Synthesis and microwave absorption enhancement of graphene@Fe3O4@SiO2@NiO nanosheet hierarchical structures

Nanoscale ◽  
2014 ◽  
Vol 6 (6) ◽  
pp. 3157-3164 ◽  
Author(s):  
Lei Wang ◽  
Ying Huang ◽  
Xu Sun ◽  
Haijian Huang ◽  
Panbo Liu ◽  
...  
Keyword(s):  
Microwave Absorption ◽  
Hydrothermal Reaction ◽  
Sol Gel ◽  
Hierarchical Structures ◽  
Absorption Enhancement ◽  
Sol Gel Process ◽  
Nio Nanosheets

Hierarchical structures of graphene@Fe3O4@SiO2@NiO nanosheets were prepared by combining the versatile sol–gel process with a hydrothermal reaction.

Synthesis and microwave absorption enhancement of NiO nanosheets@SiO2@graphene hierarchical structures

RSC Advances ◽  
2013 ◽  
Vol 3 (45) ◽  
pp. 23290 ◽  
Author(s):  
Lei Wang ◽  
Ying Huang ◽  
Xiao Ding ◽  
Panbo Liu ◽  
Meng Zong
Keyword(s):  
Microwave Absorption ◽  
Hierarchical Structures ◽  
Absorption Enhancement ◽  
Nio Nanosheets

Preparation and Microwave-Absorption Property of SiO2-SiC-Based Composites

2010 ◽  
Vol 434-435 ◽  
pp. 231-234
Author(s):  
Li Guan ◽  
Bing Bing Fan ◽  
Ming Liang Li ◽  
He Jing Wen ◽  
Kai Li ◽  
...  
Keyword(s):  
Solid State ◽  
Microwave Absorption ◽  
Solid State Reaction ◽  
Sol Gel ◽  
Composite Particles ◽  
Network Analyzer ◽  
Epoxide Resin ◽  
Maximum Reflectivity ◽  
Sol Gel Process ◽  
Sic Composites

SiO2-SiC composite particles were prepared using a sol-gel process. BaTiO3 powders were synthesize through solid-state reaction. They were mixed as microwave absorbents with Fe3O4 powders to obtain the complex absorption. Epoxide resin (EP) was used as matrix and solidified with the mixtures. The techniques of DSC-TG, XRD were used to characterize the composite particles and the obtained compacts. A vector network analyzer was used to measure the reflectivity of the SiO2-SiC-based composites. The effects of the aborbents’ contents on the reflection of the microwave absorption materials were disscussed. It was found that SiO2-SiC composites could be prepared using sol-gel process and BaTiO3 powders could be synthesize through solid-state reaction. The results indicated that SiO2-SiC composite is contribute to absorb microwave, where SiO2-SiC: BaTiO3: Fe3O4 = 6:2:2 (vol %), the frequency region in which the maximum reflectivity is more than -10 dB is 5.4-7.6 GHz.

Length-controlled synthesis and the photoluminescence of pre-perovskite PbTiO3 nanofibers

CrystEngComm ◽  
2014 ◽  
Vol 16 (17) ◽  
pp. 3567-3572 ◽  
Author(s):  
Tingting Yu ◽  
Zhaohui Ren ◽  
Siyu Gong ◽  
Shan Jiang ◽  
Chunying Chao ◽  
...  
Keyword(s):  
Hydrothermal Reaction ◽  
Sol Gel ◽  
Controlled Synthesis ◽  
Sol Gel Process

The introduced TEA solution modified the sol–gel process and decreased the length of PbTiO3 nanofibers during the subsequent hydrothermal reaction.

Synthesis and Microwave Absorption Enhancement of CoNi@SiO2@C Hierarchical Structures

2018 ◽  
Vol 57 (16) ◽  
pp. 5507-5516 ◽  
Author(s):  
Suhua Zhou ◽  
Ying Huang ◽  
Xudong Liu ◽  
Jing Yan ◽  
Xuansheng Feng
Keyword(s):  
Microwave Absorption ◽  
Hierarchical Structures ◽  
Absorption Enhancement

scholarly journals Facile Synthesis of GNPs@NixSy@MoS2 Composites with Hierarchical Structures for Microwave Absorption

Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1403 ◽  
Author(s):  
Wenfeng Zhu ◽  
Li Zhang ◽  
Weidong Zhang ◽  
Fan Zhang ◽  
Zhao Li ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Microwave Absorption ◽  
Reflection Loss ◽  
Skin Effect ◽  
Hydrothermal Reaction ◽  
Synergistic Effects ◽  
Hierarchical Structures ◽  
Dielectric Losses ◽  
Facile Synthesis ◽  
Molar Ratios

Graphene-based powder absorbers have been used to attain excellent microwave absorption. However, it is not clear if inferior microwave absorption by pure graphene materials can be attributed to impedance mismatching or inadequate attenuation capability. In this comparative study, we focus on these aspects. Graphene nanoplatelets (GNPs) multi-component composites (GNPs@NixSy@MoS2) were prepared by hydrothermal reaction with different S and Mo molar ratios. The morphologies, phase crystals, elemental composition, and magnetic properties of the composites were also analyzed. In addition, microwave absorption of the as-prepared samples was investigated and it revealed that the impedance mismatching could be responsible for inferior microwave absorption; higher conductivity can lead to skin effect that inhibits the further incidence of microwaves into the absorbers. Furthermore, the optimum reflection loss (RL) of GNPs@NixSy@MoS2-2 can reach −43.3 dB at a thickness of 2.2 mm and the corresponding bandwidth with effective attenuation (RL < −10 dB) of up to 3.6 GHz (from 7.0 to 10.6 GHz). Compared with the GNPs, the enhanced microwave absorption can be assigned to the synergistic effects of conductive and dielectric losses.

