Control of hydrophobic properties of polyester fabric coatings deposited with use of polytetrafluoroethylene telomers and silicon dioxide nanoparticles

2021 ◽  
Vol 22 (10) ◽  
pp. 447-457
Author(s):  
N. P. Prorokova ◽  
◽  
T. Yu. Kumeeva ◽  
I. V. Kholodkov ◽  
V. M. Bouznik ◽  
...  
Keyword(s):  
Silicon Dioxide ◽  
Water Absorption ◽  
Sio2 Nanoparticles ◽  
Polyester Fabric ◽  
Contact Angles ◽  
Water Repellent ◽  
Silicon Dioxide Nanoparticles ◽  
Hydrophobic Properties ◽  
Additional Increase

The control possibility assessment of the water-repellent properties of polyester (PEF) fabric when its hydrophobizing with tetrafluoroethylene (TFE) telomers due to texturing by applying nanosized SiO2 is discussed. It was established that the use of a compound containing SiO2 nanoparticles and TFE telomers for hydrophobization of PEF fabrics led to an increase in roughness of the coatings, however, a decrease in contact angles of fabric and an increase in its water absorption were observed. This is due to an additional increase in hardness of the coating based on TFE telomers, when combined with SiO2 nanoparticles.

scholarly journals HYDRO- AND OLEOPHOBIC COATINGS BASED ON POLYVINYL ALCOHOL AND SILICON DIOXIDE NANOPARTICLES

2018 ◽  
Vol 62 (3) ◽  
pp. 298-303
Author(s):  
A. E. Salamianski ◽  
D. A. Kalenchanka ◽  
G. B. Melnikova ◽  
Yu. V. Sinkevich ◽  
V. E. Agabekov
Keyword(s):  
Polyvinyl Alcohol ◽  
Silicon Dioxide ◽  
Spin Coating ◽  
Composite Coatings ◽  
Sio2 Nanoparticles ◽  
Silicon Dioxide Nanoparticles ◽  
Spin Coating Method ◽  
Coating Method

The wettability of composite coatings based on polyvinyl alcohol (PVA) and silicon dioxide formed on silicon by the spin coating method from PVA colloid solutions of SiO2 nanoparticles was studied. These coatings modified with hydrolysed heptadecafluorotetrahydrodecyltrimethoxysilane are found to exhibit superhydrophobic and oleophobic properties. It was found that PVA increases the wear stability of SiO2–PVA coatings.

scholarly journals Comparative Study of Lightweight Cementitious Composite Reinforced with Different Fibre Types and the Effect of Silane-Based Admixture

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Geok Wen Leong ◽  
Hui Loo Chua ◽  
Kim Hung Mo ◽  
Zainah Ibrahim ◽  
Zhi Pin Loh
Keyword(s):  
Water Absorption ◽  
Lightweight Concrete ◽  
Water Repellent ◽  
Cementitious Composite ◽  
Hydrophobic Properties ◽  
Water Contact ◽  
Fine Grained ◽  
Overall Performance ◽  
Hardened Properties ◽  
Softening Coefficient

This study aims to develop a type of fine-grained lightweight concrete, also known as lightweight cementitious composite (LCC), containing perlite microsphere (PM) and fibres with enhanced impermeability. The effect of polypropylene (PP), polyvinyl alcohol (PVA), and basalt fibres on the fresh and hardened properties of LCC was investigated. Besides, silane-based water repellent admixture was incorporated to reduce the water absorption and enhance the hydrophobicity of LCC. The dry densities of LCC developed were in the range of 912–985 kg/m3. PP fibres have lesser influence on the strengths of LCC. However, PVA fibres enhanced the strength of LCC by up to 35.2% and 28% in the compressive strength and flexural strength, respectively, while the basalt fibres increased both strengths up to 30.1% and 43.5%, respectively. By considering the overall performance, LCC with 0.5% PVA fibres has achieved a good balance in workability and strength. Additionally, silane-based water repellent admixture had an excellent effect in reducing the water absorption and improving the hydrophobicity of LCC. By incorporating 1% of silane-based water repellent admixture, the LCC with 0.5% PVA fibres obtained water-resistant properties with the softening coefficient of 0.85 and water contact angle of 128.2°. In conclusion, a combination of PVA-LCC with 1% waterproofing admixture showed the best performance in terms of mechanical strength as well as hydrophobic properties and had the potential to be used in the fabrication of concrete façade.

scholarly journals Superhydrophobic Coatings Based on Siloxane Resin and Calcium Hydroxide Nanoparticles for Marble Protection

