Synthesis of a Low-Density Copper Oxide Monolithic Aerogel Using Inorganic Salt Precursor

Copper oxide monolithic aerogel was prepared by sol–gel method using inorganic salt as precursor, ethanol as the solvent, and propylene oxide as the gelation agent. Calcination of the as-prepared aerogels at different temperatures induced a phase change which resulted in the formation of a mesoporous copper oxide aerogels. Field emission scanning electron microscopy (FESEM), Highresolution transmission electron microscopy (HRTEM), and Brunauer-Emmett-Teller(BET) methods were used to characterize the as-prepared aerogels. The combined results indicated that the as-prepared CuO aerogel has high porosity, high surface area, and low density. The X-ray diffraction (XRD) patterns show that the as-prepared CuO aerogel is highly crystalline and is identified to be predominantly copper chloride hydroxide, Cu2Cl(OH)3。

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New Trends in Bio-Based Aerogels

Pharmaceutics ◽

10.3390/pharmaceutics12050449 ◽

2020 ◽

Vol 12 (5) ◽

pp. 449 ◽

Cited By ~ 9

Author(s):

Loredana Elena Nita ◽

Alina Ghilan ◽

Alina Gabriela Rusu ◽

Iordana Neamtu ◽

Aurica P. Chiriac

Keyword(s):

Biomedical Applications ◽

High Surface ◽

Sol Gel ◽

High Surface Area ◽

Acoustic Properties ◽

High Porosity ◽

Natural Polymers ◽

Flame Resistance ◽

Strength Limit ◽

Properties Of Materials

(1) Background: The fascinating properties of currently synthesized aerogels associated with the flexible approach of sol-gel chemistry play an important role in the emergence of special biomedical applications. Although it is increasingly known and mentioned, the potential of aerogels in the medical field is not sufficiently explored. Interest in aerogels has increased greatly in recent decades due to their special properties, such as high surface area, excellent thermal and acoustic properties, low density and thermal conductivity, high porosity, flame resistance and humidity, and low refractive index and dielectric constant. On the other hand, high manufacturing costs and poor mechanical strength limit the growth of the market. (2) Results: In this paper, we analyze more than 180 articles from recent literature studies focused on the dynamics of aerogels research to summarize the technologies used in manufacturing and the properties of materials based on natural polymers from renewable sources. Biomedical applications of these bio-based materials are also introduced. (3) Conclusions: Due to their complementary functionalities (bioactivity, biocompatibility, biodegradability, and unique chemistry), bio-based materials provide a vast capability for utilization in the field of interdisciplinary and multidisciplinary scientific research.

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Photocatalytic Degradation of Allura Red by MN-Ni Co-Doped Nanotitania under Visible Light Irradiation

International Journal of Innovative Technology and Exploring Engineering - Special Issue ◽

10.35940/ijitee.k2458.1081219 ◽

2019 ◽

Vol 8 (12) ◽

pp. 650-657

Keyword(s):

Electron Microscopy ◽

Anatase Phase ◽

High Surface ◽

Sol Gel ◽

High Surface Area ◽

X Ray ◽

Allura Red ◽

Co Doping ◽

Ft Ir ◽

Co Doped

Photocatalyst has been extensive interest because of it’s new innovation to the reduce the contamination in the environment. A straight forward and economical procedure has been employed by sol-gel technique for the co-doping of Mn2+ and Ni2+ into TiO2 . The co-doped and undoped photocatalysts were described by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive X-ray Spectroscopy (EDX), Fourier transform infrared spectroscopy (FT-IR), UV-Visible Diffused Reflectance Spectroscopy (UV Vis-DRS), Transmission electron Microscopy (TEM) and Brunauer-Emmett-Teller (BET). The portrayal results shows that anatase and rutile mixed phase was observed for some co-doped nanocatalysts and the remaining catalysts exhibits anatase phase only. It was observed by FT-IR that the shifting of frequency of Ti-O-Ti in the catalysts was seen due to substitutional doping of Mn and Ni by replace Ti and O, further the photocatalysts shows rough morphology, irregular shape of particle with size (6.5nm) and having high surface area (135.70 m2/g), less band energy (2.7 eV). The photocatalytic action of these materials was assessed by the degradation of Allura red (AR) as a contaminant. The results shows that AR has degraded within 60 minutes at doping concentrations 0.25 Wt% of Mn2+ion and 1.0 Wt% of Ni2+ ion in TiO2 (NMT2) at an optimum reaction parameters pH-4, catalyst dose 0.070g/L and at AR initial dye concentration 0.010g/L.

