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36. Janus‐Type Hybrid Paper Membranes

Author

Nau, Maximilian, primary, Herzog, Nicole, additional, Schmidt, Johannes, additional, Meckel, Tobias, additional, Andrieu‐Brunsen, Annette, additional, and Biesalski, Markus, additional

Published
2019
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38. Gravure printing for mesoporous film preparation

Author

Herzog, Nicole, primary, Brilmayer, Robert, additional, Stanzel, Mathias, additional, Kalyta, Anastasia, additional, Spiehl, Dieter, additional, Dörsam, Edgar, additional, Hess, Christian, additional, and Andrieu-Brunsen, Annette, additional

Published
2019
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42. Surface Enhanced DNP Assisted Solid-State NMR of Functionalized SiO2 Coated Polycarbonate Membranes

Author

Kumari, Bharti, primary, John, Daniel, additional, Hoffmann, Paul, additional, Spende, Anne, additional, Toimil-Molares, Maria Eugenia, additional, Trautmann, Christina, additional, Hess, Christian, additional, Ruff, Philip, additional, Schulze, Marcus, additional, Stark, Robert, additional, Buntkowsky, Gerd, additional, Andrieu-Brunsen, Annette, additional, and Gutmann, Torsten, additional

Published
2018
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46. Fluid Flow Programming in Paper-Derived Silica–Polymer Hybrids

Author

Dubois, Christelle, primary, Herzog, Nicole, additional, Rüttiger, Christian, additional, Geißler, Andreas, additional, Grange, Eléonor, additional, Kunz, Ulrike, additional, Kleebe, Hans-Joachim, additional, Biesalski, Markus, additional, Meckel, Tobias, additional, Gutmann, Torsten, additional, Gallei, Markus, additional, and Andrieu-Brunsen, Annette, additional

Published
2016
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47. N-Methyl-2-pyrrolidone as a Reaction Medium for Gold(III)-Ion Reduction and Star-like Gold Nanostructure Formation

Author

Mirdamadi Esfahani, Maleknaz, Goerlitzer, Eric Sidney Aaron, Kunz, Ulrike, Vogel, Nicolas, Engstler, Joerg, and Andrieu-Brunsen, Annette

Abstract

The efficiency of a wet chemical route to synthesize gold nanostructures with tunable size and shape significantly depends on the applied solvent and the interaction of solvent molecules with other species such as gold ions. The ability of the organic solvent N-methyl-2-pyrrolidone (NMP) as a suitable medium for application in star-like gold nanostructure (AuNS) synthesis with a tunable morphology at ambient conditions has been investigated. The time-dependent analysis of the UV–vis absorption spectra of AuIIICl₄– in a pure NMP solution illustrates the role of NMP as simultaneous complexing and reducing agents. Kinetic studies indicate that AuIIICl₄– in NMP solution is reduced to AuICl₂–, with no need to use another reducing agent, any external energy sources, or solvent pretreatment. This is because AuI species stay stable in this solution unless poly(vinylpyrrolidone) (PVP) catalyzes their disproportionation. Morphological studies by transmission electron microscopy (TEM) specify the high-yield synthesis of AuNS with monocrystalline spikes in a concentrated NMP solution by PVP. This study illustrates that the presence of seeds, as another agent to catalyze the disproportionation of AuI species, makes it possible to synthesize AuNS in varying concentrations of PVP in this medium. The role of PVP concentration and the presence of seeds in the formation kinetics, morphology, and optical properties is systematically discussed. The results achieved through this study develop a straightforward and safe procedure for AuNS synthesis in high yield in a water-miscible organic polar solvent with tunable morphology and optical properties. Considering the high capability of NMP to dissolve various types of polymers and hydrophobic ligands, synthesizing AuNS in this solvent opens a window to a practical and easy way to fabricate gold-based nanomaterials with fascinating optical properties.

