Tailoring the solution chemistry of metal halide perovskites requires a detailed understanding of precursor aggregation and coordination. In this work, we use various scattering techniques, including ...dynamic light scattering (DLS), small angle neutron scattering (SANS), and spin–echo SANS (SESANS) to probe the nanostructures from 1 nm to 10 μm within two different lead-halide perovskite solution inks (MAPbI3 and a triple-cation mixed-halide perovskite). We find that DLS can misrepresent the size distribution of the colloidal dispersion and use SANS/SESANS to confirm that these perovskite solutions are mostly comprised of 1–2 nm-sized particles. We further conclude that if there are larger colloids present, their concentration must be <0.005% of the total dispersion volume. With SANS, we apply a simple fitting model for two component microemulsions (Teubner–Strey), demonstrating this as a potential method to investigate the structure, chemical composition, and colloidal stability of perovskite solutions, and we here show that MAPbI3 solutions age more drastically than triple cation solutions.
Cellulose membranes were prepared from an EMIMAc ionic liquid solution by nonsolvent-induced phase separation (NIPS) in coagulation baths of water-acetone mixtures, ethanolwater mixtures and water at ...different temperatures. High water volume fractions in the coagulation bath result in a highly reproducible gel-like structure with inhomogeneities observed by small-angle neutron scattering (SANS). A structural transition of cellulose takes place in water-acetone baths at very low water volume fractions, while a higher water bath temperature increases the size of inhomogeneities in the gel-like structure. These findings demonstrate the value of SANS for characterising and understanding the structure of regenerated cellulose films in their wet state. Such insights can improve the engineering and structural tuning of cellulose membranes, either for direct use or as precursors for carbon molecular sieve membranes.
The structure of cellulose films prepared by nonsolvent-induced phase separation in coagulation baths of different mixtures and temperatures. High water volume fractions in the coagulation bath result in a highly reproducible gel-like structure with inhomogeneities.
Li3YX6 (X = Cl, Br) materials are Li-ion conductors that can be used as solid electrolytes in all solid-state batteries. Solid electrolytes ideally have high ionic conductivity and (electro)chemical ...compatibility with the electrodes. It was proven that introducing Br to Li3YCl6 increases ionic conductivity but, according to thermodynamic calculations, should also reduce oxidative stability. In this paper, the trade-off between ionic conductivity and electrochemical stability in Li3YBr x Cl6–x halogen-substituted compounds is investigated. The compositions of Li3YBr1.5Cl4.5 and Li3YBr4.5Cl1.5 are reported for the first time, along with a consistent analysis of the whole Li3YBr x Cl6–x (x = 0–6) tie-line. The results show that, while Br-rich materials are more conductive (5.36 × 10–3 S/cm at 30 °C for x = 4.5), the oxidative stability is lower (∼3 V compared to ∼3.5 V). Small Br content (x = 1.5) does not affect oxidative stability but substantially increases ionic conductivity compared to pristine Li3YCl6 (2.1 compared to 0.049 × 10–3 S/cm at 30 °C). This work highlights that optimization of substitutions in the anion framework provide prolific and rational avenues for tailoring the properties of solid electrolytes.
Li
YX
(X = Cl, Br) materials are Li-ion conductors that can be used as solid electrolytes in all solid-state batteries. Solid electrolytes ideally have high ionic conductivity and (electro)chemical ...compatibility with the electrodes. It was proven that introducing Br to Li
YCl
increases ionic conductivity but, according to thermodynamic calculations, should also reduce oxidative stability. In this paper, the trade-off between ionic conductivity and electrochemical stability in Li
YBr
Cl
halogen-substituted compounds is investigated. The compositions of Li
YBr
Cl
and Li
YBr
Cl
are reported for the first time, along with a consistent analysis of the whole Li
YBr
Cl
(
= 0-6) tie-line. The results show that, while Br-rich materials are more conductive (5.36 × 10
S/cm at 30 °C for
= 4.5), the oxidative stability is lower (∼3 V compared to ∼3.5 V). Small Br content (
= 1.5) does not affect oxidative stability but substantially increases ionic conductivity compared to pristine Li
YCl
(2.1 compared to 0.049 × 10
S/cm at 30 °C). This work highlights that optimization of substitutions in the anion framework provide prolific and rational avenues for tailoring the properties of solid electrolytes.
The initial formation stages of surfactant-templated silica thin films which grow at the air–water interface were studied using combined spin–echo modulated small-angle neutron scattering (SEMSANS) ...and small-angle neutron scattering (SANS). The films are formed from either a cationic surfactant or nonionic surfactant (C16EO8) in a dilute acidic solution by the addition of tetramethoxysilane. Previous work has suggested a two stage formation mechanism with mesostructured particle formation in the bulk solution driving film formation at the solution surface. From the SEMSANS data, it is possible to pinpoint accurately the time associated with the formation of large particles in solution that go on to form the film and to show their emergence is concomitant with the appearance of Bragg peaks in the SANS pattern, associated with the two-dimensional hexagonal order. The combination of SANS and SEMSANS allows a complete depiction of the steps of the synthesis that occur in the subphase.
