mean Square (roughness) properties were investigated by means of Scanning Electron Microscopy, X-ray Diffraction (XRD), and Atomic Force Microscopy (AFM). Bacterial inactivation was evaluated using TiO2-coated Petri dishes. A thin layer of photocatalytic TiO2 powder was deposited on glass substrate in order to investigate the self-cleaning effect of TiO2 nanoparticles in indoor and outdoor applications. Ultra-hydrophilicity was assessed by measuring the contact angle and it evaluated photolysis properties through the degradation of potassium permanganate (KMnO4) under direct sunlight. XRD analysis indicated that the structure of TiO2 was anatase at 500 °C and rutile at 900 °C calcination temperatures. As the calcination temperature increases, the crystallinity is improved and the crystallite size becomes larger. Coated films of TiO2 made the has permeability, low water contact angle and good optical activity. These are properties essential for the application of the surface of the self-cleaning. The final results illustrate that titanium dioxide can be used in the build materials to produce coated surfaces in order to minimize air pollutants that are placed in microbiologically sensitive circumference like hospitals and the food factory.

scholarly journals Moving toward Smart Cities: Evaluation of the Self-Cleaning Properties of Si-Based Consolidants Containing Nanocrystalline TiO2 Activated by Either UV-A or UV-B Radiation

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2577
Author(s):  
José Santiago Pozo-Antonio ◽  
Daniel Noya-Pintos ◽  
Patricia Sanmartín
Keyword(s):  
Spectral Region ◽  
Smart Cities ◽  
The Self ◽  
Ethyl Silicate ◽  
Main Peak ◽  
Nanocrystalline Tio2 ◽  
Color Changes ◽  
Self Cleaning ◽  
Coated Surfaces ◽  
Nanosized Silica

This study evaluated the self-cleaning ability and durability of Si-based consolidants (an ethyl silicate consolidant and a consolidant based on nanosized silica) spiked with nanocrystalline TiO2 activated by either UV-A radiation (spectral region between 340 and 400 nm, and main peak at 365 nm) or UV-B radiation (spectral region between 270 and 420 nm, and main peak at 310 nm). Granite samples were coated with consolidant, to which nanocrystalline TiO2 was added at different concentrations (0.5, 1, and 3%, by wt.). Diesel soot was then applied to the coated surfaces, and the samples were exposed to UV-A or UV-B radiation for 1650 h. The surface color changes, relative to the color of untreated granite, were determined every 330 h by color spectrophotometry. Slight color changes indicated a recovery of the reference color due to the degradation of the soot. The final surfaces of both the untreated and treated surfaces were compared by stereomicroscopy and scanning electron microscopy. The main findings were that: (1) In general, the consolidant containing nanosized silica induced the most intense photocatalytic activity. In the more compact xerogel coating formed by the nanosized silica, more TiO2 nanoparticles were available to interact with the radiation. (2) For all consolidant mixtures, soot degradation remained constant or decreased over time, except with ethyl silicate with 0.5 wt % TiO2 (no self-cleaning capacity). (3) Soot degradation increased with the concentration of TiO2. (4) The UV-B radiation was the most effective in terms of soot degradation, except for the surface coated with the ethyl silicate and 3% wt. TiO2.

Fabrication of Superhydrophobic Surfaces on Al Substrates for Anti-Adhesion and Self-Cleaning Applications

2010 ◽  
Vol 434-435 ◽  
pp. 534-537
Author(s):  
Tao Li ◽  
Chang Song Liu ◽  
Qiang Zhang ◽  
Zhi Wen Li
Keyword(s):  
Solution Method ◽  
The Self ◽  
Superhydrophobic Surfaces ◽  
Sliding Angle ◽  
Water Contact ◽  
Chemical Solution Method ◽  
Air Water Interface ◽  
Static Water ◽  
Self Cleaning ◽  
Water Repellence

