Browsing by Author "Kraus, Tobias"
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- ItemAdvancing environmental intelligence through novel approaches in soft bioinspired robotics and allied technologies: I-Seed project position paper for Environmental Intelligence in Europe(New York,NY,United States : Association for Computing Machinery, 2022) Mazzolai, Barbara; Kraus, Tobias; Pirrone, Nicola; Kooistra, Lammert; De Simone, Antonio; Cottin, Antoine; Margheri, LauraThe EU-funded FET Proactive Environmental Intelligence project "I-Seed"(Grant Agreement n. 101017940, https://www.iseedproject.eu/) targets towards the development of a radically simplified and environmentally friendly approach for environmental monitoring. Specifically, I-Seed aims at developing a new generation of self-deployable and biodegradable soft miniaturized robots, inspired by the morphology and dispersion abilities of plant seeds, able to perform low-cost, environmentally responsible, in-situ measurements. The natural functional mechanisms of seeds dispersal offer a rich source of robust, highly adaptive, mass and energy efficient mechanisms, and behavioral and morphological intelligence, which can be selected and implemented for advanced, but simple, technological inventions. I-Seed robots are conceived as unique in their movement abilities because inspired by passive mechanisms and materials of natural seeds, and unique in their environmentally friendly design because made of all biodegradable components. Sensing is based on a chemical transduction mechanism in a stimulus-responsive sensor material with fluorescence-based optical readout, which can be read via one or more drones equipped with fluorescent LiDAR technology and a software able to perform a real time georeferencing of data. The I-Seed robotic ecosystem is envisioned to be used for collecting environmental data in-situ with high spatial and temporal resolution across large remote areas where no monitoring data are available, and thus for extending current environmental sensor frameworks and data analysis systems.
- ItemAgeing of alkylthiol-stabilized gold nanoparticles(Hoboken, NJ : Wiley, 2015) Lacava, Johann; Weber, Anika; Kraus, TobiasThe ageing of spherical gold nanoparticles having 6-nm-diameter cores and a ligand shell of dodecanethiol is investigated under different storage conditions. Losses caused by agglomeration and changes in optical particle properties are quantified. Changes in colloidal stability are probed by analytical centrifugation in a polar solvent mixture. Chemical changes are detected by elementary analysis of particles and solvent. Fractionation occurs under all storage conditions. Ageing is not uniform but broadens the property distributions of the particles. Small-number statistics in the ligand shell density and the morphological heterogeneity of particles are possible explanations. Washing steps exacerbate ageing, a process that could not be fully reversed by excess ligands. Dry storage is not preferable to storage in solvent. Storage under inert argon atmosphere reduces losses more than all other conditions but could not prevent it entirely.
- ItemA block copolymer templated approach for the preparation of nanoporous polymer structures and cellulose fiber hybrids by ozone treatment(Cambridge : RSC Publ., 2022) Gemmer, Lea; Hu, Qiwei; Niebuur, Bart-Jan; Kraus, Tobias; Balzer, Bizan N.; Gallei, MarkusFunctional amphiphilic block copolymers (BCPs) are versatile, smart, and promising materials that are often used as soft templates in nanoscience. BCPs generally feature the capability of microphase-separation leading to various interesting morphologies at the nanometer length scale. Materials derived from BCPs can be converted into porous structures while retaining the underlying morphology of the matrix material. Here, a convenient and scalable approach for the fabrication of porous functional polyvinylpyridines (P2VP) is introduced. The BCP polyisoprene-block-P2VP (PI-b-P2VP) is obtained via sequential anionic polymerization of the respective monomers and used to form either BCP films in the bulk state or a soft template in a composite with cellulose fibers. Cross-linking of the BCPs with 1,4-diiodobutane is conducted and subsequently PI domains are selectively degraded inside the materials using ozone, while preserving the porous and tailor-made P2VP nanostructure. Insights into the feasibility of the herein presented strategy is supported by various polymer characterization methods comprising nuclear magnetic resonance (NMR), size exclusion chromatography (SEC), and differential scanning calorimetry (DSC). The resulting bulk- and composite materials are investigated regarding their morphology and pore formation by scanning electron microscopy (SEM), atomic force microscopy (AFM) and small-angle X-ray scattering (SAXS). Furthermore, chemical conversions were examined by energy dispersive X-ray spectroscopy (EDS), attenuated total reflection Fourier-transformation infrared spectroscopy (ATR-FTIR) and water contact angle (WCA) measurements. By this convenient strategy the fabrication of functional porous P2VP in the bulk state and also within sustainable cellulose composite materials is shown, paving the synthetic strategy for the generation of a new family of stimuli-responsive sustainable materials.
