Nanostructure and Shape Control in Polymer‐Ceramic Hybrids from Poly(ethylene oxide)‐block‐Poly(hexyl methacrylate) and Aluminosilicates Derived from Them

Abstract

Summary: The present study describes the use of poly(ethylene oxide)‐block‐poly(hexyl methacrylate) diblock copolymers (PEO‐b‐PHMA) as structure‐directing agents for the synthesis of nanostructured polymer‐inorganic hybrid materials from (3‐glycidylpropyl)trimethoxysilane and aluminium sec‐butoxide as precursors and organic, volatile solvents. Four different morphologies, i.e., inorganic spheres, cylinders, lamellae, and organic cylinders in an inorganic matrix, are obtained confirmed by a combination of small‐angle X‐ray scattering (SAXS) and transmission electron microscopy (TEM). The composites are further characterized by differential scanning calorimetry (DSC) and solid‐state 13C, 29Si, and 27Al NMR. It is demonstrated that the change in the hydrophobic block from polyisoprene (PI) to poly(hexyl methacrylate) (PHMA) has no significant effect on the local structure of the inorganic rich phase. By the dissolution of the composites rich in poly(hexyl methacrylate), nano‐particles of different shapes, i.e., spheres, cylinders, and lamellae, are obtained as demonstrated by atomic force microscopy (AFM) and TEM. Finally, calcination of composites with the inverse hexagonal structure at elevated temperatures up to 600 °C results in nanostructured aluminosilicates that retain their structure as evidenced through a combination of SAXS and TEM. The study opens pathways towards tailoring filler‐matrix interactions in model nanocomposites and builds the bases for the preparation of composites from multiblock copolymers with polyisoprene (PI), poly(ethylene oxide) (PEO), and poly(hexyl methacrylate) (PHMA) as building blocks.Bright field TEM micrograph of composite T55/1 with inverse hexagonal morphology after calcination.imageBright field TEM micrograph of composite T55/1 with inverse hexagonal morphology after calcination.

Free-Standing and Self-Crosslinkable Hybrid Films by Core–Shell Particle Design and Processing

“…This technique has the advantage that the nuclei of the inorganic component, i.e., 29 Si, and the nuclei of the organic component, i.e., 13 C, have specific chemical shift ranges that allow a precise analysis of their chemical environment and thus the clear identification of functional groups and their connectivity. Many examples of silica hybrid materials containing organic polymers are found in the literature [ 30 , 46 , 47 , 48 , 49 , 50 , 51 , 52 ], where the potential of 29 Si and 13 C solid-state NMR techniques were demonstrated to obtain detailed structural information. Figure 5 shows the 29 Si static spectra of the three linker systems and the corresponding 29 Si CP MAS spectra of the lyophilized powder samples for comparison.…”

Improved conductivity in dye-sensitised solar cells through block-copolymer confined TiO2crystallisation

“…16,20 The high molecular weight PI-b-PEO copolymer used in the present study exhibits several intrinsic characteristics which makes it well-suited as a structure-directing agent in polymer-derived inorganic nanostructures. 11,25,26 Most important are the high Flory-Huggins interaction parameter of PI-PEO blends of χ(T ) = 65/T + 0.125 and the low glass transition temperatures of both blocks. The large degree of polymerisation of both blocks of the copolymer used in this study of N PEO = 190, and N PI = 400 exceed values of conventional structure-directing agents and enable robust phase segregation which typically exhibits long-range order.…”

A Facile Route to Construct SiCO Nanospheres with Tunable Sizes

“…b). This result suggests that the crystallization of the PEO phase is suppressed in the yellow films due to the selective swelling of the PVSZ in the block PEO phase …”

“…The combination of two initially separated research areas of polymer‐derived ceramic and block copolymer microphase separation enables to synthesize nanostructured ceramics. The PEO‐based amphiphiles, such as PI‐b‐PEO, PB‐b‐PEO, PS‐b‐PEO, PEO‐b‐PHMA, PEO‐PPO‐PEO, and alkyl‐PEO alcohols, have been used in the conjunction with ceramic precursors in solgel processes to obtain nanostructured organic–inorganic hybrid materials, in which heat treatment is used to transform the preceramic polymer into ceramic materials, while retaining the original shape. Thus, the resultant materials have polymer‐derived structures and ceramic‐like properties.…”