scholarly journals Thermal Percolation Behavior in Thermal Conductivity of Polymer Nanocomposite with Lateral Size of Graphene Nanoplatelet

Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 323
Author(s):  
Ji-un Jang ◽  
Hae Eun Nam ◽  
Soon Oh So ◽  
Hyeseong Lee ◽  
Geon Su Kim ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Heat Dissipation ◽  
Critical Concentration ◽  
Polymer Nanocomposite ◽  
Nanocomposite Materials ◽  
Percolation Model ◽  
Lateral Size ◽  
Critical Content ◽  
Percolation Behavior ◽  
Insight Into

In this study, the thermal percolation behavior for the thermal conductivity of nanocomposites according to the lateral size of graphene nanoplatelets (GNPs) was studied. When the amount of GNPs reached the critical concentration, a rapid increase in thermal conductivity and thermal percolation behavior of the nanocomposites were induced by the GNP network. Interestingly, as the size of GNPs increased, higher thermal conductivity and a lower percolation threshold were observed. The in-plane thermal conductivity of the nanocomposite containing 30 wt.% M25 GNP (the largest size) was 8.094 W/m·K, and it was improved by 1518.8% compared to the polymer matrix. These experimentally obtained thermal conductivity results for below and above the critical content were theoretically explained by applying Nan’s model and the percolation model, respectively, in relation to the GNP size. The thermal percolation behavior according to the GNP size identified in this study can provide insight into the design of nanocomposite materials with excellent heat dissipation properties.

Development of Thermally Conductive Polymer/CNF Nanocomposite Materials via PolyJet Additive Manufacturing by Improvement of Digital Material Design

2019 ◽  
Author(s):  
Furkan Ismail Ulu ◽  
Ram Mohan ◽  
Ravi Pratap Singh Tomar
Keyword(s):  
Thermal Conductivity ◽  
Heat Dissipation ◽  
Conductive Polymer ◽  
Thermal Conductance ◽  
Polymeric Materials ◽  
Material Design ◽  
Nanocomposite Materials ◽  
Conductive Path ◽  
Thermally Conductive ◽  
Polyjet Printing

Abstract PolyJet printing technology allows building polymeric materials with complex multi-material structures in the resolution of tens of microns layer thickness providing high control over the entire 3-D part. On the other hand, thermally conductive polymer/CNF nanocomposite materials offer new opportunities for replacing metals in industry and applications that require heat dissipation to avoid degradation of materials prematurely. CNFs are one of the best promising filler types to enhance thermal conductance of polymers. However, experimental thermal conductivities of polymer/CNF nanocomposites are significantly low compared to the intrinsic thermal conductivity of CNFs. Present work focused on selectively addition CNF fillers to form a thermally conductive path which helps to control dispersion and alignment. PolyJet printing forms the material and the structure simultaneously which allows the control over the material distribution and morphology on entire 3-D parts while providing possibilities to manipulate the design and create a conductive path. In the present research, improvement of thermal conductivity of Polymer/CNF nanocomposites via PolyJet printing using voxel digital printing method was investigated. Samples were designed as VeroClear material, VeroClear with CNFs, VeroCyan material, VeroCyan with CNFs. DSC and TPS were used to perform the thermal characterization of the samples.

scholarly journals Estimations on Properties of Redox Reactions to Electrical Energy and Storage Device of Thermoelectric Pipe (TEP) Using Polymeric Nanofluids

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1812
Author(s):  
Qin Gang ◽  
Rong-Tsu Wang ◽  
Jung-Chang Wang
Keyword(s):  
Thermal Conductivity ◽  
Power Density ◽  
Heat Dissipation ◽  
Electrical Energy ◽  
Steel Tube ◽  
Storage Device ◽  
Stainless Steel Tube ◽  
The Novel ◽  
Empirical Formulas ◽  
Dissipative Heat

A thermoelectric pipe (TEP) is constructed by tubular graphite electrodes, Teflon material, and stainless-steel tube containing polymeric nanofluids as electrolytes in this study. Heat dissipation and power generation (generating capacity) are both fulfilled with temperature difference via the thermal-electrochemistry and redox reaction effects of polymeric nanofluids. The notion of TEP is to recover the dissipative heat from the heat capacity generated by the relevant machine systems. The thermal conductivity and power density empirical formulas of the novel TEP were derived through the intelligent dimensional analysis with thermoelectric experiments and evaluated at temperatures between 25 and 100 °C and vacuum pressures between 400 and 760 torr. The results revealed that the polymeric nanofluids composed of titanium dioxide (TiO2) nanoparticles with 0.2 wt.% sodium hydroxide (NaOH) of the novel TEP have the best thermoelectric performance among these electrolytes, including TiO2 nanofluid, TiO2 nanofluid with 0.2 wt.% NaOH, deionized water, and seawater. Furthermore, the thermal conductivity and power density of the novel TEP are 203.1 W/(m·K) and 21.16 W/m3, respectively.