- ItemColloidal Analysis of Particles Extracted from Microalloyed Steels(Weinheim : Wiley-VCH, 2021) Hegetschweiler, Andreas; Jochem, Aljosha-Rakim; Zimmermann, Anna; Walter, Johannes; Staudt, Thorsten; Kraus, TobiasDifferent colloidal particle characterization methods are examined for their suitability to determine the particle size distribution of particles extracted from steels. Microalloyed steels are dissolved to extract niobium and titanium carbonitride particles that are important for the mechanical properties of these steels. Such particles have sizes ranging from several nanometers to hundreds of nanometers depending on the precipitation stage during the thermomechanically controlled rolling process. The size distribution of the particles is analyzed by dynamic light scattering (DLS), analytical ultracentrifugation (AUC), and hollow fiber flow field-flow fractionation (HF5) and compared to data obtained for reference particles as well as data from electron microscopy, the standard sizing technique used in metallurgy today. AUC and HF5 provide high-quality size distributions, average over large particle numbers that enables statistical analysis, and yield useful insights for alloy design; however, DLS fails due to a lack of resolution. Important aspects in the conversion and comparison of size distributions obtained for broadly distributed particle systems with different measurement principles and the role of surfactants used in sample preparation are discussed.
- ItemComputational design and optimization of electro-physiological sensors([London] : Nature Publishing Group UK, 2021) Nittala, Aditya Shekhar; Karrenbauer, Andreas; Khan, Arshad; Kraus, Tobias; Steimle, JürgenElectro-physiological sensing devices are becoming increasingly common in diverse applications. However, designing such sensors in compact form factors and for high-quality signal acquisition is a challenging task even for experts, is typically done using heuristics, and requires extensive training. Our work proposes a computational approach for designing multi-modal electro-physiological sensors. By employing an optimization-based approach alongside an integrated predictive model for multiple modalities, compact sensors can be created which offer an optimal trade-off between high signal quality and small device size. The task is assisted by a graphical tool that allows to easily specify design preferences and to visually analyze the generated designs in real-time, enabling designer-in-the-loop optimization. Experimental results show high quantitative agreement between the prediction of the optimizer and experimentally collected physiological data. They demonstrate that generated designs can achieve an optimal balance between the size of the sensor and its signal acquisition capability, outperforming expert generated solutions.
- ItemCurled cation structures accelerate the dynamics of ionic liquids(Cambridge : RSC Publ., 2021) Rauber, Daniel; Philippi, Frederik; Kuttich, Björn; Becker, Julian; Kraus, Tobias; Hunt, Patricia; Welton, Tom; Hempelmann, Rolf; Kay, Christopher W.M.Ionic liquids are modern liquid materials with potential and actual implementation in many advanced technologies. They combine many favourable and modifiable properties but have a major inherent drawback compared to molecular liquids – slower dynamics. In previous studies we found that the dynamics of ionic liquids are significantly accelerated by the introduction of multiple ether side chains into the cations. However, the origin of the improved transport properties, whether as a result of the altered cation conformation or due to the absence of nanostructuring within the liquid as a result of the higher polarity of the ether chains, remained to be clarified. Therefore, we prepared two novel sets of methylammonium based ionic liquids; one set with three ether substituents and another set with three butyl side chains, in order to compare their dynamic properties and liquid structures. Using a range of anions, we show that the dynamics of the ether-substituted cations are systematically and distinctly accelerated. Liquefaction temperatures are lowered and fragilities increased, while at the same time cation–anion distances are slightly larger for the alkylated samples. Furthermore, pronounced liquid nanostructures were not observed. Molecular dynamics simulations demonstrate that the origin of the altered properties of the ether substituted ionic liquids is primarily due to a curled ether chain conformation, in contrast to the alkylated cations where the alkyl chains retain a linear conformation. Thus, the observed structure–property relations can be explained by changes in the geometric shape of the cations, rather than by the absence of a liquid nanostructure. Application of quantum chemical calculations to a simplified model system revealed that intramolecular hydrogen-bonding is responsible for approximately half of the stabilisation of the curled ether-cations, whereas the other half stems from non-specific long-range interactions. These findings give more detailed insights into the structure–property relations of ionic liquids and will guide the development of ionic liquids that do not suffer from slow dynamics.
