ULTRAFAST HEAT DISSIPATION DYNAMICS OF SILVER NANOPARTICLES

2011 ◽  
Vol 10 (01n02) ◽  
pp. 151-154
Author(s):  
S. P. PAL ◽  
P. SEN
Keyword(s):  
Thermal Conductivity ◽  
Silver Nanoparticles ◽  
Relaxation Time ◽  
Heat Dissipation ◽  
Surrounding Medium ◽  
Band Edge Emission ◽  
Time Resolved Fluorescence ◽  
Edge Emission ◽  
Time Resolved ◽  
Average Relaxation Time

Time-resolved fluorescence spectroscopy has been employed to study the ultrafast heat dissipation dynamics of silver nanoparticles dispersed in methanol, tetrahydrofuran, and hexane. The average relaxation time obtained is in the order of several hundreds of picoseconds indicating lack of band-edge emission where lack of scaling of these times with the thermal conductivity of the surrounding medium indicate disparate heat dissipation pathways.

Time Resolved Temperature Measurement of Single Gold Structures via Luminescence Thermometry

MRS Advances ◽  
2018 ◽  
Vol 3 (14) ◽  
pp. 747-751 ◽  
Author(s):  
Ali Rafiei Miandashti ◽  
Martin Kordesch ◽  
Hugh H. Richardson
Keyword(s):  
Thermal Conductivity ◽  
Temperature Measurement ◽  
Heat Dissipation ◽  
Time Resolved ◽  
Temperature Decay ◽  
Energy Transitions ◽  
The Absolute ◽  
532 Nm ◽  
Luminescence Thermometry

ABSTRACTHere we report the use of luminescence thermometry to measure the temperature decay from single gold structure into the substrate of AlGaN:Er3+ film. We looked at Er3+ ion photoluminescence upon illumination by modulated 532 nm laser and recorded time-resolved luminescence of 2H11/2 → 4I15/2 and the 4S3/2 → 4I15/2 energy transitions. We calculated the heat generated from gold microdisk and observed the rate of heat dissipation to the environment. We directly calculated the absolute thermal conductivity of 1.7 W/mK for AlGaN: Er3+ film which was in agreement with the literature.

Silver nanoparticles-enhanced time-resolved fluorescence sensor for VEGF165 based on Mn-doped ZnS quantum dots

2015 ◽  
Vol 74 ◽  
pp. 1053-1060 ◽  
Author(s):  
Dong Zhu ◽  
Wei Li ◽  
Hong-Mei Wen ◽  
Sheng Yu ◽  
Zhao-Yi Miao ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Silver Nanoparticles ◽  
Fluorescence Sensor ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Mn Doped

Analysis of a Convective-Radiative Continuously Moving Fin with Temperature-Dependent Thermal Conductivity

2020 ◽  
Vol 21 (3-4) ◽  
pp. 379-388
Author(s):  
Partner L. Ndlovu ◽  
Raseelo J. Moitsheki
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Heat Dissipation ◽  
Surrounding Medium ◽  
Physical Parameters ◽  
Nonlinear Boundary Value Problems ◽  
Temperature Dependent ◽  
Transform Method ◽  
Thermal Conductivity Parameter ◽  
Conductivity Parameter

AbstractIn this article, the differential transform method (DTM) is used to solve the nonlinear boundary value problems describing heat transfer in continuously moving fins undergoing convective-radiative heat dissipation. The thermal conductivity is variable and temperature dependent. The surface of the moving fin is assumed to be gray with a constant emissivity ɛ. The flow in the surrounding medium provides a constant heat transfer coefficient h over the entire surface of the moving fins. The effects of some physical parameters such as the Peclet number, Pe, thermal conductivity parameter, β, convection-conduction parameter, Nc, radiation-conduction parameter, Nr, and dimensionless convection-radiation sink temperature, θa, on the temperature distribution are illustrated and explained.

Influence of filler hybridization on thermomechanical properties of hemp/silver epoxy composite

2020 ◽  
pp. 096739112097811
Author(s):  
Munjula Siva Kumar ◽  
Santosh Kumar ◽  
Krushna Gouda ◽  
Sumit Bhowmik
Keyword(s):  
Thermal Conductivity ◽  
Silver Nanoparticles ◽  
Epoxy Polymer ◽  
Hybrid Composites ◽  
Conductive Filler ◽  
Weight Fraction ◽  
Mechanical Analysis ◽  
Thermomechanical Properties ◽  
Material Behavior ◽  
Good Crystallinity

The polymer composite material’s thermomechanical properties with fiber as reinforcement material have been widely studied in the last few decades. However, these fiber-based polymer composites exhibit problems such as fiber orientation, delamination, fiber defect along the length and bonding are the matter of serious concern in order to improve the thermomechanical properties and obtain isotropic material behavior. In the present investigation filler-based composite material is developed using natural hemp and high thermal conductive silver nanoparticles (SNP) and combination of dual fillers in neat epoxy polymer to investigate the synergetic influence. Among various organic natural fillers hemp filler depicts good crystallinity characteristics, so selected as a biocompatible filler along with SNP conductive filler. For enhancing their thermal conductivity and mechanical properties, hybridization of hemp filler along with silver nanoparticles are conducted. The composites samples are prepared with three different combinations such as sole SNP, sole hemp and hybrid (SNP and hemp) are prepared to understand their solo and hybrid combination. From results it is examined that, chemical treated hemp filler has to maximized its relative properties and showed, 40% weight % of silver nanoparticles composites have highest thermal conductivity 1.00 W/mK followed with hemp filler 0.55 W/mK and hybrid 0.76 W/mK composites at 7.5% of weight fraction and 47.5% of weight fraction respectively. The highest tensile strength is obtained for SNP composite 32.03 MPa and highest young’s modulus is obtained for hybrid composites. Dynamic mechanical analysis is conducted to find their respective storage modulus and glass transition temperature and that, the recorded maximum for SNP composites with 3.23 GPa and 90°C respectively. Scanning electron microscopy examinations clearly illustrated that formation of thermal conductivity chain is significant with nano and micro fillers incorporation.

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