Rigid Nanoparticles Research Articles

Applications of radionuclide-carrying liposomes for diagnosis and treatment of cancer

Using nanocapsules to deliver diagnostic and therapeutic agents to targeted biological sites enhances the safety and effectiveness of healthcare by decreasing toxicity and increasing the accumulation of medicinal agents at targeted sites. Liposomes, nanocapsules made of naturally occurring lipids, boast many advantages for the delivery of therapeutic agents. This article reviews both the advantages and challenges associated with liposomal drug delivery for the treatment of cancerous tumors and infectious diseases. These minute spherical sacs of phospholipid molecules are flexible carriers that can be modified in various ways to optimize their use. Examples of this include alteration of the size of liposomes to selectively accumulate in tumor microenvironments and “PEGylation” of their surface to reduce uptake of liposomes by the mononuclear phagocytic system (MPS). While one of the main challenges of liposomal drug delivery is the heightened uptake of liposomes by the MPS, this unique property can be used to target diseased areas with a significant MPS presence. Furthermore, the liposomal structure can be manipulated to allow for the triggered release of internal contents with externally controlled factors. Liposomes carrying therapeutic radionuclides can be injected directly into solid tumors and dispersed throughout the tumor by convection-enhanced delivery. The flexibility and pliability of liposomes allow them to move through tight spaces within a tumor with much greater dispersion and penetration when compared to more rigid nanoparticles. Due to the benefits of radionuclide-carrying liposomes in disease diagnosis and delivery of chemotherapeutic agents, their utilization is expected to be expanded.

Angular-Inertia Regulated Stable and Nanoscale Sensing of Single Molecules Using Nanopore-In-A-Tube.

Nanopore is commonly used for high-resolution, label-free sensing, and analysis of single molecules. However, controlling the speed and trajectory of molecular translocation in nanopores remains challenging, hampering sensing accuracy. Here, the study proposes a nanopore-in-a-tube (NIAT) device that enables decoupling of the current signal detection from molecular translocation and provides precise angular inertia-kinetic translocation of single molecules through a nanopore, thus ensuring stable signal readout with high signal-to-noise ratio (SNR). Specifically, the funnel-shaped silicon nanopore, fabricated at a 10-nm resolution, is placed into a centrifugal tube. A light-induced photovoltaic effect is utilized to achieve a counter-balanced state of electrokinetic effects in the nanopore. By controlling the inertial angle and centrifugation speed, the angular inertial force is harnessed effectively for regulating the translocation process with high precision. Consequently, the speed and trajectory of the molecules are able to be adjusted in and around the nanopore, enabling controllable and high SNR current signals. Numerical simulation reveals the decisive role of inertial angle in achieving uniform translocation trajectories and enhancing analyte-nanopore interactions. The performance of the device is validated by discriminating rigid Au nanoparticles with a 1.6-nm size difference and differentiating a 1.3-nm size difference and subtle stiffness variations in flexible polyethylene glycol molecules.

Dispersion, Dynamics, and Mechanics of Polymer Nanocomposites Filled with Rigid-Soft Janus Nanoparticles via Molecular Dynamics Simulation.

The introduction of nanoparticles (NPs) presents boundless possibilities for enhancing the performance of polymer nanocomposites (PNCs). Consequently, the design of novel NPs becomes of paramount significance for PNCs. In our study, we employ the dumbbell two-component model of Janus nanoparticles (JNPs) and design rigid-soft JNPs as fillers. Using coarse-grained molecular dynamics simulations, we systematically investigate the dispersion, dynamics, and mechanical properties of these novel PNCs. First, we determine the optimal dispersion conditions by studying rcutoff and εnp. The simulation indicates that when the interaction between polymer chains and JNPs is a repulsive potential, the JNPs tend to aggregate together, forming a cluster with soft NPs inside and rigid NPs outside. Conversely, under attractive interactions, JNPs show superior dispersion uniformity compared to the repulsive system, and as εnp increases, the dispersion improves. Then, the mean square displacement (MSD) indicates that JNPs effectively impede the mobility of polymer chains, with the degree of hindrance increasing as εnp grows; this effect is more pronounced in attractive systems. Comparing JNPs of different particle sizes, we find that smaller JNP systems exhibit higher temperature sensitivity. Furthermore, there exists a critical particle size (Dnp ≈ 5σ) under a constant filling fraction at which the NPs exert the most pronounced restriction effect on the polymer. Next, upon examining the mechanical behavior, we find that the rigid-soft JNPs demonstrate notable elasticity and variability compared to traditional NPs. This observation is confirmed through measurements of the bond orientation and mean square radius of gyration of the soft segments of JNPs. In summary, this research provides a comprehensive understanding of the intricate interplay among various factors, offering valuable insights for optimizing JNP dispersion and enhancing the mechanical properties of PNCs.

