Research Data Supporting "Gyroid Optical Metamaterials: Calculating the Effective Permittivity of Multidomain Samples"

Data Supporting Publication "Gyroid Optical Metamaterials: Calculating the Effective Permittivity of Multidomain Samples"Swiss National Science Foundation, National Center of Competence in Research Bio-Inspired Materials, [200021_163220 and PZ00P2_168223], EPSRC [Cambridge NanoDTC EP/G037221/1, EP/L027151/1, and EP/G060649/1], ERC [LINASS 320503], European Union’s Horizon 2020 Research and Innovation Programme under the Marie Sklodowska-Curie [706329], Adolphe Merkle Foundatio

Optical Imaging of Large Gyroid Grains in Block Copolymer Templates by Confined Crystallization.

Block copolymer (BCP) self-assembly is a promising route to manufacture functional nanomaterials for applications from nanolithography to optical metamaterials. Self-assembled cubic morphologies cannot, however, be conveniently optically characterized in the lab due to their structural isotropy. Here, the aligned crystallization behavior of a semicrystalline-amorphous polyisoprene-b-polystyrene-b-poly(ethylene oxide) (ISO) triblock terpolymer was utilized to visualize the grain structure of the cubic microphase-separated morphology. Upon quenching from a solvent swollen state, ISO first self-assembles into an alternating gyroid morphology, in the confinement of which the PEO crystallizes preferentially along the least tortuous pathways of the single gyroid morphology with grain sizes of hundreds of micrometers. Strikingly, the resulting anisotropic alignment of PEO crystallites gives rise to a unique optical birefringence of the alternating gyroid domains, which allows imaging of the self-assembled grain structure by optical microscopy alone. This study provides insight into polymer crystallization within a tortuous three-dimensional network and establishes a useful method for the optical visualization of cubic BCP morphologies that serve as functional nanomaterial templates.This research was supported through the Swiss National Science Foundation through grant numbers 163220 (U.S.) and 168223 (B.D.W.), the National Center of Competence in Research Bio-Inspired Materials (U.S., B.D.W, I.G.), the Adolphe Merkle Foundation (B.D.W., U.S., I.G.), the Engineering and Physical Sciences Research Council through the Cambridge NanoDTC EP/G037221/1, EP/L027151/1, EP/N016920/1, and EP/G060649/1 (R.D., J.A.D., J.J.B.), and ERC LINASS 320503 (J.J.B.). This project has also received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 706329/cOMPoSe (I.G.). Y.G. and U.W. thank the National Science Foundation (DMR-1409105) for financial support. Part of the work was conducted at beamline D1 at the Cornell High Energy Synchrotron Source (CHESS); CHESS is supported by the NSF and NIH/NIGMS via NSF award DMR-1332208. We also thank Diamond Light Source for access to beamline I22 (SM13448) that contributed to the results presented here

Porous Graded Materials Derived From Block Copolymer Self-Assembly For Water And Energy Applications

Block copolymer (BCP) self-assembly provides access to well-ordered nanostructures with tunable morphologies on a typical length scale of 5 - 50 nm. A unique approach combining BCP self-assembly and non-solvent induced phase separation (SNIPS) allows direct formation of graded porous superstructures that can be used in various applications. The graded superstructure is composed of a uniform mesoporous surface layer of ~ 100 nm thickness on top of a spongelike macroporous support layer of tens of micrometers in thickness. It has been utilized to make ultrafiltration membranes for water treatment and selective separation. In the first part, further development on SNIPS polymeric membranes is discussed. In situ grazing incidence small-angle X-ray scattering (GISAXS) was employed to study the structure evolution on doctor-bladed BCP films for membrane purposes. Transient ordered structures were observed during solvent evaporation, providing insights into the membrane formation mechanism. This method serves as a predictive tool and offers the potential to optimize the key parameters for SNIPS membrane production. By incorporating additives in the BCP self-assembly, the CNIPS (co-assembly and non-solvent induced phase separation) process is developed. CNIPS provides a new self-assembly platform upon which multifunctional and high-performance membranes can be formed. For example, an inexpensive small organic additive glycerol was successfully incorporated in membrane fabrication at various amounts. These CNIPS polymeric membranes have wide tunable pore sizes and provide a pathway to expand from ultrafiltraion towards nanofiltraion applications. In the second part, the discussion moves from purely polymeric structures towards organic-inorganic hybrid and purely inorganic graded porous structures. These hybrid/inorganic materials enable advanced membranes and a lot of other applications. To include additional functionalities, the CNIPS method was employed to introduce inorganic nanoparticles into the membranes. For example, a graded porous organic-inorganic hybrid membrane was achieved successfully by incorporating BCP and inorganic TiO2 sol nanoparticles through CNIPS. Hybrid membranes were reported to have significant increase in the permeability compared to plain polymeric membranes. Templating from SNIPS derived BCP structures, graded porous carbon, metal, and metal oxide materials were synthesized. We expect that such nanostructured porous inorganic materials may find use in applications such as separation, catalysis, biomedical implants, as well as energy conversion and storage

