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1.
Biosens Bioelectron ; 263: 116621, 2024 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-39098283

RESUMO

Constructing label-free bivariate fluorescence biosensor would be intriguing and desired for the recognizable and accurate detection of two specific DNA segments, yet the design of functional DNA structures with low overlapped interference might be challenging. Herein in this work, a double-faced Janus DNA nanoarchitecture (JDNA) with bi-responsive recognition regions on opposite sides was assembled, which consisted of two substrate strands and two template strands for loading green-/red-emissive Ag nanoclusters (gAgNC and rAgNC) as bivariate signaling reporters. Of note, the hybridized double helix in the middle rationally oriented two flank faces and stabilized the rigid conformation of JDNA, while the template sequences of bicolor clusters were blocked to minimize non-specific background leakage. Upon inputting two targets, the discernible hairpins lost their hairpin structures due to forming two dsDNA complexes. They were executed to simultaneously invade JDNA for activating two individual target-recycled strand displacement (TRSD) events, guiding signal transduction and efficient amplification. Consequently, the clustering templates were unlocked via the tailored conformation switch of JDNA, in which gAgNC and rAgNC were in situ synthesized in two diagonal positions, thereby significantly emitting bi-responsive signal without cross interference. Benefited from the logic integration of double-faced JDNA and TRSD, a label-free, sensitive and specific bivariate fluorescence approach was developed, which would open a new avenue for the potential application in biosensing and bioanalysis.


Assuntos
Técnicas Biossensoriais , DNA , Nanopartículas Metálicas , Prata , Técnicas Biossensoriais/métodos , Prata/química , DNA/química , Nanopartículas Metálicas/química , Humanos , Espectrometria de Fluorescência/métodos , Nanoestruturas/química , Hibridização de Ácido Nucleico , Limite de Detecção , Fluorescência , Corantes Fluorescentes/química
2.
Small ; 20(32): e2400041, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38497487

RESUMO

Triboelectric Nanogenerator (TENG) has proven highly effective in converting mechanical energy into electrical energy. Previous research on manipulating microstructure for performance enhancement primarily focused on the surface of TENGs. In this study, an innovative bottom-up strategic design to control the internal nano-architecture for the enhanced output of TENG is proposed. This multiscale structural design strategy consists of defect chemistry (angstrom-scale), surface modification (nano-scale), and spatial regulation of nanoparticles (meso-scale), which helps explore the optimal utilization of TENG's internal structure. After fine-tuning the nano-architecture, the output voltage is significantly increased. This optimized TENG serves as a robust platform for developing self-powered systems, including self-powered electrochemical chlorination systems for sterilization. Additionally, through the utilization of multiscale simulations (density functional theory, all-atom molecular dynamics, and dissipative particle dynamics), the underlying mechanisms governing how the optimized nanoparticle-polymer interface and spatial arrangement of nanoparticles influence the storage and transfer of charges are comprehensively elucidated. This study not only demonstrates the effectiveness of manipulating internal nano-architecture to enhance TENG performance for practical applications but also provides invaluable insights into structural engineering for TENG advancement.

3.
Angew Chem Int Ed Engl ; 63(16): e202400011, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38409577

RESUMO

Light-driven hydrogen production from biomass derivatives offers a path towards carbon neutrality. It is often however operated with the limitations of sluggish kinetics and severe coking. Herein, a disruptive air-promoted strategy is explored for efficient and durable light-driven hydrogen production from ethanol over a core/shell Cr2O3@GaN nanoarchitecture. The correlative computational and experimental investigations show ethanol is energetically favorable to be adsorbed on the Cr2O3@GaN interface, followed by dehydrogenation toward acetaldehyde and protons by photoexcited holes. The released protons are then consumed for H2 evolution by photogenerated electrons. Afterward, O2 can be evolved into active oxygen species and promote the deprotonation and C-C cleavage of the key C2 intermediate, thus significantly lowering the reaction energy barrier of hydrogen evolution and removing the carbon residual with inhibited overoxidation. Consequently, hydrogen is produced at a high rate of 76.9 mole H2 per gram Cr2O3@GaN per hour by only feeding ethanol, air, and light, leading to the achievement of a turnover number of 266,943,000 mole H2 per mole Cr2O3 over a long-term operation of 180 hours. Notably, an unprecedented light-to-hydrogen efficiency of 17.6 % is achieved under concentrated light illumination. The simultaneous generation of aldehyde from ethanol dehydrogenation enables the process more economically promising.

