scholarly journals Hybrid Sol–Gel Superhydrophobic Coatings Based on Alkyl Silane-Modified Nanosilica

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 539
Author(s):  
Dafna Heiman-Burstein ◽  
Anna Dotan ◽  
Hanna Dodiuk ◽  
Samuel Kenig
Keyword(s):  
Contact Angle ◽  
Sol Gel ◽  
Alkyl Substituent ◽  
Hybrid Coatings ◽  
Sliding Angle ◽  
Random Surface ◽  
Water Contact ◽  
Superhydrophobic Coatings ◽  
Long Chain

Hybrid sol–gel superhydrophobic coatings based on alkyl silane-modified nanosilica were synthesized and studied. The hybrid coatings were synthesized using the classic Stöber process for producing hydrophilic silica nanoparticles (NPs) modified by the in-situ addition of long-chain alkyl silanes co-precursors in addition to the common tetraethyl orthosilicate (TEOS). It was demonstrated that the long-chain alkyl substituent silane induced a steric hindrance effect, slowing the alkylsilane self-condensation and allowing for the condensation of the TEOS to produce the silica NPs. Hence, following the formation of the silica NPs the alkylsilane reacted with the silica’s hydroxyls to yield hybrid alkyl-modified silica NPs having superhydrophobic (SH) attributes. The resulting SH coatings were characterized by contact angle goniometry, demonstrating a more than 150° water contact angle, a water sliding angle of less than 5°, and a transmittance of more than 90%. Confocal microscopy was used to analyze the micro random surface morphology of the SH surface and to indicate the parameters related to superhydrophobicity. It was found that a SH coating could be obtained when the alkyl length exceeded ten carbons, exhibiting a raspberry-like hierarchical morphology.

Design and fabrication of polydopamine based superhydrophobic fabrics for efficient oil-water separation

Soft Matter ◽  
2021 ◽  
Author(s):  
Jixi Zhang ◽  
Ligui Zhang ◽  
Xiao Gong
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Sol Gel ◽  
High Water ◽  
Water Contact ◽  
Water Separation ◽  
Oil Water Separation ◽  
Oil Water ◽  
Fabric Surface

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...

Organic-inorganic composite nanocoatings with superhydrophobicity and thermal stability

2018 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
A. Syafiq ◽  
A.K. Pandey ◽  
Vengadaesvaran Balakrishnan ◽  
Syed Shahabuddin ◽  
Nasrudin Abd Rahim
Keyword(s):  
Thermal Stability ◽  
Surface Roughness ◽  
Glass Substrate ◽  
Alkyl Chain ◽  
Sol Gel ◽  
High Thermal Stability ◽  
Sliding Angle ◽  
Water Contact ◽  
Content Type ◽  
Superhydrophobic Coatings

Purpose This paper aims to investigate the thermal stability and hydrophobicity of difference alkyl chain of silanes with silicon (Si) micro- and nanoparticles. Design/methodology/approach Sol-gel methods have been used to design superhydrophobic glass substrates through surface modification by using low-surface-energy Isooctyl trimethoxysilane (ITMS) and Ethyl trimethoxysilane (ETMS) solution. Hierarchical double-rough scale solid surface was built by Si micro- and nanoparticles to enhance the surface roughness. The prepared sol was applied onto glass substrate using dip-coating method and was dried at control temperature of 400°C inside the tube furnace. Findings The glass substrate achieved the water contact angle as high as 154 ± 2° and 150.4 ± 2° for Si/ITMS and Si/ETMS films, respectively. The Si/ITMS and Si/ETMS also were equipped with low sliding angle as low as 3° and 5°, respectively. The Si micro- and nanoparticles in the coating system have created nanopillars between them, which will suspend the water droplets. Both superhydrophobic coatings have showed good stability against high temperature up to 200°C as there are no changes in WCA shown by both coatings. Si/ITMS film sustains its superhydrophobicity after impacting with further temperature up to 400°C and turns hydrophobic state at 450°C. Research limitations/implications Findings will be useful to develop superhydrophobic coatings with high thermal stability. Practical implications Sol method provides a suitable medium for the combination of organic-inorganic network to achieve high hydrophobicity with optimum surface roughness. Originality/value Application of different alkyl chain groups of silane resin blending with micro- and nanoparticles of Si pigments develops superhydrophobic coatings with high thermal stability.

