scholarly journals Slot-Die Process of a Sol–Gel Photocatalytic Porous Coating for Large-Area Fabrication of Functional Architectural Glass

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 711
Author(s):  
Adrián Angulo-Ibáñez ◽  
Estibaliz Aranzabe ◽  
Garikoitz Beobide ◽  
Oscar Castillo ◽  
Amaia M. Goitandia ◽  
...  
Keyword(s):  
Large Scale ◽  
Dye Degradation ◽  
Sol Gel ◽  
Dip Coating ◽  
Porous Coating ◽  
Operational Parameters ◽  
Large Area ◽  
Glass Substrates ◽  
Slot Die ◽  
Titania Sol

The slot-die process is an appealing technology for the fabrication of coatings on large-area substrates. However, its application on the production of photocatalytic coatings based on sol–gel formulations remains virtually unexplored. Thus, assessing the suitable formulation of the sol and operational parameters that allow one to yield high-efficacy photocatalyst coatings is a current challenge. This work aims to analyze the transferability of titania sol formulation optimized for dip-coating processes to slot-die technology. In this sense, firstly, the sol formulation is optimized by analyzing the influence of several types of surfactants on the microstructural features and photoactivity of TiO2 coatings’ growth on glass substrates. All formulations rendered a meaningful porosity and nanoscopic anatase crystallites (11–15 nm) with optical band gap values close to the expectation (3.25–3.31 eV). Accordingly, the performance of the photocatalytic dye degradation was closely related to the porosity and crystallite size led by each titania sol, and no meaningful differences were found between the results provided by the coatings developed by dip-coating and the slot-die method, which demonstrates the capability of the latter for its application on a large-scale fabrication of photocatalytic coatings.

scholarly journals Development of Adhesive, Bioactive and Antibacterial Titania Sol-Gel Coating on Titanium Substrate by Dip-Coating Technique

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 243
Author(s):  
Diana Horkavcová ◽  
Quentin Doubet ◽  
Gisèle Laure Lecomte-Nana ◽  
Eva Jablonská ◽  
Aleš Helebrant
Keyword(s):  
Simulated Body Fluid ◽  
Body Fluid ◽  
Sol Gel ◽  
Titanium Substrate ◽  
Dip Coating ◽  
Coating Technique ◽  
Metal Implants ◽  
Excellent Adhesion ◽  
Titania Sol ◽  
Dip Coating Technique

The sol-gel method provides a wide variety of applications in the medical field. One of these applications is the formation of coatings on the metal implants. The coatings containing specific additive can enhance or improve the existing surface properties of the substrate. In this work, titania sol-gel coatings were doped with two forms of silver (AgNO3, Ag3PO4) and synthetic hydroxyapatite and applied on the titanium samples by dip-coating technique. After drying and slow firing, all coatings were characterized with scanning electron microscopy. Thin coatings were successfully prepared with excellent adhesion to the substrate (measured by ASTM D 3359-2), despite cracks. Coatings containing silver and hydroxyapatite demonstrated a 100% antibacterial effect against Escherichia coli after 24 h. The bioactivity of the coatings containing hydroxyapatite tested in modified simulated body fluid under static-dynamic conditions was confirmed by bone-like hydroxyapatite precipitation. To better understand the interaction of the coatings with simulated body fluid (SBF), changes of Ca2+ and (PO4)3− ions concentrations and pH values were studied.

scholarly journals Fabrication Techniques for Graphene Oxide-Based Molecular Separation Membranes: Towards Industrial Application

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 757
Author(s):  
Ohchan Kwon ◽  
Yunkyu Choi ◽  
Eunji Choi ◽  
Minsu Kim ◽  
Yun Chul Woo ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Large Scale ◽  
Spray Coating ◽  
Dip Coating ◽  
Small Scale ◽  
Scale Production ◽  
Separation Membranes ◽  
Current Review ◽  
Slot Die ◽  
Continuous Fabrication

