GIANT最新文献

In the human body, non-centrosymmetric biological structures exhibit piezoelectric effect across from microscopic biomolecular building blocks to macroscopic tissues and organs. However, the fabrication of piezoelectric devices from discarded natural tissues and organs has rarely been exploited for energy harvesting applications. Herein, the extracted human teeth were recycled as an active layer in a piezoelectric nanogenerator for power generation. Due to the piezoelectric effect of enamel and dentin, a human teeth-based sandwiched piezoelectric nanogenerator was fabricated, producing high and stable power outputs with an open-circuit voltage of approximately 0.9 V under an external force at 60 N. Furthermore, the high mechanical durability of the piezoelectric nanogenerator was also verified after 1600 pressing-and-releasing cycles without noticeable output degradation. Notably, for the first time, a light-emitting diode (LED) was illuminated by the human teeth-based piezoelectric device. This work exemplifies a sustainable strategy to recycle the extracted human teeth by fabricating a piezoelectric nanogenerator for energy harvesting, providing inspiration for converting waste into wealth toward green energy in bionanotechnology.

The perfluorosulfonic acid (PFSA) ionomers are key materials for proton exchange membranes (PEMs) and catalyst layers (CLs). Their morphology is profoundly influenced by the chain assembly behavior of PFSA in dispersions. Hence, we combine the characterization techniques of dynamic light scattering (DLS), small-angle X-ray scattering (SAXS), and cryo-transmission electron microscopy (Cryo-TEM) to study the nanostructures of PFSA dispersions, and provide a structure model for diverse PFSA ionomers in water/ethanol solvent. It is seen that PFSA ionomers self-assembly into a rod-like particle in dilute dispersion. As the concentration increases, the primary rod aggregates gradually assemble into a swollen- or Gaussian-network structure. Beyond this feature, we see that different PFSA ionomers show different nanostructures in dispersion. For the long-side-chain (LSC) PFSA ionomers, the 800-LSC PFSA tends to form monodisperse rod-like aggregates that is in a highly ordered arrangement with a rod diameter of 3.16 nm and a length of 28.72 nm. As the equivalent weight (EW) increases to 960, the poor solubility of the main chains in water/ethanol solvents leads to the “end-to-end” assemblies of the primary rod particles and dendritic secondary aggregates. The short-side-chain (SSC) PFSA ionomer that shares the same backbone with 960-LSC PFSA exhibit remarkable mono-dispersity and ordered arrangement of rod-like aggregates in water/ethanol solvents due to the strong electrostatic repulsion.

Organic photovoltaic materials have been widely used in organic solar cells (OSCs) and organic photodetectors (OPDs) systems, owing to their numerous advantages such as low cost, light weight, high structural tunability, and ease of solution processing. Among these materials, near-infrared (NIR)-responsive materials, especially those with NIR II-region (1000–1700 nm) response, are crucial in the construction of tandem OSCs and semitransparent OSCs to achieve high power conversion efficiency and high light utilization efficiency, respectively. Meanwhile, OPDs with NIR II-region response show great application potential in industrial, military, and medical fields. In recent years, some progress has been made in the development of organic photovoltaic materials and devices with NIR II-region response. This review provides an overview of the design strategies for NIR organic photovoltaic materials, followed by a classification and summary of representative organic NIR II-region responsive materials and their performance in OSCs and OPDs. Lastly, we conclude with an outlook on the development of organic photovoltaic materials with NIR II-region response.

Liquid crystal (LC) phases have been used in various self-assembly technologies owing to their stimuli-responsive characteristics. Especially, orientation-controlled LC structures on and in surfaces are extensively studied in physics, chemistry, and materials science because they can be used in patterning applications beyond the conventional LC display. The key idea in recent development is to control the surface anchoring condition between the substrate and LC materials. Specifically, defects in the LC phases have been introduced as an effective lithographic tool for fabricating distinguished patterns. In this review, the bulk and surface-induced structures of LC materials are overviewed to show the relationship between the surface characteristics of the substrates and the elastic properties of LC materials. The two main themes are (1) orientation control, which can be achieved by micro- and nano-confinement using solid and fluid substrates, and (2) the application of LC materials as optoelectronics and sensors. Finally, the review discusses the defect structures of LC materials fabricated on flexible substrates and their possible applications.

