Nanobuilding Blocks Research Articles

A Universal Biomacromolecule-Enabled Assembly Strategy for Constructing Multifunctional Aerogels with 90% Inorganic Mass Loading from Inert Nano-Building Blocks.

Inert inorganic nano-building blocks, such as carbon nanotubes (CNTs) and boron nitride (BN) nanosheets, possess excellent physicochemical properties. However, it remains challenging to build aerogels with these inert nanomaterials unless they are chemically modified or compounded with petrochemical polymers, which affects their intrinsic properties and is usually not environmentally friendly. Here, a universal biomacromolecule-enabled assembly strategy is proposed to construct aerogels with 90 wt% ultrahigh inorganic loading. The super-high inorganic content is beneficial for exploiting the inherent properties of inert nanomaterials in multifunctional applications. Taking chitosan-CNTs aerogel as a proof-of-concept demonstration, it delivers sensitive pressure response as a pressure sensor, an ultrahigh sunlight absorption (94.5%) raising temperature under light (from 25 to 71°C within 1min) for clean-up of crude oil spills, and superior electromagnetic interference shielding performance of up to 68.9dB. This strategy paves the way for the multifunctional application of inert nanomaterials by constructing aerogels with ultrahigh inorganic loading.

Insight into the drying-mediated and thioether bond activated chiral inversion assembly of nano building blocks

Supramolecular materials are typically obtained from a solvent environment, while the assembled nano-structures always affected and unpredictably changed by irreversible evaporation of solvents, which brings great challenges for the precise controlling of assembled structures. Herein, a drying-mediated and thioether bond activated chiral inversion assembly behavior of organic/inorganic nano-building blocks polyhedral oligomeric silsesquioxane (POSS) was investigated. The POSS was modified by eight methylated terminal cysteine, while the existence of thioether bond could capture the hydrogen bonds belonging to amide groups during drying process, resulting in weaken of the inter-molecular hydrogen bonds and displacing the stacking of the nano-building blocks, which activates the forming of super-helical structures opposite to the original chirality. This research reveals the solvent-induced chiral assembly principle of the giant molecules and helpful for the construction of the precise architecture.

Visible Microfluidic Deprotonation for Aramid Nanofibers as Building Blocks of Cascade-Microfluidic-Processed Colloidal Aerogels.

Microfluidic deprotonation approach is proposed to realize continuous, scalable, efficient, and uniform production of aramid nanofibers (ANFs)by virtue of large specific surface area, high mixing efficiency, strong heat transfer capacity, narrow residence time distribution, mild laminar-flow process, and amplification-free effect of the microchannel reactor. By means of monitoring capabilities endowed by the high transparency of the microchannel, the kinetic exfoliation process of original aramid particles is in situ observed and the corresponding exfoliation mechanism is established quantificationally. The deprotonated time can be reduced from the traditional several days to 7 min for the final colloidal dispersion due to the synergistic effect between enhanced local shearing/mixing and the rotational motion of aramid particles in microchannel revealed by numerical simulations. Furthermore, the cascade microfluidic processing approach is used to make various ANF colloidal aerogels including aerogel fibers, aerogel films, and 3D-printed aerogel articles. Comprehensive characterizations show that these cascade-microfluidic-processed colloidal aerogels have identical features as those prepared in batch-style mode, revealing the versatile use value of these ANFs. This work achieves significant progress toward continuous and efficient production of ANFs, bringing about appreciable prospects for the practical application of ANF-based materials and providing inspiration for exfoliating any other nano-building blocks.

Hybrid Amyloid-Chitin Nanofibrils for Magnetic and Catalytic Aerogels.

