Interaction of electromagnetic fields withmolecular rotors. Coherent dynamics and transfer

of energy at quantum systems.

11

Motivation and target of nanotechnology

To construct molecular engines below 100 nm with specific functionality.

How;

1)By decoding physical laws in the mesoscopic region (<100nm). 2)Controlling the parameters. 3)Implementing the technology.

I) Top down → lithography (40 nm)II) Bottom-up → Imitating and copying nature (1-10 nm)

Decoding the physical laws

MesoscopicregionQuantum mechanics Thermodynamics,hydrodynamics

1)Polar–entropic competition.2) Flow of energy at interphases

3) Long range fields4) Asymmetries

5) Quantum effects-coherence

polar bonding (hydrogen)Entropy (hydrophobicity)

Self assemblyMolecular engines-motionMolecular rotors-transferingand storing energy

1nm 10nm 100 nm

OutlineOutline

A Working experimental exampleA Working experimental exampleControl over crystallization and shapes at the nanoscaleControl over crystallization and shapes at the nanoscale

Questions to be addressedQuestions to be addressed(1) Transfer of energy (1) Transfer of energy (2) Storage of energy(2) Storage of energyThrough coherent interactionsThrough coherent interactions→→ EMFEMF--mattermatterThe symmetricThe symmetric--antisymmetric coherent state at the antisymmetric coherent state at the nanoscalenanoscaleIndustrial applicationsIndustrial applications

Facing experimental challenges Would be possible to control nano-crystallization

symmetry?

Calcite Orthorombic

Aragonite Triclinic

Vaterite Amorphous

Crystal symmetry of CaCO3

Free energy of formation

Ground electronic states of calcite and aragonite separated by 25 eV- (ab-initio ).

CALCITE

25 eV

ARAGONITE

Ca + C+ -

Ca + C+ -

),(),( PTAFPTF =

AF ( 2 5 ) cF F eV= + ∆

A. C. Cefalas, et al, Cryst. Eng. 5, 243 (2002)

Required energy

12 310 J/mF∆ =549.5 , 2 10

h nm T X Kper moleculeν = =

A simple experiment

TEM images of structures

A B

(A) TEM image. (B) diffraction pattern (SAED). →Calcite

A

B

(A) TEM image. (B) diffraction pattern (SAED). Aragonite

TEM - Vaterite

• Decomposition of vaterite phase under the electron beam• Formation of 5 – 10 nm sized crystals of CaO.

• SAED pattern of decomposed vaterite crystals where spots (arcs) indicate texture of CaO in [110] zone axis. Circles correspond to randomly oriented nanocrystals of CaO.•The comparison of experimental and simulated SAED patterns for cubic (Fm3-m) CaO.

X – Ray Analysis

0

10

20

30

40

50

60

70

80

90

100

20 25 30 35 40 45 50 55 60 65 70

2 θ (°)

Inte

nsity

(%)

Vaterite

Calcite

Aragonite

non-treatedmag.-treated

Quantitative X-ray analyses of crystals

Experiments

Magnetic field

Calcite (%)

Aragon. (%)

Vaterite (%)

1-7 0 90.2 9.6 0.2

1-7 400 mT 80.0 10.4 9.6

1-7 1250 mT 12.5 87.0 0.5

Reproducibility of results at 1.2T

XRD analyses

0

20

40

60

80

100

120

1 2 3 4 5 6 7

No. of experiments

wt %

Calcite

Aragonite + Vaterite

Questions to be answeredFrom where the system takes its energy to change its thermodynamic state to form aragonite in solutions.How the energy is stored and then is amplified?Classical models have failed till now!Quantum theory

