Wetting Transition on Patterned Surfaces: Transition States and Energy Barriers

Langmuir ◽  
2014 ◽  
Vol 30 (10) ◽  
pp. 2879-2885 ◽  
Author(s):  
Weiqing Ren
Keyword(s):  
Transition States ◽  
Wetting Transition ◽  
Patterned Surfaces ◽  
Energy Barriers

scholarly journals Wetting Transitions of Liquid Gallium Film on Nanopillar-Decorated Graphene Surfaces

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2407 ◽  
Author(s):  
Junjun Wang ◽  
Tao Li ◽  
Yifan Li ◽  
Yunrui Duan ◽  
Yanyan Jiang ◽  
...  
Keyword(s):  
Metal Droplet ◽  
Adhesion Energy ◽  
Wetting Transition ◽  
Liquid Gallium ◽  
Patterned Surfaces ◽  
Final State ◽  
Wetting Transitions ◽  
Graphene Surface ◽  
Wenzel State ◽  
Wetting Model

Molecular dynamics (MD) simulation has been employed to study the wetting transitions of liquid gallium droplet on the graphene surfaces, which are decorated with three types of carbon nanopillars, and to explore the effect of the surface roughness and morphology on the wettability of liquid Ga. The simulation results showed that, at the beginning, the Ga film looks like an upside-down dish on the rough surface, different from that on the smooth graphene surface, and its size is crucial to the final state of liquid. Ga droplets exhibit a Cassie–Baxter (CB) state, a Wenzel state, a Mixed Wetting state, and a dewetting state on the patterned surfaces by changing distribution and the morphology of nanopillars. Top morphology of nanopillars has a direct impact on the wetting transition of liquid Ga. There are three transition states for the two types of carbon nanotube (CNT) substrates and two for the carbon nanocone (CNC) one. Furthermore, we have found that the substrates show high or low adhesion to the Ga droplet with the variation of their roughness and top morphology. With the roughness decreasing, the adhesion energy of the substrate decreases. With the same roughness, the CNC/graphene surface has the lowest adhesion energy, followed by CNT/graphene and capped CNT/graphene surfaces. Our findings provide not only valid support to previous works but also reveal new theories on the wetting model of the metal droplet on the rough substrates.

Droplets on Micro Structured or Patterned Surfaces With Different Roughness Parameters

2010 ◽  
Author(s):  
Y. Y. Yan ◽  
Y. Q. Zu ◽  
C. Q. Tian ◽  
N. Gao
Keyword(s):  
Dynamic Contact Angle ◽  
Dynamic Contact ◽  
Wetting Transition ◽  
Patterned Surfaces ◽  
Roughness Parameters ◽  
Surface Wetting ◽  
Wetting Properties ◽  
Proposed Model ◽  
Simulation Based ◽  
Boltzmann Method

Surface wetting properties play important roles in boiling and condensation. In this paper, the wetting behaviours of a single droplet on micro structured or patterned surfaces with different roughness parameters are investigated theoretically and numerically. A theoretical model is proposed to study wetting transitions. Comparison between results obtained by theoretical analysis with those of experiment indicates that the proposed model can give a better prediction of wetting transition. In addition, a numerical simulation based on lattice Boltzmann method (LBM) is performed to study surface wetting properties and also the evolution of droplet shapes, dynamic contact angle and corresponding velocity fields. In the simulation, the droplet size is comparable with the scale of micro posts on the surface.

scholarly journals Hydrogen Molecule Interaction with CpCr(CO)3 Catalyst

2012 ◽  
Vol 7 (2) ◽  
pp. 21-26
Author(s):  
T. Spataru ◽  
F. Fernandez
Keyword(s):  
Hydrogen Molecule ◽  
Transition States ◽  
Reaction Pathways ◽  
Basis Sets ◽  
Free Energies ◽  
Energy Barriers ◽  
Molecule Interaction ◽  
Good Agreement

The hydrogen molecule interaction with CpCr(CO)3 catalyst has been studied using the B3LYP, B86 functionals and the 6-311++G**, LACV3P basis sets. The best results in the testing calculations of the analyzed reaction have been obtained by using the B86/6-311++G** DFT version giving quite good agreement between experimental and theoretical calculated enthalpies. The dispersion corrected DFT Grimme’s and Head-Gordon and coworkers’functionals have been attempted without any improvement of the results. The free energies of the initial reactants, transition states, intermediate compounds and fi nal products of the typical six-ring bond modifi cation mechanism have been calculated. The energy barriers of the reaction pathways are too high in the DFT approximation.