Multiscale modelling of nanoparticle toughening in epoxy: Effects of particle-matrix interface, particle size, and volume fraction

Toughening matrix materials by incorporating rigid nanoparticles has received significant interest for mitigating matrix microcracking in fibre-reinforced polymer-matrix composites, particularly at cryogenic temperatures. Despite recent experimental observations indicating the effectiveness of nanoparticle toughening, a notable gap remains in understanding the effects of nanoparticle size and volume fraction, and particle-matrix interfacial properties, on toughening efficacy. To address this gap, a multiscale model has been developed which employs a high-fidelity micromechanical model to quantify the deformation and energy dissipation caused by the rigid nanoparticles under a triaxial strain state determined from a macroscopic elastoplastic analysis. The interface between the nanoparticle and the matrix is characterized by a cohesive zone model (CZM), revealing a size-dependent phenomenon distinct to nanoparticles, sharply contrasting with micrometre-sized particles. Furthermore, the results reveal, for the first time, an optimum particle size that maximizes the toughening effect for a given particle-matrix combination. The existence of an optimum size is ascribed to the incomplete particle debonding from the matrix as the particle radius approaches the critical separation distance of the CZM. This revelation challenges the prevailing belief that, for a fixed volume fraction of nanoparticles, the enhancement in toughness rises as the particle size decreases as a result of the increase in total particle surface area. The implications for enhancing cryogenic performance are explored.

A Single-Dose mRNA Vaccine Employing Porous Silica Nanoparticles Induces Robust Immune Responses Against the Zika Virus.

Recently, lipid nanoparticles (LNPs)-based mRNA delivery has been approved by the FDA for SARS-CoV-2 vaccines. However, there are still considerable points for improvement in LNPs. Especially, local administration of LNPs-formulated mRNA can cause off-target translation of mRNA in distal organs which can induce unintended adverse effects. With the hypothesis that large and rigid nanoparticles can be applied to enhance retention of nanoparticles at the injection site, a polyethyleneimine (PEI)-coated porous silica nanoparticles (PPSNs)-based mRNA delivery platform is designed. PPSNs not only facilitate localized translation of mRNA at the site of injection but also prolonged protein expression. It is further demonstrated that the development of a highly efficacious Zika virus (ZIKV) vaccine using mRNA encoding full-length ZIKV pre-membrane (prM) and envelope (E) protein delivered by PPSNs. The ZIKV prME mRNA-loaded PPSNs vaccine elicits robust immune responses, including high levels of neutralizing antibodies and ZIKV E-specific T cell responses in C57BL/6 mice. Moreover, a single injection of prME-PPSNs vaccine provided complete protection against the ZIKV challenge in mice.

Multi-functionalization and recycling of basalt fibre/polypropylene laminated composites based on mixed plain-woven fabric and related interfacial decorations