Coatings ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 334 ◽  
Author(s):  
Aikaterini Chatzigrigoriou ◽  
Ioannis Karapanagiotis ◽  
Ioannis Poulios
Keyword(s):  
Electron Microscopy ◽  
Calcium Hydroxide ◽  
Composite Coatings ◽  
Exchange Process ◽  
Sio2 Nanoparticles ◽  
Contact Angles ◽  
Water Repellent ◽  
Aqueous Emulsion ◽  
Aesthetic Appearance ◽  
Static Contact

Calcium hydroxide (Ca(OH2)) nanoparticles are produced following an easy, ion exchange process. The produced nanoparticles are characterized using transmission electron microscopy (TEM) and Fourier- transform infrared spectroscopy (FTIR) and are then dispersed in an aqueous emulsion of silanes/siloxanes. The dispersions are sprayed on marble and the surface structures of the deposited coatings are revealed using scanning electron microscopy (SEM). By adjusting the nanoparticle concentration, the coated marble obtains superhydrophobic and water repellent properties, as evidenced by the high static contact angles of water drops (> 150°) and the low sliding angles (< 10°). Because Ca(OH)2 is chemically compatible with limestone-like rocks, which are the most common stones found in buildings and objects of the cultural heritage, the produced composite coatings have the potential to be used for conservation purposes. For comparison, the wetting properties of another superhydrophobic and water repellent coating composed of the same siloxane material and silica (SiO2) nanoparticles, which were commonly used in several previously published reports, were investigated. The suggested siloxane+Ca(OH)2 composite coating offers good protection against water penetration by capillarity and has a small effect on the aesthetic appearance of marble, according to colorimetric measurements.

scholarly journals THE EFFECT OF SILICON DIOXIDE NANOPARTICLES ON THE LEAD HEPATOTOXICITY

2016 ◽  
Author(s):  
I. A. Bandas ◽  
M. I. Kulitska ◽  
M. M. Korda
Keyword(s):  
Alkaline Phosphatase ◽  
Silicon Dioxide ◽  
Lead Acetate ◽  
Total Bilirubin ◽  
Sio2 Nanoparticles ◽  
The Body ◽  
Total Plasma ◽  
Silicon Dioxide Nanoparticles ◽  
Phosphatase Activities ◽  
Total Plasma Protein

Nanoparticles are known to facilitate transport of chemicals and medications through membrane barriers into cells. This results in the raising of toxic effect when two contaminants act on the body at the same time. The aim of this study was to determine how silicon dioxide (SiO2) nanoparticles affect the hepatotoxic properties of lead. Alanine and aspartate transaminases, alkaline phosphatase activities, as well as total protein, total bilirubin, creatinine and urea contents were measured in rat blood plasma. It was shown that SiO2 nanoparticles did not significantly affect the above listed markers. Administration of lead acetate to the animals caused cytolysis of hepatocytes, as evidenced by significant increase of alanine and aspartate transaminases, alkaline phosphatase activities, along with significant decrease of total plasma protein and increase of total bilirubin levels. The increase of aminotransferases and alkaline phosphatase activities in animals that received both SiO2 nanoparticles and lead acetate was significant comparedto the animals that received only lead acetate. This suggests that SiO2 nanoparticles, which are normally present inthe environment and food products as contaminants, can enhance the negative hepatotoxic effects of lead.

scholarly journals Inexpensive and non-toxic water repellent coatings comprising SiO2 nanoparticles and long chain fatty acids

RSC Advances ◽  
2018 ◽  
Vol 8 (48) ◽  
pp. 27064-27072 ◽  
Author(s):  
Frances L. Heale ◽  
Kristopher Page ◽  
James S. Wixey ◽  
Philip Taylor ◽  
Ivan P. Parkin ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Silica Nanoparticles ◽  
Sio2 Nanoparticles ◽  
Contact Angles ◽  
Water Repellent ◽  
Long Chain Fatty Acids ◽  
Water Contact ◽  
Hydrophobic Silica ◽  
Long Chain ◽  
Chain Fatty Acids

Special wettability durable coatings, with water contact angles exceeding 140°, have been fabricated using inexpensive and non-toxic functionalised hydrophobic-silica nanoparticles embedded in fatty acids.

scholarly journals Enhanced X-ray Attenuating Efficiency of Silicon Dioxide Nanoparticles with Cesium Lead Bromide and 2,5-Diphenyloxazole Co-Embedded Therein

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1531
Author(s):  
Geunpyo Choe ◽  
Hyemin Kwon ◽  
Ilhwan Ryu ◽  
Sanggyu Yim
Keyword(s):  
Silicon Dioxide ◽  
Early Stage ◽  
Imaging Techniques ◽  
Fluorescence Emission ◽  
Hounsfield Unit ◽  
Sio2 Nanoparticles ◽  
Silicon Dioxide Nanoparticles ◽  
X Ray ◽  
Lead Bromide

