Adhesion of Solids

I am very glad to write a few introductory words to this important book by Professor Deryagin and his colleagues Drs. Krotova and Smilga. Ever since he first burst on the scientific scene in the 1930s, Professor Deryagin has continued to produce papers of seminal value in the general field of surface science, particularly those aspects of interest to physical chemists and colloid scientists. Many of the ideas introduced by Professor Deryagin and his long list of collaborators have entered into the broad stream of sci­ entific thought. Of course not all these ideas have been accepted and some have generated vigorous controversy. I am not sure that Professor Deryagin would have it otherwise for I sometimes have the feeling that he enjoys the cut and thrust of the scientific dia­ lectic. But none of these differences of opinion can detract from the quality of his work over many decades and from the impact of his contributions to surface science. In particular the ideas which he introduced with Landau (developed later but quite independently by Verwey and Overbeek in Holland) have laid the foundation for the whole of our present approach to colloid stability (the DLVO theory). A large part of Professor Deryagin's work has been con­ cerned with solid -liquid and liquid -liquid interactions. In the present book he and Drs.

I. Introduction.- Literature cited.- II. Theoretical Concepts of the Role of Electrical Phenomena in the Breakdown of Adhesion and the Fracture of Solids.- §1. General remarks on the problem of adhesion.- §2. Principal conclusions from theory of electrostatic component of adhesion.- §3. Role of electrostatic forces in adhesion phenomena, and the relation between electrostatic interaction and the chemical nature of the contacting bodies.- §4. Analysis of macroscopic approximation in calculating the force of adhesion.- §5. Critical review of earlier studies.- Literature cited.- III. Experimental Investigation of Electroadhesion and Electrocohesion Phenomena in the Breakdown of Adhesive Contact of Solids and the Fracture of Crystals.- §1. Introduction.- §2. Neutralization of electrical double layer charges by gas discharge in the process of detachment.- Gas discharge phenomena in the process of detachment.- Emission of radio waves in breakdown of adhesion.- Residual surface charges after detachment.- §3. Relationships for polymer film detachment in liquid media.- §4. Effect of ionizing radiation on adhesion.- §5. Obtaining adhesive contact by the action of an external electric field.- §6. Gas discharge phenomena during fracture of crystals.- §7. Exoelectron emission.- §8. Emission of fast electrons in adhesive contact breaking or crystal cleavage.- Topography of emitting surface and influence influence of mechanical working on emission.- Velocity of emitted electrons and adhesion.- Emission intensity and adhesion.- §9. Influence of chemical nature of contacting surfaces on intensity of fast-electron emission 92 Emission of fast electrons in fracture of crystals.- Electron emission in deformation and abrasion of polymers.- §10. Properties of surfaces freshly formed by breaking an adhesive bond or by mechanical breakdown of polymers.- §11. Radiation effect of fast electrons.- Literature cited.- IV. Theory of the Electrostatic Component of Adhesion.- §1. The electrical double layer caused by donor-acceptor bonding at boundaries between amorphous solids, and its role in adhesion phenomena.- §2. Investigation of general relationships in behavior of electrostatic component in contact of a metal and a semiconductor with an arbitrary spectrum of surface states.- §3. Role of surface properties in double-layer formation and adhesion phenomena.- Calculation of electrostatic component of adhesive force at the contact of a metal and a semiconductor with surface states of two types.- Statement and solution of the problem.- §4. Determination of specific force of adhesion (sticking pressure) upon contact of a metal with a semiconductor film.- §5. Study of adhesive force with semiconductor interlayer between two metals, and correlation of results.- §6. Role of tunneling in breakdown of double layer.- Literature cited.- V. Electroadhesion Phenomena on Semiconductors.- §1. Introduction.- §2. The space-charge layer.- §3. Surface recombination velocity.- §4. Surface states of semiconductors.- §5. Methods of investigating semiconductor surfaces with formation of an adhesive contact.- Dc field-effect method.- Photoconductivity decay method and determination of minority carrier lifetime.- Combination field-effect method with large sinusoidal signals and steady-state photoconductivity.- Monitoring the operation of semiconductor devices.- Method for determining contact potential difference.- Method for determining electrophysical parameters of polymer/semiconductor surface and adhesion in vacuum.- Specimen preparation.- Etching germanium specimens.- Application of polymeric films to semiconductor surfaces.- §6. Investigation of changes in electrophysical properties of germanium surface when an adhesive bond is formed.- §7. Electrical phenomena in breaking adhesive bonds between semiconductors and polymers.- §8. Comparison with theory.- §9. Methods of protecting germanium surfaces by application of varnishes and treatment with organosilicon compounds.- Literature cited.- VI. Adhesion of Dielectrics.- §1. Introduction.- §2. Interfacial chemical interactions of polymers an and functional groups.- §3. Investigation of contact surface by IR spectroscopy.- §4. Relation between electroadhesion phenomena and the chemical structure of interfacial compounds.- §5. Methods of regulating adhesion properties.- §6. Chemistry of adhesion interactions.- Literature cited.- VII. Sticking of Polymers.- §1. Introduction.- §2. Factors in strength of adhesive bonding between polymers.- §3. Role of polymer chain diffusion in mechanism of sticking and self-sticking of polymers.- Literature cited.- VIII. Sticking and Adhesion of Convex Solid Bodies and Powders.- §1. Introduction.- §2. Thermodynamic theory of adhesion at “convex” contact.- Influence of forces of adhesion on contact deformation.- §3. Sticking and adhesion of particles in liquid media.- §4. Study of the sticking and adhesion of surfaces in liquid media.- Modeling the interaction of colloidal particles.- Crossed-fiber method.- Simulation of colloidal particle interaction on the basis of the crossed-fiber method.- §5. Influence of liquid medium on particle sticking.- Adhesion of spherical particles in a liquid.- Interaction of particles in the presence of capillary-condensed liquid.- Influence of liquid bridge.- Influence of relative vapor pressure on particle adhesion.- §6. Sticking and adhesion of particles in a dry atmosphere.- §7. Kinetic adhesion and tack..- Literature cited.- IX. Influence of Adhesion on Friction.- §1. Influence of electrical double layer on rolling friction.- Electrical component of rolling friction.- §2. Investigation of the velocity dependence of rolling friction as a method of studying adhesion.- §3. Influence of adhesion on external sliding friction.- Literature cited.- Conclusion.- A. Methods of adhesiometry.- Pendulum adhesiometer of Deryagin.- Bifilar adhesiometer of Deryagin.- Three-roll adhesiometer of Deryagin.- Rotating-plate method of Deryagin and Krotova.- Determination of adhesion of nonwetting liquid to solid surface under nonequilibrium conditions.- Methods of measuring adhesion in liquid media.- Roll adhesiometer.- Vacuum roll adhesiometers.- Adhesiometers with present detachment velocity.- Adhesiometer with periodic detachment.- Determination of adhesion with ultra-centrifuge.- A. The form of a strip during detachment.- C. The effect of contact deformation on particle adhesion.- Background.- Determination of the shape of the surface of a spherical elastic particle near the zone of particle contact with a flat rigid surface.- Macroscopic calculation of sticking force with allowance for contact deformation of ball.- Summary.- D. The effect of discrete structure of charges of the double layer on the electrostatic component of adhesion.- Literature cited.