Ninth Asian Thermophysical Properties Conference – ATPC 2010, October 19-22, Beijing Specific Heat at the Nanoscale Thomas Prevenslik QED Radiations Discovery

Ninth Asian Thermophysical Properties Conference – ATPC 2010, October 19-22, Beijing

Specific Heat at the Nanoscale

Thomas PrevenslikQED Radiations

Discovery Bay, Hong Kong


Introduction

Specific heat theories by Einstein’s characteristic vibrations in 1907 and Debye's phonons in 1912 provide accurate fits to macroscopic data at high

temperatures, although Debye’s theory follows data near absolute zero

In the 1950’s, Raman argued the thermal energy of a solid depends on atomic vibrations at IR frequencies - not normal mode by phonons.

Material damping negates normal modes.

Despite Raman’s objections, Debye’s phonon theory of macroscopic specific heat based on normal modes is accepted today.

1

t

TCTK

Lavoisier and Laplace in the 1780’s determined the specific heat that was to be used in the time dependent heat conduction equation by Fourier in 1822.


Specific Heat at Nanoscale

Like the erroneous extension of the Dulong-Petit law for specific heat from high to low temperatures, Debye’s macroscopic theory is similarly extended to the nanoscale because specific heat is an intensive

thermophysical property independent of quantity or size.

But at the nanoscale, macroscopic specific heat is challenged by quantum mechanics

Quantum Mechanics = QM

Propose specific heat is an extensive thermophysical property of a substance depending on quantity or size that vanishes at the nanoscale

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Richard Feynman -1970

Classical physics by statistical mechanics allows the atom to have heat capacity at the nanoscale.

QM also allows atoms to have heat capacity at the nanoscale, but only at high temperature.

Submicron wavelengths that “fit inside” nanostructures have heat capacity only at temperatures > 6000 K

At 300 K, heat capacity is therefore “frozen out” at submicron wavelengths

Paraphrasing Feynman 40 years later:

QM does not allow nanostructures at ambient temperature to conserve absorbed EM energy by an increase in temperature

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Classical v. QM Heat Capacity

0.00001

0.0001

0.001

0.01

0.1

1 10 100 1000

Wavelength - l - microns

Pla

nck

Ene

rgy

- E -

eV

l

l1

kT

hcexp

hc

E

4

Nanoscale

kT 0.0258 eV

Classical

QM

By QM, absorbed EM energy at the nanoscale cannot be conserved

by an increase in temperature . How conserved?

FIR

Ninth Asian Thermophysical Properties Conference – ATPC 2010, October 19-22, Beijingp

Conservation by QEDRecall from QM, QED photons of wavelength l are created by supplying EM

energy to a box having sides separated by l / 2.QED = quantum electrodynamics EM = electromagnetic

Absorbed EM energy is conserved by creating QED photons inside the nanostructure - by frequency up or down - conversion to:

If NP, TIR confinement frequency If molecule, EM frequencies

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For a spherical NP having diameter D, QED photons have l = 2D

l rn/c

f hfE

f = QED photon frequency E = Planck energy c = light speed nr = refractive index h = Planck’s constant


TIR Confinement

NPs D << l l / 2 D

f = c’ / l = c’ / 2D

c’ = c / nr

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l / 2


Raman’s Argument Proposed specific heat is given by Einstein’s characteristic vibrations using

frequencies of IR spectral lines

For Al, Ag, Cu, and Pb, the IR lines are 222, 175, 121, and 53 cm-1 correspond to the FIR > 50 microns.

NPs emit FIR radiation, but specific heat C 0 because FIR cannot “fit inside” the NP. Only in structures > 100 microns is C > 0.

At the nanoscale, the FIR is excluded because l = 2nrD < 3 microns < 45 microns zero specific heat

Raman’s argument is consistent with QM in that at the nanoscale specific heat vanishes, but not Debye’s phonons

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8

AbsorbQ

QEDQ

CondQ

T = 0

Instead, QQED is prompt non-thermal emission.

In < 5 fs, before phonons move, conservation gives

0 CondAbsorbQED QQQ

QQED is not Stefan-Boltzmann – no high temperatures

T. Prevenslik, “QED Induced Heat Transfer,” ECI – Nanofluids Fundamentals & Applications II, Montreal, 15-19 August, 2010

QED Induced Heat Transfer

dt

dNEQAbsorb

Replace Fourier Equation by:

E = Photon Planck Energy

dN/dt = Photon Rate

t

TcTK


QED Applications

Classical Physics unable to explain nanoscale observations

Molecular DynamicsHeat transfer simulations invalid for discrete nanostructures

NanofluidsExcluding QED emission leads to unphysical results

Cancer ResearchQED emission at UV levels damages DNA Cancer

Big Bang Theory QED Redshift in cosmic dust

means Universe is not expanding

Thin FilmsQED emission negates reduced conductivity by phonons 9


Molecular Dynamics

Akimov, et al. “Molecular Dynamics of Surface-Moving Thermally Driven Nanocars,”

J. Chem. Theory Comput. 4, 652 (2008). Discrete kT = 0, but kT > 0 assumed

Car distorts but does not moveClassical Analogy

Instead, QM forbids any increase in car temperature. Hence, QED radiation is produced that by the photoelectric effect charges the cars that move by

electrostatic interaction with each other.

