Nanoscience News (<front>)

The carrier transport behavior is regulated rather than the previously oversimplified limitation strategy to reduce losses and enhance energy storage efficiency. It is expected to offer a novel and effective theoretical basis for the design and fabrication of advanced polymer dielectrics with high capacitive energy storage level at harsh environments.

Abstract

Polymer dielectrics with high capacitive energy-storage levels in harsh environments have become key components in electrostatic capacitors. However, excessive losses in polymer dielectrics caused by high carrier densities at high temperatures and strong electric fields often result in low energy storage efficiency, which is the most challenging problem that urgently needs to be solved. In existing studies, the losses are mainly suppressed by limiting carrier formation; however, it is very challenging to completely limit carrier formation, especially at high temperatures and strong electric fields. Therefore, this perspective proposes to regulate the carrier transport behavior through “guiding/constraining/blocking” forms rather than the previously oversimplified carrier limitation strategy, which further clarifies dominant structure factors that inhibit carrier transport to reduce losses and enhance energy storage efficiency. Meanwhile, the influence of different structural designs on carrier transport behavior, individually or collaboratively, must be systematically studied to determine the specific mode of carrier transport behavior, thereby establishing a relationship between carrier transport behavior and energy storage efficiency. The presented perspective is expected to offer a novel and effective theoretical basis for the design and fabrication of advanced polymer dielectrics with high capacitive energy storage levels in harsh environments.

The degradable additive couple is developed to enable pure and preferential-oriented α-FAPbI3 perovskite with a bandgap of 1.489 eV and robustness against light, heat, and moisture over 1000 h, without the additive residue. The resultant perovskite solar cells achieve a power conversion efficiency of 25.20% with a short current density of 26.40 mA cm−2 and long-term operational stability of over 1000 h.

Abstract

Pure black-phase FAPbI3 has always been pursued because of its ideal bandgap (E g) and high thermal stability. Here, a pair of sacrificial agents containing diethylamine hydrochloride (DEACl) and formamide (Fo) is reported, which can induce the oriented growth of black-phase FAPbI3 along (111) and will disappear by the aminolysis reaction during perovskite annealing, retaining the E g of FAPbI3 as 1.49 eV. In addition, the tensile strain of the target FAPbI3 is found to be mitigated with a stabilized black phase due to the tilt of FA+. The devices based on the pure and stable black-phase (111)-FAPbI3 achieved a power conversion efficiency of 25.2% and 24.2% (certified 23.51%) with an aperture area of 0.09 and 1.04 cm2, respectively. After 1080 h of operation at the maximum power point under 1-sun illumination (100 mW cm−2), the devices maintained 91.68 ± 0.72% of the initial efficiencies.

Nature Energy, Published online: 28 March 2025; doi:10.1038/s41560-025-01763-3

Publisher Correction: Navigating thermal stability intricacies of high-nickel cathodes for high-energy lithium batteries

Nature Materials, Published online: 28 March 2025; doi:10.1038/s41563-025-02195-w

Characterizing the interference of phonons at the single-molecule level remains a challenging task. Here, the authors observe and characterize destructive phonon interference in molecular junctions at room temperature.

Nature Materials, Published online: 28 March 2025; doi:10.1038/s41563-025-02191-0

Achieving both high efficiency and narrow emission in organic light-emitting transistors (OLETs) remains a challenge. Here the authors demonstrate laterally integrated OLETs with an intrinsic microcavity that achieve both enhanced efficiency and narrow emission.

Nature Materials, Published online: 28 March 2025; doi:10.1038/s41563-025-02194-x

Fracture behaviours in multilayer h-BN, involving interlayer-friction toughening and edge-reconstruction embrittlement, are identified through in situ experiments and theoretical analyses.