- ItemDense arrays of uniform submicron pores in silicon and their applications(Washington D.C. : American Chemical Society, 2015) Brodoceanu, Daniel; Elnathan, Roey; Prieto-Simón, Beatriz; Delalat, Bahman; Guinan, Taryn M.; Kroner, Elmar Karsten; Voelcker, Nicolas H.; Kraus, TobiasWe report a versatile particle-based route to dense arrays of parallel submicron pores with high aspect ratio in silicon, and explore the application of these arrays in sensors, optics, and polymer micropatterning. Polystyrene (PS) spheres are convectively assembled on gold-coated silicon wafers and sputter-etched, resulting in well-defined gold disc arrays with excellent long-range order. The gold discs act as catalysts in Metal-Assisted Chemical Etching (MACE), yielding uniform pores with straight walls, flat bottoms and high aspect ratio. The resulting pore arrays can be used as robust antireflective surfaces, in biosensing applications, and as templates for polymer replica molding.
- ItemDynamic Light Scattering on Nanoparticles in Microgravity in a Drop Tower(Heidelberg : Springer, 2022) Pyttlik, Andrea; Kuttich, Björn; Kraus, TobiasGravity affects colloidal dispersions via sedimentation and convection. We used dynamic light scattering (DLS) to quantify the mobility of nanoparticles on ground and in microgravity. A DLS instrument was adapted to withstand the accelerations in a drop tower, and a liquid handling set-up was connected in order to stabilize the liquid temperature and enable rapid cooling or heating. Light scattering experiments were performed in the drop tower at ZARM (Bremen, Germany) during a microgravity interval of 9.1 s and compared to measurements on ground. Particle dynamics were analyzed at constant temperature and after a rapid temperature drop using a series of DLS measurements with 1 s integration time. We observed nanoparticles with average gold core diameters of 7.8 nm and non-polar oleylamine shells that were dispersed in tetradecane and had an average hydrodynamic diameter of 21 nm. The particles did not change their diameter in the observed temperature range. The particle dynamics inferred from DLS on ground and in microgravity were in good agreement, demonstrating the possibility to perform reliable DLS measurements in a drop tower.
- ItemEther functionalisation, ion conformation and the optimisation of macroscopic properties in ionic liquids(Cambridge : RSC Publ., 2020) Philippi, Frederik; Rauber, Daniel; Kuttich, Björn; Kraus, Tobias; Kay, Christopher W.M.; Hempelmann, Rolf; Hunt, Patricia A.; Welton, TomIonic liquids are an attractive material class due to their wide liquid range, intrinsic ionic conductivity, and high chemical as well as electrochemical stability. However, the widespread use of ionic liquids is hindered by significantly higher viscosities compared to conventional molecular solvents. In this work, we show how the transport properties of ionic liquids can be altered significantly, even for isostructural ions that have the same backbone. To this end, structure–property relationships have been determined for a set of 16 systematically varied representative ionic liquids. Variations in molecular structure include ammonium vs. phosphonium, ether vs. alkyl side chains, and rigid vs. flexible anions. Ab initio calculations are used to relate molecular structures to the thermal, structural and transport properties of the ionic liquids. We find that the differences in properties of ether and alkyl functionalised ionic liquids are primarily dependent on minimum energy geometries, with the conformational flexibility of ether side chains appearing to be of secondary importance. We also show unprecedented correlations between anion conformational flexibility and transport properties. Critically, increasing fluidity upon consecutive introduction of ether side chains and phosphonium centres into the cation is found to be dependent on whether the anion is flexible or rigid. We demonstrate that targeted design of functional groups based on structure–property relationships can yield ionic liquids of exceptionally high fluidity.
- ItemFabrication of metal nanoparticle arrays by controlled decomposition of polymer particles(Bristol : IOP Publishing, 2013) Brodoceanu, Daniel; Fang, Cheng; Voelcker, Nicolas Hans; Bauer, Christina T.; Wonn, Anne; Kroner, Elmar; Arzt, Eduard; Kraus, TobiasWe report a novel fabrication method for ordered arrays of metal nanoparticles that exploits the uniform arrangement of polymer beads deposited as close-packed monolayers. In contrast to colloidal lithography that applies particles as masks, we used thermal decomposition of the metal-covered particles to precisely define metal structures. Large arrays of noble metal (Au, Ag, Pt) nanoparticles were produced in a three-step process on silicon, fused silica and sapphire substrates, demonstrating the generality of this approach. Polystyrene spheres with diameters ranging between 110 nm and 1 µm were convectively assembled into crystalline monolayers, coated with metal and annealed in a resistive furnace or using an ethanol flame. The thermal decomposition of the polymer microspheres converted the metal layer into particles arranged in hexagonal arrays that preserved the order of the original monolayer. Both the particle size and the interparticle distance were adjusted via the thickness of the metal coating and the sphere diameter, respectively.