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Structural Evolution in Carbon Aerogels as a function of Precursor Material and Pyrolysis Temperature

MRS Proceedings ◽

10.1557/proc-431-123 ◽

1996 ◽

Vol 431 ◽

Cited By ~ 9

Author(s):

J. Gross ◽

C. T. Alviso ◽

R. W. Pekala

Keyword(s):

Pyrolysis Temperature ◽

Phenol Formaldehyde ◽

High Surface ◽

Sol Gel ◽

High Surface Area ◽

Structural Evolution ◽

Vitreous Carbon ◽

Carbon Aerogels ◽

High Porosity ◽

Precursor Material

AbstractSeveral organic reactions that proceed through a sol-gel transition have been identified at LLNL. The most-studied reaction involves the aqueous polycondensation of resorcinol (1,3- dihydroxybenzene) with formaldehyde. Recently, we have shown that phenol can be added to this polymerization as a comonomer. The resultant crosslinked gels are supercritically dried from carbon dioxide (Tc=31°C, Pc = 7.4 MPa) to give resorcinol-phenol-formaldehyde (RPF) aerogels. Because RPF aerogels are composed of a highly crosslinked aromatic polymer, they can be pyrolyzed in an inert atmosphere to form vitreous carbon monoliths (CRPF). The resultant aerogels are black in color and no longer transparent, yet they retain the high porosity (40–98 %), ultrafine cell/pore size (< 50 nm), high surface area (600–800 m2/g), and interconnected particle (˜10 nm) morphology of their organic precursors. In this study, we examine the acoustic and mechanical properties of these materials as a function of precursor material and pyrolysis temperature. It is shown that the elastic moduli of RPF and CRPF is higher than that of pure RF / CRF aerogels at a given density. Upon pyrolysis RPF aerogels tend to shrink to a larger extent.

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Preparation of modified paints with nano-structured additives and its potential applications

Nanomaterials and Nanotechnology ◽

10.1177/1847980420909188 ◽

2020 ◽

Vol 10 ◽

pp. 184798042090918

Author(s):

Ricardo Solano ◽

David Patiño-Ruiz ◽

Adriana Herrera

Keyword(s):

Electron Microscopy ◽

Zno Nanoparticles ◽

Uv Light ◽

High Surface ◽

High Surface Area ◽

Antibacterial Properties ◽

Normal Function ◽

High Porosity ◽

X Ray ◽

Self Cleaning

Recently, an increase in the production of intelligent nanomaterials has been reported for the application of solid surface coating. These nanomaterials provide a wide number of functionalities such as anticorrosive, antibacterial, and self-cleaning properties. Hence, titanium dioxide (TiO2) and zinc oxide (ZnO) nanoparticles were synthesized using a green chemistry approach. These nanoparticles were fully characterized by scanning electron microscopy, energy-dispersive X-ray, high-resolution transmission electron microscopy, X-ray diffraction, ultraviolet (UV)–visible spectroscopy, Brunauer–Emmett–Teller test, and nitrogen adsorption–desorption isotherm. Then, a commercial enamel-type paint was modified by using different concentrations (2, 3.5, and 5 w/v%) of nanoparticles. These nanofilled paints were then brushed onto the surface of different types of materials such as carbon steel sheets, wood sheets, and aluminum disks. Anticorrosive, self-cleaning, and antibacterial properties of the nanofilled paints were evaluated, with the aim to determine the capability for this application. According to the characterization results, TiO2 and ZnO nanoparticles exhibited similar physicochemical properties compared to those synthesized using traditional methods. The anticorrosion results revealed that nanofilled paints provide a barrier using low concentrations of nanoparticles, due to the decrease of agglomerates on the surface avoiding the presence of high porosity. In the case of self-cleaning, a proposed mechanism of degradation demonstrated that the presence of both nanoparticles in the paint provided high degradation of methylene blue due to the high surface area offered by the nanoparticles. On the other hand, antibacterial activity under UV light was observed only for ZnO nanoparticles, which may be related to the diffusion of nanoparticles into the cell membrane of the bacteria, affecting the normal function. These results showed to be promising for the modification of paints with TiO2 and ZnO nanoparticles, and the application on solid surfaces for the construction, and even in textile fields.