In the quest for a sustainable and circular economy, it is essential to explore environmentally friendly alternatives to traditional petroleum-based materials. A promising pathway toward this goal lies in the leveraging of biopolymers derived from food waste, such as proteins and polysaccharides, to develop advanced sustainable materials. Here, we design versatile hybrid materials by hybridizing amyloid nanofibrils derived by self-assembly of whey, a dairy byproduct, with chitin nanofibrils exfoliated from the two distinct allomorphs of α-chitin and β-chitin, extracted from seafood waste. Various hydrogels and aerogels were developed via the hybridization and reassembly of these biopolymeric nanobuilding blocks, and they were further magnetized upon biomineralization with iron nanoparticles. The pH-phase diagram highlights the significant role of electrostatic interactions in gel formation, between positively charged amyloid fibrils and negatively charged chitin nanofibrils. Hybrid magnetic aerogels exhibit a ferromagnetic response characterized by a low coercivity (<50 Oe) and a high specific magnetization (>40 emu/g) at all temperatures, making them particularly suitable for superparamagnetic applications. Additionally, these aerogels exhibit a distinct magnetic transition, featuring a higher blocking temperature (200 K) compared to previously reported similar nanoparticles (160 K), indicating enhanced magnetic stability at elevated temperatures. Finally, we demonstrate the practical application of these hybrid magnetic materials as catalysts for carbon monoxide oxidation, showcasing their potential in environmental pollution control and highlighting their versatility as catalyst supports.

Sustainable Materials via the Assembly of Biopolymeric Nanobuilding Blocks Valorized from Agri-Food Waste

This paper presents an overview of current state-of-the-art agri-food waste valorization for developing advanced materials via the nanoscale assembly of biopolymeric building blocks. Emphasizing the imperative shift from a linear to a circular economy, the environmental impacts of agri-food waste, including its substantial contribution to global carbon dioxide (CO2) emissions and resource depletion, are underscored. This study explores the potential of harnessing proteins and polysaccharides extracted from agri-food waste to synthesize advanced materials, such as films, hydrogels, and aerogels. The two categories of fibrillar nanobuilding blocks, including exfoliated fibrils from structural biopolymers like cellulose, chitin, silk, and collagen, as well as self-assembled protein nanofibrils from different proteins valorized from food industries’ waste, are showcased. These biopolymeric nanofibrils can be further assembled to develop hierarchical advanced materials, with many applications in energy, environmental fields, and beyond. However, in this context, there are critical considerations, including the sustainability of the valorization methods, challenges associated with the heterogeneity of food waste, and the imperative need for a life cycle assessment to ensure complete sustainability. The delicate balance between integrating waste into the food chain and exploring alternative scenarios is discussed, along with challenges related to the short lifespan of agri-food waste, its heterogeneity, and the economic viability of valorization processes. Finally, the ongoing pursuit of developing high-performance, sustainable materials and the importance of societal cultivation to foster a circular economy mindset are discussed.

Architecting the Microenvironment Skeleton of Active Materials in High-Capacity Electrodes by Self-Assembled Nano-Building Blocks.

In analogy to the cell microenvironment in biology, understanding and controlling the active-material microenvironment (ME@AM) microstructures in battery electrodes is essential to the successes of energy storage devices. However, this is extremely difficult for especially high-capacity active materials(AMs) like sulfur, due to the poor controlling on the electrode microstructures. To conquer this challenge, here, a semi-dry strategy based on self-assembled nano-building blocks is reported to construct nest-like robust ME@AM skeleton in a solvent-and-stress-less way. To do that, poly(vinylidene difluoride) nanoparticle binder is coated onto carbon-nanofibers (NB@CNF) via the nanostorm technology developed in the lab, to form self-assembled nano-building blocks in the dry slurry. After compressed into an electrode prototype, the self-assembled dry-slurry is then bonded by in-situ nanobinder solvation. With this strategy, mechanically strong thick sulfur electrodes are successfully fabricated without cracking and exhibit high capacity and good C-rate performance even at a high AM loading (25.0mgcm-2 by 90wt% in the whole electrode). This study may not only bring a promising solution to dry manufacturing of batteries, but also uncover the ME@AM structuring mechanism with nano-binder for guiding the design and control on electrode microstructures.