- ItemFabrication of silicon nanowire arrays by near-field laser ablation and metal-assisted chemical etching(Bristol : IOP Publishing, 2016) Brodoceanu, Daniel; Alhmoud, Hashim Z.; Elnathan, Roey; Delalat, Bahman; Voelcker, Nicolas H.; Kraus, TobiasWe present an elegant route for the fabrication of ordered arrays of vertically-aligned silicon nanowires with tunable geometry at controlled locations on a silicon wafer. A monolayer of transparent microspheres convectively assembled onto a gold-coated silicon wafer acts as a microlens array. Irradiation with a single nanosecond laser pulse removes the gold beneath each focusing microsphere, leaving behind a hexagonal pattern of holes in the gold layer. Owing to the near-field effects, the diameter of the holes can be at least five times smaller than the laser wavelength. The patterned gold layer is used as catalyst in a metal-assisted chemical etching to produce an array of vertically-aligned silicon nanowires. This approach combines the advantages of direct laser writing with the benefits of parallel laser processing, yielding nanowire arrays with controlled geometry at predefined locations on the silicon surface. The fabricated VA-SiNW arrays can effectively transfect human cells with a plasmid encoding for green fluorescent protein.
- ItemFlexible and transparent electrodes imprinted from Au nanowires: stability and ageing(Cambridge : Royal Society of Chemistry, 2022) Engel, Lukas F.; González-García, Lola; Kraus, TobiasWe study the stability of flexible transparent electrodes (FTEs) that were self-assembled from ultra-thin gold nanowires (AuNW) by direct nanoimprinting of inks with different particle concentrations (1 to 10 mg mL−1). The resulting lines were less than 3 μm wide and contained bundles of AuNW with oleylamine (OAm) ligand shells. Small-angle X-ray scattering confirmed a concentration-independent bundle structure. Plasma sintering converted the wire assemblies into lines with a thin metal shell that contributes most to electrical conductivity and covers a hybrid core. We studied the relative change in sheet resistance and the morphology of the FTEs with time. The sheet resistance increased at all concentrations, but at different rates. The metal shell aged by de-wetting and pore formation. The hybrid core de-mixed and densified, which led to a partial collapse of the shell. Residual organics migrated through the shell via its pores. Lines formed at low concentration (cAu = 2 to 3 mg mL−1) contained less residual organics and aged slower than those formed at high cAu ≥ 5 mg mL−1. We passivated the conductive shell with thin, adsorbed layers of PEDOT:PSS and found that it decelerated degradation by slowing surface diffusion and hindering further rupture of the shell. Thick capping layers prevented degradation entirely and stopped pore formation.