4.
Adv Sci (Weinh) ; 11(17): e2309392, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38403451

RESUMO

MXene-based thermal camouflage materials have gained increasing attention due to their low emissivity, however, the poor anti-oxidation restricts their potential applications under complex environments. Various modification methods and strategies, e.g., the addition of antioxidant molecules and fillers have been developed to overcome this, but the realization of long-term, reliable thermal camouflage using MXene network (coating) with excellent comprehensive performance remains a great challenge. Here, a MXene-based hybrid network comodified with hyaluronic acid (HA) and hyperbranched polysiloxane (HSi) molecules is designed and fabricated. Notably, the presence of appreciated HA molecules restricts the oxidation of MXene sheets without altering infrared stealth performance, superior to other water-soluble polymers; while the HSi molecules can act as efficient cross-linking agents to generate strong interactions between MXene sheets and HA molecules. The optimized MXene/HA/HSi composites exhibit excellent mechanical flexibility (folded into crane structure), good water/solvent resistance, and long-term stable thermal camouflage capability (with low infrared emissivity of ≈0.29). The long-term thermal camouflage reliability (≈8 months) under various outdoor weathers and the scalable coating capability of the MXene-coated textile enable them to disguise the IR signal of various targets in complex environments, indicating the great promise of achieved material for thermal camouflage, IR stealth, and counter surveillance.

5.
Infect Disord Drug Targets ; 24(2): e021123223053, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38291868

RESUMO

Infections caused by fungi can be mildly bothersome or fatal, causing life-threatening conditions or even death. Antifungal drugs have used synthetic chemicals, organic compounds, and phytoconstituents in their formulations to treat fungal infections. Research into novel antifungal drugs has progressed more rapidly than into antibacterial treatments. This can be attributed to the low resistance of fungal infections to antifungal bioactivities and the relatively low incidence of these diseases. Carrier systems based on nanotechnology have generated much interest recently because of the incredible potential of these systems. By using nanoarchitecture as a better carrier and drug delivery system (DDS), we can have greater antifungal effectiveness, bioavailability, targeted action, and less cytotoxicity, a development made possible using nanotechnology. This review discusses various nanocarrier-based technologies in addition to other nanotechnological methods. These include liposomes, transfersomes, ethosomes, niosomes, dendrimers, polymeric nanoparticles, polymer nanocomposites, metallic nanoparticles, carbon nanomaterials, etc. This review focused on general information regarding fungi infections, different antifungal agent types and mechanisms of action, and an overview of formulation strategies such as nanotechnology systems, which are frequently researched for antifungal therapies. We concluded that new drug delivery systems are crucial to delivering antifungal medicines to their target site with the optimum concentration. The researchers also concentrated on these innovative drug delivery systems, which primarily focus on regulating and maintaining the release of antifungal drugs.


Assuntos
Nanopartículas Metálicas , Micoses , Humanos , Antifúngicos/uso terapêutico , Antifúngicos/química , Sistemas de Liberação de Medicamentos , Lipossomos/química , Nanotecnologia
6.
Small ; 20(25): e2307986, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38189535

