scholarly journals Embedding two-dimensional graphene array in ceramic matrix

2020 ◽  
Vol 6 (39) ◽  
pp. eabb1338
Author(s):  
Chuan Sun ◽  
Yujia Huang ◽  
Qiang Shen ◽  
Wei Wang ◽  
Wei Pan ◽  
...  
Keyword(s):  
Load Transfer ◽  
Sliding Friction ◽  
Low Cost ◽  
Ceramic Composites ◽  
Graphene Sheets ◽  
Two Dimensional ◽  
Stable Crack Propagation ◽  
Propagation Behavior ◽  
Microcrack Propagation ◽  
Structural And Functional Properties

Dispersing two-dimensional (2D) graphene sheets in 3D material matrix becomes a promising route to access the exceptional mechanical and electrical properties of individual graphene sheets in bulk quantities for macroscopic applications. However, this is highly restricted by the uncontrolled distribution and orientation of the graphene sheets in 3D structures as well as the weak graphene-matrix bonding and poor load transfer. Here, we propose a previously unreported avenue to embed ordered 2D graphene array into ceramics matrix, where the catastrophic fracture failure mode of brittle ceramics was transformed into stable crack propagation behavior with 250 to 500% improvement in the mechanical toughness. An unprecedentedly low dry sliding friction coefficient of 0.06 in bulk ceramics was obtained mainly due to the inhibition of the microcrack propagation by the ordered 2D graphene array. These unique and low-cost 2D graphene array/ceramic composites may find applications in severe environments with superior structural and functional properties.

Ti3C2-MXene/Bismuth Ferrite Nanohybrids for Efficient Degradation of Organic Dye and Colorless Pollutant

2019 ◽  
Author(s):  
Ayesha Tariq ◽  
M. Abdullah Iqbal ◽  
S. Irfan Ali ◽  
Muhammad Z. Iqbal ◽  
Deji Akinwande ◽  
...  
Keyword(s):  
Surface Area ◽  
Low Cost ◽  
Bismuth Ferrite ◽  
Organic Dye ◽  
Two Dimensional ◽  
Electron Hole ◽  
Photocatalytic Application ◽  
Electron Hole Pair ◽  
Pair Generation ◽  
Photocatalytic Applications

<p>Nanohybrids, made up of Bismuth ferrites/Carbon allotropes, are extensively used in photocatalytic applications nowadays. Our work proposes a nanohybrid system composed of Bismuth ferrite nanoparticles with two-dimensional (2D) MXene sheets namely, the BiFeO<sub>3</sub> (BFO)/Ti<sub>3</sub>C<sub>2</sub> (MXene) nanohybrid for enhanced photocatalytic activity. We have fabricated the BFO/MXene nanohybrid using simple and low cost double solvent solvothermal method. The SEM and TEM images show that the BFO nanoparticles were attached onto the MXene surface and in the inter-layers of two-dimensional (2D) MXene sheets. The photocatalytic application is tested for the visible light irradiation which showed the highest efficiency among all pure-BFO based photocatalysts, i.e. 100% degradation in 42 min for organic dye (Congo Red) and colorless aqueous pollutant (acetophenone) in 150 min, respectively. The present BFO-based hybrid system exhibited the large surface area of 147 m<sup>2</sup>g<sup>-1</sup>measured via Brunauer-Emmett-Teller (BET) sorption-desorption technique, and is found to be largest among BFO and its derivatives. Also, the photoluminescence (PL) spectra indicate large electron-hole pair generation. Fast and efficient degradation of organic molecules is supported by both factors; larger surface area and lower electron-hole recombination rate. The BFO/MXene nanohybrid presented here is a highly efficient photocatalyst compared to other nanostructures based on pure BiFeO<sub>3</sub> which makes it a promising candidate for many future applications.</p>

scholarly journals Microfabrication with Very Low-Average Power of Green Light to Produce PDMS Microchips

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 607
Author(s):  
Lucero M. Hernandez-Cedillo ◽  
Francisco G. Vázquez-Cuevas ◽  
Rafael Quintero-Torres ◽  
Jose L. Aragón ◽  
Miguel Angel Ocampo Mortera ◽  
...  
Keyword(s):  
Low Cost ◽  
Average Power ◽  
Green Light ◽  
Microfluidic Devices ◽  
Processing Parameters ◽  
Coating Film ◽  
Two Dimensional ◽  
Dimethyl Siloxane ◽  
Visible Laser ◽  
High Absorption

In this article, we show an alternative low-cost fabrication method to obtain poly(dimethyl siloxane) (PDMS) microfluidic devices. The proposed method allows the inscription of micron resolution channels on polystyrene (PS) surfaces, used as a mold for the wanted microchip’s production, by applying a high absorption coating film on the PS surface to ablate it with a focused low-power visible laser. The method allows for obtaining micro-resolution channels at powers between 2 and 10 mW and can realize any two-dimensional polymeric devices. The effect of the main processing parameters on the channel’s geometry is presented.

