Kinetics for the hydrolysis of Ti(OC3H7)4: A molecular dynamics simulation study

Synthesis of Metal Oxide Nanoparticles in Flame Sprays: Review on Process Technology, Modeling, and Diagnostics

“…For accurate tracking of separated atoms or larger atomic clusters, MD uses relatively short time steps (e.g., ∼1 fs) that enable time-resolved investigations typically up to the range of nanosecond (e.g., ∼100 ns). For example, MD has been employed for the analysis of droplet evaporation, precursor reaction, particle nucleation, , particle–particle interactions (e.g., adhesion, coalescence/sintering, and crystal-phase transformation), and gas–surface interactions, among others. Recent reviews ,,,− also emphasize the importance of MD simulation with regard to the gas-phase particle synthesis and extensively discuss the large variety of nanomaterials that has already been investigated by MD (e.g., soot, TiO 2 , ,,,,− SiO 2 , Si, − Cu, Ag, Au, Ag–Au, Au–Mg, Si–Ag, etc.).…”

“…For example, MD has been employed for the analysis of droplet evaporation, precursor reaction, particle nucleation, , particle–particle interactions (e.g., adhesion, coalescence/sintering, and crystal-phase transformation), and gas–surface interactions, among others. Recent reviews ,,,− also emphasize the importance of MD simulation with regard to the gas-phase particle synthesis and extensively discuss the large variety of nanomaterials that has already been investigated by MD (e.g., soot, TiO 2 , ,,,,− SiO 2 , Si, − Cu, Ag, Au, Ag–Au, Au–Mg, Si–Ag, etc.). To highlight the potential of MD in the context of multiscale modeling of flame aerosol synthesis, this section will solely address some paradigms, such as the derivation of sinter kinetics, crystal-phase transformations, and precursor kinetics, that have been conducted exclusively for single metal oxides (i.e., TiO 2 ).…”

“…Coupling reactive force field potentials (ReaxFF) , with classical MD is a promising approach because it allows for implementation of chemical reactions between various species, hence providing a more accurate modeling of the formation of initial particle clusters. Wei et al suggested ReaxFF–MD with the canonical NVT ensemble to describe the evolution of main Ti-containing intermediates during TTIP hydrolysis at elevated temperatures (1500–3000 K). On the basis of ReaxFF–MD, they found a second-order rate constant for the hydrolysis of TTIP of k = 1.23 × 10 14 exp­(−11323/ T ) in mol –1 cm 3 s –1 that reasonably agrees with the experimental value by Shmakov et al [ k = 2 × 10 12 exp­(−6160/ T ) in mol –1 cm 3 s –1 ].…”

Accounting for hydrolysis in the modeling of titanium dioxide nanoparticle synthesis in laminar TiCl4-seeded flames

“…As a first step toward a better description of combustion processes in TiO 2 synthesis, the first objective of this work is to account for hydrolysis in Section 2.1 by adding to a detailed oxidation scheme a fivestep reaction mechanism for TiCl 4 hydrolysis, in analogy with the recent works performed for titanium tetraisopropoxide (TTIP) flames [27,28]. Then, the second objective is to examine the role of hydrolysis on laminar flame synthesis of TiO 2 nanoparticles by evaluating the possible inaccuracies of a kinetic mechanism when only TiCl 4 oxidation is considered.…”

Atomic Insights into Mechanisms of Carbon Coating on Titania Nanoparticle During Flame Synthesis

“…However, the high computational cost of AIMD restricts routine simulations to ∼10 2 atoms and ∼10 −2 − 10 −1 nanoseconds [31,32], which is insufficient to capture the carbon coating process in terms of system sizes and time scales. Therefore, ReaxFF MD as a powerful computational tool has already been extensively applied to simulate a variety of physicochemical processes in flames [33][34][35][36][37]. For instance, we have previously elucidated the inception mechanism of TTIP precursor converting to Ti-containing clusters in the context of flame-synthesized nanomaterials using ReaxFF MD simulations [37].…”