RESUMO

The volume collapse and slow kinetics reaction of anode materials are two key issues for sodium ion batteries (SIBs). Herein, an "embryo" strategy is proposed for synthesis of nanorod-embedded MoO2/MoS2/C network nanoarchitecture as anode for SIBs with high-rate performance. Interestingly, L-cysteine which plays triple roles including sulfur source, reductant, and carbon source can be utilized to produce the sulfur vacancy-enriched heterostructure. Specifically, L-cysteine can combine with metastable monoclinic MoO3 nanorods at room temperature to encapsulate the "nutrient" of MoOx analogues (MoO2.5(OH)0.5 and MoO3·0.5H2O) and hydrogen-deficient L-cysteine in the "embryo" precursor affording for subsequent in situ multistep heating treatment. The resultant MoO2/MoS2/C presents a high-rate capability of 875 and 420 mAh g-1 at 0.5 and 10 A g-1, respectively, which are much better than the MoS2-based anode materials reported by far. Finite element simulation and analysis results verify that the volume expansion can be reduced to 42.8% from 88.8% when building nanorod-embedded porous network structure. Theoretical calculations reveal that the sulfur vacancies and heterointerface engineering can promote the adsorption and migration of Na+ leading to highly enhanced thermodynamic and kinetic reaction. The work provides an efficient approach to develop advanced electrode materials for energy storage.

7.
Small ; 20(24): e2309983, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38174596

RESUMO

Plasmon-mediated catalysis utilizing hybrid photocatalytic ensembles promises effective light-to-chemical transformation, but current approaches suffer from weak electromagnetic field enhancements from polycrystalline and isotropic plasmonic nanoparticles as well as poor utilization of precious co-catalyst. Here, efficient plasmon-mediated catalysis is achieved by introducing a unique catalyst-on-hotspot nanoarchitecture obtained through the strategic positioning of co-photocatalyst onto plasmonic hotspots to concentrate light energy directly at the point-of-reaction. Using environmental remediation as a proof-of-concept application, the catalyst-on-hotspot design (edge-AgOcta@Cu2O) enhances photocatalytic advanced oxidation processes to achieve superior organic-pollutant degradation at ≈81% albeit having lesser Cu2O co-photocatalyst than the fully deposited design (full-AgOcta@Cu2O). Mass-normalized rate constants of edge-AgOcta@Cu2O reveal up to 20-fold and 3-fold more efficient utilization of Cu2O and Ag nanoparticles, respectively, compared to full-AgOcta@Cu2O and standalone catalysts. Moreover, this design also exhibits catalytic performance >4-fold better than emerging hybrid photocatalytic platforms. Mechanistic studies unveil that the light-concentrating effect facilitated by the dense electromagnetic hotspots is crucial to promote the generation and utilization of energetic photocarriers for enhanced catalysis. By enabling the plasmonic focusing of light onto co-photocatalyst at the single-particle level, the unprecedented design offers valuable insights in enhancing light-driven chemical reactions and realizing efficient energy/catalyst utilizations for diverse chemical, environmental, and energy applications.

8.
Small ; 20(6): e2305311, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37798936

RESUMO

Structural engineering and hybridization of heterogeneous 2D materials can be effective for advanced supercapacitor. Furthermore, architectural design of electrodes particularly with vertical construction of structurally anisotropic graphene nanosheets, can significantly enhance the electrochemical performance. Herein, MXene-derived TiO2 nanocomposites hybridized with vertical graphene is synthesized via CO2 laser irradiation on MXene/graphene oxide nanocomposite film. Instantaneous photon energy by laser irradiation enables the formation of vertical graphene structures on nanocomposite films, presenting the controlled anisotropy in free-standing film. This vertical structure enables improved supercapacitor performance by forming an open structure, increasing the electrolyte-electrode interface, and creating efficient electron transport path. In addition, the effective oxidation of MXene nanosheets by instantaneous photon energy leads to the formation of rutile TiO2 . TiO2 nanoparticles directly generated on graphene enables the effective current path, which compensates for the low conductivity of TiO2 and enables the functioning of an effective supercapacitor by utilizing its pseudocapacitive properties. The resulting film exhibits excellent specific areal capacitance of 662.9 mF cm-2 at a current density of 5 mA cm-2 . The film also shows superb cyclic stability during 40 000 repeating cycles, maintaining high capacitance. Also, the pseudocapacitive redox reaction kinetics is evaluated, showing fast redox kinetics with potential for high-performance supercapacitor applications.