An X-ray-attenuation-based in vivo imaging can be a promising candidate for real-time detection of cancer in an early stage due to its significantly longer penetration depth compared to currently investigated fluorescence-emission-based imaging techniques. It has recently been demonstrated that this novel concept of imaging is feasible using cesium lead bromide (CPB) quantum dots (QDs) stably embedded in silicon dioxide (SiO2) nanoparticles (NPs). However, further improvements are necessary to realize its practical use, especially in terms of X-ray attenuation efficiency. In this study, we have found that the X-ray attenuation capability of CPB/SiO2 NPs was significantly enhanced by embedding an organic X-ray scintillator, 2,5-diphenyloxazole (PPO), together with CPB QDs in the NPs. The embedment not only solved the water dispersibility and stability problem of PPO, but also significantly increased the Hounsfield unit of the NPs, which was proportional to the degree of X-ray attenuation, by 2.7 times.

scholarly journals Inter-ligand energy transfer in dye chromophores attached to high bandgap SiO2 nanoparticles

2019 ◽  
Vol 55 (60) ◽  
pp. 8804-8807 ◽  
Author(s):  
Michael B. Price ◽  
Andrew Paton ◽  
Jeffrey Gorman ◽  
Isabella Wagner ◽  
Geoffry Laufersky ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Silicon Dioxide ◽  
Light Harvesting ◽  
Sio2 Nanoparticles ◽  
Covalent Attachment ◽  
Artificial Light ◽  
Silicon Dioxide Nanoparticles ◽  
Organic Chromophores

Simple artificial light harvesting networks can be created by the covalent attachment of organic chromophores to silicon dioxide nanoparticles.

scholarly journals Effect of Hydrophobic Treatments on Improving the Salt Frost Resistance of Concrete

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5361
Author(s):  
Guo Li ◽  
Chunhua Fan ◽  
Yajun Lv ◽  
Fujun Fan
Keyword(s):  
Water Absorption ◽  
Frost Resistance ◽  
Contact Angles ◽  
Water Repellent ◽  
Freezing And Thawing ◽  
Ordinary Water ◽  
Salt Scaling ◽  
Mass Losses ◽  
Hydrophobic Treatment ◽  
Freezing And Thawing Cycles

Hydrophobic treatment is an important method to improve the waterproof properties of concrete. To evaluate the effectiveness of hydrophobic treatments on improving the salt frost resistance of concrete, two representative commercial ordinary water repellent agents of silane and organosilicone emulsion were selected, and concrete specimens with three water/cement ratios were fabricated. After the application of repellent agents on concrete surfaces, accelerated saline (5% MgCl2) freeze-thaw cycles were conducted on the specimens. The mass losses and relative dynamic modulus of elasticity (RDME) of concrete were tested periodically. The contact angles and water absorption ratios of concrete with and without hydrophobic treatments were also tested. Results showed that the repellent agents could substantially enhance the hydrophobicity of concrete and greatly reduce its water absorption. Different repellent agents exerted diverse improvements on concrete hydrophobicity. Meanwhile, the repellent agents could improve concrete resistance against salt scaling and RDME losses to a certain degree, and concrete with strong hydrophobicity showed relatively high salt frost resistance. However, the ordinary water repellent agents cannot achieve the same enhancement on salt frost resistance of concrete as that on the water hydrophobicity of concrete. With saline freezing and thawing cycles, the hydrophobic layer formed by the repellent agents on superficial concrete was destroyed gradually. As a result, the salt frost resistance of concrete from the hydrophobic treatments was ultimately lost.

A facile coating with water-repellent and flame-retardant properties on cotton fabric

2019 ◽  
Vol 43 (25) ◽  
pp. 10183-10189 ◽  
Author(s):  
Jing Fu ◽  
Fuchao Yang ◽  
Guopeng Chen ◽  
Guofeng Zhang ◽  
Can Huang ◽  
...  
Keyword(s):  
Silicon Dioxide ◽  
Flame Retardant ◽  
Phytic Acid ◽  
Cotton Fabric ◽  
Fire Resistance ◽  
Superhydrophobic Surface ◽  
Water Repellent ◽  
Silicon Dioxide Nanoparticles ◽  
Resistance Property ◽  
Flame Retardant Properties

We herein present a facile method to fabricate functional cotton fabric (CF) with superhydrophobic surface and excellent fire-resistance property by coating with chitosan (CS)/phytic acid (PA) layer and hydrophobic silicon dioxide nanoparticles.

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