RSC Applied Interfaces最新文献

Chemical warfare agents (CWAs) pose a threat to humanity, which motivates research focused on their destruction. Often, research deals with non-toxic simulants of CWAs, such as dimethyl methyl phosphonate (DMMP) and diisopropyl methyl phosphonate (DIMP). These compounds, like CWAs, are liquids at room temperature and boil just below 200 °C. In different scenarios, their interactions with inorganic solids may initially involve either liquid or vapor phases. This paper reviews published experimental data describing how the initial phase (vapor or liquid) of DMMP or DIMP influences the properties of their residues adsorbed to different inorganic surfaces. To facilitate comparisons between different sets of experiments, the focus is on the commonly reported shift and possible split of the PO peak assigned to the phosphoryl group, sensitive to molecular interactions in organophosphorus liquids and detected by Fourier Transform Infrared (FTIR) spectroscopy. Data sets for multiple metal oxides and salts are compared to one another. Systematic and distinct trends are found for the PO peak behavior for residues of evaporated and liquid DMMP and DIMP left on different surfaces. The literature data offer compelling evidence that the properties of residues left by organophosphonates on inorganic surfaces vary depending on the initial phase of the organophosphonate.

Hybrid membranes, consisting of phospholipids and amphiphilic block polymers, offer enhanced stability compared to liposomes and greater biocompatibility than polymersomes. These qualities make them a versatile platform for a wide range of applications across various fields. In this study, we have investigated the ability of solid-supported polymer-lipid hybrid membranes (SSHM) to act as a platform for bioelectrochemistry of membrane proteins. The redox enzyme, cytochrome bo ₃ (cyt bo ₃ ), a terminal oxidase in Escherichia coli, was reconstituted into hybrid vesicles (HVs), which were subsequently tested for their ability to form SSHMs on different self-assembled monolayers (SAMs) on gold electrodes. SSHM formation was monitored with electrochemical impedance spectroscopy (EIS), quartz crystal microbalance with dissipation (QCM-D), and atomic force microscopy (AFM). SSHMs were successfully formed on gold electrodes with mixed SAMs of 6-mercapto-1-hexanol and 1-hexanethiol at a 1 : 1 ratio. The activity of cyt bo ₃ was confirmed using cyclic voltammetry (CV), with electron transfer to cyt bo ₃ mediated by a lipophilic substrate-analogue decylubiquinone (DQ). SSHMs formed with HVs-cyt bo ₃ samples, stored for more than one year before use, remain bioelectrocatalytically active, confirming our previously established longevity and stability of HV systems.

Structurally coloured materials composed of monodisperse particles have attracted considerable attention as environmentally benign colourants. However, these materials exhibit poor mechanical robustness and colour degradation. Although efforts have been made to enhance the mechanical properties of structurally coloured materials, research specifically focusing on their mechanical robustness remains limited. This study investigates the preparation and mechanical robustness of structurally coloured photonic balls (PBs) composed of SiO₂ particles, emphasising the effects of preparation parameters on the particle arrangement and structural colour. We systematically varied the pH and ionic strength of SiO₂ dispersions, alongside the preparation temperatures, to examine their effects on the particle arrangement within PBs. The results indicated that at pH values near the isoelectric point, PBs adopted a colloidal amorphous-type structure, whereas higher pH levels led to colloidal crystalline-type arrangements characterised by vivid structural colours. Notably, increasing the ionic strength transitioned the particle arrangement towards a more disordered state, further emphasising the critical role of surface charge dynamics. In terms of mechanical robustness, the colloidal crystalline-type structures were stronger than their colloidal amorphous-type counterparts. The incorporation of a water-soluble silane compound as a binder in PBs significantly enhanced the interparticle necking formation during heat treatment, thereby improving the mechanical robustness. This study highlights the potential of optimising the preparation conditions for structurally coloured PBs with enhanced mechanical properties, offering a promising alternative to traditional inorganic pigments.

