THE STRENGTH OF NANOCOMPOSITES POLYMER / 2D-NANOFILLER WITH ULTRASMALL FILLER CONTENTS

2020 ◽  
pp. 3-6
Author(s):  
Gasan M. Magomedov ◽  
Guseyn M. Magomedov ◽  
I. V. Dolbin
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Fibers ◽  
Interfacial Adhesion ◽  
Fracture Process ◽  
Interfacial Strength ◽  
Geometrical Parameters ◽  
Correct Description ◽  
Two Phase ◽  
Small Aggregation ◽  
Appreciable Reduction

The theoretical model, using the notions of fractal analysis is proposed for description of strength of nanocomposites polymer/2D-nanofiller on the example of nanocomposites polyvinylalcohol/boron nitride. For correct description of strength of these two-phase nanomaterial the knowledge of initial characteristics of matrix polymer (stress of fracture), geometrical parameters of nanofiller and level of interfacial adhesion polymer matrix-nanofiller is necessary. The indicated level, characterizing by shear interfacial strength, was determined theoretically within the framework of fractal conception of adhesion. Its absolute values found high enough – they are comparable with this characteristic in systems polymer-carbon nanotubes and are higher essentially than in systems polymer-microfiber (glassy and carbon fibers). This factor defines high enough strength of the considered nanocomposites. The important factor for fracture process of nanomaterials is aggregation of initial platelets of nanofiller, which forms “packets” (tactoids) of such platelets. The relatively small aggregation degree of nanofiller gives appreciable reduction of strength of nanocomposites polymer/2D-nanofiller. The indicated reduction is connected with transition of 2D-nanofiller structure from exfoliated to intercalated one, i.e. from separate platelets to their tactoids.

scholarly journals Thermoelectric Properties of Thin Films from Sorted Single-Walled Carbon Nanotubes

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3808 ◽  
Author(s):  
Blazej Podlesny ◽  
Bogumila Kumanek ◽  
Angana Borah ◽  
Ryohei Yamaguchi ◽  
Tomohiro Shiraki ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Thermoelectric Properties ◽  
Large Scale ◽  
Single Walled Carbon Nanotubes ◽  
Parent Material ◽  
Free Standing ◽  
Two Phase ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes ◽  
Aqueous Two Phase Extraction

Single-walled carbon nanotubes (SWCNTs) remain one of the most promising materials of our times. One of the goals is to implement semiconducting and metallic SWCNTs in photonics and microelectronics, respectively. In this work, we demonstrated how such materials could be obtained from the parent material by using the aqueous two-phase extraction method (ATPE) at a large scale. We also developed a dedicated process on how to harvest the SWCNTs from the polymer matrices used to form the biphasic system. The technique is beneficial as it isolates SWCNTs with high purity while simultaneously maintaining their surface intact. To validate the utility of the metallic and semiconducting SWCNTs obtained this way, we transformed them into thin free-standing films and characterized their thermoelectric properties.

Effects of Varying Geometrical Parameters on Boiling From Microfabricated Enhanced Structures

2003 ◽  
Vol 125 (1) ◽  
pp. 103-109 ◽  
Author(s):  
C. Ramaswamy ◽  
Y. Joshi ◽  
W. Nakayama ◽  
W. B. Johnson
Keyword(s):  
Heat Dissipation ◽  
Layer Structure ◽  
Single Layer ◽  
Nucleate Boiling ◽  
Heat Fluxes ◽  
Working Fluid ◽  
Geometrical Parameters ◽  
Small Range ◽  
Two Phase ◽  
Wall Superheat

The current study involves two-phase cooling from enhanced structures whose dimensions have been changed systematically using microfabrication techniques. The aim is to optimize the dimensions to maximize the heat transfer. The enhanced structure used in this study consists of a stacked network of interconnecting channels making it highly porous. The effect of varying the pore size, pitch and height on the boiling performance was studied, with fluorocarbon FC-72 as the working fluid. While most of the previous studies on the mechanism of enhanced nucleate boiling have focused on a small range of wall superheats (0–4 K), the present study covers a wider range (as high as 30 K). A larger pore and smaller pitch resulted in higher heat dissipation at all heat fluxes. The effect of stacking multiple layers showed a proportional increase in heat dissipation (with additional layers) in a certain range of wall superheat values only. In the wall superheat range 8–13 K, no appreciable difference was observed between a single layer structure and a three layer structure. A fin effect combined with change in the boiling phenomenon within the sub-surface layers is proposed to explain this effect.

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.

Interfacial adhesion of nanoporous zeolite thin films

2006 ◽  
Vol 21 (2) ◽  
pp. 505-511 ◽  
Author(s):  
Lili Hu ◽  
Junlan Wang ◽  
Zijian Li ◽  
Shuang Li ◽  
Yushan Yan
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Interfacial Adhesion ◽  
Interfacial Strength ◽  
Future Generation ◽  
In Situ Growth ◽  
Seeded Growth ◽  
Si Substrates ◽  
Film Substrate

Nanoporous silica zeolite thin films are promising candidates for future generation low-dielectric constant (low-k) materials. During the integration with metal interconnects, residual stresses resulting from the packaging processes may cause the low-k thin films to fracture or delaminate from the substrates. To achieve high-quality low-k zeolite thin films, it is important to carefully evaluate their adhesion performance. In this paper, a previously reported laser spallation technique is modified to investigate the interfacial adhesion of zeolite thin film-Si substrate interfaces fabricated using three different methods: spin-on, seeded growth, and in situ growth. The experimental results reported here show that seeded growth generates films with the highest measured adhesion strength (801 ± 68 MPa), followed by the in situ growth (324 ± 17 MPa), then by the spin-on (111 ± 29 MPa). The influence of the deposition method on film–substrate adhesion is discussed. This is the first time that the interfacial strength of zeolite thin films-Si substrates has been quantitatively evaluated. This paper is of great significance for the future applications of low-k zeolite thin film materials.

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