The modulated intensity by zero effort small‐angle neutron scattering (MI‐SANS) technique is used to measure scattering with a high energy resolution on samples normally ill‐suited for neutron ...resonance spin echo. The self‐diffusion constant of water is measured over a q–t range of 0.01–0.2 Å−1 and 70–500 ps. In addition to demonstrating the methodology of using time‐of‐flight MI‐SANS instruments to observe diffusion in liquids, the results support previous measurements on water performed with different methods. This polarized neutron technique simultaneously measures the intermediate scattering function for a wide range of time and length scales. Two radio frequency flippers were used in a spin‐echo setup with a 100 kHz frequency difference in order to create a high‐resolution time measurement. The results are compared with self‐diffusion measurements made by other techniques and the general applicability of MI‐SANS at a pulsed source is assessed.
A measurement of the self‐diffusion of water is presented, using the high‐resolution neutron scattering technique modulated intensity small‐angle neutron scattering (MI‐SANS). This technique uses two tuned radio frequency flippers to create a modulation in the neutron intensity that can resolve dynamics on the picosecond time scale.
We conduct simulations of Spin Echo Small Angle Neutron Scattering (SESANS) by employing Monte Carlo methods to a setup using four magnetic Wollaston prisms. Our primary focus involves the validation ...of these models, encompassing monochromatic scenarios across various neutron wavelengths to ascertain the reliability of the simulations. Subsequently, we extend this validation to encompass simulations in time-of-flight mode. Our model consistently and precisely predicts the scattering patterns emanating from dilute spheres in both monochromatic and time-of-flight modes. Notably, it also accurately reproduces the intricate encoding associated with scattering occurring between the third and fourth magnetic Wollaston prism, which provides us with another approach to increase the solid angle coverage of a SESANS instrument. This validation process conclusively demonstrates the efficacy of our simulation methods. Importantly, it paves the way for simulating more intricate and realistic instrumental configurations, broadening the horizons for future research endeavours.
Waterborne polyurethane (WPU) has attracted significant interest as a promising alternative to solvent-based polyurethane (SPU) due to its positive impact on safety and sustainability. However, ...significant limitations of WPU, such as its weaker mechanical strength, limit its ability to replace SPU. Triblock amphiphilic diols are promising materials to enhance the performance of WPU due to their well-defined hydrophobic–hydrophilic structures. Yet, our understanding of the relationship between the hydrophobic–hydrophilic arrangements of triblock amphiphilic diols and the physical properties of WPU remains limited. In this study, we show that by controlling the micellar structure of WPU in aqueous solution via the introduction of triblock amphiphilic diols, the postcuring efficiency and the resulting mechanical strength of WPU can be significantly enhanced. Small-angle neutron scattering confirmed the microstructure and spatial distribution of hydrophilic and hydrophobic segments in the engineered WPU micelles. In addition, we show that the control of the WPU micellar structure through triblock amphiphilic diols renders WPU attractive in the applications of controlled release, such as drug delivery. Here, curcumin was used as a model hydrophobic drug, and the drug release behavior from WPU-micellar-based drug delivery systems was characterized. It was found that curcumin-loaded WPU drug delivery systems were highly biocompatible and exhibited antibacterial properties in vitro. Furthermore, the sustained release profile of the drug was found to be dependent on the structure of the triblock amphiphilic diols, suggesting the possibility of controlling the drug release profile via the selection of triblock amphiphilic diols. This work shows that by shedding light on the structure–property relationship of triblock amphiphilic diol-containing WPU micelles, we may enhance the applicability of WPU systems and move closer to realizing their promising potential in real-life applications.
Abstract The local inflammatory environment of the cell promotes the growth of epithelial cancers. Therefore, controlling inflammation locally using a material in a sustained, non-steroidal fashion ...can effectively kill malignant cells without significant damage to surrounding healthy cells. A promising class of materials for such applications are the nanostructured scaffolds formed by epitope containing minimalist self-assembled peptides (SAPs), as they are bioactive on a cellular length scale, while presenting as an easily handled hydrogel. Here, we show that the assembly process distributes an anti-inflammatory polysaccharide, fuccoidan, localized to the nanofibers to function as an anti-inflammatory biomaterial for cancer therapy. We show that it supports healthy cells, while inducing apoptosis in cancerous endothelial cells, as demonstrated by the downregulation of the proinflammatory gene and protein expression pathways associated with epithelial cancer progression. Our findings highlight an innovative material approach with potential applications as local epithelial cancer immunotherapy and drug delivery vehicles.
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