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Practical Application of Intermolecular Forces. A Study of Adhesives. By Babi Hijau (Photo taken by own) [Public domain], via Wikimedia Commons. Intermolecular Forces. Forces between molecules Permanent dipoles Induced dipoles van der Waals or London Dispersion forces Hydrogen bonds.
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Practical Application of Intermolecular Forces A Study of Adhesives By BabiHijau (Photo taken by own) [Public domain], via Wikimedia Commons
Intermolecular Forces • Forces between molecules • Permanent dipoles • Induced dipoles • van der Waals or London Dispersion forces • Hydrogen bonds
Applications • Determines various physical properties of a molecular solid • Melting point • Boiling point • Vapor pressure • Adhesive force of glue
An adhesive is a substance that sticks to the surface of an object such that two surfaces become bonded. By Amirreza Saharkhiz (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons
The adhesive will “wet” or cover the substrate, when the Intermolecular forces between the glue and the substrate are stronger than the Intermolecular forces between the glue and glue. By Mk2010 (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0) or GFDL (http://www.gnu.org/copyleft/fdl.html)], via Wikimedia Commons
For an adhesive to wet a surface, the adhesive should have a lower surface tension, than the solid’s surface energy (or critical surface tension), By MesserWoland (own work created in Inkscape) [GFDL (http://www.gnu.org/copyleft/fdl.html), CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/) or CC BY-SA 2.5-2.0-1.0 (http://creativecommons.org/licenses/by-sa/2.5-2.0-1.0)], via Wikimedia Commons
Adhesive Curing Once the adhesive is applied to the substrate, it will begin to cure, or form a permanent bond Different Adhesives have different mechanisms in which the curing takes place Theilr’s Flickr account – Creative Commons Attribution
So HOW do glues compare? In the following lab you will investigate the differences in the adhesive ability of some different types of glues By Selena Wilke (Own work) [Public domain], via Wikimedia Commons