The development of laminated composites of thermoplastic polypropylene (PP)/continuous basalt fabric is limited by poor mutual infiltration and weak interfacial interactions between the matrix and fabric, as well as the intrinsic flammability and susceptibility of the PP matrix to ultraviolet (UV) aging. To solve the above shortcomings in a high-efficiency manner, a multi-functional transition layer was constructed between the PP matrix and long basalt fibres (LBFs) based on a hybrid plain-woven fabric composed of LBFs weft yarns and PP warp yarns. After hot-laminating these hybrid plain-woven prepregs, the mechanical performance of the resultant laminates was optimised and strengthened by selecting the compositions of the multi-functional transition layers (comprising flexible alkyl glycidyl ether chains, various rigid inorganic nanoparticles, or a flexible-rigid hybrid layer). Among these different transition layers, the interface between the LBFs-g-MWCNTs-OH and the PP matrix presented better mutual infiltration due to the lower interfacial energy, stronger mechanical engagement effect derived from the rougher fibre surface, and higher interfacial modulus. Therefore, the fewer structural defects and more effective transfer of the applied load at the interface caused the tensile strength/modulus and flexural strength/modulus of the related hybrid weaving laminates (HWLs) to reach 278.1 MPa/31.8 GPa and 264.2 MPa/12.4 GPa, respectively. The rigid interfaces formed by the deposited nanoparticles also accelerated heat transfer from the matrix to the fibre and the absorption of UV-light inside composite, then improving the flame-retardancy and anti-UV aging performances of the corresponding HWLs. Finally, recyclability evaluations indicated that the waste LBFs-g-SiO2/PP HWLs can be used as anti-UV aging and flame-retardant agents to fabricate new modified PP pellets with multiple functions.

Modulating the conformation of microgels by complexation with inorganic nanoparticles

HypothesisThe complexation of microgels with rigid nanoparticles is an effective way to impart novel properties and functions to the resulting hybrid particles for applications such as in optics, catalysis, or for the stabilization of foams/emulsions. The nanoparticles affect the conformation of the polymer network, both in bulk aqueous environments and when the microgels are adsorbed at a fluid interface, in a non-trivial manner by modulating the microgel size, stiffness and apparent contact angle. ExperimentsHere, we provide a detailed investigation, using light scattering, in-situ atomic force microscopy and nano-indentation experiments, of the interaction between poly(N-isopropylacrylamide) microgels and hydrophobized silica nanoparticles after mixing in aqueous suspension to shed light on the network reorganization upon nanoparticle incorporation. FindingsThe addition of nanoparticles decreases the microgels' bulk swelling and thermal response. When adsorbed at an oil-water interface, a higher ratio of nanoparticles influences the microgel's stiffness as well as their hydrophobic/hydrophilic character by increasing their effective contact angle, consequently modulating the monolayer response upon interfacial compression. Overall, these results provide fundamental understanding on the complex conformation of hybrid microgels in different environments and give inspiration to design new materials where the combination of a soft polymer network and nanoparticles might result in additional functionalities.

Rigid nanoparticles for efficient tumor immunotherapy through mechanical force mediated reprogramming of tumor-associated macrophages

The enrichment of M2-phenotype tumor-associated macrophages (TAMs) is the main factor to create an immunosuppressive microenvironment, which seriously attenuates antitumor treatment. Herein, we explored the capability of rigid nanoparticles to reprogram TAMs to the M1-like phenotype via mechanical force. We designed and synthesized amphiphilic copolymer PLA-b-PItEG initiated by the HO-Pd(II) complex. In contrast to polyethylene glycol, the hydrophilic PItEG segments have a helical conformation, which endows the self-assembled PLA-b-PItEG nanoparticles with stiff surface characteristics of higher Young’s modulus and hydrophobicity. The rigid nanoparticles displayed strong interaction with TAMs to produce greater deformation of cell membrane and activated mechanosensitive potassium ion channel. Consequently, rigid nanoparticles exerted a positive effect on the proinflammatory polarization of TAMs. The expression level of CD86, a typical M1 macrophage marker, was increased by 60% compared with that in the soft PEG-NP group while CD206, a typical M2 macrophage marker, was decreased. Furthermore, several M1-related cytokines such as TNF-α, IL12p40, IL-6 and IL-1β were upregulated. In vitro and in vivo immune responses triggered by rigid nanoparticles could significantly inhibit B16F10 tumor growth with 71.44% tumor inhibitory rate. This study offers new insight into the use of mechanical forces for tumor immunotherapy.

Enzymatic Reaction Enhanced Diffusion Accelerates Cargo Transport through Micro/Nano-Channels.