Controllable and Reversible Assembly of Nanofiber from Natural Macromolecules via Protonation and Deprotonation.

Nanofiber is the critical building block for many biological systems to perform various functions. Artificial assembly of molecules into nanofibers in a controllable and reversible manner will create "smart" functions to mimic those of their natural analogues and fabricate new functional materials, but remains an open challenge especially for nature macromolecules. Herein, the controllable and reversible assembly of nanofiber (CSNF) from natural macromolecules with oppositely charged groups are successfully realized by protonation and deprotonation of charged groups. By controlling the electrostatic interaction via protonation and deprotonation, the size and morphology of the assembled nanostructures can be precisely controlled. A strong electrostatic interaction contributes to large nanofiber with high strength, while poor electrostatic interaction produces finer nanofiber or nanoparticle. And especially, the assembly, disassembly, and reassembly of the nanofiber occurs reversibly through protonation and deprotonation, thereby paving a new way for precisely controlling the assembly process and structure of nanofiber. The reversible assembly allows the nanostructure to dynamically reorganize in response to subtle perturbation of environment. The as-prepared CSNF is mechanical strong and can be used as a nano building block to fabricate high-strength film, wire, and straw. This study offers many opportunities for the biomimetic synthesis of new functional materials.

Self-assembly of Au@AgNR along M13 framework: A SERS nanocarrier for bacterial detection and killing

Self-assembled functional nanomaterials with electromagnetic hot spots are crucial and highly desirable in surface-enhanced Raman scattering (SERS). Due to its versatile biological scaffold, the M13 phage has been employed to produce novel nano-building blocks and devices. In this study, we propose a novel M13 phage-based SERS nanocarrier, that utilizes the pVIII capsid in M13 to conjugate Au@Ag core-shell nanorod (Au@AgNR) with linker carboxy-PEG-thiol (M13-Au@AgNR) and the pIII capsid to specifically target Escherichia coli (E. coli). The M13-Au@AgNR@DTTC (3,3′- diethylthiocarbocyanine iodide) SERS probe was used to detect E. coli in a concentration range of 6 to 6 × 105 cfu/mL, achieving a limit of detection (LOD) of 0.5 cfu/mL. The proposed SERS platform was also tested in real samples, showing good recoveries (92%–114.3%) and a relative standard deviation (RSD) of 1.2%–4.7%. Furthermore, the system demonstrated high antibacterial efficiency against E. coli, approximately 90%, as measured by the standard plate-count method. The investigation provides an effective strategy for in vitro bacteria detection and inactivation.

Membrane Nanodomains: Dynamic Nanobuilding Blocks of Polarized Cell Growth.

Cell polarity is intimately linked to numerous biological processes, such as oriented plant cell division, particular asymmetric division, cell differentiation, cell and tissue morphogenesis, and transport of hormones and nutrients. Cell polarity is typically initiated by a polarizing cue that regulates the spatiotemporal dynamic of polarity molecules, leading to the establishment and maintenance of polar domains at the plasma membrane (PM). Despite considerable progress in identifying key polarity regulators in plants, the molecular and cellular mechanisms underlying cell polarity formation have yet to be fully elucidated. Recent work suggests a critical role for membrane protein/lipid nanodomains in polarized morphogenesis in plants. One outstanding question is how the spatiotemporal dynamics of signaling nanodomains are controlled to achieve robust cell polarization. In this review, we first summarize the current state of knowledge on potential regulatory mechanisms of nanodomain dynamics, with a special focus on RHO GTPases of Plants (ROPs). We then discuss the pavement cell system as an example of how cells may integrate multiple signals and nanodomain-involved feedback mechanisms to achieve robust polarity. A mechanistic understanding of nanodomains' roles in plant cell polarity is still in the early stages and will remain an exciting area for future investigations.

Leveraging Ligand and Composition Effects: Morphology-Tailorable Pt-Bi Bimetallic Aerogels for Enhanced (Photo-)Electrocatalysis.

