Nanoscale Interphase Characterization of Porous CNT Buckypaper Composites in Correlation to Interlaminar Mode I Fracture

2020 ◽  
Author(s):  
Masoud Yekani Fard ◽  
Jack Mester ◽  
Alek Pensky
Keyword(s):  
Surface Roughness ◽  
Mode I ◽  
Interphase Region ◽  
Property Data ◽  
Multi Walled Carbon Nanotube ◽  
Three Phase ◽  
Composite Peak ◽  
Inhomogeneous Properties ◽  
Tip Radius

Abstract In this conference paper, nanoscale material property data and ASTM mode I interlaminar fracture results for three-phase buckypaper samples are presented and analyzed. Vacuum filtration and surfactant-free methods were used to manufacture buckypaper membranes. Epoxy infused buckypaper membranes were placed in front of the crack tip in a stitch bonded carbon fiber polymer matrix composite. Peak Force Quantitative Nanomechanical Mapping (PFQNM), using probes with nominal tip radius in the range of 5–8 nm were used. PFQNM characterized the interphase region between a three-phase sample of carbon monofilament, epoxy resin, and multi-walled carbon nanotube (MWCNT) buckypaper. This experiment captured reproducible nanoscale morphological, viscoelastic, elastic and energy properties of porous MWCNT buckypaper samples. An enlarged interphase region surrounding the CNT buckypaper was found. The buckypaper and epoxy interphase thickness was found to be 50nm, higher than the 10–40nm reported for epoxy and carbon monofilaments. The observed MWCNT structure provides explanation of the increased surface roughness compared to the smooth carbon monofilaments. The increased surface roughness likely improves mechanical interlocking with the epoxy of adjacent lamina. The nanoscale interphase and subsurface characterization data provide explanation for a change in crack propagation toughness. Buckypaper exhibited inhomogeneous properties at micrometer length scales.

scholarly journals Post-Processing and Surface Characterization of Additively Manufactured Stainless Steel 316L Lattice: Implications for BioMedical Use

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1376
Author(s):  
Alex Quok An Teo ◽  
Lina Yan ◽  
Akshay Chaudhari ◽  
Gavin Kane O’Neill
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Surface Characterization ◽  
High Surface ◽  
Surface Characteristics ◽  
Post Processing ◽  
Stainless Steel 316L ◽  
Processing Methods ◽  
Particulate Debris

Additive manufacturing of stainless steel is becoming increasingly accessible, allowing for the customisation of structure and surface characteristics; there is little guidance for the post-processing of these metals. We carried out this study to ascertain the effects of various combinations of post-processing methods on the surface of an additively manufactured stainless steel 316L lattice. We also characterized the nature of residual surface particles found after these processes via energy-dispersive X-ray spectroscopy. Finally, we measured the surface roughness of the post-processing lattices via digital microscopy. The native lattices had a predictably high surface roughness from partially molten particles. Sandblasting effectively removed this but damaged the surface, introducing a peel-off layer, as well as leaving surface residue from the glass beads used. The addition of either abrasive polishing or electropolishing removed the peel-off layer but introduced other surface deficiencies making it more susceptible to corrosion. Finally, when electropolishing was performed after the above processes, there was a significant reduction in residual surface particles. The constitution of the particulate debris as well as the lattice surface roughness following each post-processing method varied, with potential implications for clinical use. The work provides a good base for future development of post-processing methods for additively manufactured stainless steel.

scholarly journals Fatigue characterization of polyethylene under mixed mode I/III conditions

2021 ◽  
Vol 145 ◽  
pp. 106084
Author(s):  
Anja Gosch ◽  
Florian J. Arbeiter ◽  
Michael Berer ◽  
Tomáš Vojtek ◽  
Pavel Hutař ◽  
...  
Keyword(s):  
Mixed Mode ◽  
Mode I

Synthesis and Characterization of Poly(2,5-benzimidazole) (ABPBI) Grafted Carbon Nanotubes

2009 ◽  
Vol 1240 ◽  
Author(s):  
Ji-Ye Kang ◽  
Su-Mi Eo ◽  
Loon-Seng Tan ◽  
Jong-Beom Baek
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Interfacial Adhesion ◽  
Synthesis And Characterization ◽  
Acylation Reaction ◽  
Single Walled Carbon Nanotube ◽  
Mechanical And Electrical Properties ◽  
Multi Walled Carbon Nanotube

AbstractSingle-walled carbon nanotube (SWCNT) and multi-walled carbon nanotube (MWCNT) were functionalized with 3,4-diaminobenzoic acid via “direct” Friedel-Crafts acylation reaction in PPA/P2O5 to afford ortho-diamino-functionalized SWCNT (DIF-SWCNT) and MWCNT (DIF-MWCNT). The resultant DIF-SWCNT and DIF-MWCNT showed improved solubility and dispersibility. To improve interfacial adhesion between CNT and polymer matrix, the grafting of ABPBI onto the surface of DIF-SWCNT (10 wt%) or DIF-MWCNT (10 wt%) was conducted by simple in-situ polymerization of AB monomer, 3,4-diaminobenzoic acid dihydrochloride, in PPA. The resultant ABPBI-g-MWCNT and ABPBI-g-SWCNT showed improved the mechanical and electrical properties.

scholarly journals Skewness and Kurtosis: Important Parameters in the Characterization of Dental Implant Surface Roughness—A Computer Simulation

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Karl Niklas Hansson ◽  
Stig Hansson
Keyword(s):  
Surface Roughness ◽  
Shear Strength ◽  
Roughness Parameter ◽  
Interface Shear Strength ◽  
Interface Shear ◽  
Implant Surface ◽  
Bone Response ◽  
Dental Implant Surface ◽  
Skewness And Kurtosis

The surface roughness affects the bone response to dental implants. A primary aim of the roughness is to increase the bone-implant interface shear strength. Surface roughness is generally characterized by means of surface roughness parameters. It was demonstrated that the normally used parameters cannot discriminate between surfaces expected to give a high interface shear strength from surfaces expected to give a low interface shear strength. It was further demonstrated that the skewness parameter can do this discrimination. A problem with this parameter is that it is sensitive to isolated peaks and valleys. Another roughness parameter which on theoretical grounds can be supposed to give valuable information on the quality of a rough surface is kurtosis. This parameter is also sensitive to isolated peaks and valleys. An implant surface was assumed to have a fairly well-defined and homogenous “semiperiodic” surface roughness upon which isolated peaks were superimposed. In a computerized simulation, it was demonstrated that by using small sampling lengths during measurement, it should be possible to get accurate values of the skewness and kurtosis parameters.

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