We developed a cost-effective silica gel-supported palladium nanocatalyst in a three-step reactions process. Initially, silica gel (60–120 mesh) underwent amino group functionalization using 3-aminopropyltriethoxysilane, leading to the formation of a Schiff base through a reaction with the 1,10-phenanthroline-2,9-dicarboxaldehyde ligand. Subsequently, palladium nanocatalyst was introduced to the silica matrix ligand in the presence of palladium salt and hydrazine hydrate, resulting in the formation of the silica gel-supported Schiff-base palladium nanocatalyst (Si@SBPdNPs 3). Successful functionalization of the silica matrix was confirmed using various spectroscopic techniques. FT-IR spectra demonstrated the incorporation of organic moieties onto the silica surface, while SEM images revealed the modified spherical shape of the silica gel. TEM and XRD analyses confirmed the presence of palladium on the silica matrix. ICP and EDX measurements validated the anchoring of 0.55 mmol/g of palladium to the catalyst. Additionally, XPS analysis showed the complexation of Pd⁽⁰⁾ with the organic ligand on the silica matrix, confirming the successful integration of palladium into the system. This nanocatalyst demonstrated outstanding performance in Mizoroki-Heck reactions, yielding high product outputs in the cross-coupling of various aryl halides and olefins under mild conditions. Additionally, the nanocatalyst was effectively utilized in synthesizing Ozagrel, a thromboxane A2 synthesis inhibitor used for treating noncardioembolic stroke patients. Remarkably, the catalyst demonstrated excellent reusability, maintaining high productivity across five consecutive cycles, underscoring its economic and sustainable potential for industrial applications.

Liquid crystal elastomers (LCEs) are a kind of soft actuating materials with large reversible deformation ability, which can work as the “motor” to exhibit complex deformations and drive the locomotion of soft robots. The deformation of LCEs depends on the three-dimensional (3D) shape of whole structure and alignment patterns of mesogens. Various methods have been employed to fabricate the LCE structure with desired shapes and mesogen alignments. However, conventional 3D printed LCEs require continuous thermal energy input to maintain their actuated shapes. The LCEs cannot be reprocessed and reprogrammed once cured. Herein, we introduce dynamic boronic ester bonds into the ink, with which the printed LCE structures are capable of being reprogrammed from polydomain into monodomain state and vice versa. We further explore the effects of printing parameters and content of dynamic covalent bonds on the actuation performance and reprogramming ability. The actuated shape could be well predicted with finite element method. The dynamic printable LCEs developed here offer new strategy and large design space for LCE structures.

Single crystal growth and characterization of the lithium bis(trifluoromethyl sulfonyl)imide (LiTFSI), the most common electrolyte salt for lithium-ion batteries, have been performed and succeeded in unraveling the atomic structures of its different crystalline phases. The structures of two crystalline phases (phase I: orthorhombic, Pccn; phase II: monoclinic, P2₁/c) have been determined through temperature-dependent X-ray crystallography of the LiTFSI single crystal on heating, and the solid-solid phase transformation between phase I and phase II has been dictated. Interestingly, a conformational change of TFSI⁻ from transoid to cisoid has been discovered during the transition from phase I to phase II, which has been further confirmed by the temperature-dependent Raman spectroscopy. The coordination of Li⁺ with the TFSI⁻ ions of different conformations has been also elucidated in the polymorphic crystalline structures. The solid-solid phase transformation of the first-order leads to the cracking of the LiTFSI crystal, probably along the lithium-ion or the fluorine-rich layer in phase II. In the molten state, the coexistence of the transoid conformation and the cisoid conformation is found in the TFSI⁻ ions, affirming the recent observation in the concentrated non-crystalline state. This work is anticipated to shed light on the (de)solvation and the transport of lithium ions in complex fluids encompassing LiTFSI electrolyte solutions from the structural aspects.