Metal aerogels (MAs) are emerging porous materials displaying unprecedented potential in catalysis, sensing, plasmonic technologies, etc. However, the lack of efficient regulation of their nano-building blocks (NBBs) remains a big hurdle that hampers the in-depth investigation and performance enhancement. Here, by harmonizing composition and ligand effects, Pt- and Bi-based single- and bimetallic aerogels bearing NBBs of controlled dimensions and shapes are obtained by facilely tuning the metal precursors and the applied ligands. Particularly, by further modulating the electronic and optic properties of the aerogels via adjusting the content of the catalytically active Pt component and the semiconducting Bi component, both the electrocatalytic and photoelectrocatalytic performance of the Pt-Bi aerogels can be manipulated. In this light, an impressive catalytic performance for electro-oxidation of methanol is acquired, marking a mass activity of 6.4-fold higher under UV irradiation than that for commercial Pt/C. This study not only sheds light on in situ manipulating NBBs of MAs, but also puts forward guidelines for crafting high-performance MAs-based electrocatalysts and photoelectrocatalysts toward energy-related electrochemical processes.

Design Synthesis of ZnO Tube Bundles Rich in Oxygen Vacancies Assembled by Nanorods/Quasi-Nanospheres for Enhanced Sensing to NO/NO2

How to in situ construct homo-nanostructures assembled from diverse nanobuilding blocks and achieve high sensing of NO/NO2 gases is still challenging. To this end, two biomorphic ZnO materials cross-linked by nanorods and quasi-nanospheres were obtained through facile zinc nitrate solution infiltration and calcination using kitchen garbage of a discarded loofah sponge as the biotemplate. Among the tube bundles obtained by calcination at 600 °C, ZnO-6 possesses good crystallinity, small-sized mesopore distribution, and large specific surface area, as well as abundant oxygen vacancies. The synergy of the aforementioned microstructural features can improve electron transport efficiency, promote fast gas diffusion, increase the content of adsorbed oxygen species, and expose more surface active sites, thereby efficiently improving its sensing properties toward nitrogen oxides. At 92 °C, the ZnO-6 sensor simultaneously achieves large response values from 100 to 10 ppm of NO and 342 to 10 ppm of NO2, and their recovery times are reduced to 12 and 15 s, respectively. These indicators have apparent superiority over most reported corresponding metal oxide-based sensors. In addition, the sensor can apply the detection of trace NOx in real environments.

Defect reduction to enhance the mechanical strength of nanocellulose carbon aerogel

Carbon aerogels prepared from renewable nano building blocks are rising-star materials and hold great promise in many fields. However, various defects formed during carbonization at high temperature disfavor the stress transfer and thus the fabrication of flexible carbon aerogel from renewable nano building blocks. Herein, a structural defect-reducing strategy is proposed by altering the pyrolysis route of cellulose nanofiber. Inorganic salt that inhibits the generation of tar volatilization during pyrolysis can prevent the formation of various structural defects. Microstructure with fewer defects can reduce stress concentration and remarkably enhance the compressibility of carbon aerogel, thus increasing the maximum stress retention of carbon aerogel. The carbon aerogel also has high stress sensor sensitivity and excellent temperature coefficient of resistance. The structural defect-reducing strategy will pave a new way to fabricate high-strength carbon materials for various fields.

Synergistically Achieving Superior Sodium Storage of Metal Selenides by Constructing N-Doped Carbon Foams and Utilizing Cu-Driven Replacement Reaction.

