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

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Presentation on theme: "Ninth Asian Thermophysical Properties Conference – ATPC 2010, October 19-22, Beijing Specific Heat at the Nanoscale Thomas Prevenslik QED Radiations Discovery."— Presentation transcript:

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

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

3 Ninth Asian Thermophysical Properties Conference – ATPC 2010, October 19-22, Beijing 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 2

4 Ninth Asian Thermophysical Properties Conference – ATPC 2010, October 19-22, Beijing 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 3

5 Ninth Asian Thermophysical Properties Conference – ATPC 2010, October 19-22, Beijing Classical v. QM Heat Capacity 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

6 Ninth Asian Thermophysical Properties Conference – ATPC 2010, October 19-22, Beijingp Conservation by QED Recall from QM, QED photons of wavelength are created by supplying EM energy to a box having sides separated by / 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 5 For a spherical NP having diameter D, QED photons have = 2D f = QED photon frequency E = Planck energy c = light speed n r = refractive index h = Planck’s constant

7 Ninth Asian Thermophysical Properties Conference – ATPC 2010, October 19-22, Beijing TIR Confinement NPs D << / 2  D f = c’ / = c’ / 2D c’ = c / n r 6 / 2

8 Ninth Asian Thermophysical Properties Conference – ATPC 2010, October 19-22, Beijing 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 = 2n r D < 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 7

9 Ninth Asian Thermophysical Properties Conference – ATPC 2010, October 19-22, Beijing 8  T = 0 Instead, Q QED is prompt non-thermal emission. In < 5 fs, before phonons move, conservation gives Q QED 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 Replace Fourier Equation by: E = Photon Planck Energy dN/dt = Photon Rate 

10 Ninth Asian Thermophysical Properties Conference – ATPC 2010, October 19-22, Beijing QED Applications Classical Physics unable to explain nanoscale observations Molecular Dynamics Heat transfer simulations invalid for discrete nanostructures Nanofluids Excluding QED emission leads to unphysical results Cancer Research QED emission at UV levels damages DNA  Cancer Big Bang Theory QED Redshift in cosmic dust means Universe is not expanding Thin Films QED emission negates reduced conductivity by phonons 9

11 Ninth Asian Thermophysical Properties Conference – ATPC 2010, October 19-22, Beijing 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 move Classical 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, valid Metropolis & Teller, 1950 10 For discrete nanostructures, MD of heat transfer is not valid, but DFT and dynamics under isothermal conditions are valid.

12 Ninth Asian Thermophysical Properties Conference – ATPC 2010, October 19-22, Beijing 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. 11

13 Ninth Asian Thermophysical Properties Conference – ATPC 2010, October 19-22, Beijing 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 Classical physics FIR  FIR No Enhancement

14 Ninth Asian Thermophysical Properties Conference – ATPC 2010, October 19-22, Beijing *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? 13

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

16 Ninth Asian Thermophysical Properties Conference – ATPC 2010, October 19-22, Beijing Effects on Cosmology The redshift: Z = ( o - )/  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. 15

17 Ninth Asian Thermophysical Properties Conference – ATPC 2010, October 19-22, Beijing 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 16 * 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*

18 Ninth Asian Thermophysical Properties Conference – ATPC 2010, October 19-22, Beijing Reduced Conductivity 17 Q Cond TT Current Approach Q Cond = Q Joule K eff  T = Q cond (d f + d S )/A  T large, K eff small Reduced Conductivity Q Joule Film Substrate dfdf dSdS KfKf KSKS QED Heat Transfer Q Cond = Q Joule - Q QED ~ 0 K eff  T = (Q Joule - Q QED ) (d f + d S ) / A  T small, K eff ~ Bulk No Reduced Conductivity Q QED Classical physics Unphysical Reduced Conductivity

19 Ninth Asian Thermophysical Properties Conference – ATPC 2010, October 19-22, Beijing 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 18

20 Ninth Asian Thermophysical Properties Conference – ATPC 2010, October 19-22, Beijing Questions & Papers Email: nanoqed@gmail.com http://www.nanoqed.org 19


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