The study of amphiphilic polymer based functional organic−inorganic hybrid materials is an emerging research area offering enormous scientific and technological promise. Here, we show that employing poly(isoprene-block-ethylene oxide) block copolymers (PI-b-PEO) and a silicon precursor, which contains a polymerizable organic moiety, unprecedented morphology control on the nanoscale is obtained. This control is based on a unique polymer−ceramic interface, which is characterized using a multi-nuclei solid-state NMR approach. The results show that the hydrophilic parts of the polymer are completely integrated into the ceramic phase, thereby leading to a quasi “two-phase system”, allowing for a more rational hybrid morphology design based on the current understanding of the phase behavior of block copolymers and copolymer−homopolymer mixtures. Examination of the full phase space of the hybrid materials reveals the existence of a new bicontinuous cubic structure that was not known to exist in polymer systems. ...