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Flexible hybrid xerogels bringing together high optical transparency up to 96%, low shrinkage down to 5.5%, very smooth surface (average roughness of about 0.3 nm) and thermal stability up to 200 °C were achieved as a result of the optimization of sol‐gel preparative method and a new combination of sol‐gel precursors. Two types of hybrid materials (hereafter referred, respectively, as urea‐silicate and amino‐alcohol‐silicate gels) were synthesized in this work. The shrinkage and the transparency of these materials have been drastically improved by using two different derived siloxanes (3‐isocyanate propyltriethoxysilane and 3‐glycidoxypropyltrimethoxysilane) and two amine‐terminated polyether precursors with different molecular weights. A drying process was implemented to minimize yellowing of prepared samples. Under these conditions, we were able to efficiently reproduce a well‐defined imprinted pattern at materials surface by using an original casting mould. The study of the diffraction characteristics of the obtained grating revealed a good reproducibility of the imprinted grating that shows to be comparable with the original mould. The developed methodology opens the possibility to produce diffraction lenses with a wide range of forms by a simple method based on sol‐gel process. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012

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