Superhydrophobic surfaces, which have anti-adhesion and self-cleaning properties, were fabricated on Al substrates. The self-cleaning surface was prepared by two steps: firstly, a chemical solution method was used to create the surface roughness with disorderly veins micronanostructures. Secondly, fluoroalkylsilane was deposited on the rough surface to lower its surface energy. The combination of veins micronanostructures and fluoroalkylsilane modification gave the surface a superhydrophobicity with static water contact angle of 166° and sliding angle of smaller than 1°. Additionally, the surface showed a strong anti-adhesion with water and a satisfied self-cleaning property. Water droplets easily rolled off the surface and picked up dirt and debris with them. The surfaces obviously corresponded to Cassie (not Wenzel) -model. Air entrapped within the veins microstructures greatly increases the air/water interface, effectively preventing the penetration of water into the grooves, and finally exhibiting the self-cleaning property. The results will greatly extend Al substrates for specific functions such as water-repellence, self-cleaning and anti-fouling.

Studies on Self-Assembly of Methoxy Polyethylene Oxide Propyl Trimethoxysilane on Silicon Substrate

2012 ◽  
Vol 557-559 ◽  
pp. 1916-1920
Author(s):  
Wen Shi Ma ◽  
Fang Yang ◽  
Bang Jun Deng ◽  
Hai Yan Sun ◽  
Xiao Dan Lin
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Polyethylene Oxide ◽  
Silicon Substrate ◽  
Average Length ◽  
Average Molecular Weight ◽  
The Self ◽  
Water Contact ◽  
Self Assembled ◽  
Self Assembled Layer

A novel hydrophilic and self-assemble functional methoxy polyethylene oxide propyl trimethoxysilane was synthesized by hydrosilylation reaction using methoxy polyethylene oxide monoallyl ether and trimethoxysilane. The self-assembled layer of methoxy polyethylene oxide propyl trimethoxysilane was prepared by immersing hydroxylate silicon substrate in silane solution. The structure, morphology and hydrophilicity of self-assembled layer were characterized by means of X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and water contact angle method. The results show that methoxy polyethylene oxide propyl trimethoxysilane can self-assemble on the surface of hydroxylate silicon substrate. At concentration of 0.80 g/100 mL and the self-assembling time of 60 minutes, the self-assembled layer of methoxy polyethylene oxide propyl trimethoxysilane of average molecular weight of 682 shows a brush-like structure with each brush column size of 10~15 nm in diameter and 5~8 nm in height. The correspondence of the columns height with the average length of the silane molecules suggests that the layer obtained is monolayer and the brush columns are constituted by extended PEO molecular chain units in the silane. The distribution of columns is uniform and the root-mean-square（RMS） roughness of self-assembled monolayer is 0.98 nm. Water contact angle of the monolayer is 7.4°. A super-hydrophilic surface is obtained.

End-Blocked Silanization of Side-Chain Fluoroalkyl Oligoether and its Surface Properties

2018 ◽  
Vol 71 (11) ◽  
pp. 855
Author(s):  
Lei Wang ◽  
Lei Chen ◽  
Zhanxiong Li
Keyword(s):  
Contact Angle ◽  
Photoelectron Spectroscopy ◽  
Contact Angles ◽  
Side Chain ◽  
Chemical Compositions ◽  
Silicon Substrates ◽  
Water Contact ◽  
Molecular Weights ◽  
Self Assembled ◽  
Surface Morphologies

In this study, three novel side-chain fluoroalkyl oligoethers with different molecular weights were synthesised via a ring-opening reaction of 2,2,3,3,4,4,5,5,5-nonafluoropentyloxirane. The fluorooligoethers were then silanized and characterised by FT-IR,1H, and 19F NMR spectroscopies. These silanlized fluorooligoethers were used to fabricate hydrophobic coatings on silicon substrates, which were pre-treated with O2 plasma, by the method of liquid phase deposition. The chemical compositions and structures of the film surfaces were analysed by X-ray photoelectron spectroscopy and the results showed that silanized fluorooligoethers formed self-assembled films on the silicon wafer. The surface wettability of the coatings was measured by water contact angles. It is noted that the annealing process can improve the hydrophobicity with the highest water contact angle being 115.2 ± 1° and hexadecane contact angle being 67.2 ± 1°. The surface morphologies and roughness of the self-assembled films were measured by atomic force microscopy (AFM), as a result, the surface was found to be rougher with the increment of the molecular weight of the fluorooligoethers.

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