9.
Materials (Basel) ; 16(23)2023 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-38068027

RESUMO

The lignin-based mesoporous hollow carbon@MnO2 nanosphere composites (L-C-NSs@MnO2) were fabricated by using lignosulfonate as the carbon source. The nanostructured MnO2 particles with a diameter of 10~20 nm were uniformly coated onto the surfaces of the hollow carbon nanospheres. The obtained L-C-NSs@MnO2 nanosphere composite showed a prolonged cycling lifespan and excellent rate performance when utilized as an anode for LIBs. The L-C-NSs@MnO2 nanocomposite (24.6 wt% of MnO2) showed a specific discharge capacity of 478 mAh g-1 after 500 discharge/charge cycles, and the capacity contribution of MnO2 in the L-C-NSs@MnO2 nanocomposite was estimated ca. 1268.8 mAh g-1, corresponding to 103.2% of the theoretical capacity of MnO2 (1230 mAh g-1). Moreover, the capacity degradation rate was ca. 0.026% per cycle after long-term and high-rate Li+ insertion/extraction processes. The three-dimensional lignin-based carbon nanospheres played a crucial part in buffering the volumetric expansion and agglomeration of MnO2 nanoparticles during the discharge/charge processes. Furthermore, the large specific surface areas and mesoporous structure properties of the hollow carbon nanospheres significantly facilitate the fast transport of the lithium-ion and electrons, improving the electrochemical activities of the L-C-NSs@MnO2 electrodes. The presented work shows that the combination of specific structured lignin-based carbon nanoarchitecture with MnO2 provides a brand-new thought for the designation and synthesis of high-performance materials for energy-related applications.

10.
Nanomaterials (Basel) ; 13(17)2023 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-37686907

RESUMO

In the pursuit of advanced functional materials, the role of low-dimensional van der Waals (vdW) heterointerfaces has recently ignited noteworthy scientific interest, particularly in assemblies that incorporate quasi-2D graphene and quasi-1D nanocellulose derivatives. The growing interest predominantly stems from the potential to fabricate distinct genres of quasi-2D/1D nanoarchitecture governed by vdW forces. Despite the possibilities, the inherent properties of these nanoscale entities are limited by in-plane covalent bonding and the existence of dangling π-bonds, constraints that inhibit emergent behavior at heterointerfaces. An innovative response to these limitations proposes a mechanism that binds multilayered quasi-2D nanosheets with quasi-1D nanochains, capitalizing on out-of-plane non-covalent interactions. The approach facilitates the generation of dangling bond-free iso-surfaces and promotes the functionalization of multilayered materials with exceptional properties. However, a gap still persists in understanding transition and alignment mechanisms in disordered multilayered structures, despite the extensive exploration of monolayer and asymmetric bilayer arrangements. In this perspective, we comprehensively review the sophisticated aspects of multidimensional vdW heterointerfaces composed of quasi-2D/1D graphene and nanocellulose derivatives. Further, we discuss the profound impacts of anisotropy nature and geometric configurations, including in-plane and out-of-plane dynamics on multiscale vdW heterointerfaces. Ultimately, we shed light on the emerging prospects and challenges linked to constructing advanced functional materials in the burgeoning domain of quasi-3D nanoarchitecture.

11.
Insects ; 14(8)2023 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-37623426

RESUMO

The colour of the butterfly wing serves as an important sexual and species-specific signal. Some species produce structural colouration by developing wing scales with photonic nanoarchitectures. These nanostructures are highly conservative, allowing only a ±10 nm peak wavelength deviation in the reflectance spectra of the blue structural colour in natural Common Blue (Polyommatus icarus) populations. They are promising templates of future artificial photonic materials and can be used in potential applications, too. In this work, we present methodology and infrastructure for breeding laboratory populations of Common Blue as a cost-effective and environmentally friendly source of nanostructures. Our technology enables the production of approximately 7500 wing samples, equivalent to 0.5-1 m2 of photonic nanoarchitecture surface within a year in a single custom-made insectarium. To ascertain the reliability of this method, we compared reflectance properties between different populations from distant geographic locations. We also provide genetic background of these populations using microsatellite genotyping. The laboratory population showed genetic erosion, but even after four generations of inbreeding, only minimal shifts in the structural colouration were observed, indicating that wild Common Blue populations may be a reliable source of raw material for photonic surfaces.