Published
2022
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52. Surface Enhanced DNP Assisted Solid-State NMR of Functionalized SiO2 Coated Polycarbonate Membranes

Author

Kumari, Bharti, John, Daniel, Hoffmann, Paul, Spende, Anne, Toimil-Molares, Maria Eugenia, Trautmann, Christina, Hess, Christian, Ruff, Philip, Schulze, Marcus, Stark, Robert, Buntkowsky, Gerd, Andrieu-Brunsen, Annette, and Gutmann, Torsten

Subjects
technology, industry, and agriculture
Abstract

Surface enhanced solid-state NMR by dynamic nuclear polarization (DNP SENS) enables the characterization of the inner-pore surface functionalization of porous etched ion-track membranes exhibiting low specific surface areas compared to typical SBA- or MCM-type mesoporous silica materials. The membranes were conformally coated with a 5 nm thin SiO2 layer by atomic layer deposition. This layer was subsequently modified by aminopropyl silane linkers that allow further functionalization via the terminal amine group. The results evidence that in principle DNP SENS is a capable tool to analyze more complex porous systems, e.g. bioinspired functional etched ion-track membranes down to the molecular level. These results are relevant also for single nanopore systems, for which a direct analysis of the channel surface functionalization is not feasible by classical characterization methods. The applicability of DNP SENS to complex porous systems requires the optimization of the sample preparation and measurement parameters.

Published
2021

53. Effect of Asymmetry on Plasmon Hybridization and Sensing Capacities of Hole-Disk Arrays

Author

Mohammadi, Reza, Ochs, Maria, Andrieu-Brunsen, Annette, and Vogel, Nicolas

Abstract

Plasmonic complementary structures are interesting model systems that combine propagating and localized surface plasmon resonances and allow the fundamental study of their hybridization. In the simplest form, such structures are formed by stacking arrays of nanodisks and nanoholes with matching dimensions. Here, we produce such hole-disk arrays in an experimentally easy and parallel colloidal lithography process with accurate control over vertical alignment and separation between the individual disks and holes. Importantly, our process readily enables symmetry breaking and the design of asymmetric hole-disk arrays with controlled lateral offset between each hole-disk pair. We investigate the coupling between the parental resonances of the two elements as a function of feature size and separation distance and provide a plasmon hybridization scheme to rationalize the resonances. We find that for the asymmetric hole-disk structure, a new, hybrid resonance arises as a peak in the transmission spectra, which is not found in their symmetric analogues. We demonstrate that this new resonance imparts a higher sensitivity in refractive index sensing as it features a pronounced near-field enhancement in between holes and disks. The near-field structure, paired with the accessibility of this separation region in the presented hole-disk structures, implies that this architecture should be sensitive to local changes in the refractive index at the surface of the dielectric layer separating the plasmonic elements. We demonstrate this sensitivity of the asymmetric hole-disk arrays by the detection of the binding of a silane monolayer at the walls of the dielectric silica spacer layer.

Published
2020
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54. Surface Enhanced DNP Assisted Solid-State NMR of Functionalized SiO2 Coated Polycarbonate Membranes.

Author

Kumari, Bharti, John, Daniel, Hoffmann, Paul, Spende, Anne, Toimil-Molares, Maria Eugenia, Trautmann, Christina, Hess, Christian, Ruff, Philip, Schulze, Marcus, Stark, Robert, Buntkowsky, Gerd, Andrieu-Brunsen, Annette, and Gutmann, Torsten

Subjects
DYNAMIC nuclear polarisation, PARTICLE tracks (Nuclear physics), SOLID-state nuclear track detectors
Abstract

Surface enhanced solid-state NMR by dynamic nuclear polarization (DNP SENS) enables the characterization of the inner-pore surface function- alization of porous etched ion-track membranes exhibiting low specific surface areas compared to typical SBA- or MCM-type mesoporous silica materials. The membranes were conformally coated with a 5 nm thin SiO2 layer by atomic layer deposition. This layer was subsequently modified by aminopropyl silane linkers that allow further functionalization via the terminal amine group. The results evidence that in principle DNP SENS is a capable tool to analyze more complex porous systems, e.g. bioinspired functional etched ion-track membranes down to the molecular level. These results are relevant also for single nanopore systems, for which a direct analysis of the channel surface functionalization is not feasible by classical characterization methods. The applicability of DNP SENS to complex porous systems requires the optimization of the sample preparation and measurement parameters. [ABSTRACT FROM AUTHOR]

Published
2018
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55. Programming Ionic Pore Accessibility in Zwitterionic Polymer Modified Nanopores.

