Читать книгу Materials for Biomedical Engineering - Mohamed N. Rahaman - Страница 49

The types of bonds in materials can be classified broadly into two main types: primary bonds and secondary bonds. Primary bonds are interatomic bonds, that is, chemical bonds between atoms. They are strong bonds characterized by a high bond strength and a high bonding energy in the range of ~20–250 kJ/mol (Table 2.2). Primary bonds are formed by transfer of one electron or more from one atom to another which leads to the formation of ions with discrete charges, or by sharing of electrons between atoms. There are three types of primary bonds: ionic, covalent, and metallic bonds.

Secondary bonds are intermolecular bonds. They are physical bonds formed by attraction of molecules that are nonpolar or that have a permanent dipole moment and, thus, they do not involve chemical transfer or sharing of electrons. Secondary bonds are weak, with a low bonding energy of ~2–12 kJ/mol (Table 2.2). Common types of secondary bonds are the van der Waals bond and the hydrogen bond.