High Thermal Diffusivity in Thermally Treated Filamentous Virus-Based Assemblies with a Smectic Liquid Crystalline Orientation

Polymers are generally considered thermal insulators because the amorphous arrangement of the polymeric chains reduces the mean free path of heat-conducting phonons. Recent studies reveal that individual chains of polymers with oriented structures could have high thermal conductivity, because such stretched polymeric chains effectively conduct phonons through polymeric covalent bonds. Previously, we have found that the liquid crystalline assembly composed of one of the filamentous viruses, M13 bacteriophages (M13 phages), shows high thermal diffusivity even though the assembly is based on non-covalent bonds. Despite such potential applicability of biopolymeric assemblies as thermal conductive materials, stability against heating has rarely been investigated. Herein, we demonstrate the maintenance of high thermal diffusivity in smectic liquid crystalline-oriented M13 phage-based assemblies after high temperature (150 °C) treatment. The liquid crystalline orientation of the M13 phage assemblies plays an important role in the stability against heating processes. Our results provide insight into the future use of biomolecular assemblies for reliable thermal conductive materials.

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Thermal management of electronics and thermoelectric power generation from waste heat enabled by flexible Kevlar@SiC thermal conductive materials with liquid-crystalline orientation

Energy Conversion and Management ◽

10.1016/j.enconman.2021.114957 ◽

2021 ◽

pp. 114957

Author(s):

Bing Yao ◽

Hengheng Zhu ◽

Yue Ding ◽

Congcong Luo ◽

Teng Chen ◽

...

Keyword(s):

Power Generation ◽

Thermoelectric Power ◽

Thermal Management ◽

Liquid Crystalline ◽

Waste Heat ◽

Crystalline Orientation ◽

Thermoelectric Power Generation ◽

Conductive Materials ◽

Thermal Management Of Electronics

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Liquid crystalline orientation of polyfluorenes for polarized electroluminescence devices

10.1117/12.386372 ◽

2000 ◽

Cited By ~ 3

Author(s):

Katharine S. Whitehead ◽

Martin Grell ◽

Donal D. C. Bradley ◽

Markus Jandke ◽

Peter Strohriegl

Keyword(s):

Liquid Crystalline ◽

Crystalline Orientation

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Measurement of High Thermal Diffusivity Values by a Novel Method on Copper and Tungsten

Thermal Conductivity 14 ◽

10.1007/978-1-4899-3751-3_63 ◽

1976 ◽

pp. 479-490 ◽

Cited By ~ 1

Author(s):

Vladimir V. Mirkovich

Keyword(s):

Thermal Diffusivity ◽

High Thermal Diffusivity ◽

Novel Method ◽

And Tungsten

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Investigation on the Tensile Strength of the Friction Stir Welded similar joint of Al/Al alloy using high thermal diffusivity backing plate material.

International Journal of Thermal Technologies ◽

10.14741/ijtt/v.8.2.1 ◽

2018 ◽

Vol 8 (2) ◽

Author(s):

Akshansh Mishra ◽

Abhishek Kumar Sharma ◽

Hardik Kapoor ◽

Jaspreet Singh ◽

Krishna Kumar

Keyword(s):

Tensile Strength ◽

Thermal Diffusivity ◽

Welding Process ◽

Soft Materials ◽

Work Piece ◽

Al Alloy ◽

Plate Material ◽

Friction Stir ◽

Backing Plate ◽

High Thermal Diffusivity

Friction Stir Welding process is a novel green solid state joining process for soft materials such as aluminium alloys. The weld quality is governed by the proper selection of parameters such as forge force rotational speed of the tool, welding speed, backing plate material etc. Thermal boundary condition at the bottom of the work piece plays an important role for obtaining the sound joint. The backing plate material governs these thermal conditions. In this case study, high thermal diffusivity backing plate material which consisted of AA2099 was used for joining of the plates of Structural Aluminium alloy. It was observed that the tensile strength was improved.

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Validation and Development of DNS Database for Low Prandtl Numbers in Rod Bundle

Volume 2: Computational Fluid Dynamics ◽

10.1115/ajkfluids2019-5036 ◽

2019 ◽

Author(s):

Jonathan K. Lai ◽

Elia Merzari ◽

Yassin A. Hassan ◽

Aleksandr Obabko

Keyword(s):

Heat Transfer ◽

Thermal Diffusivity ◽

Prandtl Number ◽

Liquid Metals ◽

Heat Transfer Characteristics ◽

Reynolds Analogy ◽

Transfer Characteristics ◽

Rod Bundle ◽

High Thermal Diffusivity ◽

Prandtl Numbers

Abstract Difficulty in capturing heat transfer characteristics for liquid metals is commonplace because of their low molecular Prandtl number (Pr). Since these fluids have very high thermal diffusivity, the Reynolds analogy is not valid and creates modeling difficulties when assuming a turbulent Prandtl number (Prt) of near unity. Baseline problems have used direct numerical simulations (DNS) for the channel flow and backward facing step to aid in developing a correlation for Prt. More complex physics need to be considered, however, since correlation accuracy is limited. A tight lattice square rod bundle has been chosen for DNS benchmarking because of its presence of flow oscillations and coherent structures even with a relatively simple geometry. Calculations of the Kolmogorov length and time scales have been made to ensure that the spatial-temporal discretization is sufficient for DNS. In order to validate the results, Hooper and Wood’s 1984 experiment has been modeled with a pitch-to-diameter (P/D) ratio of 1.107. The present work aims at validating first- and second-order statistics for the velocity field, and then analyzing the heat transfer behavior at different molecular Pr. The effects of low Pr flow are presented to demonstrate how the normalized mean and fluctuating heat transfer characteristics vary with different thermal diffusivity. Progress and future work toward creating a full DNS database for liquid metals are discussed.

