Multifunctional nanocomposite transparent UV-blocking films sythesized by sol-gel process for optical, automotive and aeronautic applications

2005 ◽  
Vol 901 ◽  
Author(s):  
Phani Ratna Ayalasomayajula ◽  
S. Santucci
Keyword(s):  
Thin Films ◽  
Contact Angle ◽  
Morphological Changes ◽  
Sol Gel ◽  
Chemical Properties ◽  
Contact Angles ◽  
Nanocomposite Films ◽  
Energy Materials ◽  
Water Contact ◽  
Uv Blocking

AbstractDevelopment of UV blocking thin films with effective cut-off features with steep edges and high transmission in the visible and IR region have been developed. The unique optical, mechanical and chemical properties of silica and ceria nanocomposites with surface functional groups making them most promising candidate for applications in opto-electronic, automotive, and aeronautic industries. On the other hand, highly hydro and oleophobic films are being actively considered in optical, automotive and aeronautic industries to increase adhesion and scratch, abrasion resistance properties. In order to fill the gap, and fulfill the requirements to meet both ends, it could be proved that morphological changes in the nanometer range influences the water contact angles and their hystersis of low energy materials. Nanocomposite films of SiO2 and CeO2 with surface functionalisation with decafluorooctly-triethoxy silane itself forms nano-hemispheres (similar to lotus leaf) at and above 100°C favoring an increase in water contact angle from 122° (25°C) to 145°(400°C). The structural, optical, and hydrophobic properties have been examined by employing X-ray diffraction, UV-visible spectroscopy, contact angle techniques, respectively. The cut-off behavior of the deposited and annealed nanocomposite thin films have been tuned by varying different amounts of CeO2 in SiO2.

Optical Transparent and Hydrophobic Properties of TEOS/OTES Hybrid Materials by Sol-Gel Processing

2019 ◽  
Vol 798 ◽  
pp. 134-139
Author(s):  
Usanee Pantulap ◽  
Benjamon Petchareanmongkol ◽  
Waraporn Kaewdang ◽  
Kanit Tapasa
Keyword(s):  
Contact Angle ◽  
Sol Gel ◽  
Contact Angles ◽  
Light Transmittance ◽  
Film Properties ◽  
Water Contact ◽  
Atomic Force ◽  
Commercial Glass ◽  
Gel Processing ◽  
Hydrolysis Of

The objective of this project was to develop the hydrophobic film for self-cleaning glasses. The effects of octyltriethoxysilane (OTES) additions to hydrolysis of tetraethylorthosilicate (TEOS) on hydrophobic and optically transparent properties were studied. The film was prepared by sol-gel method from the precursors namely, TESO, OTES, isopropanol alcohol (IPA), and deionized water (DI). The sols for coating were obtained with TEOS/OTES ratio of 50:50 to 99:1. The sols were deposited on a commercial glass and dried at 60oC for an hour. After drying, the film properties were characterized by fourier transform infrared spectroscopy (FTIR), UV-VIS Spectrophotometer, x-Ray Diffractometer (XRD), atomic force microscope (AFM), optical microscopy and contact angle meter. It was found that contact angles of the hybrid films increased with the OTES addition, reaching a maximum at 10 wt.%, and the contact angle values were the same as for further addition. The light transmittance was rather stable with increasing amounts of OTES. For the optimized condition, the water contact angle of 108o and light transmittance of 91%, was obtained with TEOS/OTES ratio of 90:10.

Preparation and Properties of TiO2 Thin Films Deposited on Different Substrates by Sol-Gel Method

2014 ◽  
Vol 979 ◽  
pp. 355-358 ◽  
Author(s):  
Tanattha Rattana ◽  
Nirun Witit-Anun ◽  
Sumetha Suwanboon ◽  
Surasing Chaiyakun
Keyword(s):  
Thin Films ◽  
Contact Angle ◽  
Stainless Steel ◽  
Silicon Wafer ◽  
Irradiation Time ◽  
Sol Gel ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Ambient Atmosphere ◽  
Water Contact

In this work, TiO2thin films were prepared by a sol-gel spin coating method on glass slide, stainless steel 304 and silicon wafer substrates. The thin films were annealed at different temperatures at ambient atmosphere. The effect of substrates and annealing temperatures on microstructure, surface morphology and hydrophilicity of the films were characterized by Raman spectroscopy, atomic force microscopy and water contact angle measurement, respectively. The Raman spectra indicated that the annealed TiO2thin films (at 550 °C) coated on stainless steel and silicon wafer exhibited anatase structure. The contact angle of all samples decreased with increasing the UV-irradiation time and annealing temperature.