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Direct Synthesis of Nano Alumina from Natural Bauxite

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.67.143 ◽

2009 ◽

Vol 67 ◽

pp. 143-148 ◽

Cited By ~ 6

Author(s):

P. Manivasakan ◽

V. Rajendran ◽

P.R. Rauta ◽

B.B. Sahu ◽

B.K. Panda

Keyword(s):

Calcination Temperature ◽

Direct Synthesis ◽

High Surface ◽

Sol Gel ◽

High Surface Area ◽

Alumina Powder ◽

Morphological Studies ◽

Nano Alumina ◽

Different Temperatures ◽

Unique Method

The nano alumina have been synthesised employing a novel eco-friendly route from natural bauxite ore. The synthesis of alumina powder from natural bauxite is of great interest owing to the fact that it enables mass production without the use of expensive chemical resources and processing techniques. Employing the Bayer process, synthesis of nano alumina has been made from natural bauxite followed by sol-gel route. The ultra fine alumina powder with high surface area is obtained through the digestion of gel followed by sintering. The size of the particle and its morphology was controlled by calcination temperature and processing time. The crystallite size of the nano alumina powder has been measured using XRD pattern and the FTIR spectrum of nano powder after calcination at different temperatures (873 K and 1273 K) were measured. The results from the energy dispersive X-ray analysis (EDAX) and morphological studies reveal interesting informations. The observed results indicate that one can control the particle size by controlling the aging and calcination temperature. The obtained results indicate that the above process technique is an unique method for the preparation of nano alumina (Al2O3) from natural source such as bauxite.

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High Photodegradation Performance of ZnO Nanoparticles Supported on Porous Zeolite Na-a: Effects of ZnO Loading

10.21203/rs.3.rs-430420/v1 ◽

2021 ◽

Author(s):

Lawrence Kioko Munguti ◽

Francis Birhanu Dejene

Keyword(s):

Electron Microscopy ◽

Surface Area ◽

Zno Nanoparticles ◽

Diffuse Reflectance Spectroscopy ◽

High Surface ◽

Sol Gel ◽

High Surface Area ◽

Textural Properties ◽

Bonding Properties ◽

Bet Technique

Abstract Zeolite Na-A supported ZnO nanocomposites (ZnO/Zeolite Na-A NCs) were synthesized at low temperature (70 ℃) via the sol-gel process and characterized by X-ray diffraction technique (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-visible diffuse reflectance spectroscopy (UV-vis DRS) and Fourier transform infrared (FTIR) spectroscopy for structural, morphological, optical and bonding properties. The textural properties and porosity were obtained by Brunauer-Emmett-Teller (BET) technique. The obtained XRD and microscopy results indicated that the obtained nanopowders were crystalline in nature and no collapse of the structure of zeolite Na-A. In addition, the synthesized ZnO nanoparticles occurred mainly on the surface of the zeolite support. It is clear that the zeolite supported ZnO nanoparticles were more dispersed as compared to the pure ZnO with improved porosity and high surface area. Photocatalytic activity for the ZnO/zeolite Na-A was tremendously increased which was attributed to the synergetic combined effects of both ZnO and zeolite aluminosilicate network such as increased surface area (SBET), high adsorption and restrained charge recombination.