12.
ACS Appl Mater Interfaces ; 15(31): 37361-37370, 2023 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-37500097

RESUMO

Solar energy is the most promising, efficient, environmentally friendly energy source with the potential to meet global demand due to its non-polluting nature. Herein, a porous Zn1-xCdxSe/ZnO nanorod (NR) heterojunction was synthesized by hydrothermal and low-temperature solvothermal methods. First, the ZnO NR was grown on a Zinc foil, and an inorganic-organic hybrid ZnSe(en)0.5 material was developed by the low-temperature solvothermal method. In this work, the ZnO NR acted as a base material and a building block for the growth of ZnSe(en)0.5. Moreover, after the solvothermal process, the reduced Se2- reacts with the ZnO NR and forms inorganic-organic hybrid ZnSe(en)0.5. After the selenization process, the obtained material shows a red brick color due to the absorbance of excessive Se metal particles during the solvothermal process. Furthermore, in order to enhance the photoelectrochemical properties, the Cd2+ ion exchange method was applied at various temperatures (140, 160, and 180 °C for 3 h) to produce a precursor material to a porous Zn1-xCdxSe/ZnO NR nanostructure. The optimum Zn1-xCdxSe/ZnO NR-160 photoanode showed a high photocurrent density of 7.8 mA·cm-2 at -0.5 V vs. Ag/AgCl with a hydrogen evolution rate of 199 µmol·cm-2/3 h. The improved photocurrent performance was attributed to effective light absorption and prolonged recombination lifetime.

13.
Nanomicro Lett ; 15(1): 157, 2023 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-37336833

RESUMO

NiMo-based nanostructures are among the most active hydrogen evolution reaction (HER) catalysts under an alkaline environment due to their strong water dissociation ability. However, these nanostructures are vulnerable to the destructive effects of H2 production, especially at industry-standard current densities. Therefore, developing a strategy to improve their mechanical strength while maintaining or even further increasing the activity of these nanocatalysts is of great interest to both the research and industrial communities. Here, a hierarchical interconnected NiMoN (HW-NiMoN-2h) with a nanorod-nanowire morphology was synthesized based on a rational combination of hydrothermal and water bath processes. HW-NiMoN-2h is found to exhibit excellent HER activity due to the accomodation of abundant active sites on its hierarchical morphology, in which nanowires connect free-standing nanorods, concurrently strengthening its structural stability to withstand H2 production at 1 A cm-2. Seawater is an attractive feedstock for water electrolysis since H2 generation and water desalination can be addressed simultaneously in a single process. The HER performance of HW-NiMoN-2h in alkaline seawater suggests that the presence of Na+ ions interferes with the reation kinetics, thus lowering its activity slightly. However, benefiting from its hierarchical and interconnected characteristics, HW-NiMoN-2h is found to deliver outstanding HER activity of 1 A cm-2 at 130 mV overpotential and to exhibit excellent stability at 1 A cm-2 over 70 h in 1 M KOH seawater.