Energy conversion and transfer of enzyme-catalyzed reactions at molecular level are an interesting and challenging scientific topic that helps understanding biological processes in nature. In this study, it is demonstrated that enzyme-catalyzed reactions can enhance diffusion of surrounding molecules and thus accelerate cargo transport within 1D micro/nanochannels. Specifically, urease is immobilized on the inner walls of silica micro/nano-tubes to construct bio-catalytically active micro/nanochannels. The catalytic reaction inside the channels drives a variety of cargoes, including small dye molecules, polymers, and rigid nanoparticles (e.g., quantum dots, QDs), to pass through these micro/nanochannels much faster than they will by free diffusion. The enhanced diffusion of molecular species inside the channels is validated by direct observation of the Brownian motion of tracer particles, and further confirmed by significantly enhanced Raman intensity of reporter molecules. Finite element and Brownian dynamics simulations provide a theoretical understanding of these experimental observations. Furthermore, the effect of the channels' size on the diffusion enhancement is examined. The acceleration effect of the cargo transport through these enzymatically active micro/nanochannels can be turned on or off via chemical activators or inhibitors. This study provides valuable insights on the design of biomimetic channels capable of controlled and efficient transmembrane transport.

Constructing a Novel Moderately Modulus "Rigid-Flexible" Structure with Synergistic Reinforcement on the Carbon Fiber Surface to Enhance the Mechanical Properties of Carbon Fiber/Epoxy Composites at Elevated Temperatures.

To improve the mechanical performance of carbon fiber (CF)/epoxy composites in high-temperature environments, a moderately modulus gradient modulus interlayer was constructed at the interface phase region of composites. This involved the design of a "rigid-flexible" synergistic reinforcement structure, incorporating rigid nanoparticle GO@CNTs and a flexible polymer polynaphthyl ether nitrile ketone onto the CF surface. Notably, at 180 °C, compared to commercial CF composites, the CF-GO@CNTs-PPENK composites displayed a remarkable improvement in their mechanical characteristics (interfacial shear, interlaminar shear, flexural strength, and modulus), achieving enhancements of 173.0, 91.5, 225.7, and 376.4%, respectively. The principal reason for this the moderately modulus interface phase composed of GO@CNTs-PPENK (where GO and CNTs predominantly consist of carbon atoms with sp2-hybridized orbitals, forming highly stable C-C structures, while PPENK possesses a "twisted non-coplanar" structure), which exhibited resistance to deformation at high temperatures. Moreover, it greatly improved the mechanical interlocking, wettability, and chemical compatibility between CF and the epoxy. It also played a crucial role in balancing and buffering the modulus disparity. The interface failure behavior and reinforcement mechanisms of the CF composites were analyzed. Furthermore, validation of the presence of a moderately modulus gradient interlayer at the interface phase region of CF-GO@CNTs-PPENK composites was performed by using atomic force microscopy. This study has established a theoretical foundation for the development of high-performance CF composites for use in high-temperature fields.

Reversibly stable and highly stretchable transparent polymer nanocomposite adhesives using hierarchical spring-like molecular nanobridges

For the development of stretchable optoelectronic devices, optically transparent composite adhesives should afford reversible stretchability and high optical transmittance as well as strong interfacial adhesion. However, simultaneous achievement of these essential prerequisites for advanced stretchable optical composite adhesives remains challenging. Herein, we offer an unprecedented approach for the fabrication of reversibly stretchable and optically transparent polymer nanocomposite adhesives based on the construction of hierarchical elastic molecular nanobridges between rigid-flexible hybrid nanoparticles and matrix resin. Photoreactive flexible poly(propylene glycol) (meth)acrylate chains were chemically combined with a rigid nano-silica core to form rigid and flexible hybrid nanoparticles. Subsequently, multiple elastic molecular nanobridges between the embedded hybrid nanoparticles and acrylate resin matrix were constructed inside the polymer composite through UV curing, which results in a stretchable interconnection that allows efficient repeated stretching and recovery of stretchable polymer nanocomposite adhesives. The newly fabricated nanocomposite adhesive film with a low content of rigid-flexible hybrid nanoparticles afforded an excellent reversible stretchability and outstanding cyclic elastic durability, and simultaneously maintained high optical transparency (95.1%) and interfacial adhesion strength (21.5 N/25 mm) of the film compared to those of conventional optical adhesive film.