- ItemFlexible and transparent electrodes imprinted from metal nanostructures: morphology and opto-electronic performance(Cambridge : Royal Society of Chemistry, 2022) Engel, Lukas F.; González-García, Lola; Kraus, TobiasWe directed the self-assembly of nanoscale colloids via direct nanoimprint lithography to create flexible transparent electrodes (FTEs) with metal line widths below 3 μm in a roll-to-roll-compatible process. Gold nanowires and nanospheres with oleylamine shells were imprinted with soft silicone stamps, arranged into grids of parallel lines, and converted into metal lines in a plasma process. We studied the hierarchical structure and opto-electronic performance of the resulting grids as a function of particle geometry and concentration. The performance in terms of optical transmittance was dominated by the line width. Analysis of cross-sections indicated that plasma sintering only partially removed the insulating ligands and formed lines with thin conductive shells and a non-conductive core. We provide evidence that the self-assembly of high-aspect nanowires can compensate for defects of the stamp and substrate irregularities during imprinting, while spheres cannot. The wire-based electrodes thus outperformed the sphere-based electrodes at ratios of optical transmittance to sheet resistance of up to ≈ 0.9% Ωsq−1, while spheres only reached ≈ 0.55% Ωsq−1
- ItemFormation mechanism for stable hybrid clusters of proteins and nanoparticles(Washington D.C. : American Chemical Society, 2015) Moerz, Sebastian T.; Kraegeloh, Annette; Chanana, Munish; Kraus, TobiasCitrate-stabilized gold nanoparticles (AuNP) agglomerate in the presence of hemoglobin (Hb) at acidic pH. The extent of agglomeration strongly depends on the concentration ratio [Hb]/[AuNP]. Negligible agglomeration occurs at very low and very high [Hb]/[AuNP]. Full agglomeration and precipitation occur at [Hb]/[AuNP] corresponding to an Hb monolayer on the AuNP. Ratios above and below this value lead to the formation of an unexpected phase: stable, microscopic AuNP–Hb agglomerates. We investigated the kinetics of agglomeration with dynamic light scattering and the adsorption kinetics of Hb on planar gold with surface-acoustic wave-phase measurements. Comparing agglomeration and adsorption kinetics leads to an explanation of the complex behavior of this nanoparticle–protein mixture. Agglomeration is initiated either when Hb bridges AuNP or when the electrostatic repulsion between AuNP is neutralized by Hb. It is terminated when Hb has been depleted or when Hb forms multilayers on the agglomerates that stabilize microscopic clusters indefinitely.
- ItemHybrid Dielectric Films of Inkjet-Printable Core-Shell Nanoparticles(Weinheim : Wiley-VCH, 2021) Buchheit, Roman; Kuttich, Björn; González-García, Lola; Kraus, TobiasA new type of hybrid core-shell nanoparticle dielectric that is suitable for inkjet printing is introduced. Gold cores (dcore ≈ 4.5 nm diameter) are covalently grafted with thiol-terminated polystyrene (Mn = 11000 Da and Mn = 5000 Da) and used as inks to spin-coat and inkjet-print dielectric films. The dielectric layers have metal volume fractions of 5 to 21 vol% with either random or face-centered-cubic structures depending on the polymer length and grafting density. Films with 21 vol% metal have dielectric constants of 50@1 Hz. Structural and electrical characterization using transmission electron microscopy, small-angle X-ray scattering, and impedance spectroscopy indicates that classical random capacitor-resistor network models partially describe this hybrid material but fail at high metal fractions, where the covalently attached shell prevents percolation and ensures high dielectric constants without the risk of dielectric breakdown. A comparison of disordered to ordered films indicates that the network structure affects dielectric properties less than the metal content. The applicability of the new dielectric material is demonstrated by formulating inkjet inks and printing devices. An inkjet-printed capacitor with an area of 0.79 mm2 and a 17 nm thick dielectric had a capacitance of 2.2±0.1 nF@1 kHz .
- ItemInfluence of core size and capping ligand of gold nanoparticles on the desorption/ionization efficiency of small biomolecules in AP‐SALDI‐MS(Hoboke, NJ : Wiley, 2020) Liu, Zhen; Zhang, Peng; Pyttlik, Andrea; Kraus, Tobias; Volmer, Dietrich A.Gold nanoparticles (AuNP) are frequently used in surface‐assisted laser desorption/ionization mass spectrometry (SALDI‐MS) for analysis of biomolecules because they exhibit suitable thermal and chemical properties as well as strong surface plasmonic effects. Moreover, the structures of AuNP can be controlled by well‐established synthesis protocols. This was important in the present work, which studied the influence of the nanoparticles’ structures on atmospheric pressure (AP)‐SALDI‐MS performance. A series of AuNP with different core sizes and capping ligands were investigated, to examine the desorption/ionization efficiency (DIE) under AP‐SALDI conditions. The results showed that both the AuNP core size as well as the nature of the surface ligand had a strong influence on DIE. DIE increased with the size of the AuNP and the hydrophobicity of the ligands. Chemical interactions between ligand and analytes also influenced DIE. Moreover, we discovered that removing the organic ligands from the deposited AuNP substrate layer by simple laser irradiation prior to LDI further amplified DIE values. The optimized AuNP were successfully used to analyze a wide arrange of different low molecular weight biomolecules as well as a crude pig brain extract, which readily demonstrated the ability of the technique to detect a wide range of lipid species within highly complex samples.
