Multifunctional Non-Woven Carbon Nanopaper: Fabrication, Properties, and Applications

2013 ◽  
Vol 423-426 ◽  
pp. 97-105 ◽  
Author(s):  
Ji Hua Gou ◽  
Fei Liang ◽  
Yun Jun Xu ◽  
Bob Mabbott
Keyword(s):  
Carbon Nanofibers ◽  
Shape Memory Polymer ◽  
High Energy ◽  
Lightning Strike ◽  
Fundamental Study ◽  
Infiltration Process ◽  
Pressure Infiltration ◽  
Infiltration Pressure ◽  
Unique Material ◽  
High Energy Dissipation

This paper presents a fundamental study of processing, morphologies, properties, and applications of a novel non-woven nanopaper based on carbon nanofibers (CNFs). Unique material formulations were developed to tailor the non-woven nanopaper to specific engineering applications. The non-woven nanopaper was made from a variety of nanomaterials (e.g. carbon nanotubes, carbon nanofibers, graphene, nanoclay, nickel nanostrands, POSS, etc.) with tailored nanostructures by precisely controlling composition, dispersion, functionalization, orientation, porosity, and thickness during the vacuum infiltration, pressure infiltration, or spray/infiltration process. The polymer matrix was impregnated into the stacked nanopapers to form multi-layered laminated composites. Such non-woven nanopaper based composites were designed and fabricated to achieve high energy dissipation capability for vibrational damping, high thermal conductivity and thermal stability for fire retardancy, ultra-high electrical conductivity and current-carrying capacity for lightning strike protection, and electro-actuation of shape memory polymer composites.

Molecular Dynamics Investigation on Shearing between Osteopontin and Hydroxyapatite in Biological Materials

2014 ◽  
Vol 891-892 ◽  
pp. 3-8
Author(s):  
Zheng Bo Lai ◽  
Cheng Yan ◽  
Adekunle Oloyede
Keyword(s):  
Molecular Dynamics ◽  
Mechanical Response ◽  
Building Blocks ◽  
Biological Materials ◽  
High Energy ◽  
Shear Loading ◽  
Mineral Surfaces ◽  
Protein Matrix ◽  
Unique Material ◽  
High Energy Dissipation

Bone, a hard biological material, possesses a combination of high stiffness and toughness, even though the main basic building blocks of bone are simply mineral platelets and protein molecules. Bone has a very complex microstructure with at least seven hierachical levels. This unique material characteristic attracts great attention, but the deformation mechanisms in bone have not been well understood. Simulation at nanolength scale such as molecular dynamics (MD) is proven to be a powerful tool to investigate bone nanomechanics for developing new artificial biological materials. This study focuses on the ultra large and thin layer of extrafibrillar protein matrix (thickness = ~ 1 nm) located between mineralized collagen fibrils (MCF). Non-collagenous proteins such as osteopontin (OPN) can be found in this protein matrix, while MCF consists mainly of hydroxyapatite (HA) nanoplatelets (thickness = 1.5 4.5 nm). By using molecular dynamics method, an OPN peptide was pulled between two HA mineral platelets with water in presence. Periodic boundary condition (PBC) was applied. The results indicate that the mechanical response of OPN peptide greatly depends on the attractive electrostatics interaction between the acidic residues in OPN peptide and HA mineral surfaces. These bonds restrict the movement of OPN peptide, leading to a high energy dissipation under shear loading.

Prediction of Critical Pressure in the Preparation of Composites by Vacuum - Pressure Infiltration Process

2012 ◽  
Vol 512-515 ◽  
pp. 427-430 ◽  
Author(s):  
Ming Tao Huang ◽  
Yang Wei Wang ◽  
Fu Chi Wang ◽  
Ju Bin Gao
Keyword(s):  
Molten Aluminum ◽  
Vacuum Pressure ◽  
Model Parameters ◽  
Infiltration Process ◽  
Pressure Infiltration ◽  
Pressure Threshold ◽  
Al Composite ◽  
Infiltration Pressure ◽  
Molten Aluminum Alloy ◽  
Main Factors

The SiC3D/Al composite with high SiC content were prepared by vacuum– pressure infiltration process, and the prediction model of infiltration pressure threshold involving capillary pressure and viscous resistance was established. The effects of model parameters on the critical infiltration pressure were analyzed. The results show that the main factors are the permeability coefficient of SiC performs and the temperature of molten aluminum alloy. Temperature affects the melt viscosity and the wetting angle between SiC and molten alloy. The ingiltration pressure threshold of the specific infiltration system had been calculated by this model, which is in agreement with experimental results.

Effects of Macroscopic Pores on the Damping Behaviors of Metal Materials

2011 ◽  
Vol 66-68 ◽  
pp. 1155-1162
Author(s):  
Jian Ning Wei ◽  
Gen Mei Li ◽  
Li Ling Zhou ◽  
Xue Yun Zhou ◽  
Jian Min Yu ◽  
...  
Keyword(s):  
Internal Friction ◽  
Pure Aluminum ◽  
Air Pressure ◽  
Damping Capacity ◽  
Infiltration Process ◽  
Pressure Infiltration ◽  
Temperature Range ◽  
Commercially Pure ◽  
Damping Behavior ◽  
Metal Materials

A large number of macroscopic pores were introduced into commercially pure aluminum (Al) and Zn-Al eutectoid alloy by air pressure infiltration process to comparatively study the influence of macroscopic pores on the damping behaviors of the materials. Macroscopic pores size are on the order of a millimetre (0.5~1.4mm) and in large proportions, typically high 76vol.%. The damping behavior of the materials is characterized by internal friction (IF). The IF was measured on a multifunction internal friction apparatus (MFIFA) at frequencies of 0.5, 1.0 and 3.0 Hz over the temperature range of 25 to 400 °C, while continuously changing temperature. The damping capacity of the metal materials is shown to increase with introducing macroscopic pores. Finally, the operative damping mechanisms in the metal materials with macroscopic pores were discussed in light of IF measurements.

