If you would give more information about the used polymer, one could suggest measurements for you.

E.g. If your polymer is transparent, you could quantify the silica percentage optically by measuring the index of refraction of you filled polymer with respect to the pure material as reference.

I suggest using Thermogravimetry analysis (TGA) under the oxygen atmosphere. The weight loss will provide the organic content and the residual will give the silica percentage.

Please refer to the following paper: DOI: 10.1016/j.jcis.2013.04.004 

https://www.researchgate.net/publication/236927051_Molecularly_imprinted_polydopamine_nano-layer_on_the_pore_surface_of_porous_particles_for_protein_capture_in_HPLC_column

Article Molecularly imprinted polydopamine nano-layer on the pore su...

Dear Rajkumar Arumugam 

I am agree with Dr. Ali Nematollahzadeh. Organic compounds are usually degraded by heating up to 500 ºC. Hence, you can determine the content of an inorganic compound in organic/inorganic composites using TGA. For example, please refer to the attached papers.

This is the second paper.

I agree with the use of TGA, as mentioned above. However, this assumes that the residue is pure silica. If there are other inorganics present then you might want to consider ashing the sample and performing XRF on the residue (I doubt that there would be sufficient residue following TGA to do this).

 Dear Dr. Leon,

Thank you. For the case, what if he runs TGA for the inorganic material (i.e. unpure silica) and subtracts any weight loss from the weight loss of the composite?

Dear Dr Nematollahzadeh,

I don't think so. That would still require all of the non-volatile residue to be silica, and you would be repeating the same process of heating the material.

The link below shows that silica content can range from 6 to 22% from bark/wood chips to barley/wheat straw, while calcium ranges from 28.5 to 8%, and potassium from 5 to 18.6%.

I think, Rajkumar, more information is needed as to the source of the inorganic material (and then also on what you want to do with the ash, if you can share that information).

Regards,

Leon

http://www.sciencedirect.com/science/article/pii/096195349500004Q

Hi, You can use ICP or atomic absorption by dissolving the sample in organic solvent, you may also use XPS it requires minimum amount of sample.