DNA-Encoded Chemical Libraries - A BIOLOGICAL RIG SEMINAR

The discovery of small organic ligands, capable of specific recognition of protein targets of interest, is a central problem in Chemistry, Pharmacy, Biology and Medicine. Traditionally, small organic ligands to proteins are discovered by screening, one by one, individual compounds from chemical libraries. However, the technology is cumbersome, very expensive and is typically limited to the testing of up to one million compounds. DNA -encoded chemical library (DEL) technology allows the construction and screening of much larger compound libraries, without the need for expensive instrumentations and logistics. DELs are collections of molecules, individually coupled to distinctive DNA fragments, serving as amplifiable identification barcodes. Binding compounds can be selected using affinity capture procedures, with the protein target of interest immobilised on magnetic beads. After this “fishing” experiment, the DNA barcodes can be PCR amplified and quantified using high-throughput DNA sequencing [1]. In this lecture, I will present theory and applications of DEL technology. I will also show examples of DEL -derived ligands, isolated in our laboratories, which have been tested in patients with cancer, with promising clinical results.

• Speaker: Professor Dario Neri - CEO and CSO of Philogen, Professor of ETH Zürich, Honorary Senior Visiting Fellow, Department of Radiology, University of Cambridge (UK)
• Monday 31 March 2025, 15:00-16:00
• Venue: Department of Chemistry, Cambridge, Pfizer LT.
• Series: Biological Chemistry Research Interest Group; organiser: Xani Thorman.

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Recent aspects of chaperone functions in health and disease - A BIOLOGICAL RIG SEMINAR

Abstract not available

• Speaker: Prof. Ulrich Hartl - Max-Planck-Institute of Biochemistry
• Tuesday 08 April 2025, 13:30-14:30
• Venue: Department of Chemistry, Cambridge, Pfizer LT.
• Series: Biological Chemistry Research Interest Group; organiser: Xani Thorman.

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Joint ChemBio and Synthesis RIG Seminar - Chemical Biology Tools for Measuring Drug Delivery

Large-molecule therapeutics including peptides, oligonucleotides, and proteins make up a large and growing portion of the drug development pipeline. One of the greatest barriers to developing these drugs is cell penetration. Most enter the cell through a complex pathway involving endocytosis followed by endosomal escape. This process is so poorly understood and difficult to study that it is challenging simply to measure how much compound has actually accessed the cytosol at any given point. The Kritzer Lab has developed new tools for making these and related measurements. The Chloroalkane Penetration Assay (CAPA) is a versatile assay that measures cell penetration using cellularly expressed HaloTag protein and a small chloroalkane tag on the molecule-of-interest. CAPA has been used by the Kritzer group to measure cell penetration for many classes of peptide and oligonucleotide therapeutics, to measure penetration to different subcellular compartments, and to measure relative penetration in different cell types. CAPA has also been adopted by academic and industrial groups all over the world to investigate cell penetration. The Kritzer group has also used molecular evolution to produce new HaloTag variants which work optimally with a fluorogenic benzothiadiazole dye. The resulting “BenzoTag” system allows for turn-on, no-wash cell labeling in seconds. BenzoTag is currently being applied to produce a “turn-on” version of CAPA for continued investigation of drug delivery and mechanisms of endosomal escape

• Speaker: Joshua Kritzer (Tufts University)
• Friday 23 May 2025, 14:00-15:00
• Venue: Dept. of Chemistry, Wolfson Lecture Theatre.
• Series: Synthetic Chemistry Research Interest Group; organiser: Jasmine Mitchell.

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The Druggable Transcriptome Project: From Chemical Probes to Precision Medicines

A scientific challenge is to understand biological pathways and to exploit the targets within them for therapeutic development. Coding and non-coding RNAs both directly cause disease, whether by mutation or aberrant expression. Akin to proteins, RNA structure often dictates its function in health or dysfunction in disease. RNA , however, is generally not considered a target for small molecule chemical probes and lead medicines, despite its immense potential. The focus of our research program is to uncover fundamental principles that govern the molecular recognition of RNA structures by small molecules to enable design of chemical probes that targeting disease relevant RNA structures to perturb and study their function.