Toughening epoxy by nano-structured block copolymer to mitigate matrix microcracking of carbon fibre composites at cryogenic temperatures

The incorporation of rigid nanoparticles has proven to enhance microcracking resistance in carbon fibre reinforced polymer (CFRP) composites at cryogenic temperatures, enabling CFRP tanks to store cryogenic liquid like hydrogen without requiring liners. Herein, we investigate efficacy of low-modulus soft nanoparticles in addressing the microcracking challenges inherent in CFRP at cryogenic temperatures. By incorporating a tri-block copolymer (BCP) into an epoxy, nano-structured fillers with an average diameter of approximately 100 nm are formed. Experimental results reveal that, at a 2.5 wt% loading, the BCP significantly increase the fracture energy of the nanocomposite by 392% at −196 °C while maintaining stiffness and strength. More importantly, composite laminates made with the BCP-modified nanocomposite matrix can withstand cryogenic temperatures without matrix microcracking, even when they contain multiple plies with the same orientation, such as [04/904]s, which are known to be highly susceptible to matrix microcracking at cryogenic temperatures. An advanced high-fidelity micromechanical model revealed that the observed toughening effect of nanostructured block copolymer at cryogenic temperatures can be attributed to the increased fracture resistance of the nanocomposite matrix. The findings of this research demonstrate that low concentration of block copolymer can effectively mitigate the initiation and propagation of matrix microcracks in carbon fibre composites at ultra-cold temperatures.

Molecular dynamics simulation and experimental study on the mechanical properties of PET nanocomposites filled with CaCO3, SiO2, and POE-g-GMA

Abstract This work investigated the mechanical properties of polyethylene terephthalate (PET) reinforced with calcium carbonate (CaCO3) and silica (SiO2) nanoparticles, respectively, and the improvement in toughness of the ternary system with the incorporation of graft-modified ethylene-1-octene copolymer (POE-g-GMA). PET nanocomposites were prepared by melt blending extrusion and injection molding. Molecular dynamics (MD) simulation was employed to construct models for binary system filled with nanoparticles and ternary system with the additional inclusion of POE-g-GMA elastomers. The results of mechanical property tests and MD simulation revealed that the binary system exhibited increased elastic modulus and tensile strength, mainly attributed to the effective reinforcement of rigid nanoparticles and the surface adsorption between nanoparticles and the PET matrix enhanced the interfacial interactions. CaCO3 indicated a more pronounced reinforcing effect, possibly due to the higher crystallinity of its composites. The incorporation of POE-g-GMA resulted in a significant improvement in impact strength and the elongation at break of PET nanocomposites. This enhancement in toughness is attributed to the elastomer’s ability to absorb a substantial amount of impact energy, while the elastic modulus is higher than that of pure PET.

Einstein–Stokes relation for small bubbles at the nanoscale

As the physicochemical properties of ultrafine bubble systems are governed by their size, it is crucial to determine the size and distribution of such bubble systems. At present, the size or size distribution of nanometer-sized bubbles in suspension is often measured by either dynamic light scattering or the nanoparticle tracking analysis. Both techniques determine the bubble size via the Einstein–Stokes equation based on the theory of the Brownian motion. However, it is not yet clear to which extent the Einstein–Stokes equation is applicable for such ultrafine bubbles. In this work, using atomic molecular dynamics simulation, we evaluate the applicability of the Einstein–Stokes equation for gas nanobubbles with a diameter less than 10 nm, and for a comparative analysis, both vacuum nanobubbles and copper nanoparticles are also considered. The simulation results demonstrate that the diffusion coefficient for rigid nanoparticles in water is found to be highly consistent with the Einstein–Stokes equation, with slight deviation only found for nanoparticle with a radius less than 1 nm. For nanobubbles, including both methane and vacuum nanobubbles, however, large deviation from the Einstein–Stokes equation is found for the bubble radius larger than 3 nm. The deviation is attributed to the deformability of large nanobubbles that leads to a cushioning effect for collision-induced bubble diffusion.

