scholarly journals Термодинамическая модель зародышеобразования кристаллов n-терфенила с анизотропией поверхностной энергии на межфазной границе жидкость-воздух

2019 ◽  
Vol 61 (12) ◽  
pp. 2432
Author(s):  
В.А. Постников ◽  
А.А. Кулишов ◽  
А.А. Островская ◽  
А.С. Степко ◽  
П.В. Лебедев-Степанов
Keyword(s):  
Free Energy ◽  
Crystal Growth ◽  
Surface Energy ◽  
Force Field ◽  
Structural Data ◽  
Field Method ◽  
Experimental Information ◽  
Growth From Solutions ◽  
Atomic Force ◽  
Air Interface

An analysis of the change in the Gibbs free energy ∆G upon the formation of a flat nucleus of a p-terphenyl crystal at the liquid – air interface is presented, taking into account the anisotropy of the surface energy of the faces. The surface energy values of the p-terphenyl crystal faces were calculated by the atomic force field method OPLS, based on structural data. Experimental information on crystal growth from solutions and their surface properties was used to analyze the model.

scholarly journals On the role of surface energy in the flattening of a crystal face

2005 ◽  
Vol 3 (1) ◽  
pp. 188-197
Author(s):  
Christo Nanev
Keyword(s):  
Free Energy ◽  
Crystal Growth ◽  
Surface Energy ◽  
Atomic Scale ◽  
Crystal Face ◽  
Screw Dislocations ◽  
The Face ◽  
Kinetic Effects ◽  
Face Morphology

AbstractThe question addressed in this paper is the flattening of the valley separating two growth hillocks emanating from screw dislocations during crystal growth. It is argued that both thermodynamic and kinetic effects contribute to this result, at least on a quasi-atomic scale. If performed under low enough supersaturation the growth leads to the formation of the face morphology corresponding to the minimum of the surface free energy. Accelerated step annihilation in the valley floor is a universal factor, which favors face flatting under any supersaturation.

Investigation on the surface free energy of a single flax fiber through adhesion measurement by atomic force microscopy

2018 ◽  
Vol 52 (23) ◽  
pp. 3233-3239
Author(s):  
Shabbir Ahmed ◽  
Xinnan Wang ◽  
Kai Li ◽  
Chad A Ulven
Keyword(s):  
Free Energy ◽  
Composite Materials ◽  
Surface Energy ◽  
Surface Free Energy ◽  
Adhesion Force ◽  
Fiber Surface ◽  
Flax Fiber ◽  
Interfacial Bond Strength ◽  
Dispersive Component ◽  
Atomic Force

Surface free energy of a fiber is an important parameter for predicting the interfacial bond strength of fiber-matrix adhesion of composite materials. For mechanical characterization of bio-composite materials, the measurement of the surface energy of individual single microfibers is complicated due to their surface roughness, formation of chemical bonds, wicking characteristics, etc. This paper demonstrates a novel method for determining the dispersive component of surface free energy [Formula: see text] of single flax fiber by directly measuring the adhesion force between the probe tip of an atomic force microscope and the fiber surface. Johnson–Kendal–Roberts theory was employed to correlate the adhesion force with the surface energy and tip radius. Finally, the value of [Formula: see text] was determined, and its significance with respect to other methods was analyzed.

Examination of the lubricant storing and releasing ability of thermally sprayed surfaces

2011 ◽  
Vol 2 (2) ◽  
pp. 101-105
Author(s):  
L. Fazekas ◽  
Z. S. Tiba ◽  
G. Kalácska
Keyword(s):  
Free Energy ◽  
Surface Energy ◽  
Surface Free Energy ◽  
Essential Role ◽  
Index Number ◽  
Adhesion Ability ◽  
Thermally Sprayed ◽  
Proper Operation

Abstract The lubricant storing and releasing ability of the thermally sprayed surfaces plays an essential role in the proper operation of the components. In the case of porous sprayed surfaces the lubricant storing and releasing ability depends mainly on porosity and the surface energy (adhesion susceptibility). The adhesion ability can also be expressed indirectly with an index number that is by determining the surface free energy.

scholarly journals Dopants Modulate Crystal Growth in Molten Salts Enabled by Surface Energy Tuning

2021 ◽  
Author(s):  
Xiaoqiao Li ◽  
Linming Zhou ◽  
Han Wang ◽  
Dechao Meng ◽  
Guannan Qian ◽  
...  
Keyword(s):  
Crystal Growth ◽  
High Temperature ◽  
Surface Energy ◽  
Molten Salts ◽  
Rational Approach ◽  
Temperature Synthesis ◽  
Crystalline Materials ◽  
Size Dependent ◽  
High Temperature Synthesis ◽  
Energy Tuning

Crystalline materials are routinely produced via high-temperature synthesis and show size-dependent properties; however, a rational approach to regulating their crystal growth has not been established. Here we show that dopants...

scholarly journals Crystal growth of the core and rotated epitaxial shell of a heterometallic metal-organic framework revealed with atomic force microscopy

2021 ◽  
Author(s):  
Fajar Inggit Pambudi ◽  
Michael William Anderson ◽  
Martin Attfield
Keyword(s):  
Atomic Force Microscopy ◽  
Crystal Growth ◽  
Metal Organic Framework ◽  
Metal Organic Frameworks ◽  
Force Microscopy ◽  
The Core ◽  
Atomic Force ◽  
Metal Organic ◽  
Surface Crystal ◽  
Organic Framework

