md_2

md_1

n24_24_spindens

qm_somo

Description:

Theoretical and numerical investigation of the dynamics, nucleation, and agglomeration processes in complex plasmas at the quantum and atomistic level.

em_agdna

em_agdna_2

Description:

Studying the electromagnetic absorption of DNA and silver nanoparticle composites using quantum mechanics and molecular dynamics computations.

np_dst

np_dodecane

np_E

np_q_s

np_all

np_T

np_o2-1

Description:

The catalytic effects of metal nanoparticles were explored, as fuel additives or substitutes, along with the influence of external electric fields. Results show that oriented external electric fields affect the transition states of oxygen adsorption on iron and oxygen diffusion inside iron lattice reactions. The oxygen migration reaction is aided by the external electric field. In addition, results suggest that iron nanoparticle additives significantly accelerate hydrocarbon consumption. In particular, the decomposition of n-dodecane is initiated at the nanoparticle’s surface by hydrogen abstraction and subsequent absorption of the hydrogen and carbon atoms.

The absorbed species diffuse along the surface of the nanoparticle to counteract the externally applied electric field. This species rearrangement leads to the formation of an anisotropic shell with varying chemical composition. This study suggests that the use of electrostatic fields with nanomaterial-based catalysis can offer new possibilities for the control of the reaction process as well as for the synthesis of tailored nanoparticles.

Relevant publications:

1. Efstratios M Kritikos, Andrea Giusti: Investigation of the effect of iron nanoparticles on n-dodecane combustion under external electrostatic fields. In: Proceedings of the Combustion Institute, vol. 39, no. 4, pp. 5667–5676, 2023.
2. Majd Sayed Ahmad, Efstratios M Kritikos, Andrea Giusti: A Reactive Molecular Dynamics Investigation of Nanoparticle Interactions in Hydrocarbon Combustion. In: Combustion Science and Technology, vol. 195, no. 14, pp. 3281–3295, 2023.
3. Leon C Thijs, Efstratios M Kritikos, Andrea Giusti, Marie-Aline Van Ende, Adri CT van Duin, XiaoCheng Mi: Effect of Fe–O ReaxFF on liquid iron oxide properties derived from reactive molecular dynamics. In: The Journal of Physical Chemistry A, vol. 127, no. 48, pp. 10339–10355, 2023.
4. Efstratios M Kritikos, Andrea Giusti: Investigation of Iron Nanoparticle Oxidation under External Electrostatic Fields Using Reactive Molecular Dynamics. In: The Journal of Physical Chemistry C, vol. 128, no. 30, pp. 12364–12385, 2024.
5. Emin Saridede, Efstratios M Kritikos, Andrea Giusti: Investigation of the effect of electrostatic fields and iron nanoparticles on hydrogen-oxygen combustion. In: Proceedings of the Combustion Institute, vol. 40, no. 1-4, pp. 105769, 2024.

TOC_graphic

qtpie_ef02-1

Hirshfield_efx1

graph_C2H5OH_reac_NEB_manyefs-1

Description:

The effects of electrostatic fields on hydrocarbon reaction kinetics are investigated using Quantum Mechanics (QM) and reactive Molecular Dynamics (MD) computations. To more accurately model the physics involved in these interactions, the MD code was developed to shield the charge transfers up to the overlap of the atomic orbitals and describe electric field-induced polarization.

Results on the minimum energy path suggest that electric fields can cause catalysis or inhibition of oxidation reactions, whereas pyrolysis reactions are not affected due to the weaker electronegativity of the hydrogen and carbon atoms. MD simulations of isolated reactions show that the reaction kinetics is also affected by applied external Lorentz forces and interatomic Coulomb forces since they can increase or decrease the energy of collision depending on the molecular conformation. In addition, electric fields can affect the kinetics of polar species and force them to align in the direction of field lines. These effects are attributed to energy transfer via intermolecular collisions and stabilization under the external Lorentz force. Under strong electric fields, the hydrocarbons, oxidizer, and most product molecules experience translational and rotational acceleration mainly due to close charge transfer along with a reduction in their vibrational energy due to stabilization.

This study serves as a basis to improve the current methods used in MD and to develop novel methodologies for the modeling of macroscale reacting flows under external electrostatic fields.

Relevant publications:

1. Kritikos, Efstratios M; Giusti, Andrea: Reactive molecular dynamics investigation of toluene oxidation under electrostatic fields: effect of the modeling of local charge distribution. In: The Journal of Physical Chemistry A, vol. 124, no. 51, pp. 10705–10716, 2020.
2. Kritikos, Efstratios M; Lele, Aditya; van Duin, Adri CT; Giusti, Andrea: A reactive molecular dynamics study of the effects of an electric field on n-dodecane combustion. In: Combustion and Flame, vol. 244, pp. 112238, 2022.
3. Kritikos, Efstratios M; Lele, Aditya; van Duin, Adri CT; Giusti, Andrea: Atomistic insight into the effects of electrostatic fields on hydrocarbon reaction kinetics. In: The Journal of Chemical Physics, vol. 158, no. 5, 2023.

magnetic_field_and_potential

case_3_Fz_electrons_all

magnetization_force_oxygen

qden_positive-1

Description:

A novel computational fluid dynamics methodology has been formulated to describe electrostatic, magnetostatic, and electromagnetic wave interactions with neutral and ionic species in compressible reacting flows. The numerical formulation takes into account contributions from classical electrodynamics and quantum mechanics. The software, called EMI-SENGA, is used to investigate the macroscale effects of electromagnetic fields on ionized reacting flows.