Лако-красочные материалы — производство

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 Hopkins to the present day has greatly contributed to this understanding. Much has been achieved by rationalizing adhesion phenomena in terms of these distinct theories. Of these, the mechan­ical theory of adhesion is associated with adhesion to rough and porous surfaces. It has proved valuable historically, as it has concentrated attention on surface roughness and the influence this may have on adhesion. It remains of value as the roughening of interfaces, on a scale which may range from hundreds of microns to nanometers, is important in the more effective use of bonding techniques, and in the development of new materials.

In surveying the effect of roughness on adhesion, we can see how the concepts of adsorption, diffusion, and mechanical theories overlap and merge seamlessly in providing a model of the empirical observations. This is not surprising. We should remember that scientific theories are intellectual models—mental constructs—which are used to rationa­lize observations ‘‘and [are] not more real than the phenomena from which they are drawn’’ [87]. While accepting that reductionism has been an extremely fruitful methodol­ogy in science, especially physical science, we should not forget that it is a methodological device and beware of attributing an immutable objective reality to the concepts it con­structs. We should avoid the tendency to reduce the interpretation of adhesion phenomena to narrowly conceived theories of adhesion, and should not hesitate to take a broader view, using whichever blend of concepts best suits the purpose.