scholarly journals Rapid Microwave-Assisted Synthesis of Organo-Modified Nanostructured Silica Coatings with Tunable Water-Repellence Properties

Coatings ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1319
Author(s):  
Catalina Ioana Gȋfu ◽  
Bogdan Trică ◽  
Claudia Mihaela Ninciuleanu ◽  
Cătălin Ionuţ Mihăescu ◽  
Cristian Petcu ◽  
...  
Keyword(s):  
Low Cost ◽  
Sol Gel ◽  
Cost Effective ◽  
Contact Angles ◽  
Water Repellent ◽  
Microwave Assisted Synthesis ◽  
Modified Silica ◽  
Simple Method ◽  
Silica Coatings ◽  
Modified Silica Nanoparticles

A simple method to fabricate organo-modified silane coatings for water-repellent surface modification was proposed, by using a microwave sol-gel synthesis of hybrid materials. Low-cost fluorine-free tetraethoxysilane (TEOS) and dodecyltriethoxysilane (DDTES) were used as silane derivatives. The organo-modified silica coatings were prepared by the drop-casting method and were characterized by UV-VIS, FTIR spectroscopy, and AFM and SEM microscopy. The morphology of the film show the existence of submicrometer scale roughness due to the aggregation of modified silica nanoparticles. Contact angles of water and diiodomethane on surfaces modified with as prepared nanostructured film were determined in order to assess the hydrophobic and oleophobic properties. The TEOS/DDTES ratio was proved to be a crucial factor in tuning the wettability properties. The results suggest that significant increase of hydrophobicity could be achieved by using non-fluorinated cost-effective silica nanomaterials produced with a rapid ecofriendly method.

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.

Portable, Low-Cost, Solid-State Luminescence-Based O2 Sensor

1998 ◽  
Vol 52 (5) ◽  
pp. 750-754 ◽  
Author(s):  
A. Neal Watkins ◽  
Brett R. Wenner ◽  
Jeffrey D. Jordan ◽  
Wenying Xu ◽  
James N. Demas ◽  
...  
Keyword(s):  
Solid State ◽  
Response Times ◽  
Ruthenium Complex ◽  
Light Emitting Diode ◽  
Low Cost ◽  
Sol Gel ◽  
Cost Effective ◽  
Fast Response ◽  
Color Filter ◽  
Silicon Photodiode

A novel sensor for quantifying molecular O2 based entirely on solid-state electronics is presented. The sensor is based on the luminescence quenching of tris(4,7-diphenyl-1, 10-phenanthroline)ruthenium(II) ([Ru(dpp)3]2+) by molecular O2. The sensor involves immobilizing the ruthenium complex within a porous sol-gel-processed glass film and casting this film directly onto the surface of a blue quantum-well light-emitting diode (LED). The ruthenium complex is excited by the LED, the [Ru(dpp)3]2+ emission is filtered from the excitation with a low-cost acrylic color filter, and the emission is detected with an inexpensive silicon photodiode. The sensor response to gaseous O2 and dissolved O2 in water is presented. The sensor exhibits fast response times and good reversibility, and detection limits are 0.5%, 0.02%, and 110 ppb, respectively, for O2 in the gaseous (linear Stern–Vobner and multi-site Stern–Volmer analysis) and aqueous phase. This sensor provides a cost-effective alternative to traditional electrochemical-based O2 sensing and also provides a platform for other optically based sensors.

scholarly journals Facile Approach to Develop Hierarchical Roughness fiber@SiO2 Blocks for Superhydrophobic Paper

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1393 ◽  
Author(s):  
Qing Wang ◽  
Jieyi Xiong ◽  
Guangxue Chen ◽  
Ouyang Xinping ◽  
Zhaohui Yu ◽  
...  
Keyword(s):  
Large Scale ◽  
Low Cost ◽  
Sol Gel ◽  
Sio2 Nanoparticles ◽  
Contact Angles ◽  
Preparation Process ◽  
Water Contact ◽  
Mechanical Durability ◽  
Complex Preparation ◽  
Superhydrophobic Paper

Papers with nanoscaled surface roughness and hydrophobically modification have been widely used in daily life. However, the relatively complex preparation process, high costs and harmful compounds have largely limited their applications. This research aims to fabricate superhydrophobic papers with low cost and nontoxic materials. The surface of cellulose fibers was initially coated with a film of SiO2 nanoparticles via sol-gel process. After papermaking and subsequent modification with hexadecyltrimethoxysilane through a simple solution-immersion process, the paper showed excellent superhydrophobic properties, with water contact angles (WCA) larger than 150°. Moreover, the prepared paper also showed superior mechanical durability against 10 times of deformation. The whole preparation process was carried out in a mild environment, with no intricate instruments or toxic chemicals, which has the potential of large-scale industrial production and application.

scholarly journals Effective and Green Removal of Trichloroacetic Acid from Disinfected Water

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 827
Author(s):  
Keren Trabelsi ◽  
Michael Meistelman ◽  
Rosaria Ciriminna ◽  
Yael Albo ◽  
Mario Pagliaro
Keyword(s):  
Trichloroacetic Acid ◽  
Low Cost ◽  
Sol Gel ◽  
Chloroacetic Acid ◽  
Reductive Dehalogenation ◽  
Silica Xerogel ◽  
Modified Silica ◽  
Carcinogenic Agent ◽  
Cytotoxic Effects ◽  
Continuous Processes