14.
Materials (Basel) ; 16(9)2023 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-37176465

RESUMO

Photonic nanoarchitectures of butterfly wings can serve as biotemplates to prepare semiconductor thin films of ZnO by atomic layer deposition. The resulting biotemplated ZnO nanoarchitecture preserves the structural and optical properties of the natural system, while it will also have the features of the functional material. The ZnO-coated wings can be used directly in heterogeneous photocatalysis to decompose pollutants dissolved in water upon visible light illumination. We used the photonic nanoarchitectures of different Morpho butterflies with different structural colors as biotemplates and examined the dependence of decomposition rates of methyl orange and rhodamine B dyes on the structural color of the biotemplates and the thickness of the ZnO coating. Using methyl orange, we measured a ten-fold increase in photodegradation rate when the 20 nm ZnO-coated wings were compared to similarly coated glass substrates. Using rhodamine B, a saturating relationship was found between the degradation rate and the thickness of the deposited ZnO on butterfly wings. We concluded that the enhancement of the catalytic efficiency can be attributed to the slow light effect due to a spectral overlap between the ZnO-coated Morpho butterfly wings reflectance with the absorption band of dyes, thus the photocatalytic performance could be changed by the tuning of the structural color of the butterfly biotemplates. The photodegradation mechanism of the dyes was investigated by liquid chromatography-mass spectroscopy.

15.
ACS Nano ; 17(10): 8918-8934, 2023 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-37131272

RESUMO

Hollow covalent organic frameworks (COFs) have gained significant attention because of their specific properties, including enhanced surface-to-volume ratio, large surface area, hierarchical structure, highly ordered nanostructures, and excellent chemical stability. These intrinsic characteristics endow hollow COFs with fascinating physicochemical properties and make them highly attractive for widespread applications, such as catalysis, energy storage, drug delivery, therapy, sensing, and environmental remediation. This review focuses on the recent developments in the synthesis of hollow COFs and their derivatives. In addition, their practical applications in various fields are summarized. Finally, challenges and future opportunities in terms of their synthetic methodologies and practical applications are discussed. Hollow COFs are expected to play an important role in the future of materials science.

16.
Nanomicro Lett ; 15(1): 142, 2023 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-37258997

RESUMO

Advanced electromagnetic devices, as the pillars of the intelligent age, are setting off a grand transformation, redefining the structure of society to present pluralism and diversity. However, the bombardment of electromagnetic radiation on society is also increasingly serious along with the growing popularity of "Big Data". Herein, drawing wisdom and inspiration from nature, an eco-mimetic nanoarchitecture is constructed for the first time, highly integrating the advantages of multiple components and structures to exhibit excellent electromagnetic response. Its electromagnetic properties and internal energy conversion can be flexibly regulated by tailoring microstructure with oxidative molecular layer deposition (oMLD), providing a new cognition to frequency-selective microwave absorption. The optimal reflection loss reaches ≈ - 58 dB, and the absorption frequency can be shifted from high frequency to low frequency by increasing the number of oMLD cycles. Meanwhile, a novel electromagnetic absorption surface is designed to enable ultra-wideband absorption, covering almost the entire K and Ka bands. More importantly, an ingenious self-powered device is constructed using the eco-mimetic nanoarchitecture, which can convert electromagnetic radiation into electric energy for recycling. This work offers a new insight into electromagnetic protection and waste energy recycling, presenting a broad application prospect in radar stealth, information communication, aerospace engineering, etc.

17.
ACS Nano ; 17(9): 7953-7978, 2023 05 09.
Artigo em Inglês | MEDLINE | ID: mdl-37071059

RESUMO

Hydrogels, as one of the most feasible soft biomaterials, have gained considerable attention in therapeutic applications by virtue of their tunable properties including superior patient compliance, good biocompatibility and biodegradation, and high cargo-loading efficiency. However, hydrogel application is still limited by some challenges like inefficient encapsulation, easy leakage of loaded cargoes, and the lack of controllability. Recently, nanoarchitecture-integrated hydrogel systems were found to be therapeutics with optimized properties, extending their bioapplication. In this review, we briefly presented the category of hydrogels according to their synthetic materials and further discussed the advantages in bioapplication. Additionally, various applications of nanoarchitecture hybrid hydrogels in biomedical engineering are systematically summarized, including cancer therapy, wound healing, cardiac repair, bone regeneration, diabetes therapy, and obesity therapy. Last, the current challenges, limitations, and future perspectives in the future development of nanoarchitecture-integrated flexible hydrogels are addressed.


