A morphology transition from spherical mesopores to worm-shaped mesopores within titania block copolymer composite thin films has been observed by varying the sol–gel reaction time from 40 min to 48 h in the four-component templating system of polystyrene-b-poly(ethylene oxide) (PS-b-PEO), 1,4-dioxane, concentrated HCl, and titanium tetraisopropoxide (TTIP) with a PS-b-PEO mass concentration of 0.25 wt.-%. The impact of the sol–gel reaction time on the local structure, long-range lateral structure, and vertical structure of the as-prepared, calcined, and UV-degraded thin films as well as the structural changes in solution have been systematically investigated by scanning electron microscopy (SEM), atomic force microscopy (AFM), grazing-incidence small-angle X-ray scattering (GISAXS), X-ray reflectivity (XRR), and dynamic light scattering (DLS). With sol–gel reaction times of up to 5 h, hexagonally organized spherical micelles are present within the as-prepared composite films, in which the core of the spherical micelles is composed of the polystyrene (PS) block, and the corona is composed of the poly(ethylene oxide)–titania (PEO–titania) hybrid. Upon calcination or UV exposure, ordered mesoporous structures are formed owing to the removal of the PS block. With the sol–gel reaction time extended to 25 and 48 h, worm-shaped micelles appear, and their quantity increases with increasing sol–gel reaction time. Worm-shaped mesopores are formed by calcination or UV degradation. The GISAXS results prove that the local structural changes are representative over a macroscopic scale. The XRR results suggest that with the sol–gel reaction time extended to 48 h there is an additional thin layer beneath the mesoporous titania layer owing to the presence of a large amount of worm-shaped micelles. The results of the DLS studies imply that the morphology transition from spherical micelles to worm-shaped micelles is caused by a fusion process of the spherical micelles in solution.

A new concept to achieve the generalized synthesis of crystalline mesoporous rare earth (RE) oxide thin films templated with an ionic amphiphilic block copolymer is developed. Mesoporous La₂O₃, Eu₂O₃, Tb₂O₃, and Yb₂O₃ thin films as representatives of the light and heavy RE groups are synthesized by using polystyrene-block-poly(acrylic acid) (PS-b-PAA) as a templating agent. The impact of the concentration of PS-b-PAA on the morphologies of the mesopores is investigated. The local and long-range lateral structures, vertical structures, and crystallinities of the mesoporous thin films are probed by scanning electron microscopy, atomic force microscopy, grazing-incidence small-angle X-ray scattering, X-ray reflectivity, and transmission electron microscopy. The mechanism of formation of the mesoporous RE oxide thin films is discussed.

A facile route to reassemble titania nanoparticles within the titania-block copolymer composite films has been developed. The titania nanoparticles templated by the amphiphilic block copolymer of poly(styrene)-block-poly (ethylene oxide) (PS-b-PEO) were frozen in the continuous PS matrix. Upon UV exposure, the PS matrix was partially degraded, allowing the titania nanoparticles to rearrange into chain-like networks exhibiting a closer packing. The local structures of the Titania chain-like networks were investigated by both AFM and SEM; the lateral structures and vertical structures of the films were studied by GISAXS and X-ray reflectivity respectively. Both the image analysis and X-ray scattering characterization prove the reassembly of the titania nanoparticles after UV exposure. The mechanism of the nanoparticle assembly is discussed.