Magnetic Nanocomposite Aerogels

2011 ◽  
Vol 1306 ◽  
Author(s):  
Anna Corrias ◽  
Danilo Loche ◽  
Maria F. Casula
Keyword(s):  
Metal Oxide ◽  
Metal Oxide Nanoparticles ◽  
Sol Gel ◽  
Structural Features ◽  
Oxide Nanoparticles ◽  
X Ray ◽  
Nanoparticle Agglomeration ◽  
Transmission Electron ◽  
Average Size

ABSTRACTAerogels are regarded as ideal candidates for the design of functional nanocomposites containing supported metal or metal oxide nanoparticles. The large specific surface area together with the open pore structure enables aerogels to effectively host finely dispersed nanoparticles up to the desired loading, to provide nanoparticle accessibility and/or to prevent nanoparticle agglomeration, as required to supply their specific functionalities.The preparation of highly porous nanocomposite aerogels containing magnetic metal, alloy or metal oxide nanoparticles dispersed into amorphous silica, with high purity and homogeneity, was successfully achieved by a novel sol-gel procedure involving urea-assisted co-gelation of the precursor phases. This method allows fast gelation, giving rise to aerogels with 97% porosity, and it is very versatile allowing to vary composition, loading and average size of the nanoparticles.The characterization of the morphological and structural features of the nanocomposite aerogels is carried out using different techniques, such as X-ray diffraction, Transmission Electron Microscopy and X-ray Absorption Spectroscopy. The characterization of the magnetic properties is carried out by SQUID magnetometry.

Characterization of Metal-Oxide Nanoparticles: Synthesis and Dispersion in Polymeric Coatings

2002 ◽  
Vol 740 ◽  
Author(s):  
Li-Piin Sung ◽  
Stephanie Scierka ◽  
Mana Baghai-Anaraki ◽  
Derek L. Ho
Keyword(s):  
Metal Oxide ◽  
Metal Oxide Nanoparticles ◽  
Sol Gel ◽  
Polymeric Materials ◽  
Oxide Nanoparticles ◽  
Structure Property ◽  
Structure Property Relationships ◽  
Yield Information ◽  
Sol Gel Synthesis

ABSTRACTMetal-oxide nanoparticles can be used to optimize UV absorption and to enhance the stiffness, toughness, and probably the service life of polymeric materials. Characterization of the nano- and microstructure dispersion of particles is necessary to optimize the structure-property relationships. Characterizations of both TiO2 particles dispersed in an acrylic-urethane matrix and TiO2 nanostructured films obtained through sol-gel synthesis are discussed. Experimental methods include microscopy (confocal, AFM) and small angle neutron scattering (SANS). Results from SANS experiments, which yield information about the cluster size of the nano-TiO2 particles and the spatial dispersion in various nanoparticle/polymer samples are presented and compared to the results of microscopy studies.

Synthesis and Characterization of Novel Organic-Inorganic Nancomposite Coatings

2003 ◽  
Vol 788 ◽  
Author(s):  
Brian P. Mosher ◽  
Taofang Zeng
Keyword(s):  
Metal Oxide Nanoparticles ◽  
Sol Gel ◽  
Nanocomposite Coatings ◽  
Synthesis And Characterization ◽  
Oxide Nanoparticles ◽  
Cross Link ◽  
3 Dimensional ◽  
Transmission Electron ◽  
Dimensional Network

ABSTRACTIn this paper, we report the synthesis and characterization of three novel water-based nanocomposite coatings. Throughout the paper, these coatings will be referred to as coatings 1, 2 and 3. The coatings are silica-based and are sol-gel derived using surfactant assemblies, with aluminum perchlorate as a catalyst. After synthesis, curing causes cross-link polymerization of silica, forming Si-O-Si network. The formation of this 3-Dimensional network can be verified using Fourier Transform Infrared Spectroscopy (FTIR) and Transmission Electron Microscopy (TEM). Incorporating metal oxide nanoparticles gives the material unique properties.

Characterization of ordered mesoporous films on silicon (001) surface using X-ray and electron diffraction

2005 ◽  
Vol 38 (1) ◽  
pp. 211-216 ◽  
Author(s):  
Pang-Hung Liu ◽  
Kuei-Jung Chao ◽  
Xing-Jian Guo ◽  
Kuo-Ying Huang ◽  
Yen-Ru Lee ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Sol Gel ◽  
Dip Coating ◽  
Silica Film ◽  
Continuous Film ◽  
X Ray ◽  
Transmission Electron ◽  
Ordered Mesoporous ◽  
Direction Dependence

A continuous silica film with well aligned mesochannels parallel to the Si(001) surface was found to be formed through sol–gel dip-coating of a silica precursor with nonionic ethylene oxide surfactant. Two two-dimensional mesoporous structures in centered and non-centered rectangular symmetries and with the short axes of elongated ellipsoidal pores normal to the surface were observed by X-ray and electron diffraction. Detailed transmission electron microscopy investigations were employed to view the direction dependence of the channel or pore packing in the continuous film.

scholarly journals Effect of Nanoparticles on Wettability of Nanocoating on Carbon Steel