scholarly journals Functional Superhydrophobic Coating Systems for Possible Corrosion Mitigation

2020 ◽  
Vol 14 (2) ◽  
pp. 148-158 ◽  
Author(s):  
Sarah F. Jurak ◽  
◽  
Emil F. Jurak ◽  
Md. Nizam Uddin ◽  
Ramazan Asmatulu
Keyword(s):  
Sol Gel ◽  
Chemical Vapor ◽  
Layer By Layer ◽  
Superhydrophobic Coating ◽  
Sliding Angle ◽  
One Pot ◽  
Water Contact ◽  
Superhydrophobic Coatings ◽  
Run Off ◽  
Self Cleaning

Because of their repellent, corrosion-mitigating, anti-icing, and self-cleaning properties, superhydrophobic coatings have numerous applications from windshields to textiles. A superhydrophobic coating is defined as one having a water contact angle (WCA) greater than 150° with a surface sliding angle less than 10°, and very low hysteresis between the advancing and receding angles. Its surface exhibits the so-called “lotus leaf effect,” whereby water bounces and balls up on contact. Here, water droplets run off readily, taking along dirt and dust for a self-cleaning effect that keeps the surface dry. The chemical composition of a surface affects the WCA, which can rise to 120°, but to achieve a WCA greater than 150°, which is considered superhydrophobic, an additional micro- and nanostructural component is needed. This functional hierarchical micro- and nanomorphology is exhibited in nature by plants and insects. A superhydrophobic coating on metallic substrates promises to provide corrosion mitigation by blocking oxygen and electrolytes, which are needed for the initiation of corrosion at the surface and interface. The methods used for preparing functional superhydrophobic coatings include sol-gel processing, layer-by-layer assembly, etching, lithography, chemical and electrochemical depositions, chemical vapor deposition, electrospinning, hydrothermal synthesis, and one-pot reactions. In this work, some research studies conducted to develop robust and durable superhydrophobic coatings are discussed in detail and analyzed for possible corrosion mitigation on the surfaces of metals and alloys. Scientists, engineers, students, and other participants in automotive, aircraft, energy, defense, electronics, and other industries will benefit greatly from this work.

Preparation of TiO2–SiO2 Hybrid Nanosols Coated Flame-Retardant Polyester Fabric Possessing Dual Contradictory Characteristics of Superhydrophobicity and Self Cleaning Ability

2020 ◽  
Vol 20 (3) ◽  
pp. 1780-1789 ◽  
Author(s):  
Priyanka Katiyar ◽  
Shraddha Mishra ◽  
Anurag Srivastava ◽  
N. Eswara Prasad
Keyword(s):  
Electron Microscopy ◽  
Contact Angle ◽  
Flame Retardant ◽  
Protective Clothing ◽  
Sol Gel ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Water Contact ◽  
Vis Spectroscopy ◽  
Self Cleaning

TiO2, SiO2 and their hybrid nanocoatings are prepared on inherent flame retardant textile substrates from titanium(IV)iso-proproxide (TTIP) and tetraethoxysilane (TEOS) precursors using a sol–gel process followed by hydrothermal treatment. The coated samples are further functionalized by hexadecyltrimethoxysilane (HDTMS) to impart superhydrophobicity. Sample characterization of the nanosols, nanoparticles and coated samples are investigated using, X-ray diffractometer, transmission electron microscopy, scanning electron microscopy, UV-Vis spectroscopy, contact angle measurement. Stain degradation test under mild UV irradiation shows almost 54% degradation of coffee stain within 4 hours measured by Spectrophotometer. UV-Vis Absorption Spectroscopy demonstrates complete degradation of methyl orange colorant within 3 hours. Hybrid nanosol coated and HDTMS modified inherent flame retardant polyester surfaces show apparent water contact angle as ~145°, which is much closer to proximity of superhydrophobic surfaces. Thus, the novelty of present work is, by using sol–gel technique, a bi-functional textile surface has been developed which qualifies the very specific requirements of protective clothing like self-cleaning property (imparted by TiO2 nanoparticles) and superhydrophobicity (imparted by SiO2 nanoparticles and further surface modification by HDTMS), which are entirely contradictory in nature, in a single fabric itself. Thus developed textile surfaces also possess the other attributes of protective clothing like flame retardancy and air permeability.