I will describe using evolutionary principles to identify molecular recognition patterns between small molecules and RNA structures by studying the binding of RNA fold libraries to small molecule libraries. These interactions are computationally mined across the human transcriptome to define cellular RNAs with targetable structure. Such an approach has afforded bioactive interactions that have uncovered new biology, where the small molecules bind to functional structures within a target RNA . We have devised a strategy to imbue biologically silent RNA -small molecule interactions with cellular activity. Chimeras comprising an inactive small molecule and ribonuclease recruiter trigger targeted degradation of disease-causing RNAs. These degraders affect the biology of RNA in specific ways in cells and in mouse models of various diseases and can rationally reprogram protein-targeted medicines for RNA . Lastly, we have recently devised unbiased transcriptome wide approaches to define the RNA bound by small molecules is live cells. This allows us to study the RNA targets that are bound by small molecules, the selectivity of these interactions, and ways in which compounds of various types can modulate disease biology.

• Speaker: Matthew Disney - Scripps Research Institute
• Tuesday 01 April 2025, 14:30-15:30
• Venue: Department of Chemistry, Cambridge, Pfizer lecture theatre.
• Series: Biological Chemistry Research Interest Group; organiser: Xani Thorman.

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A versatile assembly method is developed to uniformly assemble 2D single-crystal copper nanosheets (Cu NS) onto substrates with complex shapes via ultrasonication process. This technique leverages cavitation effects to deposit monolayer Cu NS films with minimal overlap. The assembly is optimized by tuning solvent polarity and substrate surface energy. Demonstrated applications include a resistive heater, highlighting the potential in flexible electronics.

Abstract

Scalable and cost-effective fabrication of conductive films on substrates with complex geometries is crucial for industrial applications in electronics. Herein, an ultrasonic-driven omni-directional and selective assembly technique is introduced for the uniform deposition of 2D single-crystalline copper nanosheets (Cu NS) onto various substrates. This method leverages cavitation-induced forces to propel Cu NS onto hydrophilic surfaces, enabling the formation of monolayer films with largely monolayer films with some degree of nanosheet overlap. The assembly process is influenced by solvent polarity, nanosheet concentration, and ultrasonic parameters, with non-polar solvents significantly enhancing Cu NS adsorption onto hydrophilic substrates. Furthermore, selective assembly is achieved by patterning hydrophobic and hydrophilic regions on the substrate, ensuring precise localization of Cu NS films. The practical potential of this approach is demonstrated by fabricating a Cu NS-coated capillary tube heater, which exhibits excellent heating performance at low operating voltages. This ultrasonic-driven and selective assembly method offers a scalable and versatile solution for producing conductive films with tailored geometries, unlocking new possibilities for applications in flexible electronics, energy storage, and wearable devices with complex structural requirements.

This study introduce a novel approach to enhancing cathode-SPE compatibility by utilizing the same poly(ionic liquid) (PolyIL)-based material in both the SPE and the cathode binder. A modified biomass-based PolyIL substrate, enriched with highly negatively charged C═O and ─OH groups, is incorporated into the SPE to improve Li+ migration and strengthen its mechanical properties. The Li||LiFePO₄ cell, assembled via in situ photopolymerization, demonstrate stable cycling for over 1100 cycles, while the Li||NCM811 cell operated reliably at a high cut-off voltage of 4.8 V for 100 cycles.

Abstract

Lithium metal batteries (LMBs) with solid polymer electrolytes (SPEs) offer higher energy density and enhance safety compared to the Li-ion batteries that use a graphite anode and organic electrolytes. However, achieving long cycle life for LMBs while enabling the use of high-voltage cathodes required the compatibility between cathode-SPE, rather than focusing solely on the individual components. This study presente a dual-functional poly(ionic liquid) (PolyIL)-based material that simultaneously serves as an SPE matrix and a cathode binder, constructing a cathode-SPE interface with exceptional (electro)chemical compatibility owing to the high ionic conductivity and wide electrochemical stability window. Additionally, a modified cellulose acetate (CA)-based PolyIL substrate, enriched with C═O and ─OH groups, is designed rationally and incorporated to assist the Li+ migration, leveraging their highly negative charge, and enhancing the mechanical strength of the SPE. Furthermore, an in situ polymerization approach is employed to assemble the cells, improving the physical compatibility at the cathode-SPE interface. As a result, the Li||LFP cell demonstrate stable cycling beyond 1100 cycles, and the Li||NCM811 cell reliably operates at a high cut-off voltage of up to 4.8 V.

