Polyamide 6,12 crystalline fibers, commercially known as Nylon 6,12, were irradiated using gamma radiation and characterised by Infrared Spectroscopy (FT-IR), Raman, Differential Scanning Calorimeter (DSC) and Thermogravimetric Analysis (TGA). The analysis of the data, by using Flory's Theory and the principles of the Compton effect, allowed establishment of a reaction mechanism to explain how the polyamide chains are modified.

A sol-gel methodology has been duly developed in order to perform a controlled covalent coupling of tetrapyrrole macrocycles (e.g., porphyrins, phthalocyanines, naphthalocyanines, chlorophyll, etc.) to the pores of metal oxide networks. The resulting absorption and emission spectra intensities in the UV-VIS-NIR range have been found to depend on the polarity existing inside the pores of the network; in turn, this polarization can be tuned through the attachment of organic substituents to the tetrapyrrrole macrocycles before bonding them to the pore network. The paper shows clear evidence of the real possibility of maximizing fluorescence emissions from metal-free bases of substituted tetraphenylporphyrins, especially when these molecules are bonded to the walls of functionalized silica surfaces via the attachment of alkyl or aryl groups arising from the addition of organo-modified alkoxides.