Polymer nanocomposite materials based on polystyrene and a layered aluminate filler

2008 ◽  
Vol 48 (10) ◽  
pp. 2027-2032 ◽  
Author(s):  
Zvonimir Matusinović ◽  
Marko Rogošić ◽  
Juraj Šipušić ◽  
Jelena Macan
Keyword(s):  
Polymer Nanocomposite ◽  
Nanocomposite Materials

scholarly journals Study of Thermometry in Two-Dimensional Sb2Te3 from Temperature-Dependent Raman Spectroscopy

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Manavendra P. Singh ◽  
Manab Mandal ◽  
K. Sethupathi ◽  
M. S. Ramachandra Rao ◽  
Pramoda K. Nayak
Keyword(s):  
Thermal Conductivity ◽  
Raman Spectroscopy ◽  
Temperature Coefficient ◽  
Heat Dissipation ◽  
Peak Position ◽  
Two Dimensional ◽  
Phonon Modes ◽  
Temperature Dependent ◽  
Excellent Candidate ◽  
High Figure

AbstractDiscovery of two-dimensional (2D) topological insulators (TIs) demonstrates tremendous potential in the field of thermoelectric since the last decade. Here, we have synthesized 2D TI, Sb2Te3 of various thicknesses in the range 65–400 nm using mechanical exfoliation and studied temperature coefficient in the range 100–300 K using micro-Raman spectroscopy. The temperature dependence of the peak position and line width of phonon modes have been analyzed to determine the temperature coefficient, which is found to be in the order of 10–2 cm−1/K, and it decreases with a decrease in Sb2Te3 thickness. Such low-temperature coefficient would favor to achieve a high figure of merit (ZT) and pave the way to use this material as an excellent candidate for thermoelectric materials. We have estimated the thermal conductivity of Sb2Te3 flake with the thickness of 115 nm supported on 300-nm SiO2/Si substrate which is found to be ~ 10 W/m–K. The slightly higher thermal conductivity value suggests that the supporting substrate significantly affects the heat dissipation of the Sb2Te3 flake.

Evaporite Palynology: a case study on the Permian (Lopgingian) Zechstein Sea

2021 ◽  
pp. jgs2020-174
Author(s):  
Martha E. Gibson ◽  
David J. Bodman
Keyword(s):  
Thermal Conductivity ◽  
Heat Flux ◽  
Rapid Growth ◽  
Western Europe ◽  
Thermal Maturity ◽  
Near Surface ◽  
Wide Range ◽  
Terrestrial Environments ◽  
Insight Into

Evaporites characterize the Lopingian of Europe but present obstacles for biostratigraphic analysis. Here we present a case study for processing the Lopingian Zechstein Group evaporites of central-western Europe for the recovery of palynomorph assemblages. We demonstrate that full recovery is easily achieved with two main modes of palynomorph preservation observed; palynomorphs are either exceptionally well-preserved and orange-brown in colour, or poorly-preserved, brown-black, opaque and fragmented. The latter are reminiscent of palynomorphs of high thermal maturity. However, we propose that the intact nature of preservation is a result of the rapid growth of near-surface halite crystals, with their darkening a consequence of locally-enhanced heat flux due to the relatively high thermal conductivity of salt. This case study has enabled novel insight into an otherwise undescribed environment, and demonstrates the utility and possibility of extracting palynomorphs from a variety of rock salt types. This method should be applicable to a wide range of ancient evaporite and could also be applied to other Permian evaporite systems, which are used as analogues for extra-terrestrial environments.

scholarly journals Polymer Nanocomposite Membranes

2018 ◽  
Vol 8 (7) ◽  
pp. 1181 ◽  
Author(s):  
Svetlana Kononova ◽  
Galina Gubanova ◽  
Eleonora Korytkova ◽  
Denis Sapegin ◽  
Katerina Setnickova ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Polymer Matrix ◽  
Scientific Literature ◽  
Morphological Characteristics ◽  
Polymer Nanocomposite ◽  
Nanocomposite Materials ◽  
Sorption Mechanism ◽  
Nanocomposite Membranes ◽  
Nanocomposite Structure ◽  
Transport Channels

Based on the results of research works reflected in the scientific literature, the main examples, methods and approaches to the development of polymer inorganic nanocomposite materials for target membranes are considered. The focus is on membranes for critical technologies with improved mechanical, thermal properties that have the necessary capabilities to solve the problems of a selective pervaporation. For the purpose of directional changes in the parameters of membranes, effects on their properties of the type, amount and conditions of nanoparticle incorporation into the polymer matrix were analyzed. An influence of nanoparticles on the structural and morphological characteristics of the nanocomposite film is considered, as well as possibilities of forming transport channels for separated liquids are analyzed. Particular attention is paid to a correlation of nanocomposite structure-transport properties of membranes, whose separation characteristics are usually considered within the framework of the diffusion-sorption mechanism.

Orientation Specific Thermal Properties of Polyimide Film

2000 ◽  
Vol 123 (3) ◽  
pp. 273-277 ◽  
Author(s):  
Robert J. Samuels ◽  
Nancy E. Mathis
Keyword(s):  
Thermal Conductivity ◽  
Heat Dissipation ◽  
Polyimide Film ◽  
New Materials ◽  
Polyimide Films ◽  
Nondestructive Technique ◽  
Theoretical Understanding ◽  
First Time ◽  
The Relationship ◽  
Transfer Mechanisms

The present study examines the relationship between thermal conductivity and planarity in polyimide films. The samples tested were specially prepared to range in orientation from three dimensionally random to highly planar. The molecular structure and orientation of the polyimide film have been characterized by polarizing microscope techniques, while the thermal conductivity measurements were done using a new rapid nondestructive technique. This correlation represents the first time thermal conductivity has been measured by modified hot wire techniques and related to the internal structure of polyimide. This work contributes to a deeper theoretical understanding of thermal conductivity and heat transfer mechanisms as they relate to orientation. Thermal conductivity evaluation could provide a new tool in the arsenal of structural characterization techniques. This relationship between thermal conductivity and orientation is key for applications of directional heat dissipation in the passive layers of chip assemblies. Such a correlation has potential to speed the development cycles of new materials during formulation as well as assure properties during production.

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