2
$\begingroup$

According to my text, "a colloid in which the dispersed phase consists of micelles is called an association colloid." An example would be soap in water. They use the term 'associated colloid' and 'association colloid' interchangeably.

They state that, "associated colloids at low concentrations, behave as normal, strong electrolytes."

I can't provide further context as they haven't provided further information.

$\endgroup$

1 Answer 1

2
$\begingroup$

Could you define associated colloids as it appears in your text? This is not a modern colloid chemistry term. A quick search of Google Books shows that this terminology is popular in Indian test preparation books. Micelle is a modern term. IUPAC defines micelle as "Particle of colloidal dimensions that exists in equilibrium with the molecules or ions in solution from which it is formed" Above a critical concentration, called the critical micellar concentration (CMC), the conductivity of solution drops very quickly. I will let you read more about micelle and conductivity of micellar solutions from the web.

You can watch this video for starting purposes: https://www.youtube.com/watch?v=M6LS4XZswNg. Basically micelle is formed by molecules which have a polar (ionizable end) and a long alkyl chain. Just like any electrolyte they conduct electricity in water. However above CMC, these molecules rather suddenly form a structure called a micelle as shown below (from Google Images). For these reasons, there is sudden change in lot of properties such as surface tension, conductivity and so on. It is not only conductivity.

Micelle

$\endgroup$
3
  • $\begingroup$ Here is a reference journal.csj.jp/doi/abs/10.1246/bcsj.67.2057 that interestingly notes, to quote: "The ionic conductivity of micelle was found to be inconsistent not only with the micellar size of the identical charge but also with the conductivity of the dynamic radius of micelle of the identical charge. The inconsistencies could be solved by the hopping reaction of counterions between micelles through the overlapping of ionic diffuse double layers around micelle that takes place when two micelles come close together." $\endgroup$
    – AJKOER
    Mar 25, 2020 at 17:08
  • $\begingroup$ My text doesn't provide much details and googling didn't help as it was clustered by Indian websites repeating my text. But I edited my question to clarify what my text said. $\endgroup$ Mar 26, 2020 at 8:04
  • $\begingroup$ @ArnabChowdhury, Watch the lecture, with that you will understand the background. $\endgroup$
    – AChem
    Mar 26, 2020 at 13:06

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.