An innovative catalyst is reported for removing suspect carcinogen trichloroacetic acid (TCA) found in water after chlorination. SilverSil, a methyl-modified silica xerogel doped with Ag nanoparticles, shows remarkably high and stable activity as heterogeneous catalyst for the reductive dehalogenation of TCA with NaBH4 as reducing agent. Chloroacetic acid and acetic acid are the main products of the highly reproducible reductive dehalogenation. The low cost, high stability and ease of application of the SilverSil sol-gel catalyst to continuous processes open the route to the industrial uptake of SilverSil to free chlorinated waters from a probable human carcinogenic agent exerting significant genotoxic and cytotoxic effects.

scholarly journals Synthesis of silica of rice husk modification (3-aminopropyl) trietoxysilane for adsorption methylene blue

2018 ◽  
Vol 197 ◽  
pp. 09009
Author(s):  
Yusmaniar Yusmaniar ◽  
Darsef Darwis ◽  
Afrizal Afrizal ◽  
Annisa Annisa
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Methylene Blue ◽  
Surface Area ◽  
Adsorption Process ◽  
Low Cost ◽  
Sol Gel ◽  
Alkaline Ph ◽  
Modified Silica ◽  
Scanning Electron

In this study, modified silica (3-Amynopropyl) triethoxysilane (APTES) synthesis and adsorption test of MB dye were performed. Silica is synthesized by sol-gel method and modified with APTES. APTES modified silica is characterized using several instruments, scanning electron microscopy (SEM), fourier transform infrared (FTIR), surface area analyzer (SAA) and UV-Vis spectrophotometer. The composite has a large surface area and has a mesoporous shape. At alkaline pH, MB dye can adsorb well. In addition, MB absorption is also maximized with the longer time of adsorption. The APTES modified silica adsorption process follows the Langmuir isotherm pattern. Thus, APTES modified silica can be used as an alternative to environmentally friendly and low-cost adsorbents.

Porous water repellent silica coatings on glass by sol–gel method

2010 ◽  
Vol 18 (3) ◽  
pp. 361-367 ◽  
Author(s):  
Annaso B. Gurav ◽  
Sanjay S. Latthe ◽  
Charles Kappenstein ◽  
S. K. Mukherjee ◽  
A. Venkateswara Rao ◽  
...  
Keyword(s):  
Sol Gel ◽  
Water Repellent ◽  
Gel Method ◽  
Sol Gel Method ◽  
Silica Coatings

scholarly journals Preparation and Characterization of Some Sol-Gel Modified Silica Coatings Deposited on Polyvinyl Chloride (PVC) Substrates

Coatings ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 11
Author(s):  
Violeta Purcar ◽  
Valentin Rădițoiu ◽  
Alina Rădițoiu ◽  
Raluca Manea ◽  
Florentina Monica Raduly ◽  
...  
Keyword(s):  
Polyvinyl Chloride ◽  
Fourier Transforms ◽  
Sol Gel ◽  
Gravimetric Analysis ◽  
Antireflective Coatings ◽  
Modified Silica ◽  
Silica Coatings ◽  
Static Contact ◽  
Vis Spectroscopy ◽  
Silica Materials

Transparent and antireflective coatings were prepared by deposition of modified silica materials onto polyvinyl chloride (PVC) substrates. These materials were obtained by the sol-gel route in acidic medium, at room temperature (25 °C), using different alkoxysilanes with various functional groups (methyl, vinyl, octyl or hexadecyl). Physicochemical and microstructural properties of resulted silica materials and of thin coatings were investigated through Fourier Transforms Infrared Spectroscopy (FTIR), UV-Vis spectroscopy, Thermal Gravimetric Analysis (TGA), Dynamic Mechanical Analysis (DMA), Atomic Force Microscopy (AFM) and ellipsometric measurements. Wetting behaviors of the silica coatings were evaluated by measurement of static contact angle against water. FTIR spectra of materials confirmed the high degree of cross-linking that result from the formation of the inorganic backbone through the hydrolysis and polycondensation reactions together with the formation of the organic network. These sol-gel silica coatings showed a reduction in the reflectance (10%) compared with uncoated PVC substrate. AFM reveals that the films are uniform, and adherent to the substrate, but their morphology is strongly influenced by the chemical composition of the coating matrices. These silica coatings can be useful for potential electronic and optical devices.

Adsorptive Removal of Chromium (VI) Ions Using Cryogel Derived from Oil Palm Fronds’ Lignin

2016 ◽  
Vol 818 ◽  
pp. 242-245 ◽  
Author(s):  
Nur Shahirah Rusli ◽  
Norzita Ngadi
Keyword(s):  
Oil Palm ◽  
Low Cost ◽  
Sol Gel ◽  
Cost Effective ◽  
Supercritical Drying ◽  
Carbon Aerogels ◽  
Oil Palm Fronds ◽  
Chromium Vi ◽  
Cost Effective Treatment ◽  
Palm Fronds

Nowadays, lignin is of special interest since it is the second most abundant biopolymer after cellulose. Given its extremely low cost and phenolic nature, lignin had become one of the leading candidates for preparing aerogels. However, production cost of carbon aerogels are considerably high due to extremely expensive supercritical drying method employed. Thus, carbon cryogels has been introduced by replacing the supercritical drying with freeze drying technique. In this study, lignin was extracted from dried and grinded oil palm fronds to be used as precursor for sol-gel polycondensation. Cryogel derived from oil palm fronds (OPF) was investigated as a suitable adsorbent for the removal of metal ions especially chromium (VI) through adsorption process. In addition, the adsorption amount was greatly increased when this cryogel was prepared with addition of ultrasonic effect instead of normal heating during the sol-gel polycondensation process. This new cryogel seems to be very promising for cost-effective treatment of heavy metals removal since the preparation is easy and being derived from a widely available and low-cost biomass feedstock.

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