Sarkar et al., “Molecular dynamics simulation of effective thermal

conductivity and study of enhance thermal transport in nanofluids,”

J. Appl. Phys, 102, 074302 (2007).Periodic Boundary Conditions

kT > 0, validMetropolis & Teller, 1950

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For discrete nanostructures, MD of heat transfer is not valid, but DFT and dynamics under isothermal conditions are valid.


Nanofluids*

* T. Prevenslik, “Nanofluids by QED Induced Heat Transfer,” IASME/WSEAS 6th Int. Conf. Heat Transfer, HTE-08, 20-22 August, Rhodes, 2008,

“Nanofluids by Quantum Mechanics,” Micro/Nanoscale Heat and Mass Transfer International Conference, December 18-21, Shanghai, 2009.

Prompted by classical physics being unable to explain how NPs increase thermal conductivity of common solvents

Unphysical enhancement in conductivity far greater than given by standard mixing rules.

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QED Enhancement

Heat into NP in the FIR (10 micron penetration)

NPs Avoid Local Thermal Equilibrium

Heat out of NP beyond the UV (1-10 centimeter penetration)

Penetration Ratio R = UV / FIR

R > 1 Heat is transferred over greater distance with NPs than without NPs

Enhancement

12

EM Emission

MolecularCollisions

NP

Classical physics FIR FIR No

Enhancement


*T. Prevenslik, “Nanoparticle induced DNA Damage,” IEEE – NANOMED 2009, Tainan, 18-21 October 2009

Proceedings of ASME2010 First Global Conference on NanoEngineering for Medicine and Biology, NEMB2010, Houston,

February 7-10, 2010

Cancer*NPs provide significant bactericidal action in burn

treatment and food processing

Experiments show NPs damage the DNA alone without lasers that can lead to cancer, but

how by NPs?

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Big Bang Theory

In 1929, Hubble measured the redshift of galaxy light that based on the Doppler Effect showed the Universe is

expanding.

However, cosmic dust which is submicron NPs permeate space and redshift galaxy light without Doppler effect.

14

Classical physics Absorbed galaxy photon

conserved by temperature increase


Effects on Cosmology

The redshift: Z = (lo - l)/l occurs without the Universe expanding.

Astronomers will not find the dark energy to explain a expanding Universe which is not expanding

Suggests a return to a static infinite Universe in dynamic equilibrium once proposed by Einstein.

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Prompted by classical heat transfer being unable to explain the reduced conductivity found in thin film experiments.

Unphysical explanations of reduced conductivity based on revisions to Fourier theory by phonons as quanta in the BTE are difficult to understand and concluded by hand-waving

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* T. Prevenslik, “Heat Transfer in Thin Films,” Third Int. Conf. on Quantum, Nano and Micro Technologies, ICQNM 2009, February 1-6, Cancun, 2009.

Proceedings of MNHMT09 Micro/Nanoscale Heat and Mass Transfer International Conference, December 18-21, 2009, Shanghai.

Thin Films*


Reduced Conductivity

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QCond

T

Current Approach QCond = QJoule

Keff T = Qcond (df + dS )/AT large, Keff small


QJoule

Film

Substrate

df

dSKf

KS

QED Heat Transfer QCond = QJoule - QQED ~ 0

Keff T = (QJoule- QQED) (df + dS ) / A T small, Keff ~ Bulk

No Reduced Conductivity

QQED

Classical physics Unphysical



Conclusions

QM requires zero specific heat capacity at the nanoscale be specified as an extensive thermophysical property of ALL materials.

Raman’s IR spectral lines in Einstein’s characteristic vibration theory is consistent with QM at the nanoscale

Phonon derivations of reduced thermal conductivity are meaningless because there is no time for conduction to occur.

MD heat transfer simulations of discrete nanostructures are not valid, but DFT and dynamics of QED charged nanostructures are valid.

Transient Fourier heat conduction may be replaced by the a priori assumption that absorbed EM energy is promptly conserved by QED

emission at the EM resonances of the nanostructure

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Questions & Papers

Email: [email protected]

http://www.nanoqed.org

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http://www.nanoqed.org/

Documents

Ninth Asian Thermophysical Properties Conference – ATPC 2010, October 19-22, Beijing Specific Heat at the Nanoscale Thomas Prevenslik QED Radiations Discovery