Atomic force microscopy has been used to determine the surface crystal growth of two isostructural metal-organic frameworks, [Zn2(ndc)2(dabco)] (ndc = 1,4-naphthalene dicarboxylate, dabco = 4-diazabicyclo[2.2.2]octane) (1) and [Cu2(ndc)2(dabco)] (2) from...

scholarly journals Antiviral Resistance against Viral Mutation: Praxis and Policy for SARS-CoV-2

2021 ◽  
Vol 9 (1) ◽  
pp. 81-89
Author(s):  
Robert Penner
Keyword(s):  
Free Energy ◽  
Vaccine Development ◽  
A Priori ◽  
Structural Data ◽  
Medical Sciences ◽  
Spike Glycoprotein ◽  
Mutagenic Potential ◽  
Viral Mutation ◽  
Novel Method ◽  
Antiviral Targets

Abstract Tools developed by Moderna, BioNTech/Pfizer, and Oxford/Astrazeneca, among others, provide universal solutions to previously problematic aspects of drug or vaccine delivery, uptake and toxicity, portending new tools across the medical sciences. A novel method is presented based on estimating protein backbone free energy via geometry to predict effective antiviral targets, antigens and vaccine cargos that are resistant to viral mutation. This method is reviewed and reformulated in light of the recent proliferation of structural data on the SARS-CoV-2 spike glycoprotein and its mutations in multiple lineages. Key findings include: collections of mutagenic residues reoccur across strains, suggesting cooperative convergent evolution; most mutagenic residues do not participate in backbone hydrogen bonds; metastability of the glyco-protein limits the change of free energy through mutation thereby constraining selective pressure; and there are mRNA or virus-vector cargos targeting low free energy peptides proximal to conserved high free energy peptides providing specific recipes for vaccines with greater specificity than the full-spike approach. These results serve to limit peptides in the spike glycoprotein with high mutagenic potential and thereby provide a priori constraints on viral and attendant vaccine evolution. Scientific and regulatory challenges to nucleic acid therapeutic and vaccine development and deployment are finally discussed.

Mass transfer processes in KDP crystal growth from solutions

1987 ◽  
Vol 84 (3) ◽  
pp. 509-514 ◽  
Author(s):  
V.I. Bredikhin ◽  
V.P. Ershov ◽  
V.V. Korolikhin ◽  
V.N. Lizyakina ◽  
S.Yu Potapenko ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Crystal Growth ◽  
Growth From Solutions ◽  
Kdp Crystal ◽  
Transfer Processes ◽  
Mass Transfer Processes

Capillary Force Induced Elastic Deformation on ZnS Nanobeams

2011 ◽  
Author(s):  
Xinnan Wang ◽  
Xiaodong Li
Keyword(s):  
Electron Microscope ◽  
Surface Energy ◽  
Total Energy ◽  
Elastic Deformation ◽  
Capillary Force ◽  
Elastic Beam ◽  
Small Strain ◽  
Beam Deflection ◽  
Atomic Force ◽  
Transmission Electron

In this study, synthesized Wurtzite-structured ZnS nanobelts was investigated using high resolution transmission electron microscope, atomic force microscope, and scanning electron microscope for structural and morphology analyses. Results show that ZnS nanobelts are tens of microns in length, mostly ∼40×50 nm2 in width and thickness. The nanobelts grow along direction [001] and are dislocation free. The distance spacing for (001) plane is 3.19A˚. The capillary force was found strong enough to deform the ZnS nanobeam down to the substrate. Theoretical analysis on small strain elastic deformation was conducted. It was found that as the maximum beam deflection increases, beam elastic energy increases; in the meantime, the surface energy decreases. The net increase in elastic beam energy is less than the net decrease in the surface energy, resulting in total energy decrease. In addition, as the volume of liquid increases, for a certain maximum beam deflection, the total energy increases, this is result of the increase of the surface energy. Furthermore, for a specific nanobeam to be deflected to the underlying surface, the amount of liquid can be calculated.

Molecular Dynamics Studies of Surface Nucleation and Crystal Growth of Si on SiO2 Substrates

2005 ◽  
Vol 899 ◽  
Author(s):  
Byoung-Min Lee ◽  
Hong Koo Baik ◽  
Takahide Kuranaga ◽  
Shinji Munetoh ◽  
Teruaki Motooka
Keyword(s):  
Thin Film ◽  
Molecular Dynamics ◽  
Crystal Growth ◽  
Surface Energy ◽  
Md Simulations ◽  
Lower Surface ◽  
Surface Nucleation ◽  
Lower Surface Energy ◽  
Potential Parameters ◽  
Si Thin Film

AbstractMolecular dynamics (MD) simulations of atomistic processes of nucleation and crystal growth of silicon (Si) on SiO2 substrate have been performed using the Tersoff potential based on a combination of Langevin and Newton equations. A new set of potential parameters was used to calculate the interatomic forces of Si and oxygen (O) atoms. It was found that the (111) plane of the Si nuclei formed at the surface was predominantly parallel to the surface of MD cell. The values surface energy for (100), (110), and (111) planes of Si at 77 K were calculated to be 2.27, 1.52, and 1.20 J/m2, respectively. This result suggests that, the nucleation leads to a preferred (111) orientation in the poly-Si thin film at the surface, driven by the lower surface energy.

Sign in / Sign up

Export Citation Format

Share Document