scholarly journals Heterogeneous Nucleation in Solutions on Rough Solid Surfaces: Generalized Gibbs Approach

Entropy ◽  
2019 ◽  
Vol 21 (8) ◽  
pp. 782 ◽  
Author(s):  
Alexander S. Abyzov ◽  
Leonid N. Davydov ◽  
Jürn W. P. Schmelzer
Keyword(s):  
Solid Surface ◽  
Heterogeneous Nucleation ◽  
Cluster Formation ◽  
Cone Angle ◽  
The State ◽  
Solid Surfaces ◽  
Supersaturated Solution ◽  
Critical Cluster ◽  
Surface Imperfections ◽  
Activity Factor

Heterogeneous nucleation of new phase clusters on a rough solid surface is studied. The ambient phase is considered to be a regular supersaturated solution. In contrast to existing studies of the same problem, the possible difference between the state parameters of the critical cluster and the corresponding parameters of a newly formed macroscopic phase is accounted for. This account is performed within the framework of the generalized Gibbs approach. Surface imperfections are chosen in the form of cones. The model allows us to simplify the analysis but also to obtain the basic results concerning the defect influence on the nucleation process. It is shown that the catalytic activity factor for nucleation of the cone depends both on the cone angle and the supersaturation in the solution determining the state parameters of the critical clusters. Both factors considerably affect the work of critical cluster formation. In addition, they may even lead to a shift of the spinodal curve. In particular, in the case of good wettability (macroscopic contact angle is less than 90 ∘ ) the presence of surface imperfections results in a significant shifting of the spinodal towards lower values of the supersaturation as compared with heterogeneous nucleation on a planar solid surface. With the decrease of the cone pore angle, the heterogeneous spinodal is located nearer to the binodal, and the metastability range is narrowed, increasing the range of states where the solution is thermodynamically unstable.

Microscopic Activation Phenomena in Heterogeneous Nucleation

2003 ◽  
Author(s):  
J. F. Lu ◽  
X. F. Peng
Keyword(s):  
Liquid Layer ◽  
Solid Surface ◽  
Heterogeneous Nucleation ◽  
Bubble Formation ◽  
Ultrathin Film ◽  
Wall Surface ◽  
Bulk Region ◽  
Heating Wall ◽  
Energy Peak ◽  
Energy Property

The energy property in liquid near the wall was theoretically investigated to understand the effects of wall surface on inception process of nucleation or embryo bubble formation in boiling systems. Analyses indicate that the liquid near heating wall has higher pressure than in bulk region owing to existence of strong attractive forces, and this pressure could maintain a stable liquid microlayer and cause a steady energy peak near the wall. So a vapor embryo is likely to occur beyond the stable microlayer instead of exactly at the solid surface. The stable liquid layer may also be the inception structure of the ultrathin film before nucleation occurs. Fluctuations enhance the phenomenon of energy peak until the nucleation occurs, while energy peak promotes nucleation. Employing the concept of energy peak, the inception phenomena of the microlayer and the formation of embryo bubbles near solid surface were described.

On the Hysteresis of Adsorption on Solid Surfaces

1952 ◽  
Vol 5 (2) ◽  
pp. 288
Author(s):  
RG Wylie
Keyword(s):  
Phase Transitions ◽  
Solid Surface ◽  
Three Dimensional ◽  
Solid Surfaces ◽  
Two Dimensional ◽  
Capillary Effects ◽  
First Order ◽  
Adsorption Of Gases ◽  
First Order Phase ◽  
Hysteresis Phenomena

Hysteresis phenomena associated with the adsorption of gases on solid surfaces are usually explained in terms of three-dimensional capillary effects or with more or less unspecific reference to phase transitions. It is shown that hysteresis effects are to be expected when two dimensional phase transitions occur on solids. In the connection, the thermodynamic equation governing the equilibrium of small, incompressible two-dimensional phases is derived. Such phases can form on an imperfect solid surface in an irreversible manner and, as calculation shows, can contribute significantly to the hysteresis of adsorption. In some cases the phase change may be responsible for the whole effect. The diffuseness of first-order phase transitions may be due to the same mechanism.

Particle Adhesion to Solid Surfaces

1990 ◽  
Vol 33 (2) ◽  
pp. 33-37
Author(s):  
Lewis Hecht
Keyword(s):  
Particle Size ◽  
Physical Properties ◽  
Solid Surface ◽  
Review Paper ◽  
Solid Surfaces ◽  
Particle Adhesion ◽  
Sources Of Information ◽  
Technical Literature ◽  
The Subject ◽  
Adhesive Forces

This review paper provides cleanroom technologists with an up-to-date overview on the subject of particle adhesion to solid surfaces. The discussion consists of four sections: (1) fundamental concepts of adhesion, (2) the nature of a solid surface, (3) the physical properties of particles, and (4) comments on the various theories of particle adhesion to solid surfaces. Some practical examples are also cited. A numeric example of adhesive forces as a function of particle size is presented in detail. The appendix contains references to other useful sources of information in the technical literature.