scholarly journals An Efficient Signal Reconstruction Algorithm for Stepped Frequency MIMO-SAR in the Spotlight and Sliding Spotlight Modes

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Jiajia Zhang ◽  
Guangcai Sun ◽  
Mengdao Xing ◽  
Zheng Bao ◽  
Fang Zhou
Keyword(s):  
Efficient Algorithm ◽  
Low Cost ◽  
Signal Reconstruction ◽  
Multiple Input Multiple Output ◽  
Reconstruction Algorithm ◽  
Synthetic Aperture ◽  
Two Dimensional ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Stepped Frequency

Multiple-input multiple-output (MIMO) synthetic aperture radar (SAR) using stepped frequency (SF) waveforms enables a high two-dimensional (2D) resolution with wider imaging swath at relatively low cost. However, only the stripmap mode has been discussed for SF MIMO-SAR. This paper presents an efficient algorithm to reconstruct the signal of SF MIMO-SAR in the spotlight and sliding spotlight modes, which includes Doppler ambiguity resolving algorithm based on subaperture division and an improved frequency-domain bandwidth synthesis (FBS) method. Both simulated and constructed data are used to validate the effectiveness of the proposed algorithm.

Helium Permeability Measurement of SiC Ceramic Composites for Advanced Reactor Application

2013 ◽  
Author(s):  
Weiqian Zhuo ◽  
Fenglei Niu ◽  
Yungan Zhao ◽  
Houbo Qi ◽  
Zulong Hao ◽  
...  
Keyword(s):  
Low Cost ◽  
Ceramic Composites ◽  
Test System ◽  
Fiber Reinforced ◽  
Water Displacement ◽  
Coated Fiber ◽  
Sic Ceramic ◽  
Carbon Coated ◽  
The Difference ◽  
Reactor Application

Permeability of helium gas of Silicon carbide ceramic composites material, which is one of the most important properties in application of SiC composite for advanced reactors, is studied by using a simple, low-cost test system. The test system can not only qualitatively determine whether the sample is permeable or not, but also quantitatively measure the permeability for the permeable ones by water displacement. The tests are conducted with low pressure in room temperature. The permeability of the SiSiC composite depends on the preparation method. In four flat-plate materials prepared by different processes for the test, the splint based SiSiC and cordierite coated fiber reinforced SiSiC are hermetic, the permeability of uncoated fiber reinforced SiSiC and CVD carbon coated fiber reinforced SiSiC are 0.216cm2/s and 0.109cm2/s, which imply that the permeability is cut in half with the coating. The samples are scanned under SEM to analyze their microscopic structures and verified that the difference of permeability is related to their coatings as well as the pores and cracks.

Two-Dimensional Icy Water Clusters Between a Pair of Graphene-Like Molecules or Graphene Sheets

2016 ◽  
Vol 120 (34) ◽  
pp. 19212-19224
Author(s):  
Seong Kyu Kim ◽  
Wenzhou Chen ◽  
Saeed Pourasad ◽  
Kwang S. Kim
Keyword(s):  
Water Clusters ◽  
Graphene Sheets ◽  
Two Dimensional

Acoustic Characterization of Glaze and Rime Ice Structures on an Oscillating Airfoil via Fully Unsteady Simulations

2020 ◽  
Vol 65 (4) ◽  
pp. 1-12
Author(s):  
Myles Morelli ◽  
Beckett Y. Zhou ◽  
Alberto Guardone
Keyword(s):  
Wind Tunnel ◽  
Computational Modeling ◽  
Low Cost ◽  
Two Dimensional ◽  
Ice Accretion ◽  
Experimental Database ◽  
Acoustic Characterization ◽  
Ice Detection ◽  
Detection Technologies

The development of low-cost and simple technologies to improve pilot awareness of icing environments is crucial to improve the safety of rotorcraft, and especially those with limited icing clearance which are admittedly operating within icing environments without full icing clearance. An acoustic characterization of glaze and rime ice structures is hereby introduced to begin to quantify different ice shape noise signatures which directly transcend from the iced performance characteristics to develop acoustic ice detection technologies. The feasibility of the detection technique is assessed for fully unsteady simulations of ice accretion on an oscillating, two-dimensional airfoil. This work focuses on the computational modeling of the experimental database of a rotor airfoil with pitching motion during icing conditions from the NASA Glenn Icing Research Wind Tunnel and computing the resultant noise signals and analyzing their topology.

Sign in / Sign up

Export Citation Format

Share Document