Author

Silies, Laura and Andrieu-Brunsen, Annette

Subjects
*POLYZWITTERIONS, *METHYL acrylate, *NANOPORES, *PORE size distribution, *MESOPOROUS materials
Abstract

Creating switchable and gradually tunable pores or channels that display transport control similar to biological pores remains a major challenge in nanotechnology. It requires the generation and manipulation of complex charge situations at the nanoscale and the understanding of how confinement influences chemistry and transport. Here, two different pore sizes, ~100 nm and less than 10 nm, functionalized with varying amounts of responsive zwitterionic polycarboxybetaine methyl acrylate (PCBMA) give fascinating insight into the confinement controlled ionic transport of pores functionalized with pH-dependent zwitterionic polymers. Under basic conditions, the zwitterionic state offers complex, strongly pore-size-dependent ionic permselectivity characteristics. For mesoporous films with pore sizes smaller than 10 nm, complete ion exclusion is observed after reaching a critical zwitterionic polymer amount, clearly indicating an electrostatic behavior of "bipolar charged" pores. This ion exclusion is not observed for pore diameters of ~100 nm. In addition, the solution pH of equal pore accessibility for oppositely charged ions and pore sizes smaller than 10 nm shifts with increasing polymer amount from a pH of 2.5 to 8.2, and the quantity of ions accessing the pores depends on the pore size. These observations clearly show the potential of controlling pore accessibility based on controlled functional composition at the nanoscale without changing the components themselves as well as the influence of spatial confinement on pore accessibility in the presence of complex (zwitterionic) charged states. [ABSTRACT FROM AUTHOR]

Published
2018
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56. Surface Enhanced DNP Assisted Solid-State NMR of Functionalized SiO2Coated Polycarbonate Membranes

Author

Kumari, Bharti, John, Daniel, Hoffmann, Paul, Spende, Anne, Toimil-Molares, Maria Eugenia, Trautmann, Christina, Hess, Christian, Ruff, Philip, Schulze, Marcus, Stark, Robert, Buntkowsky, Gerd, Andrieu-Brunsen, Annette, and Gutmann, Torsten

Abstract

Surface enhanced solid-state NMR by dynamic nuclear polarization (DNP SENS) enables the characterization of the inner-pore surface functionalization of porous etched ion-track membranes exhibiting low specific surface areas compared to typical SBA- or MCM-type mesoporous silica materials. The membranes were conformally coated with a 5 nm thin SiO2layer by atomic layer deposition. This layer was subsequently modified by aminopropyl silane linkers that allow further functionalization via the terminal amine group. The results evidence that in principle DNP SENS is a capable tool to analyze more complex porous systems, e.g. bioinspired functional etched ion-track membranes down to the molecular level. These results are relevant also for single nanopore systems, for which a direct analysis of the channel surface functionalization is not feasible by classical characterization methods. The applicability of DNP SENS to complex porous systems requires the optimization of the sample preparation and measurement parameters.

Published
2018
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58. Mesoporous Hybrid Thin Film Membranes with PMETAC@SilicaArchitectures: Controlling Ionic Gating through the Tuning of PolyelectrolyteDensity.

Author

Andrieu-Brunsen, Annette, Micoureau, Sébastien, Tagliazucchi, Mario, Szleifer, Igal, Azzaroni, Omar, and Soler-Illia, Galo J. A. A.

Subjects
*MESOPOROUS silica, *ARTIFICIAL membranes, *POLYELECTROLYTES, *IONS, *POLYMERIZATION, *SILICA films
Abstract

Manipulating molecular transportthrough mesoporous hybrid filmsis a fascinating approach toward mimicking transport in nature. Tounderstand the details in controlled transport, it is necessary togradually adjust the charge density that in turn results in a preciseadjustment of permselectivity. We have created hybrid architecturesthrough the controlled polymerization of a strong polyelectrolyte:(2-methacryloyloxy)ethyltrimethylammounium (PMETAC) in a mesoporousthin silica film. PMETAC contents from 5 to 100% filling can be obtainedby choosing a temperature or light-induced polymerization route andby varying polymerization times, as proven by ellipsoporosimetry andinfrared spectroscopy. Using cyclic voltammetry, we demonstrate thata gradual variation of ionic permselectivity from a silanol-regulatedto a PMETAC-regulated permselectivity can be obtained by tuning thePMETAC mesopore filling. The resulting behavior ranges from ion exclusionto preconcentration. The experimental observations are correlatedwith theoretical calculations that provide quantitative insights intothe organization of the ions and polymers within the pore. Our findingsshed light into the understanding of the interplay between chargedensity and space on molecular transport, leading toward the rationaldesign of selectively transporting synthetic membranes. [ABSTRACT FROM AUTHOR]