Synthesis of topological semimetal TaAs2 nanowires in situ encapsulated with a thin SiO2 shell unravel a richness of intertwined topological phases manifested by their magnetotransport features: A near-room-temperature metal-to-insulator transition, strong expressions of topologically nontrivial surface transport, giant magnetoresistance with direction-dependent sign reversal, chiral anomaly, and a unique double pattern of Aharonov–Bohm oscillations.

Abstract

Nanowires (NWs) of topological materials are emerging as an exciting platform to probe and engineer new quantum phenomena that are hard to access in bulk phase. Their quasi-1D geometry and large surface-to-bulk ratio unlock new expressions of topology and highlight surface states. TaAs2, a compensated semimetal, is a topologically rich material harboring nodal-line, weak topological insulator (WTI), C2-protected topological crystalline insulator, and Zeeman field-induced Weyl semimetal phases. We report the synthesis of TaAs2 NWs in situ encapsulated in a dielectric SiO2 shell, which enable to probe rich magnetotransport phenomena, including metal-to-insulator transition and strong signatures of topologically nontrivial transport at remarkably high temperatures, direction-dependent giant positive, and negative magnetoresistance, and a double pattern of Aharonov–Bohm oscillations, demonstrating coherent surface transport consistent with the two Dirac cones of a WTI surface. The SiO2-encapsulated TaAs2 NWs show room-temperature conductivity up to 15 times higher than bulk TaAs2. The coexistence and susceptibility of topological phases to external stimuli have potential applications in spintronics and nanoscale quantum technology.

Big Picture Talk: Bhopal 40 years on - What have we learned?

Our departmental seminar series, Bigger Picture Talks, runs throughout the academic year, inviting thought-leaders from across the world driving significant advances in our impact areas of energy, health and sustainability to share and discuss their work with us.

This talk will hear from alumni Professor Fiona Macleod, Professor of Process Safety at the University of Sheffield, who will talk about safety in the chemical engineering industry, using the worst disaster in history as a lens for why safety matters.

On the night of 2 and 3 December 1984 a toxic gas release from the Union Carbide pesticide factory in Bhopal, India caused thousands of deaths and hundreds of thousands of life-changing injuries. Forty years later, the rusting factory equipment still towers above buried hazardous waste in the abandoned factory. I visited the site of the former Union Carbide site in Bhopal India to try to understand what went so horribly wrong.

1. What caused the worst accident in the history of the chemical industry? 2. Why was the accident never properly investigated? 3. What can we learn about process safety from revisiting the accident? 4. Why has no clean-up been undertaken in 40 years?

• Speaker: Professor Fiona Macleod
• Tuesday 06 May 2025, 14:30-15:15
• Venue: Lecture Theatre 1, Department of Chemical Engineering and Biotechnology, West Cambridge Site.
• Series: Chemical Engineering and Biotechnology; organiser: ejm94.

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A thermo-electrochemically compatible polymer electrolyte is proposed with a locally conjugated structure through self-regulation of paired tertiary anilines coupled with in situ polymerization, which significantly reconstructs an improved Li+ solvation and enhances electrode/electrolyte interfacial stability of LMBs. This concept provides an important theoretical basis and technical means for achieving practical high energy/power density LMBs.

Abstract

Pursuing high energy/power density lithium metal batteries (LMBs) with good safety and lifespan is essential for developing next-generation energy-storage devices. Nevertheless, the uncontrollable degradation of the electrolyte and the subsequent formation of inferior electrolyte/electrode interfaces present formidable challenges to this endeavor, especially when paring with transition metal oxide cathode. Herein, a fireproof polymeric matrix with a local conjugated structure is constructed by 4,4′-methylenebis (N, N-diglycidylaniline) (NDA) monomer via in situ polymerization, which promotes the use of ester-based liquid electrolyte for highly stable LMBs. The conjugated tertiary anilines in this PNDA electrolyte effectively tune the Li+ solvation sheath and generate conformal protective layers on the electrode surfaces, resulting in excellent compatibility with both high-voltage cathodes and Li-metal anodes. Moreover, the accumulated electron density endows PNDA with a powerful capability to seize and eliminate the corrosive hydrofluoric acid, which strikingly mitigates the irreversible structure transformation of LiNi0.8Mn0.1Co0.1O2 (NMC) particles. As a result, the PNDA-based Li||LiFePO4 and Li||NMC cells reach excellent electrochemical and safety performance. This study provides a promising strategy for the macromolecular design of electrolytes and emphasizes the importance of “local conjugation” within the polymers for LMBs.

