Surface forces and colloidal behaviour

Surfactants ◽  
2019 ◽  
pp. 269-313
Author(s):  
Bob Aveyard
Keyword(s):  
Dlvo Theory ◽  
Surface Forces ◽  
Polymer Chains ◽  
Dispersion Forces ◽  
Liquid Interfaces ◽  
Surface Separation ◽  
Adsorbed Polymer ◽  
The Stability ◽  
Solid Liquid ◽  
Hydration Forces

The landmark DLVO theory of colloid stability sought to explain the stability of lyophobic colloids in terms of the interplay between attractive dispersion forces, and repulsive electrical (Coulombic) forces between particle surfaces. The net interaction energy between two particles (resulting from these so-called surface forces) as a function of surface separation can exhibit a maximum, a deep (primary) minimum and/or a shallow (secondary) minimum, giving stable, unstable or weakly flocculated dispersions. Other surface forces include steric forces arising from grafted or adsorbed polymer chains on the surfaces. Unadsorbed polymer can result in attractive depletion forces between particles, and polymer molecules that bridge particles can cause flocculation. Other forces mentioned are oscillatory structural forces, attractive hydrophobic forces and repulsive hydration forces between surfaces in water. Direct measurement of surface forces between both solid/liquid interfaces and between liquid/liquid interfaces is discussed at the end of the chapter.

Theory of the stabilization of colloids by adsorbed polymer

1974 ◽  
Vol 337 (1611) ◽  
pp. 509-516 ◽  
Keyword(s):  
Plane Surface ◽  
Analytic Form ◽  
Polymer Chains ◽  
Contour Length ◽  
Link Length ◽  
Excluded Volume Effects ◽  
Adsorbed Polymer ◽  
Random Flight ◽  
The Stability ◽  
Simple Analytic Form

The configurational free energy of random flight polymer chains adsorbed by one end onto a plane surface as a function of the distance from a parallel plane surface is expressed to a good approximation in simple analytic form. The result is used to discuss the stabilization of a colloid suspension by adsorbed polymer. According to this theory two types of aggregation of colloid particles may occur. If LI < AS/2π 3 NkT , where l is the link length and L the contour length of a polymer chain, A is the Hamaker constant, N /S is the number of adsorbed polymer chains per unit area and kT is the Boltzman constant multiplied by temperature, the particles adhere closely, but if AS/2π 3 kT < IL < AS/nkT lg 2N a looser association is formed. It is expected that the presence of excluded volume effects would greatly increase the stability against the looser association.

scholarly journals Surface forces measurement for materials science

2019 ◽  
Vol 91 (4) ◽  
pp. 707-716 ◽  
Author(s):  
Kazue Kurihara
Keyword(s):  
Soft Matter ◽  
Materials Science ◽  
Resonance Method ◽  
Surface Force ◽  
Surface Forces ◽  
Liquid Interfaces ◽  
Science Field ◽  
Confined Liquids ◽  
History Of ◽  
Solid Liquid

Abstract This article reviews the surface forces measurement as a novel tool for materials science. The history of the measurement is briefly described in the Introduction. The general overview covers specific features of the surface forces measurement as a tool for studying the solid-liquid interface, confined liquids and soft matter. This measurement is a powerful way for understanding interaction forces, and for characterizing (sometime unknown) phenomena at solid-liquid interfaces and soft complex matters. The surface force apparatus (SFA) we developed for opaque samples can study not only opaque samples in various media, but also electrochemical processes under various electrochemical conditions. Electrochemical SFA enables us to determine the distribution of counterions between strongly bound ones in the Stern layer and those diffused in the Gouy-Chapman layer. The shear measurement is another active area of the SFA research. We introduced a resonance method, i.e. the resonance shear measurement (RSM), that is used to study the effective viscosity and lubricity of confined liquids in their thickness from μm to contact. Advantages of these measurements are discussed by describing examples of each measurement. These studies demonstrate how the forces measurement is used for characterizing solid-liquid interfaces, confined liquids and reveal unknown phenomena. The readers will be introduced to the broad applications of the forces measurement in the materials science field.

Bovine submaxillary mucin (BSM) adsorption at solid/ liquid interfaces and surface forces

1984 ◽  
Vol 10 ◽  
pp. 43-52 ◽  
Author(s):  
Jacques Emile Proust ◽  
Adam Baszkin ◽  
Eric Perez ◽  
Marie Martine Boissonnade
Keyword(s):  
Surface Forces ◽  
Liquid Interfaces ◽  
Bovine Submaxillary Mucin ◽  
Solid Liquid

Effects of Elastic Stress on the Stability of a Solid-Liquid Interface

1990 ◽  
Vol 43 (5S) ◽  
pp. S54-S55
Author(s):  
B. J. Spencer ◽  
S. H. Davis ◽  
G. B. McFadden ◽  
P. W. Voorhees
Keyword(s):  
Elastic Stress ◽  
Melting Process ◽  
Liquid Interface ◽  
Liquid Interfaces ◽  
Morphological Stability ◽  
Directionally Solidified ◽  
Elastic Stresses ◽  
The Stability ◽  
Solid Liquid Interface ◽  
Solid Liquid

The effects of elastic stress on the stability of solid-liquid interfaces under a variety of conditions are discussed. In the cases discussed, the nonuniform composition field in the solid, which accompanies either the melting process or the development of a perturbation on the solid-liquid interface during solidification, generates nonhydrostatic stresses in the solid. Such compositionally generated elastic stresses have been shown experimentally to induce a solidifying solid-liquid interface to become unstable. We are in the process of analyzing the effects of these stresses on the conditions for morphological stability of a directionally solidified binary alloy.

Sign in / Sign up

Export Citation Format

Share Document