Published
2015
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59. Simultaneous Nanolocal Polymer and In SituReadout Unit Placement in Mesoporous Separation Layers

Author

Stanzel, Mathias, Zhao, Lucy, Mohammadi, Reza, Pardehkhorram, Raheleh, Kunz, Ulrike, Vogel, Nicolas, and Andrieu-Brunsen, Annette

Abstract

Bioinspired solid-state nanopores and nanochannels have attracted interest in the last two decades, as they are envisioned to advance future sensing, energy conversion, and separation concepts. Although much effort has been made regarding functionalization of these materials, multifunctionality and accurate positioning of functionalities with nanoscale precision still remain challenging. However, this precision is necessary to meet transport performance and complexity of natural pores in living systems, which are often based on nonequilibrium states and compartmentalization. In this work, a nanolocal functionalization and simultaneous localized sensing strategy inside a filtering mesoporous film using precisely placed plasmonic metal nanoparticles inside mesoporous films with pore accessibility control is demonstrated. A single layer of gold nanoparticles is incorporated into mesoporous thin films with precise spatial control along the nanoscale layer thickness. The local surface plasmon resonance is applied to induce a photopolymerization leading to a nanoscopic polymer shell around the particles and thus nanolocal polymer placement inside the mesoporous material. As near-field modes are sensitive to the dielectric properties of their surrounding, the in situsensing capability is demonstrated using UV–vis spectroscopy. It is demonstrated that the sensing sensitivity only slightly decreases upon functionalization. The presented nanolocal placement of responsive functional polymers into nanopores offers a simultaneous filtering and nanoscopic readout function. Such a nanoscale local control is envisioned to have a strong impact onto the development of new transport and sensor concepts, especially as the system can be developed into higher complexity using different metal nanoparticles and additional design of mesoporous film filtering properties.

Published
2021
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60. Fabrication and in situ functionalisation of mesoporous silica films by the physical entrapment of functional and responsive block copolymer structuring agents

Author

Tom, Jessica C., Appel, Christian, and Andrieu-Brunsen, Annette

Subjects
6. Clean water
Abstract

Stimuli-responsive mesoporous silica films were prepared by evaporation-induced self-assembly through the physical entrapment of a functional block copolymer structuring agent, which simultaneously serves to functionalise the mesopore. These polymer���silica hybrid materials exhibit remarkable ionic permselectivity under highly filled conditions, and offer the potential for local polymer functionalisation for enhanced and tunable ionic permselectivity. This innovative and simple approach for the in situ functionalisation of mesoporous silica has the potential to improve how we approach the design of complex architectures at the nanoscale for enhanced transport, and is thus relevant for a variety of technologies based on molecular transport in nanoscale pores including separation, sensing, catalysis, and energy conversion.

61. Photochromic spiropyran- and spirooxazine-homopolymers in mesoporous thin films by surface initiated ROMP

Author

Krohm, F., Kind, J., Savka, R., Alcaraz Jan��en, Marcel, Herold, Dominik, Plenio, H., Thiele, Christina Marie, and Andrieu-Brunsen, Annette

Subjects
7. Clean energy
Abstract

The control of ionic permselectivity in porous films is an interesting aspect in the context of lab-on-chip devices and ��-electronics. Especially, visible light triggered ionic permselectivity control is of relevance because control by light can be maintained externally without changing internal system parameters. In addition, light is a sustainable energy source if sunlight is used. Here, we present the first mesoporous films modified with two different photochromic homopolymers by surface-initiated ring opening metathesis polymerization (SI-ROMP). Spiropyran- and spirooxazine functionalized norbornene monomers and the corresponding ROMP homopolymers are synthesized in solution and in mesopores and compared concerning their optical properties such as photochromic conversion kinetics, photostability, and the ratio of converted molecules. Optical properties are investigated using UV/VIS spectroscopy and 1H-NMR spectroscopy. Especially, spirooxazine, whose surface functionalization has not been studied in detail, shows fast switching properties and higher ratios of photochromically interconverted molecules. After grafting spiropyran- and spirooxazine norbornene homopolymers into mesopores, a slightly faster photochromic interconversion of polymers located inside the mesopores is observed compared to the solution polymers.