Metal selenides are considered as one of the most promising anode materials for Na-ion batteries owing to high specific capacity and relatively higher electronic conductivity compared with metal sulfides or oxides. However, such anodes still suffer from huge volume change upon repeated Na+ insertion/extraction processes and simultaneously undergo severe shuttle effect of polyselenides, thus leading to poor electrochemical performance. Herein, a facile chemical-blowing and selenization strategy to fabricate 3D interconnected hybrids built from metal selenides (MSe, M = Mn, Co, Cr, Fe, In, Ni, Zn) nanoparticles encapsulated in in situ formed N-doped carbon foams (NCFs) is reported. Such hybrids not only provide ultrasmall active nanobuilding blocks (≈15nm), but also efficiently anchor them inside the conductive NCFs, thus enabling both high-efficiency utilization of active components and high structural stability. On the other hand, Cu-driven replacement reaction is utilized for efficiently inhibiting the shuttle effect of polyselenides in ether-based electrolyte. Benefiting from the combined merits of the unique MSe@NCFs and the utilization of the conversion of metal selenides to copper selenides, the as-obtained hybrids (MnSe as an example) exhibit superior rate capability (386.6 mAh g-1 up to 8 A g-1 ) and excellent cycling stability (347.7 mAh g-1 at 4.0 A g-1 after 1200 cycles).

General approach to surface-accessible plasmonic Pickering emulsions for SERS sensing and interfacial catalysis

Pickering emulsions represent an important class of functional materials with potential applications in sustainability and healthcare. Currently, the synthesis of Pickering emulsions relies heavily on the use of strongly adsorbing molecular modifiers to tune the surface chemistry of the nanoparticle constituents. This approach is inconvenient and potentially a dead-end for many applications since the adsorbed modifiers prevent interactions between the functional nanosurface and its surroundings. Here, we demonstrate a general modifier-free approach to construct Pickering emulsions by using a combination of stabilizer particles, which stabilize the emulsion droplet, and a second population of unmodified functional particles that sit alongside the stabilizers at the interface. Freeing Pickering emulsions from chemical modifiers unlocks their potential across a range of applications including plasmonic sensing and interfacial catalysis that have previously been challenging to achieve. More broadly, this strategy provides an approach to the development of surface-accessible nanomaterials with enhanced and/or additional properties from a wide range of nano-building blocks including organic nanocrystals, carbonaceous materials, metals and oxides.

Self-assembled MOF microspheres with hierarchical porous structure for efficient uranium adsorption

Herein, the self-assembled zirconium (Zr)-MOF microspheres formed by the octahedral nano-building blocks (UiO-66 and its derivatives) to adsorb uranium (U) was presented for the first time. The self-assembled MOF microspheres achieved the growth across orders of magnitude from nanometers (∼50 nm) to micrometers (∼2.3 μm), and exhibited ordered hierarchical porous structure (from ∼0.6 nm to ∼340 nm). The self-assembled MOF microspheres combined the advantages of nanostructures with stability and microstructures with hierarchical porous structure for effective mass diffusion. The improved mass diffusion properties of amidoxime (AO)-appended MOF microspheres (P-UiO-66-AO) endowed them with superior adsorption performance and excellent selective adsorption of U compared with AO-appended MOF (UiO-66-AO) octahedron. The adsorption equilibrium was obtained within 1400 min, and the maximum adsorption capacity of U was 283.2 mg/g. The adsorption capacity of U in simulated seawater was determined to be 11.4 mg/g and the ratio of distribution coefficients of U and vanadium (V) (Kd/U/Kd/V) increased 1.75 times than that of UiO-66-AO octahedron, overcoming the challenge of competitive adsorption of U and V with MOF. Overall, the strategy to fabricate self-assembled MOF microspheres with nano-building blocks is expected to expand the diversity and range of potential applications of MOFs.

Advanced Flexible Materials from Nanocellulose

AbstractWith the increase of environmental pollution and depletion of fossil fuel resources, the utilization of renewable biomass resources for developing functional materials or fine chemicals is of great value and has attracted considerable attention. Nanocellulose, as a well‐known renewable nanomaterial, is regarded as a promising nano building block for advanced functional materials owing to its unique structure and properties, as well as natural abundance. Typically, its high mechanical strength, structural flexibility, reinforcing capabilities, and tunable self‐assembly behavior makes it highly attractive to fabricate flexible materials for various applications. Herein, the recent progress in the design, properties, and applications of advanced flexible materials from nanocellulose is comprehensively summarized. The preparation and properties of nanocellulose are first briefly introduced and discuss its merits in fabricating flexible materials. Then, various advanced flexible materials from nanocellulose are introduced, and the critical role of nanocellulose in constructing flexible materials is highlighted based on its intrinsic properties. After that, their applications in energy storage, electronics, sensor, biomedical, thermally insulating, photonic devices, etc., are presented. At last, the outlook of the current challenges and future perspectives for developing nanocellulose‐derived flexible materials are discussed.