scholarly journals Effect of Modified Silica Materials on Polyvinyl Chloride (PVC) Substrates to Obtain Transparent and Hydrophobic Hybrid Coatings

2021 ◽  
Vol 11 (22) ◽  
pp. 11044
Author(s):  
Violeta Purcar ◽  
Valentin Rădițoiu ◽  
Alina Rădițoiu ◽  
Florentina Monica Raduly ◽  
Georgiana Cornelia Ispas ◽  
...  
Keyword(s):  
Polyvinyl Chloride ◽  
Sol Gel ◽  
Contact Angles ◽  
Hybrid Coatings ◽  
Water Contact ◽  
Silica Coatings ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Silica Materials ◽  
Window Blinds

In this research, we report a simple and inexpensive way to prepare transparent and hydrophobic hybrid coatings through deposition of different silica materials on polyvinyl chloride (PVC) substrates. The silica materials were prepared using an acid-catalyzed sol–gel method at room temperature (25 ± 2 °C), using alkoxysilanes: tetraethoxysilane (TEOS), as the silica source, and ethoxydimethylvinylsilane (DMVES), triethoxyoctylsilane (OTES), and trimethoxyhexadecylsilane (HDTMES), as modifier agents. The obtained materials were characterized (either as powders or as thin films) by Fourier-transform infrared spectroscopy (FTIR), UV/Vis spectroscopy, transmission electron microscopy (TEM), thermogravimetric analysis (TGA), atomic force microscopy (AFM), spectroscopic ellipsometry (SE), and water contact-angle measurements. UV/Vis spectra showed that the PVC substrate coated with the silica material containing TEOS/DMVES/OTES had a transmittance of about 90% in the wavelength range of 650–780 nm. The water contact angles increased from 83° for uncoated PVC substrate to ~94° for PVC substrates coated with the sol–gel silica materials. These PVC films with hybrid silica coatings can be used as the materials for outdoor applications, such as energy-generating solar panel window blinds or PVC clear Windmaster outdoor blinds.

scholarly journals Fabrication of a Novel Antifouling Polysulfone Membrane with in Situ Embedment of Mxene Nanosheets

2019 ◽  
Vol 16 (23) ◽  
pp. 4659 ◽  
Author(s):  
Zhen Shen ◽  
Wei Chen ◽  
Hang Xu ◽  
Wen Yang ◽  
Qing Kong ◽  
...  
Keyword(s):  
Contact Angle ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Water Contact Angle ◽  
Bovine Serum ◽  
Composite Membranes ◽  
Recovery Ratio ◽  
Water Contact ◽  
Polysulfone Membrane

Membrane fouling is still a critical issue for the application of ultrafiltration, which has been widely used in water treatment due to its efficiency and simplicity. In order to improve the antifouling property, a new 2D material MXene was used to fabricate composite ultrafiltration membrane with the approach of in situ embedment during the phase inversion process in this study. Scanning electron microscopy (SEM), atomic force microscopy (AFM), thermogravimetric analysis (TGA), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), water contact angle, bovine serum albumin rejection and porosity measurements were utilized to characterize the prepared membranes. Due to the hydrophilicity of the MXene, the composite membranes obtained higher hydrophilicity, confirmed by the decreased water contact angle. All the modified membranes had a high bovine serum albumin rejection above 90% while that of the pristine polysulfone membrane was 77.48%. The flux recovery ratio and the reversible fouling ratio of the membranes were also improved along with the increasing content of the MXene. Furthermore, the highest flux recovery ratio could also reach 76.1%. These indicated the good antifouling properties of MXene composite membranes. The enhanced water permeability and protein rejection and excellent antifouling properties make MXene a promising material for antifouling membrane modification.

scholarly journals Superhydrophobic organosilicon-based coating system by a novel ultravoilet-curable method

2017 ◽  
Vol 7 ◽  
pp. 184798041770279 ◽  
Author(s):  
Baojiang Liu ◽  
Taizhou Tian ◽  
Jinlong Yao ◽  
Changgen Huang ◽  
Wenjun Tang ◽  
...  
Keyword(s):  
Contact Angle ◽  
Surface Energy ◽  
Silica Nanoparticles ◽  
Water Contact Angle ◽  
Cotton Fabric ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Water Repellent ◽  
Step Method ◽  
Water Contact