62. Functional Metalloblock Copolymers for the Preparation and In Situ Functionalization of Porous Silica Films

Author

Herzog, Nicole, H��bner, Hanna, R��ttiger, Christian, Gallei, Markus, and Andrieu-Brunsen, Annette

Subjects
7. Clean energy, 6. Clean water
Abstract

Stimuli-responsive mesoporous silica films were prepared by evaporation-induced self-assembly through the physical entrapment of a functional metalloblock copolymer structuring agent, which simultaneously served to functionalize the mesopore. After end-functionalization with a silane group, the applied functional metalloblock copolymers were covalently integrated into the silica mesopore wall. In addition, they were partly degraded after the formation of the mesoporous film, which enabled the precise design of accessible mesopores. These polymer���silica hybrid materials exhibited remarkable and gating ionic permselectivity and offer the potential for highly precise pore filling design and combination with high-throughput printing techniques. This in situ functionalization strategy of mesoporous silica using responsive metalloblock copolymers has the potential to improve how we approach the design of complex architectures at the nanoscale for tailored transport. This functionalization strategy paves the way for a variety of technologies based on molecular transport in nanoscale pores, including separation, sensing, catalysis, and energy conversion.

63. PEO-b-PNBA in-situ functionalized mesoporous silica films and their light- and pH-controlled ionic mesopore accessibility.

Author

Zhao, Lucy, Mikolei, Joanna J., Ceolin, Marcelo, Pardehkhorram, Raheleh, Czerwenka, Laura, and Andrieu-Brunsen, Annette

Subjects
*SILICA films, *MESOPOROUS silica, *MESOPOROUS materials, *BLOCK copolymers, *ETHYLENE oxide, *MESOPORES
Abstract

Multistimuli-responsive, in-situ functionalized mesoporous silica films were fabricated by evaporation-induced self-assembly through physical entrapment of the functional template poly(ethylene oxide)- b -poly(2-nitrobenzyl acrylate) (PEO- b -PNBA). The light-cleavable and pH-responsive block copolymer PEO- b -PNBA simultaneously serves as structure-directing agent and for in-situ polymer functionalization of the generated mesopore space. The use of different PEO- b -PNBA compositions results in highly filled hybrid mesoporous silica films with different pore sizes, porosity, and polymer chain sequence within the mesopores. Based on these structural variations and the polymer chain sequence the ionic permselectivity of the silica-polymer hybrid thin films is adjusted. The side chains of the template PNBA block can be deprotected upon irradiation, hereby releasing pH-responsive carboxylic acid groups. The irradiation energy and irradiation time-dependent deprotection allows gradually controlled charge regulation in mesopores. This approach of in-situ functionalization using multistimuli-responsive PEO- b -PNBA block copolymers facilitates the fabrication of multi-responsive hybrid mesoporous silica films and bears high potential for the production of complex, hierarchical, multifunctional mesoporous materials. This fabrication method including direct functionalization of mesoporous structures is of high interest for many applications based on controlled molecular transport in nanoscale pores, such as sensing, separation, or catalysis. [Display omitted] • In-situ functionalization of mesoporous silica films by using PEO- b -PNBA in EISA. • Light- and pH-controlled charge regulation in in-situ functionalized mesopores. • Structure property relation: mesopore order, irradiation, ionic pore accessibility. [ABSTRACT FROM AUTHOR]

Published
2024
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64. Laser Writing of Block-Copolymer Images into Mesopores Using SBDC-Initiated Visible-Light-Induced Polymerization.

Author

Förster C, Lehn R, Saritas EM, and Andrieu-Brunsen A

Abstract

For miniaturization, as well as for improving artificial nanopore performance, precise local polymer functionalization and the combination of different functionalities are required. Imagining data driven nanopore design automated nanopore functionalization would be beneficial. Using direct laser writing as one option of automated nanopore polymer functionalization visible light induced polymerizations are beneficial. Here, we demonstrate the functionalization of mesoporous silicafilms with two different polymers using automated laser writing. For this we developed a visible light (400-700 nm and 405 nm) N,N(diethylamino)dithiocarbamoylbenzyl(trimethoxy)silane (SBDC) inifierter initiated polymerization. While transferring this visible light induced polymerization using SBDC to a commercially available microscope, direct, automated laser writing, as well as polymer re-initiation was demonstrated. Thereby, polymer spots of 37 and 40 μm in diameter were achieved using 1-5 seconds for each irradiated spot., (© 2023 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

Published
2023
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