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Porous Aerogels and Adsorption of Pollutants from Water and Air: A Review

Molecules ◽

10.3390/molecules26154440 ◽

2021 ◽

Vol 26 (15) ◽

pp. 4440

Author(s):

Paola Franco ◽

Stefano Cardea ◽

Antonio Tabernero ◽

Iolanda De Marco

Keyword(s):

Organic Dyes ◽

High Surface ◽

High Surface Area ◽

Three Dimensional ◽

Low Density ◽

High Porosity ◽

Future Developments ◽

Oxygenated Volatile Organic Compounds ◽

Volatile Organic ◽

Harmful Substances

Aerogels are open, three-dimensional, porous materials characterized by outstanding properties, such as low density, high porosity, and high surface area. They have been used in various fields as adsorbents, catalysts, materials for thermal insulation, or matrices for drug delivery. Aerogels have been successfully used for environmental applications to eliminate toxic and harmful substances—such as metal ions or organic dyes—contained in wastewater, and pollutants—including aromatic or oxygenated volatile organic compounds (VOCs)—contained in the air. This updated review on the use of different aerogels—for instance, graphene oxide-, cellulose-, chitosan-, and silica-based aerogels—provides information on their various applications in removing pollutants, the results obtained, and potential future developments.

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Development of Highly Dispersed Hybrid Nanoalumina with the Sol-Gel Method

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.87.48 ◽

2014 ◽

Vol 87 ◽

pp. 48-53 ◽

Cited By ~ 1

Author(s):

Foteini Petrakli ◽

Dimitris Sioulas ◽

Athena Tsetsekou

Keyword(s):

Electron Microscopy ◽

High Surface ◽

Sol Gel ◽

High Surface Area ◽

Alumina Powder ◽

Complexation Reaction ◽

Ethylene Imine ◽

Gel Method ◽

Sol Gel Method ◽

Highly Dispersed

A hybrid sol-gel method was employed to develop a uniform and highly dispersed alumina nanopowder in the presence of hyperbranched dendritic poly(ethylene)imine (PEI) acting as template material and complexation agent for aluminium ions. For this purpose, the hydrolysis and polycondensation reactions followed the complexation reaction between the Al(NO3)3precursor and PEI, whereas ammonium polymethacrylate was added to improve the powder dispersion. The as-formed nanopowder was characterized before and after calcination studies carried out in the temperature range 100-1200 °C. For this purpose Scanning Electron Microscopy (SEM), Field Emission SEM, Transmission Electron Microscopy (TEM), X Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric and Differential Thermal Analysis (TG-DTA), N2porosimetry and ζ-potential measurements at different pH were carried out. The analysis confirmed the successful formation of a boehmite-PEI hybrid material of uniform tiny spheroid crystals (~ 1-2 nm) and small agglomerates. The boehmite phase is kept up to 300 °C, whereas after calcination at 600 °C a stabilized γ-alumina powder of high surface area and crystal sizes around 2-5 nm results. This phase is quite stable being kept even after calcination at 1000 °C. The transformation to the stable α-alumina phase is completed at 1100 °C leading to an easily dispersed nanopowder with crystal sizes ranging between 5-25 nm.

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Pd Nanoparticles Stabilized on the Cross-Linked Melamine-Based SBA-15 as a Catalyst for the Mizoroki–Heck Reaction

Catalysis Letters ◽

10.1007/s10562-021-03691-9 ◽

2021 ◽

Author(s):

Ayat Nuri ◽

Abolfazl Bezaatpour ◽

Mandana Amiri ◽

Nemanja Vucetic ◽

Jyri-Pekka Mikkola ◽

...

Keyword(s):

Electron Microscopy ◽

Inductively Coupled Plasma ◽

High Surface ◽

High Surface Area ◽

Coupling Reaction ◽

Pd Nanoparticles ◽

Significant Activity ◽

Inductively Coupled ◽

Transmission Electron ◽

Ft Ir

AbstractMesoporous SBA-15 silicate with a high surface area was prepared by a hydrothermal method, successively modified by organic melamine ligands and then used for deposition of Pd nanoparticles onto it. The synthesized materials were characterized with infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), nitrogen physisorption, scanning electron microscopy (SEM) coupled with energy dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), nuclear magnetic resonance (NMR) and inductively coupled plasma (ICP-OES). The catalyst was effectively used in the Mizoroki–Heck coupling reaction of various reactants in the presence of an organic base giving the desired products in a short reaction time and with small catalysts loadings. The reaction parameters such as the base type, amounts of catalyst, solvents, and the temperature were optimized. The catalyst was easily recovered and reused at least seven times without significant activity losses. Graphic Abstract

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