Assuntos
Hidrogéis , Engenharia Tecidual , Humanos , Hidrogéis/uso terapêutico , Materiais Biocompatíveis/farmacologia , Cicatrização , Regeneração Óssea
18.
Small ; 19(50): e2207779, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36938897

RESUMO

The enhanced properties of nanomaterials make them attractive for advanced high-performance materials, but their role in promoting toughness has been unclear. Fabrication challenges often prevent the proper organization of nanomaterial constituents, and inadequate testing methods have led to a poor knowledge of toughness at small scales. In this work, the individual roles of nanomaterials and nanoarchitecture on toughness are quantified by creating lightweight materials made from helicoidal polymeric nanofibers (nano-Bouligand). Unidirectional ( θ $\theta $  = 0°) and nano-Bouligand beams ( θ $\theta $  = 2°-90°) are fabricated using two-photon lithography and are designed in a micro-single edge notch bend (µ-SENB) configuration with relative densities ρ ¯ $\overline \rho $ between 48% and 81%. Experiments demonstrate two unique toughening mechanisms. First, size-enhanced ductility of nanoconfined polymer fibers increases specific fracture energy by 70% in the 0° unidirectional beams. Second, nanoscale stiffness heterogeneity created via inter-layer fiber twisting impedes crack growth and improves absolute fracture energy dissipation by 48% in high-density nano-Bouligand materials. This demonstration of size-enhanced ductility and nanoscale heterogeneity as coexisting toughening mechanisms reveals the capacity for nanoengineered materials to greatly improve mechanical resilience in a new generation of advanced materials.

19.
Nanomaterials (Basel) ; 13(4)2023 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-36838994

RESUMO

An oblique angle and polarization insensitive metamaterial absorber (MA) are highly desired for the visible and infrared optical applications like, wave energy harvesting, optical filters, and detecting thermal leaks and electrical defects. In this paper, a multi-layered MA consisting of two layers of tungsten resonators on a silicon dioxide substrate, coated with additional SiO2 materials is investigated. The unit cell size of the MA is 0.5λ × 0.5λ × 0.8λ, at the lowest wavelength. The proposed MA offers an average absorption of 92% from 400 nm to 2400 nm with stable oblique incident angles up to 45°. The structure also achieves polarization insensitivity at the entire visible and near-infrared spectrum. Moreover, the MA is found highly compatible for solar absorber applications with high y AAM1.5. The structure is also compatible for filter application in optical communication system by modifying the plasmonic nano structure. The modified structure can block the wavelengths of the visible band (450 nm to 800 nm) and transmit optical communication bands (800 to 1675 nm). These versatile absorption and filtering performance make the proposed design highly potential for solar energy harvesting, photodetection, thermal imaging, photo-trapping, and optical communications applications.

20.
Beilstein J Nanotechnol ; 14: 218-232, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36793325

RESUMO

Cyclodextrins have been widely employed for drug delivery systems (DDSs) in which drugs are selectively delivered to a target site in the body. Recent interest has been focused on the construction of cyclodextrin-based nanoarchitectures that show sophisticated DDS functions. These nanoarchitectures are precisely fabricated based on three important features of cyclodextrins, namely (1) the preorganized three-dimensional molecular structure of nanometer size, (2) the easy chemical modification to introduce functional groups, and (3) the formation of dynamic inclusion complexes with various guests in water. With the use of photoirradiation, drugs are released from cyclodextrin-based nanoarchitectures at designated timing. Alternatively, therapeutic nucleic acids are stably protected in the nanoarchitectures and delivered to the target site. The efficient delivery of the CRISPR-Cas9 system for gene editing was also successful. Even more complicated nanoarchitectures can be designed for sophisticated DDSs. Cyclodextrin-based nanoarchitectures are highly promising for future applications in medicine, pharmaceutics, and other relevant fields.

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