Graphene oxide (GO) has been a prized material for fabricating separation membranes due to its immense potential and unique chemistry. Despite the academic focus on GO, the adoption of GO membranes in industry remains elusive. One of the challenges at hand for commercializing GO membranes lies with large-scale production techniques. Fortunately, emerging studies have acknowledged this issue, where many have aimed to deliver insights into scalable approaches showing potential to be employed in the commercial domain. The current review highlights eight physical methods for GO membrane fabrication. Based on batch-unit or continuous fabrication, we have further classified the techniques into five small-scale (vacuum filtration, pressure-assisted filtration, spin coating, dip coating, drop-casting) and three large-scale (spray coating, bar/doctor blade coating, slot die coating) approaches. The continuous nature of the large-scale approach implies that the GO membranes prepared by this method are less restricted by the equipment’s dimensions but rather the availability of the material, whereas membranes yielded by small-scale methods are predominately limited by the size of the fabrication device. The current review aims to serve as an initial reference to provide a technical overview of preparing GO membranes. We further aim to shift the focus of the audience towards scalable processes and their prospect, which will facilitate the commercialization of GO membranes.

Preparation and characterization of V2O5 doped SiO2-TiO2 thin films

2012 ◽  
Vol 2 (1) ◽  
Author(s):  
Marek Nocuń ◽  
Sławomir Kwaśny
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Dip Coating ◽  
Band Gap Energy ◽  
Tio2 Thin Films ◽  
Glass Substrates ◽  
Gel Technique

AbstractIn our investigation, V doped SiO2/TiO2 thin films were prepared on glass substrates by dip coating sol-gel technique. Chemical composition of the samples was studied by X-ray photoelectron spectroscopy (XPS). Transmittance of the samples was characterized using UV-VIS spectrophotometry. Subsequently band-gap energy (Eg) was estimated for these films. Powders obtained from sols were characterized by FTIR spectroscopy. It was found that vanadium decreases optical band gap of SSiO2/TiO2 films.

Fabrication of polysiloxane-modified polyurethane sponge as low-cost organics/water separation and selective absorption material

2016 ◽  
Vol 74 (8) ◽  
pp. 1936-1945 ◽  
Author(s):  
Zhengshan Cui ◽  
Wanxia He ◽  
Jun Liu ◽  
Wei Wei ◽  
Liang Jiang ◽  
...  
Keyword(s):  
Contact Angle ◽  
Mechanical Stability ◽  
Low Cost ◽  
Sol Gel ◽  
Dip Coating ◽  
Selective Absorption ◽  
Large Area ◽  
Water Separation ◽  
Good Thermal Stability ◽  
Polyurethane Sponge

Through sol-gel and dip-coating processes, commercial polyurethane sponge modified by polysiloxane was fabricated under low temperature (60 °C) and atmosphere. The contact angle of the obtained polysiloxane/polyurethane sponge is 145 ± 5°. Hence, the polysiloxane/polyurethane sponge could float on water and selectively absorb organics from the surface of the water, indicating simultaneous properties of hydrophobicity and oleophilicity. The absorbent maximum value is 50–150 times of its own weight. The polysiloxane/polyurethane sponge exhibited excellent recyclability, which could be reused by squeezing the sponge due to its high mechanical stability and flexibility. Thermogravimetry-differential thermal analysis test indicated that the polysiloxane/polyurethane sponge exhibited good thermal stability and the stable contact angle of samples tested under increasing temperature indicated its good weather resistance. Due to the commercial property of polyurethane sponge and easy-handling of polysiloxane, the polysiloxane/polyurethane sponge can be easily scaled up to recover a large-area oil spill in water and further work based on the designed equipment has been under consideration.