The structure of mRNA lipid nanoparticles (LNPs) is still under debate, with different studies presenting varying morphological characteristics, significantly hindering their biomedical potential. A typical formulation process of mRNA LNPs involves three steps: initial rapid mixing of lipids in an ethanol phase and mRNA in an acidic aqueous phase, followed by the swift removal of ethanol, and finally adjusting the solution to a neutral environment. In this study, we utilize Small Angle Neutron Scattering (SANS) with contrast matching to reveal the kinetic pathway-dependent of mRNA LNPs morphology. We find that the formulation process of the Moderna COVID-19 vaccine is controlled by a competition between aggregation and microphase separation, dictating the diverse morphologies observed in mRNA LNPs. The first step leads to the formation of polydisperse spherical droplets with an average diameter of 42±6.0 nm in an acidic ethanol aqueous solution. Ethanol removal initiates both aggregation and internal microphase separation, resulting in a polydisperse core-shell structure with an average diameter of 48±3.7 nm. Heptadecan-9-yl 8-((2-hydroxyethyl) (6-oxo-6-(undecyloxy) hexyl) amino) octanoate (SM-102) binds to mRNA via electrostatic interaction to form a reverse-wormlike micelle structure inside. The 1,2-Distearoyl-sn‑glycero-3-phosphocholine (DSPC) and PEG-lipid are just in the shell and cholesterol acting as a filler throughout the core-shell structure. Upon transitioning to a neutral environment, SM-102 loses its charge and neither the periphery nor the reverse-wormlike micelle can maintain their stabilities, leading to further aggregation and microphase separation. The average diameter of core-shell structure turns to be 66±5.2 nm. In the actual formulation process of the Moderna COVID-19 vaccine, steps 2 and 3 occur simultaneously, and the competition between aggregation and microphase separation determines the final morphology. These findings offer crucial insights into optimizing the morphology of mRNA LNPs, thereby facilitating advancements in vaccine development and mRNA vaccine delivery technologies.

This work reports the effect of 1–5 wt% epoxidized soybean oil (ESO) addition on the thermal, mechanical, and morphological properties of polybutylene succinate (PBS). ESO acts as a chain extender as well as a mild plasticizer of PBS. N-methylimidazole (NMI) is used as a catalyst to promote the reaction between PBS and ESO, and thermal, rheological, and spectroscopic analyses demonstrate increased viscoelastic properties, compatibility, crystallinity and thermal stability of the melt reacted formulations. In the presence of NMI, storage modulus (G’) values two orders of magnitude higher than that of pure PBS are achieved, confirming the completion of the chain extension reaction. A drastic refinement of the biphasic structure of the blend is observed, with the formation of a homogenous structure where ESO is well incorporated into the matrix. Finally, tensile tests reveal enhanced mechanical performance in the blends reacted in the presence of NMI. These findings pave the way for the development of a versatile family of materials which could find potential application in sustainable biodegradable packaging.

Liquid crystals, as typical anisotropic building blocks, tend to self-assemble into various ordered architectures during distinct thermodynamic processes. Research on the underlying mechanisms and rules may drastically promote our understanding of complicated structures. Here, zigzag focal conic domains (ZFCDs) are generated in rapid cooling process under an antagonistic boundary condition. After several thermal cycles beneath the nematic-smectic (N-S) phase transition point, the ZFCDs are well regularized. We found that the dislocations associated with the rapid cooling play vital roles in the formation of ZFCDs. A strong interphase correlation between the zigzag ± 1/2 disclination pairs and ZFCDs is observed above the N-S phase transition point. The orientational order inheritance and topological invariance across the phase transition indicate that similar disclination pairs exist in ZFCDs. These disclination pairs facilitate the opposite tilt direction and a half-pitch lateral shift between neighboring focal conic domains (FCDs), thus forming ZFCDs. During thermal cycles, the thermal motion of molecules induces the regularization and elimination of defect cores, further resulting in the ordered ZFCDs. Via properly controlling the cooling rate, large-area ordered ZFCDs are achieved in a wide film thickness range after thermal cycles. This study enriches the knowledge on the topological defect guided architecture of liquid crystals and may pave the way for the generation and regularization of ordered self-assembled systems.