PREPARATION AND CHARACTERIZATIONS OF PTFE GRADIENT NANOSTRUCTURE ON SILK FABRIC

2007 ◽  
Vol 14 (04) ◽  
pp. 547-551 ◽  
Author(s):  
F. L. HUANG ◽  
Q. F. WEI ◽  
W. Z. XU ◽  
Q. LI
Keyword(s):  
Contact Angle ◽  
Contact Angle Hysteresis ◽  
Dynamic Contact Angle ◽  
Chemical Properties ◽  
Dynamic Contact ◽  
Contact Angles ◽  
Attenuated Total Reflection ◽  
Silk Fabric ◽  
Water Contact ◽  
Sputter Coating

Superhydrophobic materials have been extensively studied because of their wonderful array of properties and applications. In this study, normal and superhydrophobic surface of silk fabric have been prepared via deposition of different shapes of PTFE nanostructure using magnetron sputter coating. The effects of PTFE sputter coating on surface morphology and surface chemical properties were characterized using atomic force microscopy (AFM) and ATR-FTIR (attenuated total reflection-Fourier transform infrared spectroscopy). The wettability of the fabric was characterized through measuring the surface contact angle by drop shape analysis apparatus and dynamic contact angle by Wilhelmy technique. As evaluated by water contact angle measurements, all the treatments resulted in a significant enhancement in the hydrophobicity of silk fabric, while larger sputtering pressures brought bigger PTFE nanoparticles, which led to higher contact angles. The results have also revealed that alternant working pressures, could bring gradient nanostructures which generated both high contact angle and less contact angle hysteresis.

Effects of Air Exposure Time and Annealing Temperature on Superhydrophobic Surface of Titanium Dioxide Films

2017 ◽  
Vol 751 ◽  
pp. 137-142
Author(s):  
S.Tipawan Khlayboonme ◽  
Warawoot Thowladda
Keyword(s):  
Contact Angle ◽  
Surface Morphology ◽  
Exposure Time ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Contact Angles ◽  
Angle Measurement ◽  
Elemental Distribution ◽  
Water Contact ◽  
Air Exposure

TiO2 thin films coated on glass substrates for self-cleaning applications were prepared by sol-gel dip-coating technique. The influence of annealing temperature and air exposure time on wettability was investigated by a water contact-angle measurement. Thermal annealing at temperatures of 100, 200 and 300 °C in air were conducted to the films. Surface morphology of the films was observed by FE-SEM. Elemental distribution and optical properties were examined by EDX mapping and UV-Vis transmission spectroscopy, respectively. Atomic bonding was confirmed by FTIR. The contact angle reached a maximum when the films were annealed at 200 °C. The contact angles of the as-synthesized films were 61.4±2.7°. During storage in air for 20 days, the contact angles increased to 143.1±2.1°. The films were further reannealed with 100 °C for 20 min, the contact angles were enhanced to 153.1±1.3°. The association of contact angle among the surface morphology, elemental distribution and atomic bonding of the films will be discussed.

scholarly journals The Effect of Polyethylene Glycol Addition on Wettability and Optical Properties of GO/TiO2 Thin Film

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4564
Author(s):  
Azliza Azani ◽  
Dewi Suriyani Che Halin ◽  
Kamrosni Abdul Razak ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Marcin Nabiałek ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Contact Angle ◽  
Optical Properties ◽  
Polyethylene Glycol ◽  
Water Contact Angle ◽  
Tio2 Thin Film ◽  
Sol Gel ◽  
Tio2 Thin Films ◽  
Water Contact

Modification has been made to TiO2 thin film to improve the wettability and the absorption of light. The sol-gel spin coating method was successfully used to synthesize GO/TiO2 thin films using a titanium (IV) isopropoxide (TTIP) as a precursor. Different amounts of polyethylene glycol (PEG) (20 to 100 mg) were added into the parent sol solution to improve the optical properties and wettability of the GO/TiO2 thin film. The effect of different amounts of PEG was characterized using X-ray diffraction (XRD) for the phase composition, scanning electron microscopy (SEM) for microstructure observation, atomic force microscopy (AFM) for the surface topography, ultraviolet–visible spectrophotometry (UV-VIS) for the optical properties and wettability of the thin films by measuring the water contact angle. The XRD analysis showed the amorphous phase. The SEM and AFM images revealed that the particles were less agglomerated and surface roughness increases from 1.21 × 102 to 2.63 × 102 nm when the amount of PEG increased. The wettability analysis results show that the water contact angle of the thin film decreased to 27.52° with the increase of PEG to 80 mg which indicated that the thin film has hydrophilic properties. The optical properties also improved significantly, where the light absorbance wavelength became wider and the band gap was reduced from 3.31 to 2.82 eV with the presence of PEG.