An efficient and safe circular-RNA delivery system circSCMH1@LNP1 is developed for direct nose-to-brain delivery of circRNA SCMH1 to ischemic lesions. Experiments demonstrate that intranasally administrated circSCMH1@LNP1 significantly accumulates in the peri-infarct region of PT stroke mice, thereby improving functional recovery by enhancing synaptic plasticity, vascular repair, neuroinflammation relief, and myelin sheath formation.

Abstract

Ischemic stroke represents one of the leading cerebrovascular diseases with a high rate of mortality and disability globally. To date, there are no effective clinical drugs available to improve long-term outcomes for post-stroke patients. A novel nucleic acid agent circSCMH1 which can promote sensorimotor function recovery in rodent and nonhuman primate animal stroke models has been found. However, there are still delivery challenges to overcome for its clinical implementation. Besides, its effects on post-stroke cognitive functions remain unexplored. Herein, lipid nanoparticle circSCMH1@LNP1 is established to deliver circSCMH1 and explore its therapeutic efficacy comprehensively. Distribution experiments demonstrate that intranasal administration of circSCMH1@LNP1 significantly increases circSCMH1 distribution in the peri-infarct region and reduces its non-specific accumulation in other organs compared to intravenous injection. Therapeutic results indicate that circSCMH1@LNP1 promotes synaptic plasticity, vascular repair, neuroinflammation relief, and myelin sheath formation, thereby achieving enhanced sensorimotor and cognitive function recovery in post-stroke mice. In conclusion, this research presents a simple and effective LNP system for efficient delivery of circSCMH1 via intranasal administration to repair post-stroke brain injury. It is envisioned that this study may bridge a crucial gap between basic research and translational application, paving the way for clinical implementation of novel circSCMH1 in post-stroke patient management.

Super-hard wood-based composites (WBC) are designed and developed inspired by the mesoscale homogeneous lignification process intrinsic to tree growth. This innovative hybrid structure is achieved by leveraging the infusion of low-molecular-weight phenol formaldehyde resin into the cell walls of thin wood slices, followed by a unique multi-layer construction and high-temperature compression.

Abstract

The growing demand for high-strength, durable materials capable of enduring extreme environments presents a significant challenge, particularly in balancing performance with sustainability. Conventional materials such as alloys and ceramics are nonrenewable, expensive, and require energy-intensive production processes. Here, super-hard wood-based composites (WBC) inspired by the meso-scale homogeneous lignification process intrinsic to tree growth are designed and developed. This hybrid structure is achieved innovatively by leveraging the infusion of low-molecular-weight phenol formaldehyde resin into the cell walls of thin wood slices, followed by a unique multi-layer construction and high-temperature compression. The resulting composite exhibits remarkable properties, including a Janka hardness of 24 382 N and a Brinell hardness of 40.7 HB, along with exceptional antipiercing performance. The created super-hard, sustainable materials address the limitations of nonrenewable resources while providing enhanced protection, structural stability, and exceptional resilience. The WBC approach aligns with UN Sustainable Development Goals (SDGs) by offering extra values for improving personal safety and building integrity across various engineering applications.

A tailor-made blue organic emitter with hot exciton and aggregation-induced emission characteristics serves as a sensitizer in the innovative sensitizing system with a dual-channel stepwise energy transfer feature. The established material and device approach enables efficient, stable blue organic light-emitting diodes with narrow emission and low-efficiency roll-off at high luminance.