3D-printed liquid metal polymer composites as NIR-responsive 4D printing soft robot

4D printing combines 3D printing with nanomaterials to create shape-morphing materials that exhibit stimuli-responsive functionalities. In this study, reversible addition-fragmentation chain transfer polymerization agents grafted onto liquid metal nanoparticles are successfully employed in ultraviolet light-mediated stereolithographic 3D printing and near-infrared light-responsive 4D printing. Spherical liquid metal nanoparticles are directly prepared in 3D-printed resins via a one-pot approach, providing a simple and efficient strategy for fabricating liquid metal-polymer composites. Unlike rigid nanoparticles, the soft and liquid nature of nanoparticles reduces glass transition temperature, tensile stress, and modulus of 3D-printed materials. This approach enables the photothermal-induced 4D printing of composites, as demonstrated by the programmed shape memory of 3D-printed composites rapidly recovering to their original shape in 60 s under light irradiation. This work provides a perspective on the use of liquid metal-polymer composites in 4D printing, showcasing their potential for application in the field of soft robots.

Mechanics of assembling two-dimensional materials on a solid substrate by droplet drying

Assembly of two-dimensional (2D) nanomaterials by droplet drying offers a straightforward and low-cost route to obtain their bulk forms for widespread applications in manufacturing and printing of functional structures and devices. However, unlike rigid nanoparticles that usually do not experience mechanical deformation, 2D nanomaterials are easily deformed and folded during assembly by evaporative drying, and traditional assembly theory that can address these fundamental deformation mechanisms is currently lacking. In the present study, we have developed an energy-based rotational spring-mechanical slider mechanics model to describe the mechanical deformation and assembly of 2D material graphene on a solid substrate during the evaporation of its droplet solution. In the development of theory, the mechanical folding deformation of 2D material graphene itself is modeled by the rotational spring, and the folding-induced interior interactions of graphene itself and its assembly interactions with neighboring ones and solid substrate all due to van der Waal force are modeled by the mechanical sliders. The surface wettability of substrate and the evaporative modes of droplet on substrate including constant contact angle (CCA), constant contact radius (CCR), and their combination are also incorporated into the mechanics model. In parallel, large-scale molecular dynamics (MD) simulations with the development of coarse-grained model of 2D graphene and its virtual force field interaction with liquid is performed and show remarkable agreement with theoretical predictions on both assembly patterns and dimensional sizes. The effect of graphene size and its interaction strength with substrate on assembly is also elucidated. This work uncovers fundamental assembly mechansim of mechanically deformable nanomaterials by solution drying, and also provides immediate application guidance to ink-based printing techniques for manufacturing deformable nanomaterials-enabled devices with controlled patterns on substrates.

High-performance epoxy nanocomposites via constructing a rigid-flexible interface with graphene oxide functionalized by polyetheramine and f-SiO2

Graphene oxide (GO) is an ideal reinforcement for improving mechanical properties of epoxy (EP) and reducing its coefficient of thermal expansion (CTE). However, the poor interfacial interaction between GO and polymer matrix seriously hinders the reinforcing effect of GO. To improve their interface, we first functionalized GO with flexible polyetheramine (PEA) and f-SiO2 rigid nanoparticles, obtaining PEA-GO and SiO2-PEA-GO hybrids, respectively. Then the PEA-GO and SiO2-PEA-GO were incorporated into EP to obtain nanocomposites with flexible interphases and rigid-flexible interphases, respectively. The interfaces were tuned by two PEA molecules (D230 and D2000) with different chain lengths. The effects of the different interface structures on the mechanical properties and CTE of the GO/EP nanocomposites with a 0.25 wt% filler loading were investigated. It was found that the effects of SiO2-PEA-GO on strengthening and toughening EP matrix and on reducing its CTE were much better than those of PEA-GO, because the rigid-flexible interfaces provided higher bonding strength and better energy dissipation mechanisms than the flexible interfaces. Moreover, the D230-GO/EP nanocomposite containing shorter PEA (D230) molecules exhibited higher strength but lower toughness and CTE than the D2000-GO/EP nanocomposite. However, the SiO2-D2000-GO/EP nanocomposite showed greater strength, toughness and CTE than the SiO2-D230-GO/EP nanocomposite. This indicated that the longer PEA molecules in rigid-flexible interphases produced higher improvement in strength and toughness but smaller decreases in CTE. This work provides a promising strategy of constructing an adjustable flexible-rigid interfacial structure and opens an avenue for developing GO/EP nanocomposites with high mechanical properties and low CTE.