- ItemMaximizing transfection efficiency of vertically aligned silicon nanowire arrays(Hoboken, NJ : Wiley, 2015) Elnathan, Roey; Delalat, Bahman; Brodoceanu, Daniel; Alhoud, Hashim; Harding, Frances J.; Buehler, Katrin; Nelson, Adrienne; Isa, Lucio; Kraus, Tobias; Voelcker, Nicolas H.Vertically aligned silicon nanowire (VA‐SiNW) arrays are emerging as a powerful new tool for gene delivery by means of mechanical transfection. In order to utilize this tool efficiently, uncertainties around the required design parameters need to be removed. Here, a combination of nanosphere lithography and templated metal‐assisted wet chemical etching is used to fabricate VA‐SiNW arrays with a range of diameters, heights, and densities. This fabrication strategy allows identification of critical parameters of surface topography and consequently the design of SiNW arrays that deliver plasmid with high transfection efficiency into a diverse range of human cells whilst maintaining high cell viability. These results illuminate the cell‐materials interactions that mediate VA‐SiNW transfection and have the potential to transform gene therapy and underpin future treatment modalities.
- ItemMechanism and determinants of nanoparticle penetration through human skin(Cambridge : Royal Society of Chemistry, 2011) Kraus, Tobias; Labouta, Hagar I.; El-Khordagui, Labiba K.; Schneider, MarcThe ability of nanoparticles to penetrate the stratum corneum was the focus of several studies. Yet, there are controversial issues available for particle penetration due to different experimental setups. Meanwhile, there is little known about the mechanism and determinants of their penetration. In this paper the penetration of four model gold nanoparticles of diameter 6 and 15 nm, differing in surface polarity and the nature of the vehicle, through human skin was studied using multiphoton microscopy. This is in an attempt to profoundly investigate the parameters governing particle penetration through human skin. Our results imply that nanoparticles at this size range permeate the stratum corneum in a similar manner to drug molecules, mainly through the intercellular pathways. However, due to their particulate nature, permeation is also dependent on the complex microstructure of the stratum corneum with its tortuous aqueous and lipidic channels, as shown from our experiments performed using skin of different grades of barrier integrity. The vehicle (toluene-versus-water) had a minimal effect on skin penetration of gold nanoparticles. Other considerations in setting up a penetration experiment for nanoparticles were also studied. The results obtained are important for designing a new transdermal carrier and for a basic understanding of skin–nanoparticle interaction.
- ItemMicrogravity Removes Reaction Limits from Nonpolar Nanoparticle Agglomeration(Weinheim : Wiley-VCH, 2022) Pyttlik, Andrea; Kuttich, Björn; Kraus, TobiasGravity can affect the agglomeration of nanoparticles by changing convection and sedimentation. The temperature-induced agglomeration of hexadecanethiol-capped gold nanoparticles in microgravity (µ g) is studied at the ZARM (Center of Applied Space Technology and Microgravity) drop tower and compared to their agglomeration on the ground (1 g). Nonpolar nanoparticles with a hydrodynamic diameter of 13 nm are dispersed in tetradecane, rapidly cooled from 70 to 10 °C to induce agglomeration, and observed by dynamic light scattering at a time resolution of 1 s. The mean hydrodynamic diameters of the agglomerates formed after 8 s in microgravity are 3 times (for low initial concentrations) to 5 times (at high initial concentrations) larger than on the ground. The observations are consistent with an agglomeration process that is closer to the reaction limit on thground and closer to the diffusion limit in microgravity.
- ItemMicroscopic Softening Mechanisms of an Ionic Liquid Additive in an Electrically Conductive Carbon-Silicone Composite(Weinheim : Wiley, 2022) Zhang, Long; Schmidt, Dominik S.; González‐García, Lola; Kraus, TobiasThe microstructural changes caused by the addition of the ionic liquid (IL) 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide to polydimethylsiloxane (PDMS) elastomer composites filled with carbon black (CB) are analyzed to explain the electrical, mechanical, rheological, and optical properties of IL-containing precursors and composites. Swelling experiments and optical analysis indicate a limited solubility of the IL in the PDMS matrix that reduces the cross-linking density of PDMS both globally and locally, which reduces the Young's moduli of the composites. A rheological analysis of the precursor mixture shows that the IL reduces the strength of carbon–carbon and carbon–PDMS interactions, thus lowering the filler–matrix coupling and increasing the elongation at break. Electromechanical testing reveals a combination of reversible and irreversible piezoresistive responses that is consistent with the presence of IL at microscopic carbon–carbon interfaces, where it enables re-established electrical connections after stress release but reduces the absolute conductivity.
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