Adsorption Processes at Solid Surfaces-Studied by Electrokinetic Investigations

2006 ◽  
Vol 314 ◽  
pp. 19-24 ◽  
Author(s):  
Cornelia Bellmann ◽  
Anja Caspari
Keyword(s):  
Zeta Potential ◽  
Surface Chemistry ◽  
Solid Surface ◽  
Adsorption Process ◽  
Ph Value ◽  
Streaming Potential ◽  
Solid Surfaces ◽  
Multicomponent Mixtures ◽  
Adsorption Processes ◽  
Different Shapes

The process of electrophoretic deposition depends strongly on the electrokinetic properties and with it the surface properties of the material that will be processed. Different additives, conditioners but also the suspending liquid influence the surface of the applied material by adsorption. Electrokinetic investigations reflect changes in properties at the outermost solid surface very sensitive. Streaming potential measurements are especially suited for studying such changes of surface chemistry at solids with different shapes. Two approaches are applicable: 1. The adsorption process was done before measuring. The result of this process should be shown. In this case it will be interesting to see differences in the functionality of the solid surface. The zeta potential will be measured versus different pH value. 2. The adsorption process will be studied directly. The zeta potential will be determined versus the concentration of the adsorptive. The second approach can be used for investigation of adsorption of multicomponent mixtures. Competing adsorption processes are detectable.

scholarly journals Hybrid Atomistic-Continuum Simulation of Nanostructure Defect-Induced Bubble Growth

2017 ◽  
Vol 139 (10) ◽  
Author(s):  
Yijin Mao ◽  
Bo Zhang ◽  
Chung-Lung Chen ◽  
Yuwen Zhang
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Phase Change ◽  
Molecular Dynamic ◽  
Solid Surface ◽  
Bubble Growth ◽  
Molecular Level ◽  
Liquid Argon ◽  
Solid Surfaces ◽  
Solid Copper

Effects of nanostructured defects of a copper solid surface on bubble growth in liquid argon have been investigated through a hybrid atomistic-continuum (HAC) method. The same solid surfaces with five different nanostructures, namely, wedge defect, deep rectangular defect (R-I), shallow rectangular defect (R-II), small rectangular defect (R-III), and no defect were modeled at the molecular level. Liquid argon was placed on top of hot solid copper with a superheat of 30 K after equilibration was achieved with computational fluid dynamics–molecular dynamic (CFD–MD) coupled simulation. Phase change of argon on five nanostructures has been observed and analyzed accordingly. The results showed that the solid surface with wedge defect tends to induce a nanobubble more easily than the others, and the larger the size of the defect, the easier it is for the bubble to generate.

scholarly journals Recurrent Dynamics of Rupture Transitions of Single Giant Vesicles at Solid Surfaces

2020 ◽  
Author(s):  
V.N. Ngassam ◽  
W.-C. Su ◽  
D. L. Gettel ◽  
Y. Deng ◽  
Z. Yang ◽  
...  
Keyword(s):  
Solid Surface ◽  
Hydrophobic Surface ◽  
Lipid Vesicles ◽  
Thermal Fluctuations ◽  
Solid Surfaces ◽  
Contact Boundary ◽  
Lipid Phase ◽  
Giant Vesicles ◽  
Healing Phase ◽  
Pore Closure

ABSTRACTSingle giant vesicles (GVs) rupture spontaneously from their salt-laden suspension onto solid surfaces. At hydrophilic surfaces, they rupture via a recurrent burst-heal dynamics: during burst, single pores nucleate at the contact boundary of the adhering vesicles facilitating asymmetric spreading and producing a “heart” shaped membrane patch. During the healing phase, the competing pore closure produces a daughter vesicle. At hydrophobic surfaces, by contrast, the GVs rupture via a distinctly different, yet recurrent, bouncing ball rhythm: Rendered tense by the substrate interactions, GVs porate and spread monomolecular layer on the hydrophobic surface in a symmetric manner. Here too, the competition from pore closure produces a daughter vesicle, which re-engages with the substrate. In both cases, the pattern of burst-reseal events repeats multiple times splashing and spreading the vesicular fragments as bilayer patches at the solid surface in a pulsatory manner. These remarkable recurrent dynamics arise not because of the elastic properties of the solid surface but because the competition between membrane spreading and pore healing, prompted by the surface-energy dependent adhesion, determine the course of the topological transition.STATEMENT OF SIGNIFICANCEGiant lipid vesicles adhering to a solid surface experience strong mechanical stresses. The contacting membrane segment loses thermal fluctuations and accumulates mechanical tension, the equilibration of which can give rise to global shape changes, lipid phase separation, and traction forces. Beyond a threshold tension, vesicles porate, unravel, and spread. Here, we find that a competition from pore-healing can make rupture iterative, rather than a single all-or-nothing event. During burst, single pores expand, spreading a lipid bilayer on the hydrophilic surface and a monolayer on the hydrophobic one. During heal, pore-healing can produce daughter vesicles. This burst-reseal event reiterates “splashing” portions of single vesicles at the solid surface and “bouncing” the remainder as a secondary vesicle in multiple steps.

Sign in / Sign up

Export Citation Format

Share Document