Quantum picture

ˆ ˆ ˆFk

H h κ κ κω α α+= ∑

ˆ ˆ

ˆ ˆ ˆˆˆ ˆ ˆˆ

A i i iRi

x y

x y

H

J J iJ

J J iJ

σ σ ω

σ

σ

+

+ +

+

=

= = +

= = −

∑h

2^0

^

0

e 1 2 ˆ ˆ ˆ ˆ( ) ( ) [( ) ( exp( ( )int 2m 2ˆ ˆ ˆ ˆ ˆ ˆˆ ˆ ˆ ˆ ˆ ˆ( ) ( exp( ( )) 2( ) ( exp( ( )+2( ) ( exp( ( )) R R

i cH i j a i tk

i ij a i t i j a i t i ij a i tω ω

µµ σ ωκκλτωκλ

σ ω σ ω σ ωκ κ κκλ κλ κλ

+

+ + +

= − − +∑

+ + − − +

h

Maser model-amplification

ijωRBG Bβ

µΩ =

h

(0)exp( )a i tω−

122 2 2n ( ) ( ) (0) (0) (( (tanh ) )

4 2 ,ij B

Ba t t a tg kT

nσ

γα α ωµ

ω ω γ

+ +⟨ ⟩ = ⟨ ≈ ⟨ +

= = Ω ⇒ → ∞

h

Amplification in water molecular rotors

1 5

17 1

5 6 0.4

2.2 10ij

ij

B T

x s

ω

ω− −

−

→ → ⇒ =

=

In agreement with experimental results

A.C. Cefalas etal, Appl.Surf. Scienc.25,6715 (2008)

Still questions remain –

High free energy difference → energy storage

CALCITE

25 eV

ARAGONITE

Ca + C+ -

Ca + C+ -

),(),( PTAFPTF =

AF ( 2 5 ) cF F eV= + ∆

12 310 480F Jm B T−∆ = ⇒ =

A. C. Cefalas, et al, Cryst. Eng. 5, 243 (2002)

Two atom single mode interaction

1a 2a

1b 2b

int 1 2[( ) exp( - ) ] .ijH g t a adjλ λ λσ σ ω ω += + +

1 2

( ) ( ,0) (0)

(0) 2

t U t

b b

ψ ψ

ψ λ

=

=

int0

( ,0) 1 ( ) ..tiU t H s ds= − +∫h

Mode trapping in coherent antisymmetric states

+ −X

X0 1 2 1 1 2 2 1 1 2 2 1 2 1 2( ) 2 2 [ ] [ ] 1 2 0t C b b C a b a b a b a b C a aψ λ λ λ= + + + −

A. C. Cefalas, et al Journ. Comput Theor.NanotechnologyV7, 1800 (2010)

The coherenceParticles in a small box → Quantum physicsParticles in a large box → Classical physics

2 22 2 2

2( ) ( )2

E J n m lmL

π= + + ⇒

h

particles in a large box→quantum

ApplicationsApplications

Implications

→Calcite: Strong Binding with surfaces→Aragonite: Weak binding with surfaces

Scale formation (water pipes)

Water pipes calcium carbonate scale

prevention: chemicals

environmental pollution

Chemical treatment has a long-term environmental accumulative effect;

It is detrimental for sensitive ecosystems, the most serious been algae eutrification.

Economical impact

• In UK alone, the formation of scales in industrial processing plants where water is heated or cooled is estimated to cost £1 billion per year.

•Industrial costs due to scaling, represent an annual turn over globally more than 100 billion $/year.

2828

Termoelektrarna-Toplarna Ljubljana

Clean energy for theenvironment

MWTD

conclusionsA quantum coherence can interpret energy flow and storage at the nanoscale level.By coupling EMF to molecular rotors, a collective antisymmetric quantum state (Coherence) can store the energy of the EMF field.Nanocrystalization probes the phenomenon at the nanoscale.The quantum coherent antisymmetric state interprets the ¨memory effects¨ observed in liquids by many investigators.Control of nanocrystalization can have major industrial applications.

National Hellenic Research Foundation, Athens GreeceAlkiviadis Constantinos Cefalas Evangelia Sarantopoulou Zoe Kollia

Josef Stefan Institute, Department of Nanostructured materials, Ljubljana SloveniaSpomenka Kobe Goran Drazic