Laser-induced surface roughening is a technique that facilitates the reduction of secondary electron emission (SEE) from materials, which is crucial for mitigating electron cloud (EC) formation in particle accelerators, that operate with positively charged species, such as the large hadron collider (LHC). This study focuses on the development of a selective laser surface treatment of the inner copper surface of beam screens (BS) within superconducting (SC) magnets. Several technical challenges linked to laser processing exist including the reduction of treatment time and the control of ablation depth. Based on the found correlations between laser treatment parameters and materials properties, and considering all technical constraints for execution of such a process in SC magnets, a tailored laser processing strategy is developed, which includes creation of a rough Cu surface with trenches of 15–20 μm depth and an initial secondary electron yield maximum of 1.4–1.5, only in the most relevant regions of the BS. Resulting material properties are characterized such as the surface resistance and related beam impedance, as well as the SEE at both room temperature and cryogenic conditions. The efficiency to mitigate EC formation and thus improve beam quality is demonstrated via EC simulations and electron-induced conditioning experiments. This study also explores under which circumstances the risk of particulate detachment from the surface, which could lead to critical beam interaction, can be minimized.

In the past decade, the rapidly increasing global demand for energy and extensive concerns about the greenhouse effect and environmental problems from fossil fuels have stimulated intensive research interest in developing sustainable and clean energies and new electrochemical energy storage systems. Practical utilization of clean energies requires energy conversion involving different processes such as electricity-driven water splitting facilitating the storage of electrical energy in the form of hydrogen gas, and energy storage devices such as fuel cells and supercapacitors. A key issue to realize a high-efficiency conversion process is to find stable, low-cost and environment-friendly functional materials. Due to their extreme structural and compositional flexibilities, double perovskite (DP) oxides have gained much attention in the fields of electrocatalysis and supercapacitors. Recently, high-level theoretical studies have led to significant progress in the atomic-scale understanding of the catalytic mechanism of the DP oxide-driven oxygen evolution reaction (OER) and the electrochemical energy storage mechanism in DP oxide-based supercapacitors. In parallel, numerous experimental studies have been carried out to explore novel catalytic materials with advanced properties and kinetics, and more promising pseudocapacitive DP oxides have been developed. This review first introduces the structural and compositional flexibilities of DP perovskite oxides, and their prepared methods are described. Several strategies (e.g., nanostructure designs, elemental doping, tuning morphologies, crystallinity and surface defect engineering for improving oxygen vacancies) for modulating their electrochemical performance are also described. The recent progress of their applications in the electrochemical OER and supercapacitors is summarized. Finally, we conclude this review by giving some challenges and future perspectives of DP oxides in renewable energy conversion and energy storage devices.

Thermally conductive and electrically insulating hexagonal boron nitride (h-BN) is essential for thermal interface materials (TIMs) to effectively transfer heat from the source to sink in laptops and optoelectronic devices. Currently, thermal compounds rely on energy-intensive techniques and require nanofillers in very high loading percentages. Additionally, using mixtures of several fillers is an unreliable approach for heat management. In this work, we demonstrate the high-yield synthesis of atomically thin h-BN nanosheets in a natural surfactant/aqueous medium using liquid phase exfoliation (LPE). The exfoliated nanosheets are characterized by electron microscopy, absorbance spectroscopy, and XPS techniques. Extinction and gravimetry measurements confirm an overall yield of ∼89% after four cycles of exfoliation, successfully converting thick and bulk h-BN into h-BN nanosheets (h-BNNS) in water. Approximately 90% of the exfoliated nanosheets in ink form are recovered from the dispersion through low-speed centrifugation, indicating that the surfactant molecules are loosely bonded to the surface of the nanosheets. The quality of the exfoliated h-BNNS, including the lateral length (∼269 nm) and the number of layers (∼6), remains consistent during recycling. A 20 wt% h-BNNS in PVA thermal film reduces the surface temperature of a 10 W light-emitting diode (LED) bulb by ∼11 °C, while a 20 wt% h-BNNS in silicone oil (SO) thermal grease performs comparably to commercial thermal paste with 50 wt% particle loading for heat management. The thermal conductivity of the h-BNNS-based thermal film and thermal grease was measured using a modified transient plane source (MTPS) method and modelled using finite element analysis (FEA) to calculate thermal resistance. This study explores the utilization of a high-yield LPE process for h-BN nanosheets with natural stabilizers, enabling scalable exfoliation for heat management applications.

