# A potentially stupid question: What makes things sticky? **URL:** \ **Category:** Factual Questions\ **Created:** [November 11, 2003, 2:59am UTC](https://boards.straightdope.com/t/a-potentially-stupid-question-what-makes-things-sticky/212536 "2003-11-11T02:59:48Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![gypsymoth3](https://avatars.discourse-cdn.com/v4/letter/g/85e7bf/32.png) [@gypsymoth3](https://boards.straightdope.com/u/gypsymoth3)\ **Post date:** [November 11, 2003, 2:59am UTC](https://boards.straightdope.com/t/a-potentially-stupid-question-what-makes-things-sticky/212536/1 "2003-11-11T02:59:48Z")
scientifically, what characteristics make something sticky? does it have something to do with its being somewhere in between solid and liquid? ---
**Author:** ![antechinus](https://avatars.discourse-cdn.com/v4/letter/a/fbc32d/32.png) [@antechinus](https://boards.straightdope.com/u/antechinus)\ **Post date:** [November 11, 2003, 3:25am UTC](https://boards.straightdope.com/t/a-potentially-stupid-question-what-makes-things-sticky/212536/2 "2003-11-11T03:25:51Z")
Something sticky has cohesion (sticks to itself) and adhesion (sticks to other stuff). Chewing gum on teflon is not sticky because there is a large difference in surface energy between the gum and the teflon substrate. The gum is sticky to itself because of cohesion due to forces between the molecules of the gum, which leads the gum to stretch rather than fail. An adhesive (as opposed to something ‘sticky’) starts out as a liquid and turns to a solid - pretty obvious I suppose, but water can be an adhesive of two peices of wood if it wets both and is then frozen. So it more to do with changing from liquid to solid. The liquid has to be able to wet the solid it is gluing. This has to do with the surface energy of the liquid and the solid. There are two types of bonding - chemical and physical. Chemical is where the adhesive changes to a solid through chemical reaction (eg superglue with water). Physical is via solvent evaporation (eg PVA emulsion) or cooling (eg sticking tounge to freezer door). Were you interested at what is happening at a molecular level? ---
**Author:** ![antechinus](https://avatars.discourse-cdn.com/v4/letter/a/fbc32d/32.png) [@antechinus](https://boards.straightdope.com/u/antechinus)\ **Post date:** [November 11, 2003, 3:29am UTC](https://boards.straightdope.com/t/a-potentially-stupid-question-what-makes-things-sticky/212536/3 "2003-11-11T03:29:50Z")
Do you mean sticky as in blu-tack sticky or as in enamel on metal sticky? ---
**Author:** ![AskNott](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/asknott/32/5790_2.png) [@AskNott](https://boards.straightdope.com/u/AskNott)\ **Post date:** [November 11, 2003, 3:35am UTC](https://boards.straightdope.com/t/a-potentially-stupid-question-what-makes-things-sticky/212536/4 "2003-11-11T03:35:46Z")
What’s brown and sticky? A stick. ---
**Author:** ![Thinks2Much](https://avatars.discourse-cdn.com/v4/letter/t/73ab20/32.png) [@Thinks2Much](https://boards.straightdope.com/u/Thinks2Much)\ **Post date:** [November 11, 2003, 3:58am UTC](https://boards.straightdope.com/t/a-potentially-stupid-question-what-makes-things-sticky/212536/5 "2003-11-11T03:58:17Z")
This subject has been covreed by the master.[why is tape sticky](http://www.straightdope.com/classics/a1_117a.html) ---
**Author:** ![antechinus](https://avatars.discourse-cdn.com/v4/letter/a/fbc32d/32.png) [@antechinus](https://boards.straightdope.com/u/antechinus)\ **Post date:** [November 11, 2003, 4:48am UTC](https://boards.straightdope.com/t/a-potentially-stupid-question-what-makes-things-sticky/212536/6 "2003-11-11T04:48:35Z")
> [@](#): > > \*Originally posted by chrisk72 \* > \*\*This subject has been covreed by the master.[why is tape sticky](http://www.straightdope.com/classics/a1_117a.html) \*\* What Cecil is getting at in this article is that **van der Waals forces** between two intimately enough connected surfaces provide cohesion. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [November 11, 2003, 4:58am UTC](https://boards.straightdope.com/t/a-potentially-stupid-question-what-makes-things-sticky/212536/7 "2003-11-11T04:58:02Z")
[The amazingly sticky feet of the gecko](http://news.bbc.co.uk/2/hi/science/nature/781611.stm) illustrate the role of van der Waals forces nicely. ---
**Author:** ![antechinus](https://avatars.discourse-cdn.com/v4/letter/a/fbc32d/32.png) [@antechinus](https://boards.straightdope.com/u/antechinus)\ **Post date:** [November 11, 2003, 11:16am UTC](https://boards.straightdope.com/t/a-potentially-stupid-question-what-makes-things-sticky/212536/8 "2003-11-11T11:16:04Z")
> [@](#): > > \*Originally posted by Squink \* > \*\*[The amazingly sticky feet of the gecko](http://news.bbc.co.uk/2/hi/science/nature/781611.stm) illustrate the role of van der Waals forces nicely. \*\* > [@](#): > > “Suction was regarded as an > unlikely explanation since > geckos can cling on to a > wall even in a vacuum.” This cracks me up. I wonder how many geckos they went through to work this out. [frink]mnhooey…we turn on the vacuum pump and watch the gecko…plurt… oh the exploding and the blood and the legs and the crying …mhey…nenwhey[/frink] ---
**Author:** ![mrsam](https://avatars.discourse-cdn.com/v4/letter/m/b5ac83/32.png) [@mrsam](https://boards.straightdope.com/u/mrsam)\ **Post date:** [November 11, 2003, 12:07pm UTC](https://boards.straightdope.com/t/a-potentially-stupid-question-what-makes-things-sticky/212536/9 "2003-11-11T12:07:05Z")
The mods click a little box that makes the thread stay at the top of the forum.