2016 ◽  
Vol 1 (2) ◽  
pp. 71-74
Author(s):  
Norhasnidawani Johari ◽  
Noor Azlina Hassan ◽  
Norita Hassan ◽  
Mohd Hanafi Ani
Keyword(s):  
Contact Angle ◽  
Carbon Steel ◽  
Metal Oxide ◽  
Water Drop ◽  
Metal Oxide Nanoparticles ◽  
Sol Gel ◽  
Hydrophobic Surface ◽  
Oxide Nanoparticles ◽  
Water Medium ◽  
Wetting Ability

Nanocoatings plays an important role in coating industry. The solution was being prepared through copolymerization of epoxy resin hardener and with the incorporation of metal oxide nanoparticles, Zinc Oxide (ZnO) and Silica (SiO2). ZnO and SiO2 were synthesized using sol-gel. Epoxy hardener acted as host while the metal oxide nanoparticles as guest components. The formulation of nanocoatings with excellent adhesion strength and corrosion protection of carbon steel was studied. The performance of wetting ability with different medium was analysed using contact angle. Water medium showed the addition of 3wt% of hybrid between ZnO and SiO2 was the best nanocoating to form hydrophobic surface and was also the best nanocoating surface to form hydrophilic surface with vacuum oil dropping. In oil dropping, the contact angle was smaller than 90° and the water drop tends to spreads on surface.

scholarly journals A comparison of the radiosensitisation ability of 22 different element metal oxide nanoparticles using clinical megavoltage X-rays

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Alexandra Guerreiro ◽  
Nicholas Chatterton ◽  
Eleanor M. Crabb ◽  
Jon P. Golding
Keyword(s):  
Dna Damage ◽  
Metal Oxide ◽  
Hydroxyl Radical ◽  
Singlet Oxygen ◽  
Hydroxyl Radicals ◽  
Metal Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
X Rays ◽  
X Ray ◽  
Wide Range

Abstract Background A wide range of nanoparticles (NPs), composed of different elements and their compounds, are being developed by several groups as possible radiosensitisers, with some already in clinical trials. However, no systematic experimental survey of the clinical X-ray radiosensitising potential of different element nanoparticles has been made. Here, we directly compare the irradiation-induced (10 Gy of 6-MV X-ray photon) production of hydroxyl radicals, superoxide anion radicals and singlet oxygen in aqueous solutions of the following metal oxide nanoparticles: Al2O3, SiO2, Sc2O3, TiO2, V2O5, Cr2O3, MnO2, Fe3O4, CoO, NiO, CuO, ZnO, ZrO2, MoO3, Nd2O3, Sm2O3, Eu2O3, Gd2O3, Tb4O7, Dy2O3, Er2O3 and HfO2. We also examine DNA damage due to these NPs in unirradiated and irradiated conditions. Results Without any X-rays, several NPs produced more radicals than water alone. Thus, V2O5 NPs produced around 5-times more hydroxyl radicals and superoxide radicals. MnO2 NPs produced around 10-times more superoxide anions and Tb4O7 produced around 3-times more singlet oxygen. Lanthanides produce fewer hydroxyl radicals than water. Following irradiation, V2O5 NPs produced nearly 10-times more hydroxyl radicals than water. Changes in radical concentrations were determined by subtracting unirradiated values from irradiated values. These were then compared with irradiation-induced changes in water only. Irradiation-specific increases in hydroxyl radical were seen with most NPs, but these were only significantly above the values of water for V2O5, while the Lanthanides showed irradiation-specific decreases in hydroxyl radical, compared to water. Only TiO2 showed a trend of irradiation-specific increase in superoxides, while V2O5, MnO2, CoO, CuO, MoO3 and Tb4O7 all demonstrated significant irradiation-specific decreases in superoxide, compared to water. No irradiation-specific increases in singlet oxygen were seen, but V2O5, NiO, CuO, MoO3 and the lanthanides demonstrated irradiation-specific decreases in singlet oxygen, compared to water. MoO3 and CuO produced DNA damage in the absence of radiation, while the highest irradiation-specific DNA damage was observed with CuO. In contrast, MnO2, Fe3O4 and CoO were slightly protective against irradiation-induced DNA damage. Conclusions Beyond identifying promising metal oxide NP radiosensitisers and radioprotectors, our broad comparisons reveal unexpected differences that suggest the surface chemistry of NP radiosensitisers is an important criterion for their success.

Synthesis and Characterization of Cu2FeSnS4 Semiconductor Nanocrystals with Zincblende Structure

2012 ◽  
Vol 512-515 ◽  
pp. 2019-2022 ◽  
Author(s):  
Xiao Lu Liang ◽  
Xian Hua Wei
Keyword(s):  
Random Distribution ◽  
Semiconductor Nanocrystals ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Nir Absorption ◽  
Average Size

Cu2FeSnS4semiconductor nanocrystals with zincblende structure have been successfully synthesized by a hot-injection approach. Cu+, Fe2+, and Sn4+cations have a random distribution in the zincblende unit cell, and the occupancy possibilities are 1/2, 1/4 and 1/4, respectively. Those nanocrystals were characterized by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), energy dispersive spectroscopy (EDS), and UV-Vis-NIR absorption spectroscopy. The Cu2FeSnS4 nanocrystals have an average size of 7.5 nm and a band gap of 0.92 eV.

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