The Structural and Surface Morphology of Annealed ZnO Films

2014 ◽  
Vol 903 ◽  
pp. 73-77
Author(s):  
Peh Ly Tat ◽  
Karim bin Deraman ◽  
Rosli Hussin ◽  
Wan Nurulhuda Wan Shamsuri ◽  
Zuhairi Ibrahim
Keyword(s):  
Annealing Temperature ◽  
Sol Gel ◽  
Dip Coating ◽  
Zno Films ◽  
Axis Orientation ◽  
Force Microscopy ◽  
Glass Substrates ◽  
Coating Method ◽  
Afm Micrographs ◽  
Dip Coating Method

ZnO thin films were deposited on the glass substrates via the sol-gel dip coating method. The films were annealed at various temperatures ranging from 350 °C to 550 °C. X-ray diffraction (XRD), and atomic force microscopy (AFM) were used to investigate the effect of annealing temperature on the structural and morphology properties of the films. The as grown films exhibited amorphous pattern while annealed films were polycrystalline structure with (002) preferential growth along c-axis orientation. The AFM micrographs revealed that the RMS roughness of the films increased as the annealing temperature increased. The grain size was ranging from 32.1 nm to 176.0 nm as the annealing temperature increased from 350 °C to 450 °C and decreased to 56.1 nm for 550 °C.

Properties of Sol-Gel Coating Film from Colloidal Silica-Silane Sol

2007 ◽  
Vol 544-545 ◽  
pp. 813-816
Author(s):  
Moon Kyong Na ◽  
Myeong Sang Ahn ◽  
Hoy Yul Park
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
Colloidal Silica ◽  
Sol Gel ◽  
Dip Coating ◽  
Hydroxyl Group ◽  
Coating Film ◽  
Coating Films ◽  
Glass Substrates ◽  
In The Beginning

Two kinds of colloidal silica(CS)/silane sol solutions were prepared. Two sol solutions are involved with the kinds of silane such as methyltrimethoxysilane(MTMS) and -Glycidoxypropyl trimethoxysilane(ETMS) using LS CS. MTMS was added to two sol solutions. Whether ETMS was added or not, two kinds of sol solutions were synthesized. Using two kinds of sol solutions, sol-gel coating films were formed on glass substrates via dip-coating process. Here, seasoning effect of for enhancing properties of sol-gel coating layer on glass was investigated while such sol-gel solutions were left for 7days. Also, their properties such as surface free energy, roughness, thermal property, potential hardness and elastic portion were characterized in order to understand the effect of addition of ETMS. In this case of LS/MTMS sol, the coating film had low surface free energy and more enhanced flat surface than that of the case of LS/MTMS/ETMS sol. ETMS forms hydrophilic hydroxyl group in sol solution, then surface free energy of LS/MTMS/ETMS coating film increased. In the beginning of reaction sol solution seemed to be unstable, but 4days later their coating film properties such as surface free energy and roughness enhanced. The elastic portion of coating films obtained from LS/MTMS/ETMS sol increased with addition of ETMS, but thermal stability decreased.

scholarly journals Characteristics and optical properties of Fe3+ doped SiO2/TiO2 thin films prepared by the sol-gel dip-coating method

2013 ◽  
Vol 16 (1) ◽  
pp. 92-100
Author(s):  
Chien Mau Dang ◽  
Dam Duy Le ◽  
Tam Thi Thanh Nguyen ◽  
Dung Thi My Dang
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Sol Gel ◽  
Dip Coating ◽  
X Ray Diffraction ◽  
Tio2 Thin Films ◽  
Water Contact ◽  
Glass Substrates ◽  
Coating Method ◽  
Dip Coating Method

In this study, we have successfully synthesized Fe3+ doped SiO2/TiO2 thin films on glass substrates using the sol-gel dip-coating method. After synthesizing, the samples were annealed at 5000C in the air for 1 hour. The characteristics and optical properties of Fe3+ doped SiO2/TiO2 films were then investigated by X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-vis) and Fourier transform infrared spectroscopy (FT-IR). An antifogging ability of the glass substrates coated with the fabricated film is investigated and explained by a water contact angle under visible-light. The analyzed results also show that the crystalline phase of TiO2 thin films comprised only the anatase TiO2, but the crystalline size decreased from 8.8 to 5.9 nm. We also observed that the absorption edge of Fe3+- doped SiO2/TiO2 thin films shifted towards longer wavelengths (i.e. red shifted) from 371.7nm to 409.2 nm when the Fe3+-doped concentration increased from 0 to 1 % mol.