Abstract

Marching toward next-generation ultrahigh-definition and high-resolution displays, the development of high-performance blue organic light-emitting diodes (OLEDs) with narrow emission and high luminance is essential and requires conceptual advancements in both molecular and device design. Herein, a blue organic emitter is reported that exhibits hot-exciton and aggregation-induced emission characteristics, and use it as a sensitizer in the proposed triplet–triplet annihilation (TTA)-assisted hot-exciton-sensitized fluorescence (HSF) device, abbreviated THSF. Results show that through dual-channel stepwise Förster and Dexter energy transfer processes, the THSF system can simultaneously enhance exciton utilization, accelerate exciton dynamics, and reduce the concentration of triplet excitons. The smooth management of excitons makes the overall performance of the THSF device superior to the control TTA fluorescence and HSF devices. Furthermore, a high-performance narrowband blue (CIEx,y = 0.13, 0.12) OLED is achieved using a two-unit tandem device design, providing an excellent maximum external quantum efficiency of 18.3%, a record-high L 90% (the luminance where the ƞ ext drops to 90% of its peak value) of ≈20 000 cd m−2, and a long half-lifetime at 100 cd m−2 initial luminance of ≈13 256 h. These results showcase the great potential of the THSF strategy in realizing efficient and stable blue OLEDs with narrow emission and high luminance.

This work developed a LiC6@Li counter electrode, as an alternative to Li metal for more precisely evaluating the electrochemical behavior of electrode materials at low temperatures. The low interfacial resistances facilitate preferential de-intercalation of Li+ from LiC6, resulting in a sharp decreased over-potential at low temperatures. Meanwhile, the rapid replenishment of Li+ through the solid–solid-connection reaction maintains stable LiC6@Li potential.

Abstract

Li metal, as a counter electrode, is widely used for electrode materials evaluation in coin type half-cells. However, whether this configuration is suitable for different working conditions has often been neglected. Herein, the large resistance and high cathodic/anodic over-potential of Li metal at low temperature are highlighted, revealing its incompetence as counter electrode on cryogenic condition. In view of this, a novel LiC6@Li composite electrode is developed as a promising substitution for electrode materials evaluation. In the LiC6@Li electrode, Li+ de-intercalated from LiC6 preferentially due to the low interface resistance of LiC6, presenting a cathodic/anodic over-potential of 0.05 V (67 µA cm−2) at −20 °C, which is ten times lower than that of Li metal. Moreover, the rapid lithium replenishment into LiC6 from Li metal enables a stable potential of LiC6@Li. Consequently, the LiC6@Li-based half-cells enabled more precise evaluation of the Li+ storage potential and specific capacities of a series of electrode materials at low temperature. As an extension, KC8@K is also successfully prepared as a superior counter electrode to K metal. This work proposes a suitable counter electrode for more accurately evaluating electrode materials at subfreezing scenarios, demonstrating the necessity of specialized electrode evaluation systems for particular operating conditions.

The fabricated oriented chitosan nanofibrillar hydrogels (O-CN gels), via the synergy strategy of protein templating and mechanical training, achieve cartilage-like structure and mechanical performances, as well as high-water retention similar to cartilage. The resulting O-CN gels has excellent prospects in load-bearing cartilage engineering application.

Abstract

Cartilage, as a load-bearing tissue with high-water content, exhibits excellent elasticity and high strength. However, it is still a grand challenge to develop cartilage-adaptive biomaterials for replacement or regeneration of damaged cartilage tissue. Herein, protein templating and mechanical training is integrated to fabricate crystal-mediated oriented chitosan nanofibrillar hydrogels (O-CN gels) with similar mechanical properties and water content of cartilage. The O-CN gels with an ≈74 wt% water content exhibit high tensile strength (≈15.4 MPa) and Young's modulus (≈24.1 MPa), as well as excellent biocompatibility, antiswelling properties, and antibacterial capabilities. When implanted in the box defect of rat's tails, the O-CN gels seal the cartilage (annulus fibrosus) defect, maintain the intervertebral disc height and finally prevent the nucleus herniation. This synergy strategy of protein templating and mechanical training opens up a new possibility to design highly mechanical hydrogels, especially for the replacement and regeneration of load-bearing tissues.