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A Study of Porosity Influence on Thermal Diffusivity of Aluminium Foam by Experimental Analysis and Numerical Simulation

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.297-301.814 ◽

2010 ◽

Vol 297-301 ◽

pp. 814-819 ◽

Cited By ~ 1

Author(s):

A. Adamčíková ◽

B. Taraba ◽

J. Kováčik

Keyword(s):

Thermal Conductivity ◽

Numerical Simulation ◽

Thermal Diffusivity ◽

Transfer Task ◽

Aluminium Foam ◽

Flash Method ◽

Inverse Heat Transfer ◽

High Thermal Diffusivity ◽

Specific Heat Capacities ◽

Measured Specific Heat

Aluminium foam is a unique material possessing very high thermal diffusivity due to high thermal conductivity of the cell walls accompanied with rather low overall thermal conductivity, controlled via porosity [1]. There is a presumption of increasing influence at thermal diffusivity of aluminium foam by decreasing porosity, following the presented results (e.g. by using the transient plane source method [2]) and relation between thermal diffusivity and density. Thermal diffusivity of aluminium foam considering various porosity and various compositions of precursors were observed. The Aluminium foam was prepared by the powder metallurgy route, also well known as the ALULIGHT process, and various densities were achieved by changing of parameters (temperature, time) of foaming. The following types of foamable precursors were used: AlMg1Si0.6, AlSi10, as blowing agent was used 0.8 wt. % of TiH2.The thermal diffusivity of particular precursors by the flash method was measured. Specific heat capacities of samples with different density were measured by a calorimeter for various temperatures. The coefficient of thermal conductivity as a function of temperature was calculated by heat transient experiment data and numerical simulation consequently as an inverse heat transfer task. The problem was solved by the finite element method using the engineering-scientific program code ANSYS. The results depend on the thermal diffusivity, on the porosity and the type of precursor. Despite that aluminium foam is considered as a type of composite, thermophysical properties could be calculated upon known volume of aluminium alloy and air in the pores However there is a presumption that this rule cannot be used in case of porous materials. Values obtained by the mentioned methodology shown a significant influence on the porosity and the thermal diffusivity of the aluminium foam.

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Revising the exceptionally high thermal diffusivity of spider silk

Materials Letters ◽

10.1016/j.matlet.2013.09.092 ◽

2014 ◽

Vol 114 ◽

pp. 1-3 ◽

Cited By ~ 17

Author(s):

Raquel Fuente ◽

Arantza Mendioroz ◽

Agustín Salazar

Keyword(s):

Thermal Diffusivity ◽

Spider Silk ◽

High Thermal Diffusivity

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Hydrogen-bond memory and water-skin supersolidity resolving the Mpemba paradox

Physical Chemistry Chemical Physics ◽

10.1039/c4cp03669g ◽

2014 ◽

Vol 16 (42) ◽

pp. 22995-23002 ◽

Cited By ~ 36

Author(s):

Xi Zhang ◽

Yongli Huang ◽

Zengsheng Ma ◽

Yichun Zhou ◽

Ji Zhou ◽

...

Keyword(s):

Hydrogen Bond ◽

Thermal Diffusivity ◽

System P ◽

High Thermal Diffusivity ◽

Anomalous Relaxation

O:H–O bond anomalous relaxation and the skin high thermal-diffusivity cool hotter water faster than usual in the non-adiabatic ambient system.

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Liquid Crystalline Orientation of Rod Blocks within Lamellar Nanostructures from Rod−Coil Diblock Copolymers

Macromolecules ◽

10.1021/ma101056r ◽

2010 ◽

Vol 43 (16) ◽

pp. 6531-6534 ◽

Cited By ~ 12

Author(s):

Bradley D. Olsen ◽

Xun Gu ◽

Alexander Hexemer ◽

Eliot Gann ◽

Rachel A. Segalman

Keyword(s):

Liquid Crystalline ◽

Diblock Copolymers ◽

Crystalline Orientation

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Maximum Possible Colling Rate in Ultrafast Chip Nanocalorimetry: Fundamental Limitations Due to Thermal Resistance at the Membrane/Gas Interface

10.20944/preprints202108.0041.v1 ◽

2021 ◽

Author(s):

Alexander A. Minakov ◽

Christoph Schick

Keyword(s):

Thermal Resistance ◽

Cooling Rate ◽

Materials Science ◽

Mean Free Path ◽

Heat Conducting ◽

Controlled Cooling ◽

Fundamental Limitations ◽

The Mean ◽

Gas Molecules ◽

Hot Zone

Ultrafast chip nanocalorimetry opens up remarkable possibilities in materials science by allowing samples to be cooled and heated at extremely high rates. Due to heat transfer limitations, controlled ultrafast cooling and heating can only be achieved for tiny samples in calorimeters with a micron-thick membrane. Even if ultrafast heating can be controlled under quasi-adiabatic conditions, ultrafast controlled cooling can be performed if the calorimetric cell is located in a heat-conducting gas. It was found that the maximum possible cooling rate increases as 1/r0 with decreasing radius r0 of the hot zone of the membrane. The possibility of increasing the maximum cooling rate with decreasing r0 was successfully implemented in many experiments. In this regard, it is interesting to answer the question: what is the maximum possible cooling rate in such experiments if r0 tends to zero? Indeed, on submicron scales, the mean free path of gas molecules lmfp becomes comparable to r0, and the temperature jump that exists at the membrane/gas interface becomes significant. Considering the limitation associated with thermal resistance at the membrane/gas interface and considering the transfer of heat through the membrane, we show that the controlled cooling rate can reach billions of K/s, up to 1010 K/s.

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