Complex permittivity, permeability, and microwave absorption of Zn- and Ti-substituted barium ferrite by citrate sol–gel process

2002 ◽  
Vol 96 (3) ◽  
pp. 289-295 ◽  
Author(s):  
Zhang Haijun ◽  
Liu Zhichao ◽  
Ma Chengliang ◽  
Yao Xi ◽  
Zhang Liangying ◽  
...  
Keyword(s):  
Microwave Absorption ◽  
Complex Permittivity ◽  
Barium Ferrite ◽  
Sol Gel ◽  
Sol Gel Process

The crystallization of thin-film ceramics

1992 ◽  
Vol 50 (1) ◽  
pp. 338-339
Author(s):  
J.M. Schwartz ◽  
L.F. Francis ◽  
L.D. Schmidt ◽  
P.S. Schabes-Retchkiman
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Sol Gel ◽  
Processing Route ◽  
Small Areas ◽  
Ceramic Thin Films ◽  
Complex Shapes ◽  
Sol Gel Process ◽  
Ceramic Precursors ◽  
Crystalline Ceramic

Ceramic thin films and coatings are of interest for electrical, optical, magnetic and thermal barrier applications. Critical for improved properties in thin films is the development of specific microstructures during processing. To this end, the sol-gel method is advantageous as a versatile processing route. The sol-gel process involves depositing a solution containing metalorganic or colloidal ceramic precursors onto a substrate and heating the deposited layer to form a crystalline or non-crystalline ceramic coating. This route has several advantages, including the ability to create tailored microstructures and properties, to coat large or small areas, simple or complex shapes, and to more easily prepare multicomponent ceramics. Sol-gel derived coatings are amorphous in the as-deposited state and develop their crystalline structure and microstructure during heat-treatment. We are particularly interested in studying the amorphous to crystalline transformation, because many key features of the microstructure such as grain size and grain size distribution may be linked to this transformation.

Epitaxial Growth of Sr0.3Ba0.7Nb2O6 Thin Films Prepared by Sol-Gel Process

1999 ◽  
Vol 606 ◽  
Author(s):  
Keishi Nishio ◽  
Jirawat Thongrueng ◽  
Yuichi Watanabe ◽  
Toshio Tsuchiya
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Epitaxial Growth ◽  
Raw Materials ◽  
Substrate Surface ◽  
Sol Gel ◽  
Tungsten Bronze ◽  
Monomethyl Ether ◽  
Tetragonal Tungsten Bronze ◽  
Sol Gel Process

AbstructWe succeeded in the preparation of strontium-barium niobate (Sr0.3Ba0.7Nb2O6 : SBN30)that have a tetragonal tungsten bronze type structure thin films on SrTiO3 (100), STO, or La doped SrTiO3 (100), LSTO, single crystal substrates by a spin coating process. LSTO substrate can be used for electrode. A homogeneous coating solution was prepared with Sr and Ba acetates and Nb(OEt)5 as raw materials, and acetic acid and diethylene glycol monomethyl ether as solvents. The coating thin films were sintered at temperature from 700 to 1000°C for 10 min in air. It was confirmed that the thin films on STO substrate sintered above 700°C were in the epitaxial growth because the 16 diffraction spots were observed on the pole figure using (121) reflection. The <130> and <310> direction of the thin film on STO were oriented with the c-axis in parallel to the substrate surface. However, the diffraction spots of thin film on LSTO substrate sintered at 700°C were corresponds to the expected pattern for (110).

UV Curable Organic-Inorganic Hybrid Materials

2000 ◽  
Vol 628 ◽  
Author(s):  
Guang-Way Jang ◽  
Ren-Jye Wu ◽  
Yuung-Ching Sheen ◽  
Ya-Hui Lin ◽  
Chi-Jung Chang
Keyword(s):  
Hybrid Materials ◽  
Colloidal Silica ◽  
Sol Gel ◽  
Solution Ph ◽  
Uv Curable ◽  
Inorganic Hybrid ◽  
Degradation Temperature ◽  
Sol Gel Process ◽  
The Stability ◽  
Thermal Degradation Temperature

This work successfully prepared an UV curable organic-inorganic hybrid material consisting of organic modified colloidal silica. Applications of UV curable organic-inorganic hybrid materials include abrasion resistant coatings, photo-patternable thin films and waveguides. Colloidal silica containing reactive functional groups were also prepared by reacting organic silane and tetraethyl orthosilicate (TEOS) using sol-gel process. In addition, the efficiency of grafting organic moiety onto silica nanoparticles was investigated by applying TGA and FTIR techniques. Experimental results indicated a strong interdependence between surface modification efficiency and solution pH. Acrylate-SiO2 hybrid formation could result in a shifting of thermal degradation temperature of organic component from about 200°C to near 400°C. In addition, the stability of organic modified colloidal silica in UV curable formula and the physical properties of resulting coatings were discussed. Furthermore, the morphology of organic modified colloidal silica was investigated by performing TEM and SEM studies‥

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