Re: polarizing microscope for the refractive index calculation

It occured to me that an Abbe Refractometer might be adapted to
meausring the R.I. of thin film polymers.  I did a Google search with
the phrase "Abbe Refractometer polymer film"  Enough articles appeared
to tell me that this instrument has been used for this purpose and
there is a body of experience. One fact mentioned is that  the R.I of
polymer films  is very high.  Some instruments are advertized as
suitable.  Some researchers caution about the limited range of
instruments thay had available.  

I cannot tell if your request is an assignment from your instructors
or some sort of research project.  Perhaps you could tell us the
origin of your question.  Are you looking for a method of determining
R.I. for your experimental work or is this a theoretical question for
discussion in your classes?  

Aaron

On 1 Dec 2003 08:01:50 -0800, [EMAIL PROTECTED] (tzavalas) wrote:

>Hello everybody, i´m spiros from greece.
>
>I´m taking a course on polymer science and recently I heard that the
>non-isotropic substances are not bound to have the same rerfactive
>index on all directions. So in the most general case every a sample
>bears 2 vertical and one parallel reflactive index. The parallel or
>vertical dirctions are regarded in relation to an axis of orientation
>of specific groups, like liquid crystals, polymer chains, fibres or
>even bonds between atoms etc(which are in the sample and whose
>"preference" for a direction is what causes the sample to be
>"non-isotropic.")
>
>So  in my case, where I have a stretched polymer film, I guess the
>same thing is taking place. I know that I can use a polarizing
>microscope to calculate the values of the refractive index as the
>incident (planar-polarized) on the sample light rotates.
>
>BUT I DONT KNOW HOW?????????????
>
>thanks in advance, spiros tzavalas.