Читать книгу Sticking Together - Steven Abbott - Страница 10

We start by admiring those pioneers of adhesion who managed to take crude raw materials such as birch bark tar or boiled bones to create really rather impressive adhesives. We then switch to some necessary basics to become familiar with the few core ideas needed to understand the rest of the book. By looking at how geckos manage to stick to walls, we see the sort of adhesion we mostly don't want, getting ready to find out how to get the (usually) strong adhesion we do want. But before getting to strong adhesion we need to know how to measure if our adhesion is strong. Because adhesion is a property of the system, this is by no means obvious. Then we can get to understand how strong adhesives work (and when they will fail). Because much of strong adhesion depends on strong polymers, we need then to switch to pressure sensitive adhesives (common tapes) that give strong adhesion thanks to very weak polymers. What unites the strengths of both types of adhesives is that they each manage to dissipate the energy of a potential crack; adhesion is much more about dissipation than it is about “strength”. That completes the next five chapters and provides all the principles we need. The final five chapters are about specific systems and how they work with the principles we've worked hard to understand.