<i>In Situ</i> Study of Evaporation-Induced Surface Structure Evolution in Asymmetric Triblock Terpolymer Membranes

Evaporation-induced asymmetric triblock terpolymer membrane formation from polyisoprene-<i>block</i>-polystyrene-<i>block</i>-poly­(4-vinyl­pyridine) (ISV) that relies on self-assembly of doctor bladed solutions was studied using <i>in situ</i> grazing incidence small-angle X-ray scattering (GISAXS). Transient ordered structures were observed for two ISV terpolymers at intermediate evaporation times in the top surface layers of the films as a function of molar mass and solution concentration. Analysis of the GISAXS patterns revealed the evolution from disordered to ordered structures including a transition from body-centered cubic (BCC) to simple cubic (SC) lattices and finally to an amorphous mesoscale structure. The BCC to SC transition solves an apparent structural puzzle resulting from comparisons of, on one side, earlier quiescent solution SAXS studies suggesting BCC terpolymer micelle structures at higher concentrations and, on the other side, electron microscopy studies consistent with SC lattices originating from polymer micelles in the top separation layer of asymmetric ISV membranes. Gaining insights into the structural evolution of asymmetric triblock terpolymer film formation may enable further optimization of self-assembly plus non-solvent-induced phase separation (SNIPS) based high performance isoporous asymmetric block copolymer ultrafiltration membranes

Dynamically Responsive Multifunctional Asymmetric Triblock Terpolymer Membranes with Intrinsic Binding Sites for Covalent Molecule Attachment

Asymmetric ultrafiltration membranes derived from block copolymer self-assembly have seen growing attention as a result of their ordered pore structures and scalable fabrication process. One route to extend their utility is to provide, through the molecular architecture of the block copolymer, covalent binding sites for facile attachment of foreign functional molecules. Here, we report the synthesis of triblock terpolymer poly­(styrene)-<i>block</i>-poly­(4-vinylpyridine)-<i>block</i>-poly­(propylene sulfide) (SVPS) and its fabrication into isoporous ultrafiltration membranes. Final SVPS membrane top surfaces exhibit narrowly dispersed mesopores with 6-fold symmetry. Membranes show a switchable response to pH changes demonstrating the potential as a chemical gate. Membrane pore surfaces are decorated with thiol groups providing active covalent binding sites via versatile thiol–ene click chemistry. The work may open pathways to produce high-performance multifunctional membranes for chem- and bio-sensing and for separation and as membrane reactors

Carbon‐Assisted Stable Silver Nanostructures

International audienceNanostructured silver stands out among other plasmonic materials because its optical losses are the lowest of all metals. However, nanostructured silver rapidly degrades under ambient conditions, preventing its direct use in most plasmonic applications. Here, a facile and robust method for the preparation of highly stable nanostructured silver morphologies is introduced. 3D nanostructured gyroid networks are fabricated through electrodeposition into voided, self-assembled triblock terpolymer scaffolds. Exposure to an argon plasma degraded the polymer and stabilized the silver nanostructure for many weeks, even in high humidity and under high-dose UV irradiation. This stabilization protocol enables the robust manufacture of low-loss silver nanostructures for a wide range of plasmonic applications

Multicomponent Nanomaterials with Complex Networked Architectures from Orthogonal Degradation and Binary Metal Backfilling in ABC Triblock Terpolymers

Selective degradation of block copolymer templates and backfilling the open mesopores is an effective strategy for the synthesis of nanostructured hybrid and inorganic materials. Incorporation of more than one type of inorganic material in orthogonal ways enables the synthesis of multicomponent nanomaterials with complex yet well-controlled architectures; however, developments in this field have been limited by the availability of appropriate orthogonally degradable block copolymers for use as templates. We report the synthesis and self-assembly into cocontinuous network structures of polyisoprene-<i>block</i>-polystyrene-<i>block</i>-poly­(propylene carbonate) where the polyisoprene and poly­(propylene carbonate) blocks can be orthogonally removed from the polymer film. Through sequential block etching and backfilling the resulting mesopores with different metals, we demonstrate first steps toward the preparation of three-component polymer–inorganic hybrid materials with two distinct metal networks. Multiblock copolymers in which two blocks can be degraded and backfilled independently of each other, without interference from the other, may be used in a wide range of applications requiring periodically ordered complex multicomponent nanoarchitectures