Synthesis Of a Thick Gradient Structure Material Under UV Irradiation From Homogeneous System

We present here the results about a new synthesis of gradient structure materials involving a photopolymerization reaction. A previous work 1] showed the feasibility of this method which, unlike most of the existing methods encountered in literature, proceeds with a homogeneous system, that is to say a mixture of monomers and oligomers. Thanks to the sample absorbance and the decay of light intensity through the thickness of the material predicted by Beer-Lambert's law, an intensity gradient, and subsequently a polymerization gradient, can be created inside the sample when exposed to UV radiation. A later thermal crossliriking step is required to set the gradient photochemically created.