Super-tough, super-elastic, temperature-responsive, and tunable viscoelastic elastomer enabled by embedding nanosized liquid metal droplets

Liquid metal (LM) based composites are playing irreplaceable roles in many emerging fields such as stretchable and wearable electronics, soft robotics. However, it is still challenging to facilely fabricate the LM-based elastomers with nanosized and well-dispersed LM domains. Herein, the LM droplets filled elastomer nanocomposites (ENCs) with temperature-responsive, super-tough, super-elastic and tunable viscoelastic properties are introduced. By employing the conventional rubber processing method, LM is fragmented into nanoscale droplets and dispersed uniformly in cross-linked natural rubber (NR) without compromising the soft and highly stretchable properties of the matrix. In addition to the remarkable enhancement in tear resistance, the toughness of the resulting composites is strikingly improved as lowering the applied temperature, which is attributed to the phase transition and the simultaneous volume expansion of LM droplets. Surprisingly, for the viscoelasticity, this LM-based ENCs exhibit almost the same dynamic hysteresis with the pure NR system at the service condition of automobile tires, which is remarkably reduced compared to the traditional ENCs filled with rigid nanoparticles. Furthermore, this material also shows a good damping property for noise attenuation in the case of submarine covering. Collectively, this work opens a new avenue for the next generation of high-performance and multifunctional ENCs equipped in low-temperature working conditions.

Particle Deformability Enables Control of Interactions between Membrane-Anchored Nanoparticles.

Nanoparticles adsorbed on a membrane can induce deformations of the membrane that give rise to effective interactions between the particles. Previous studies have focused primarily on rigid nanoparticles with fixed shapes. However, DNA origami technology has enabled the creation of deformable nanostructures with controllable shapes and mechanical properties, presenting new opportunities to modulate interactions between particles adsorbed on deformable surfaces. Here we use coarse-grained molecular dynamics simulations to investigate deformable, hinge-like nanostructures anchored to lipid membranes via cholesterol anchors. We characterize deformations of the particles and membrane as a function of the hinge stiffness. Flexible particles adopt open configurations to conform to a flat membrane, whereas stiffer particles induce deformations of the membrane. We further show that particles spontaneously aggregate and that cooperative effects lead to changes in their shape when they are close together. Using umbrella sampling methods, we quantify the effective interaction between two particles and show that stiffer hinge-like particles experience stronger and longer-ranged attraction. Our results demonstrate that interactions between deformable, membrane-anchored nanoparticles can be controlled by modifying mechanical properties of the particles, suggesting new ways to modulate the self-assembly of particles on deformable surfaces.

Flexible Puncture-Resistant Composites for Antistabbing Applications: Silica and Silicon Carbide Nanoparticle-/TPU-Coated Aramid Fabrics.

In harsh environments, it is crucial to design personal protective materials that possess both puncture/cut resistance and chemical resistance. In order to fulfill these requirements, this study introduces an innovative approach that combines hydrophobically modified rigid nanoparticles with thermoplastic polyurethane elastomers. These materials are then laminated with high-performance aramid fabrics through a scraping process, resulting in a multifunctional composite with puncture/cut resistance, superhydrophobicity, self-cleaning properties, and acid/alkali resistance. The quasi-static puncture tests conducted reveal the remarkable performance of the composite. The maximum spike puncture resistance reaches 267.62 N, which is 17.14 times higher than that of the pure fabric (15.61 N). Similarly, the maximum knife puncture resistance reaches 115.02 N, exhibiting a 5.01 times increase compared to that of the pure aramid fabric (22.97 N). Furthermore, the results obtained from the yarn pull-out, fabric burst strength, and tearing experiments demonstrate that the incorporation of rigid nanoparticles significantly enhances the friction between the yarns, enabling a greater number of yarns to participate in the dissipation of impact energy. As a result, the puncture resistance of the fabric is greatly improved. Significantly, the composite exhibits sustained superhydrophobicity even after exposure to harsh chemicals such as concentrated sulfuric acid and sodium hydroxide as well as undergoing cyclic mechanical wear. These findings highlight the composite's exceptional durability and resistance to corrosion. Overall, this study offers insights and methods for the development of multifunctional flexible puncture-resistant equipment for individuals.