Double gyroid structure

A systematic comparative study of triblock terpolymers in the bulk and thin-film state was carried out on polystyrene-fo-poly(2-vinyl pyridine)-b-poly(ferf-bulyl methacrylate), PS-fr-P2VP-fr-PfBMA. A diblock precursor with a minority of PS leading to a double gyroid structure was used. Upon increase of PfBMA content this morphology changed from lamellae with... 

An A-B diblock copolymer is a polymer consisting of a sequence of A-type monomers chemically joined to a sequence of B-type monomers. Even a small amount of incompatibility (difference in interactions) between monomers A and monomers B can induce phase transitions. However, A-homopolymer and B-homopolymer are chemically joined in a diblock therefore a system of diblocks cannot undergo a macroscopic phase separation. Instead a number of order-disorder phase transitions take place in the system between the isotropic phase and spatially ordered phases in which A-rich and B-rich domains, of the size of a diblock copolymer, are periodically arranged in lamellar, hexagonal, body-centered cubic (bcc), and the double gyroid structures. The covalent bond joining the blocks rests at the interface between A-rich and B-rich domains. 

Fig. 28 SEM images of about 60 nm thick films of SVT block terpolymers along with expected structural elements of the thin-film structure, (a) Core-shell cylinders (b) helices wound around a cylindrical core (c) (112) plane of an ideal double gyroid structure. Copyright (2002) Wiley. Used with permission from [18]...

M. R. J. Scherer, Double-Gyroid-Structured Functional Materials, Springer Theses, DOI 10.1007/978-3-319-00354-2 l,... 

The internal surface area of the double-gyroid structure formed by P(F)S49- -PLA192 was indirectly measured by hydrogen adsorption using cyclic voltammetry [44, 57, 58]. BET surface area measurements were not performed since larger quantities of the precious material would have been needed. For this purpose a platinum replica of the double-gyroid with a known deposition area (0.95 mm ) and thickness (1.15 p.m) was prepared by electroplating on a SU-8 patterned FTO substrate, see Fig. 4.21 [49]. The templated electrodeposition of platinum is discussed in detail in Chap. 6. 

Fig. 5.4 Supercapacitor cell assembly, a Schematic illustration of the supercapacitor design based on two laterally offset double-gyroid structured electrodes, b Photograph of a fully transparent electrochromic supercapacitor consisting of an oxidized yellow top electrode, a laterally offset green/gray bottom electrode in the reduced state...

Given that the density of electrodeposited nontemplated vanadia is 2.87 g cm , the average density of double-gyroid structured vanadia with a volume fraction of 37.9 % is1.09 g cm, illustrating the porous nature of the DG structure [16]. Thus, the specific surface area of DG-structured V2O5 is 1.48 m g . Furthermore, the mass m of vanadia electrodes was calculated using these densities, the electrode area and thickness. The V2O5 film thickness was determined by cross-sectional SEM or with a surface profilometer. 

Thermal Oxidation of Double-Gyroid-Structured Metals... 

Fig. 6.7 a TEM revealing the nanotubular character and polycrystallinity of the double-gyroid-structured NiO. b Magnified view of (a) resolving nanocrystals with dimensions of 5-lOnm. c Corresponding selected area electron diffraction pattern of polycrystalline NiO. 

A second, more sophisticated type of devices was fabricated in the following way. First a temporary gold layer, which closed the nonconducting gap between the two chromium electrodes, was evaporated. Subsequently a voided double-gyroid-structured template was prepared on this continuously metal-coated substrate and refilled with PPy. Then the redundant template was dissolved with xylene. Finally the superficial gold layer was etched with a wet gold etchant, which reestablished the gap between the chromium electrodes. 

The sheet resistance of both nontemplated and double-gyroid-structured films was determined by measuring the current through a 1 cm long film section for a... 

Despite committing a respectable amount of time to this project, we have not yet succeeded to obtain crystalline double-gyroid-structured Ti02 films. Based on the here represented results we are planing to test a homebuilt ALD which is currently under construction and was especially designed for high precursor concentrations... 

Furthermore, the thermal stability of double-gyroid-structured P(F)S49- 174°C... 

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