Search results
Results from the WOW.Com Content Network
Solid-phase electrical conductivity: Variable, [6] depending on the nature of the bonding: network solids in which all electrons are used for sigma bonds (e.g. diamond, quartz) are poor conductors, as there are no delocalized electrons. However, network solids with delocalized pi bonds (e.g. graphite) or dopants can exhibit metal-like conductivity.
As this example shows, there can be no sharp boundary between molecular and network covalent solids. Intermediate kinds of bonding: A solid with extensive hydrogen bonding will be considered a molecular solid, yet strong hydrogen bonds can have a significant degree of covalent character. As noted above, covalent and ionic bonds form a continuum ...
Gels consist of a solid three-dimensional network that spans the volume of a liquid medium and ensnares it through surface tension effects. This internal network structure may result from physical bonds such as polymer chain entanglements (see polymers) (physical gels) or chemical bonds such as disulfide bonds (see thiomers) (chemical gels), as well as crystallites or other junctions that ...
[10] [28] Examples of molecular solids that halogen bond are hexachlorobenzene [11] [29] and a cocrystal of bromine 1,4-dioxane. [27] For the second example, the δ- bromine atom in the diatomic bromine molecule is aligning with the less electronegative oxygen in the 1,4-dioxane. The oxygen in this case is viewed as δ+ compared to the bromine ...
Molecular binding is an attractive interaction between two molecules that results in a stable association in which the molecules are in close proximity to each other. It is formed when atoms or molecules bind together by sharing of electrons.
The engineering principle behind chemical adhesion in this sense is fairly straightforward: if surface molecules can bond, then the surfaces will be bonded together by a network of these bonds. It bears mentioning that these attractive ionic and covalent forces are effective over only very small distances – less than a nanometer. This means ...
IUPAC definition for a crosslink in polymer chemistry. In chemistry and biology, a cross-link is a bond or a short sequence of bonds that links one polymer chain to another. These links may take the form of covalent bonds or ionic bonds and the polymers can be either synthetic polymers or natural polymers (such as proteins).
For example, it was shown recently that the incorporation of disulfide bonds in PU foams led to their malleability and reprocessability into elastomers. [18] Another possible solution is the addition of catalyst to post-consumer PU, which activates the exchange of urethane bonds and makes them reprocessable .