Лако-красочные материалы — производство

A. Definition Acid-base interactions including hydrogen bonds are specific and not ubiquitous like the London dispersive interactions. They occur when a base (electron donor or a proton acceptor) and an acid (electron acceptor or proton donor) are brought close together. This can be described by the general equation A + : B! A: B (1) […]

Mohamed M. Chehimi and Ammar Azioune Interfaces, Traitement, Organisation et Dynamique des Systemes (ITODYS), Universite Paris 7- Denis Diderot, Paris, France Eva Cabet-Deliry Laboratoire d’Electrochimie Moleculaire, Universite Paris 7 — Denis Diderot, Paris, France I. INTRODUCTION The thermodynamic work of adhesion (W) is by definition the free energy change per unit area required to separate […]

Despite the advances since the days of Chauvet, it is still true today that the tacit knowledge of adhesion is in advance of our theoretical understanding. Nevertheless, we have, of course, made impressive advances since the time when Newton threw down his challenge. The development of theories of adhesion from the work of McBain and […]

Why does surface roughness affect adhesion? More particularly, why does increasing interfacial roughness often increase adhesion? In a simple way, we can rationalize this in terms of Eq. (6), at the same time summarizing the points made in the previous sections. Figure 9 Schematic representation of solidlike (crystalline), amorphous solid, and liquidlike sur­face layers. (Reproduced […]

Some interesting light has been thrown on the nature and roughness of surface layers in contact by experiments of Israelachvili and co-workers with the surface force apparatus [55,79,83,84]. This apparatus enables the surface energy to be evaluated both when the surfaces are advancing into closer contact, yA, and when they are receding further apart, уR. […]

Adhesion of thermodynamically incompatible polymers is of current interest because of its implications for developing new multiphase polymer materials and for recycling of mixed plastic wastes. Many elegant experiments have been reported in which various types of copolymer are introduced at the interface as putative compatibilizers. The interface may be strengthened as a result of […]

Wool [57] has considered the fractal nature of polymer-metal and polymer-polymer interfaces. He argues that diffusion processes often lead to fractal interfaces. Although the concentration profile varies smoothly with the dimension of depth, the interface, considered in two or three dimensions is extremely rough [75]. Theoretical predictions, supported by practical measurements, suggest that the two-dimensional […]

It has been emphasized above that a surface molecule on a rough surface will often have a different environment—for example, fewer nearest neighbors, more ‘‘broken bonds’’— than a similar molecule on a smoother surface. In addition to this, it must be remembered that most, if not all, of the chemical or physical treatments used to […]

There are obvious similarities between the polymer which has solidified within the pores of a microfibrous surface and fibers embedded in the matrix of a composite material (cf. Fig. 1). Standard treatments of fiber composites (e. g., [72]) draw attention to the signifi­cance of the critical length of fiber. When short fibers are stressed axially, […]

The increased energy dissipated for adhesion to a rough surface is usually a result of plastic dissipation processes, evidence of which can often be obtained by examining the fracture surfaces. However Gent and Lin have shown that large amounts of energy can also be involved in peeling an elastic material from a rough surface [71]. […]