Refractive Index Controlled Plasmon Tuning of Au Nanoparticles in SiO2-ZrO2 Film Matrices

2008 ◽  
Vol 8 (8) ◽  
pp. 3868-3876
Author(s):  
Sucheta De ◽  
Samar Kumar Medda ◽  
Goutam De
Keyword(s):  
Heat Treatment ◽  
Refractive Index ◽  
Au Nanoparticles ◽  
Sol Gel ◽  
Dip Coating ◽  
Uv Treatment ◽  
Final Heat ◽  
Molar Ratios ◽  
Glass Substrates ◽  
Heat Treated

Au-plasmon tuning has been accomplished by controlling the refractive index (n) of the embedding film matrix. The refractive index of the film matrices were controlled by changing the molar ratios of low (SiO2) and high index (ZrO2) components following sol–gel reactions. Thus, Au nanoparticles doped films were prepared from SiO2-ZrO2 inorganic–organic hybrid sols of variable molar ratios containing HAuCl4 following the dip-coating method. The film samples deposited on glass substrates were obtained after drying, UV-treatment, and subsequent heat-treatment at 500 °C in air. The nominal mol ratios of SiO2:ZrO2 were 1:0, 1:1, 1:2.3, and 1:4. 3 equivalent mol% Au–97% total oxide (SiO2 + ZrO2) was maintained in the final heat-treated films. FTIR studies confirmed good homogeneity of Si-Zr network in the Zr-containing films. The UV-treatment has been introduced to facilitate the decomposition of HAuCl4 in the hybrid matrix prior to the heat-treatment step. The main Au-plasmon peak, in the case of a SiO2 host (SiO2:ZrO2 = 1:0, n = 1.410), observed at about 546 nm, gradually red-shifted to 592 nm upon increasing the ZrO2 content (SiO2:ZrO2 = 1:4, n = 1.847). Transmission electron microscopy of the final heat-treated (500 °C) films showed existence of plate-like (triangular and hexagonal) Au nanoparticles (25–50 nm) along with relatively smaller nanoparticles of about 10 nm in size. X-ray diffraction patterns reveal that the Au nanoparticles have a (111) orientation.

Porous TiO2 Films Prepared by Sol-Gel Method Using Different Kinds of Templates

2011 ◽  
Vol 382 ◽  
pp. 344-347
Author(s):  
Wen Jie Zhang ◽  
Bo Yang ◽  
Hong Bo He
Keyword(s):  
Degradation Rate ◽  
Sol Gel ◽  
Dip Coating ◽  
High Photocatalytic Activity ◽  
Maximum Activity ◽  
Coating Process ◽  
Tio2 Films ◽  
Methyl Orange Degradation ◽  
Porous Tio2 ◽  
Glass Substrates

Porous TiO2 films were prepared through dip-coating on glass substrates using several different templates. Dip-coating process was optimized to prepare the three layered films. The film prepared with PEG1000 has the maximum activity compared with the other films using CTAB and HST. While PEG molecular weight is in the range from 400 to 6000, methyl orange degradation rate reaches its maximal value when using PEG1000. Two comparatively high activities can be found at the ratios of PEG1000:PEG400 as 3:1 and 1:2. The 1:2 ratio is the optimal one. PEG1000 seems to be more suitable of being used as a template to prepare porous TiO2 film with high photocatalytic activity. After 200 min of irradiation, 98.6 % of the initial dye can be degraded on the film prepared using 2 g of PEG1000.

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