scholarly journals The role of contact angle and pore width on pore condensation and freezing

2020 ◽  
Vol 20 (15) ◽  
pp. 9419-9440 ◽  
Author(s):  
Robert O. David ◽  
Jonas Fahrni ◽  
Claudia Marcolli ◽  
Fabian Mahrt ◽  
Dominik Brühwiler ◽  
...  
Keyword(s):  
Contact Angle ◽  
Active Sites ◽  
Water Saturation ◽  
Sol Gel ◽  
Contact Angles ◽  
Ice Nucleation ◽  
Pore Width ◽  
Water Contact ◽  
Pore Condensation

Abstract. It has recently been shown that pore condensation and freezing (PCF) is a mechanism responsible for ice formation under cirrus cloud conditions. PCF is defined as the condensation of liquid water in narrow capillaries below water saturation due to the inverse Kelvin effect, followed by either heterogeneous or homogeneous nucleation depending on the temperature regime and presence of an ice-nucleating active site. By using sol–gel synthesized silica with well-defined pore diameters, morphology and distinct chemical surface-functionalization, the role of the water–silica contact angle and pore width on PCF is investigated. We find that for the pore diameters (2.2–9.2 nm) and water contact angles (15–78∘) covered in this study, our results reveal that the water contact angle plays an important role in predicting the humidity required for pore filling, while the pore diameter determines the ability of pore water to freeze. For T>235 K and below water saturation, pore diameters and water contact angles were not able to predict the freezing ability of the particles, suggesting an absence of active sites; thus ice nucleation did not proceed via a PCF mechanism. Rather, the ice-nucleating ability of the particles depended solely on chemical functionalization. Therefore, parameterizations for the ice-nucleating abilities of particles in cirrus conditions should differ from parameterizations at mixed-phase clouds conditions. Our results support PCF as the atmospherically relevant ice nucleation mechanism below water saturation when porous surfaces are encountered in the troposphere.

Improvement of Interfacial Adhesion in PP/PS Blends Enhanced with Polyethylene-Polyamine Surface Treated Carbon Fiber

2014 ◽  
Vol 1061-1062 ◽  
pp. 170-174
Author(s):  
Jian Li
Keyword(s):  
Contact Angle ◽  
Carbon Fiber ◽  
Photoelectron Spectroscopy ◽  
Interfacial Adhesion ◽  
Morphological Changes ◽  
Water Contact ◽  
Polyethylene Polyamine ◽  
Adhesion Behavior ◽  
Interlaminar Shear ◽  
Treated Carbon

The effects of surface treatment of a carbon fiber (CF) by Polyethylene-polyamine (PEPA) on the interfacial adhesion behavior and morphology of polypropylene/polystyrene (PP/PS) matrix blends filled CF composites were investigated. Effects of surface treated a commercial CF on mechanical properties are studied. Contact angle was measured to examine the changes in wettability of the carbon fiber. The chemical and morphological changes were characterized by using X-ray photoelectron spectroscopy (XPS). PP/PS/CF composites were fabricated with and without PEPA treatment, and their interlaminar fracture toughnesses were compared. The results showed that the interlaminar shear strength (ILSS) of composites has been greatly improved filled PEPA modification CF. The water contact angle of resin sample decreased 50% after addition of PEPA surface treated CF.

Preparation of Super Hydrophobic Surfaces by the Stainless Steel Wire Mesh as Templates

2012 ◽  
Vol 562-564 ◽  
pp. 56-59 ◽  
Author(s):  
Jian Zhuang ◽  
Meng Meng Du ◽  
Heng Zhi Cai ◽  
Ya Jun Zhang ◽  
Da Ming Wu
Keyword(s):  
Contact Angle ◽  
Stainless Steel ◽  
Steel Wire ◽  
Contact Angles ◽  
Wire Mesh ◽  
Stainless Steel Wire ◽  
Hydrophobic Surfaces ◽  
Water Contact ◽  
Stainless Steel Wire Mesh ◽  
Steel Wire Mesh

A facile method for manufacturing super hydrophobic surfaces is presented using the stainless steel wire mesh as templates. The rough surfaces of polymers including polycarbonate, polypropylene and PMMA are prepared with hot embossing on different specifications of stainless steel wire mesh. Scanning electron microscopy (SEM) results reveal that the surfaces roughness of the polymers can be controlled by selecting templates. Contact angle measurement shows that the water contact angles(WCA) rise with the increase of surface roughness, especially, the water contact angle on the PC surfaces prepared with specifications of 635mesh screen can reach to 152.3°, alias super hydrophobic surfaces.

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.

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