Pyrolysis of (thio)carbonates via computation analysis

2018 ◽  
Vol 17 (06) ◽  
pp. 1850041
Author(s):  
Jingjing Xia ◽  
Abdullah M. Asiri ◽  
Khalid A. Alamry ◽  
Ping Wu ◽  
Zhihao Huang
Keyword(s):  
Transition States ◽  
Membered Ring ◽  
The Other ◽  
Energy Barriers ◽  
Calculation Results ◽  
Computation Analysis ◽  
Step Mechanism ◽  
Pyrolysis Processes

The regioselective production of alkenes from (thio)carbonates was calculated by MP2/6-31G(d) method via pyrolysis processes. Four (thio)carbonates were calculated in this paper. They are S-sec-butyl O-methyl thiocarbonate (I), O-sec-butyl S-methyl thiocarbonate (II), sec-butyl methyl thioncarbonate (III), and sec-butyl methyl dithiocarbonate (IV). Thirteen potential thermolysis routes were revealed for the pyrolysis of each substance, including nine routes to produce regioselective alkenes and four rearrangement/decompose alternatives. Among nine alkene generation routes, six-membered ring transition states via a two-step mechanism required the lowest energy, while the other routes exhibited higher energy barriers. The calculation results demonstrated an alkene distribution hierarchy of 1-butene [Formula: see text] E-butene [Formula: see text] Z-butene for substances I and II, and an order of E-butene [Formula: see text] 1-butene [Formula: see text] Z-butene for substances III and IV.

scholarly journals Mechanistic Studies on the Intramolecular Cyclization of O-Tosyl Phytosphingosines to Jaspines

2014 ◽  
Vol 9 (8) ◽  
pp. 1934578X1400900
Author(s):  
Ramón Crehuet ◽  
David Mormeneo ◽  
Josep M. Anglada ◽  
Antonio Delgado
Keyword(s):  
Intramolecular Cyclization ◽  
Theoretical Study ◽  
Weak Interactions ◽  
Transition States ◽  
Elementary Reaction ◽  
Cyclization Reaction ◽  
Mechanistic Studies ◽  
Energy Barriers ◽  
Limiting Step

A theoretical study to elucidate the mechanistic aspects involved in the tosylation-cyclization reaction of diastereomeric phytosphingosines 1a-1d to jaspines 4a-4d is presented. The stereochemistry of the starting stereoisomers is crucial for the development of weak interactions, both in the reactants and in the transition states. The analysis of the energy barriers of each elementary reaction is consistent with the observed reluctance of tosylate 2d to undergo cyclization. In addition, the initial tosylation can be identified as the limiting step in cyclizations from 1a and 1b.

scholarly journals Frontorbitale und 1.2-Hydridwanderungen in Carbeniumionen/ Frontier Orbitals and 1,2-Hydrogen Shifts in Carbenium Ions

1981 ◽  
Vol 36 (7) ◽  
pp. 797-801 ◽  
Author(s):  
Gernot Frenking ◽  
Helmut Schwarz
Keyword(s):  
Significant Influence ◽  
Transition States ◽  
Frontier Orbitals ◽  
Energy Barriers ◽  
Carbenium Ions ◽  
Energy Value ◽  
Hydrogen Shifts

AbstractFor various carbenium ions it is shown that the energy value and the degree of localization of the LUMO have a significant influence on the energy barriers of 1,2-hydrogen shifts. The structures of the transition states are in line with the Hammond-Postulate.

THEORETICAL STUDY ON THE SELF-REACTION MECHANISM OF CH2ClO2 RADICALS

2009 ◽  
Vol 08 (01) ◽  
pp. 119-142 ◽  
Author(s):  
WEN-MEI WEI ◽  
REN-HUI ZHENG ◽  
YAN TIAN ◽  
ZHI-HONG GU ◽  
YONG-YAN XIE
Keyword(s):  
Reaction Mechanism ◽  
Potential Energy ◽  
Potential Energy Surface ◽  
Complex Potential ◽  
Energy Surface ◽  
Theoretical Study ◽  
Transition States ◽  
The Self ◽  
Stationary Points ◽  
Energy Barriers

The complex potential energy surface for the self-reaction of CH 2 ClO 2 radicals, including 12 intermediates, 33 interconversion transition states, and 21 major dissociation products, was theoretically probed at the CCSD(T)/cc-pVDZ//B3LYP/6-311G(2d,2p) level of theory. The geometries and relative energies for various stationary points were determined. Based on the calculated CCSD(T)/cc-pVDZ potential energy surface, the possible mechanism for the studied system was proposed. It is shown that the most feasible channels are those leading to 22 CH 2 ClO + 3 O 2, 2 CH 2 ClO + 2 HO 2 + CHClO , 2 CH 2 ClO + HCl + 2 CH(O)O 2, 2 CH 2 ClO + 3 O 2 + 2 Cl + CH 2 O , and p,s,o- CH 2 ClOOOCl + CH 2 O with the energy barriers of 5.6, 11.8, 12.4, 12.4, and 13.5 kcal/mol, respectively. Their mechanisms are that CH 2 ClO 2 and CH 2 ClO 2 form a tetroxide intermediate first, then the intermediate dissociates to yield the productions or through multi-steps reactions to produce the final products.

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