A robust superhydrophobic organosilica sol-gel-based coating on a cotton fabric substrate was successfully fabricated via a cost-effective one-step method. The coating was prepared by modification of silica nanoparticles with siloxane having long alkyl chain that allow to reduce surface energy. The coating on cotton fabric exhibited water contact angle of 151.6°. The surface morphology was evaluated by scanning electron microscopy, and surface chemical composition was measured with X-ray photoelectron spectroscopy. Results showed the enhanced superhydrophobicity that was attributed to the synergistic effect of roughness created by the random distribution of silica nanoparticles and the low surface energy imparted of long-chain alkane siloxane. In addition, the coating also showed excellent durability against washing treatments. Even after washed for 30 times, the specimen still had a water contact angle of 130°, indicating an obvious water-repellent property. With this outstanding property, the robust superhydrophobic coating exhibited a prospective application in textiles and plastics.

UV-curable fluorine-containing hybrid coatings via thiol-ene “click” reaction and an in situ sol–gel method

2012 ◽  
Vol 70 (3) ◽  
pp. 1037-1048 ◽  
Author(s):  
Emrah Çakmakçı ◽  
Yusuf Mülazim ◽  
Memet Vezir Kahraman
Keyword(s):  
Click Reaction ◽  
Sol Gel ◽  
Hybrid Coatings ◽  
Uv Curable ◽  
Gel Method ◽  
Sol Gel Method

scholarly journals Transparent superhydrophobic PTFE films via one-step aerosol assisted chemical vapor deposition

RSC Advances ◽  
2017 ◽  
Vol 7 (47) ◽  
pp. 29275-29283 ◽  
Author(s):  
Aoyun Zhuang ◽  
Ruijin Liao ◽  
Sebastian C. Dixon ◽  
Yao Lu ◽  
Sanjayan Sathasivam ◽  
...  
Keyword(s):  
Contact Angle ◽  
Chemical Vapor Deposition ◽  
Water Contact Angle ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Sliding Angle ◽  
Water Contact ◽  
Visible Transmittance ◽  
One Step

Hierarchical micro/nano-structured transparent superhydrophobic polytetrafluoroethylene films with water contact angle 168°, water sliding angle <1° and visible transmittance >90% were prepared on glass via aerosol-assisted chemical vapor deposition.

Synthesis and Characterization of ZnO-SiO2/Epoxy Nanocomposite Coating by Sol-Gel Process

2012 ◽  
Vol 16 ◽  
pp. 1-7
Author(s):  
Nazanin Farhadyar ◽  
Mirabdullah Seyed Sadjadi
Keyword(s):  
Polyethylene Glycol ◽  
Sol Gel ◽  
Nanocomposite Coating ◽  
Contact Angles ◽  
Hybrid Coatings ◽  
Coating Film ◽  
Water Contact ◽  
Unit Form ◽  
Hybrid Solution ◽  
Sol Gel Process

In this paper, we report preparation of hydrophilic hybrid nanocomposite coatings on glass substrates using Zinc acetate solutions based on 3-glycidoxypropyltrimethoxysilane (GPTMS), epoxy resin, aromatic amine (HY850), polyethylene glycol (PEG) and surfactant (polyoxyethylene(4)laurylether) by the sol-gel process. Furthermore, the effects of PEG addition to the precursor solutions on the hydrophilic property and microstructure of the resultant coating film were studied. The hydrophilic behavior study of the synthesized hybrid was performed by adding different amounts of polyethylene glycol precursor to the hybrid solution. Experimental results show that, among different amounts of PEGs, the best results are obtained by addition of PEGs (400) to the hybrid solution which can decrease the water contact angles down to 16 and using surfactant down to 0, and increase the free surface energy. Coated glass exhibits a higher strength than uncoated glass. Attenuated total reflectance infrared spectroscopic (ATR-IR) technique was used to characterize the structure of the hybrid films. The chemical structure of obtained network affects morphology of the coating. The morphology of the hybrid coatings was examined by transmission electron microscopy (TEM). The hybrid systems have a unit form structure and the inorganic phases were in the nanosize scale,

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