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The continuously growing concerns connected to the pollution produced by the extensive use of non-biodegradable composites strongly justify the need to find renewable and bio-degradable alternatives which are able to replace the already established synthetic composite materials. All-biopolymer composites with cellulose as the main component are emerging as excellent replacement candidates, combining full biodegradability with interesting properties. In the present work, such composites containing a cellulose-based textile reinforcement and a biopolymer-based matrix were prepared by two routes: 1) partial dissolution of the reinforcement fibers by impregnation with an ionic liquid (IL) to generate the matrix, or 2) impregnation of the reinforcement with a biopolymer-containing solution in an IL : DMSO mixture as a precursor for the matrix. For both routes, subsequent immersion in water to induce phase separation and thermal drying to complete the lamination yielded the final materials. The influences of the reinforcement textile composition (cotton vs. linen) and matrix generation route as well as the structure of the IL (route 1) or additional biopolymer (cellulose vs. chitosan; route 2) on the composite structure formation and the resulting mechanical properties were investigated in detail. Very high tensile modulus values of ∼2.8 ± 0.4 GPa and ∼3.3 ± 0.4 GPa were recorded for the composites obtained by the impregnation of a cotton textile with pure ionic liquids 1-ethyl-3-methyimidazolium acetate (EmimOAc) and 1-butyl-3-methylimidazolium acetate (BmimOAc), respectively. The tensile moduli of the composites obtained by the impregnation with BmimOAc were higher than the ones of the composites obtained under the same conditions by the impregnation with EmimOAc. Additionally, the composites obtained by the impregnation of the reinforcement textiles with a diluted solution of a similar biopolymer, namely chitosan, were less hydrophilic, as demonstrated by the increase of the contact angle from below 40° to ∼80°.

Materials that possess a porous and defected structure can have a range of useful properties that are sought after, which include their tolerance to nuclear radiation, ability to efficiently store and release isotopes, immobilize nuclear waste, and exhibit phase stability even at elevated temperatures. Since nanoscale pores and surface structures can serve as sinks for radiation-induced amorphization, one-dimensional (1D) porous nanorods, due to their high surface-to-volume ratio, have the potential for use as advanced materials in nuclear science applications. In this study, we demonstrate a synthesis and a detailed analysis of microporous 1D octahedral molecular sieves of disodium diniobate hydrate [(Na₂Nb₂O₆·H₂O) or Sandia octahedral molecular sieves (SOMS)]. In addition, the stability of these SOMS is evaluated following their exposure to elevated temperatures and neutron irradiation. A solvothermal method is used to prepare these SOMS-based nanorods. This relatively low temperature, solution-phase approach can form crystalline nanorods of microporous Na₂Nb₂O₆·H₂O. These 1D structures had an average diameter of ∼50 nm and lengths >1 μm. The nanorods adopted a defected microporous phase and matched the C2/c space group, which also exhibited resistance to radiation-induced amorphization. The dimensions, phase, and crystallinity of the SOMS-based nanorods after exposure to a high incident flux of neutrons were comparable to those of the as-synthesized products. The radiation tolerance of these microporous SOMS could be useful in the design of materials for nuclear reactors, resilient nuclear fuels, thermally resilient materials, high temperature catalysts, and durable materials for the handling and storage of radioactive waste.

Parylene is one of the most widely used polymers to fabricate flexible bioelectronic devices due to its flexibility, excellent barrier property, and photolithography-compatible fabrication. However, the extensively presented biofouling and the lack of biofunctionalities on the parylene surface prevent the bioelectronic device from constructing intimate coupling with cells/tissues. We herewith fabricated an intrinsically antifouling and soft parylene thin film featuring specific biointeraction, which consists of a bottom layer of pristine parylene and a top layer of 2-bromoisobutyrate functionalized parylene with ligand conjugated zwitterionic polymers. This layer-by-layer structure helps ensure the encapsulation property while allowing for tuning surface function for biomedical applications. This biomimetic parylene thin film presents an excellent barrier property (<10 pA leakage current after 12 weeks of soaking in 37 °C PBS buffer), a three-orders-of-magnitude reduced surface modulus (∼45 kPa), and exceptional mechanical compliance and conformability, all of which are crucial for constructing stable coupling with cells/tissues. Remarkably, the biomimetic parylene demonstrated a highly selective interaction toward PC12/HL-1 cells in the presence of a much higher density of white blood cells, thanks to the construction of specific cell interaction on a biofouling-resistant background. We envision that this biomimetic parylene material would offer bioelectronic devices a controllable interaction with biological systems, allowing seamless integration with cells/tissues and promoting the practical use of bioelectronic devices in real-life situations.