Microstructure and Hardness of Ni-Cr Porous Preform Reinforced Al-Based Composites by Low Infiltration Method

2011 ◽  
Vol 275 ◽  
pp. 251-254
Author(s):  
Hua Wei Rong ◽  
Cheol Hong Park ◽  
Won Jo Park ◽  
Han Ki Yoon
Keyword(s):  
Intermetallic Compounds ◽  
Rapid Development ◽  
High Hardness ◽  
Optical Microscope ◽  
Matrix Composites ◽  
X Ray Diffraction ◽  
Infiltration Process ◽  
Pressure Infiltration ◽  
X Ray ◽  
Infiltration Method

With the rapid development of aerospace and automobile industries, metal matrix composites (MMCs) have attracted much attention because of its excellent performance. In this paper, Ni-Cr/AC8A composites reinforced with porous Ni-Cr preform were manufactured by low pressure infiltration process, infiltration temperatures are 700oC~850oC. The microstructure and phase composition of composites were evaluated using optical microscope, X-ray diffraction (XRD) and electro-probe microanalysis (EPMA), It's found that they're intermetallic compounds generated in the composites. Recently, intermetallic compounds have attracted much attention as high-temperature material. We study the hardness of Ni-Cr/AC8A composites, the results show the Ni-Cr/AC8A composite has high hardness due to the intermetallic compounds exist.

scholarly journals N-Enriched carbon nanofibers for high energy density supercapacitors and Li-ion batteries

RSC Advances ◽  
2019 ◽  
Vol 9 (62) ◽  
pp. 36075-36081 ◽  
Author(s):  
Sayali B. Kale ◽  
Manjiri A. Mahadadalkar ◽  
Chang Hyo Kim ◽  
Yoong Ahm Kim ◽  
Manish S. Jayswal ◽  
...  
Keyword(s):  
Energy Density ◽  
Carbon Nanofibers ◽  
High Energy ◽  
High Energy Density ◽  
Li Ion Batteries ◽  
One Step ◽  
Li Ion

Nitrogen enriched carbon nanofibers have been obtained by one-step carbonization/activation of PAN-based nanofibers with various concentrations of melamine at 800 °C under a N2 atmosphere.

Test Study on the Rigidity Degradation and Energy Dissipation of High-Strength Reinforced Concrete Columns with Central Reinforcement

2010 ◽  
Vol 163-167 ◽  
pp. 398-405
Author(s):  
San Sheng Dong ◽  
Zi Xue Lei ◽  
Jun Hai Zhao
Keyword(s):  
Energy Dissipation ◽  
High Strength ◽  
Concrete Columns ◽  
High Energy ◽  
Affecting Factors ◽  
Static Test ◽  
Test Study ◽  
Core Areas ◽  
Energy Dissipation Capacity ◽  
High Energy Dissipation

Based on the pseudo-static test of 6 high-strength RC columns with central reinforcement skeletons, this paper studied their hysterisis performance, degradation of strength and rigidity, and energy dissipation capacity, with the affecting factors analyzed. The result shows that the central reinforcement skeletons can compensate for the low plasticity and brittle failure susceptibility of high-strength concrete so that all the specimens have stable strength, slow rigidity degradation and high energy dissipation capacity at later stage of loading; the larger the core areas the higher the strengths and ductility of the specimens, but slightly faster the degradation of strength and energy dissipation capacity as compared with the specimens with smaller core areas; the spacing of ties, longitudinal reinforcement ratio of core area both influence the strength degradation and energy dissipation capacity of the specimens, but they have little effect on their strengths.

Stiffness, Ductility, and Energy Dissipation of RC Elements under Cyclic Shear

2005 ◽  
Vol 21 (4) ◽  
pp. 1093-1112 ◽  
Author(s):  
Thomas T. C. Hsu ◽  
Mohamad Y. Mansour
Keyword(s):  
Energy Dissipation ◽  
High Energy ◽  
Shear Stresses ◽  
Principal Stresses ◽  
Element Analysis ◽  
Rc Structures ◽  
Cyclic Shear ◽  
Steel Bar ◽  
High Energy Dissipation ◽  
Reversed Cyclic

A new Cyclic Softened Membrane Model (CSMM) was recently developed to predict the stiffness, ductility, and energy dissipation of reinforced concrete (RC) elements subjected to reversed cyclic shear. Using the nonlinear finite element analysis, we can integrate these responses of elements to predict the behavior of a whole structure, such as a low-rise shear wall, subjected to earthquake action. This study of CSMM summarizes systematically the effects of the two primary variables: the steel bar angle with respect to the direction of the applied principal stresses and the steel percentage. The results clearly show that RC structures under cyclic shear stresses could be designed to be very ductile, have large stiffness, and possess high energy-dissipation capacities (just like flexural-dominated elements), if the steel bars are properly oriented in the directions of principal stresses and if the steel percentages are kept within certain limits.

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