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Specialty Chemistry Forums => Biochemistry and Chemical Biology Forum => Topic started by: 503 on May 11, 2009, 03:08:50 PM

Title: Unimers
Post by: 503 on May 11, 2009, 03:08:50 PM
Hey,

My professor sent me a journal article to read on micelle formation and there's one structure in it that I can't seem to find any basic information on.  That structure is a unimer.  Everytime I try to search it I only find journals that assume that you know what a unimer is.  I know that if critical micelle temperature or concentration are not obtained that unimers will begin to form, however I do not know exactly what a unimer is.  Any type of introductory literature or just any beginner information at all would be appreciated.  Thanks. 
Title: Re: Unimers
Post by: Arkcon on May 11, 2009, 03:30:19 PM
This Google books result gives a definition for unimer, as distinct from monomer.  http://books.google.com/books?id=lOaK77U34lYC&pg=PA3&lpg=PA3&dq=unimer+monomer&source=bl&ots=xyXYSyfIt4&sig=7m7P-gQbac1Q0YPPztM_ewjd444&hl=en&ei=mXsISrm0MdPG-QbiyrmSAw&sa=X&oi=book_result&ct=result&resnum=6

Unimer appears to be the solo subunit of a surfactant micelle, as opposed to monomer, the subunit of a polymer.  Still, seems like something of an arbitrary definition to me.
Title: Re: Unimers
Post by: 503 on May 11, 2009, 03:46:38 PM
Thanks a lot.
Title: Re: Unimers
Post by: jef6550 on February 20, 2014, 05:53:03 AM
The main purpose in my reply is just for clarification of future visitors because there really is no basic, introductory level information on unimers that is easily available.

First off, the term unimer is rarely used but is commonly come across when studying surfactants and micelles.
The term "unimer" is actually a made-up word when a scientist cannot properly describe something, and it is not proper scientific practice to use the term (hence why it is so uncommon).

Definition of a unimer:
A unimer is a special case polymer in which that polymer belongs to a group of polymers.

Explanation:
A monomer (simply put) is an element.
A polymer is 2 or more elements that have bonded together (which is a molecule).
Sometimes many molecules (or polymers) come together to form some functioning structure.
     Ex: a micelle is actually a spherical structure made up of many different polymers.
A unimer is then a term that is sometimes used to define a single polymer that belongs to a group of other polymers.
So polymer and unimer are actually synonymous terms but only when the polymer is just a piece of a larger structure.

To be frank, the term unimer is quite unnecessary.

Title: Re: Unimers
Post by: DrCMS on February 20, 2014, 12:49:35 PM
@jef  Do not post on things you are not really sure about and do not "borrow" terms to use incorrectly.

The term "unimer" is actually a made-up word when a scientist cannot properly describe something, and it is not proper scientific practice to use the term (hence why it is so uncommon).

To be frank, the term unimer is quite unnecessary.

I'll agree with you there

Definition of a unimer:
A unimer is a special case polymer in which that polymer belongs to a group of polymers.

No not really.  Arkcon already gave a better definition than yours. 

Explanation:
A monomer (simply put) is an element.

NO IT IS NOT.  An element has a particular meaning in chemistry DO NOT misuse it when it is quite easy to use a different phrase.

A monomer is a molecule that reacts with other monomers to form polymers.  Monomers are the subunits of polymers.  If only a single type of monomer reacts that is a homopolymer if there are two or more different monomers they produce co-polymers.

Explanation:
A polymer is 2 or more elements that have bonded together (which is a molecule).

Again do not misuse the term elements.  Also most definitions of polymers talk about at least 3 monomers.  If 2 monomers react together that is a dimer.

A unimer is then a term that is sometimes used to define a single polymer that belongs to a group of other polymers.

No a single polymer chain inside a solid block of nylon fits this description but is unlikely to be called a unimer.

So polymer and unimer are actually synonymous terms

No they are not; surfactants and polymers are not the same thing.