Overall structure of Au12Ag60(S-c-C6H11)31Br9(Dppp)6: achieving a stronger assembly of icosahedral M13 units.

Precise atomically assembled nanoclusters provide a great platform to elucidate the evolution of the assembly of building blocks. Herein, a large icosahedral (M13)-based silver-gold alloy nanocluster [Au12Ag60(S-c-C6H11)31Br9(Dppp)6]Br2 (dppp = 1,3-bis(diphenylphosphino)propane) is reported. Structurally, Au12Ag60 consists of an Au12Ag40 kernel, which is viewed as the interpenetration of ten twisted complete icosahedrons (M13) and two missing icosahedrons (M12), and this is surrounded by a complex metal-organic shell. Benefiting from the extra doping of eight to twelve Au atoms, the octameric assembly was increased to a twelve-mer assembly. The time-dependent density functional theory (TDDFT) method with a Tamm-Dancoff approximation (TDA) was performed to investigate the difference in the optical properties of Au12Ag60 and Au8Ag57. The results indicate that the difference in the amount of Au atoms results in different optical properties. Furthermore, transient absorption spectroscopy (TA) was also performed, revealing that a twelve-mer assembly greatly enhances the excited-state lifetime. The [Au12Ag60(S-c-C6H11)31Br9(Dppp)6]Br2 alloy nanocluster has provided a breakthrough in the number of icosahedral M13 assemblies, i.e., achieving a twelve-mer assembly, helping to elucidate the fusion growth of M13-based assembled nanoclusters as well as their geometric/electronic structure correlations, which will promote further research on the assembly of M13 nano-building blocks, especially on their optical properties.

Protein Cages and Nanostructures Constructed from Protein Nanobuilding Blocks.

Protein cages and nanostructures are promising biocompatible medical materials, such as vaccines and drug carriers. Recent advances in designed protein nanocages and nanostructures have opened up cutting-edge applications in the fields of synthetic biology and biopharmaceuticals. A simple approach for constructing self-assembling protein nanocages and nanostructures is the design of a fusion protein composed of two different proteins forming symmetric oligomers. In this chapter, we describe the design and methods of protein nanobuilding blocks (PN-Blocks) using a dimeric de novo protein WA20 to construct self-assembling protein cages and nanostructures. A protein nanobuilding block (PN-Block), WA20-foldon, was developed by fusing an intermolecularly folded dimeric de novo protein WA20 and a trimeric foldon domain from bacteriophage T4 fibritin. The WA20-foldon self-assembled into several oligomeric nanoarchitectures in multiples of 6-mer. De novo extender protein nanobuilding blocks (ePN-Blocks) were also developed by fusing tandemly two WA20 with various linkers, to construct self-assembling cyclized and extended chain-like nanostructures. These PN-Blocks would be useful for the construction of self-assembling protein cages and nanostructures and their potential applications in the future.

Ultra‐High Toughness Fibers Using Controlled Disorder of Assembled Aramid Nanofibers

AbstractAssembling nanoscale building blocks with reduced defects has emerged as a promising approach to exploit nanomaterials in the fabrication of simultaneously strong and tough architectures at larger scales. Aramid nanofibers (ANFs), a type of organic nanobuilding block, have been spotlighted due to their superior mechanical properties and thermal stability. However, no breakthrough research has been conducted on the high mechanical properties of a structure composed of ANFs. Here, assembling ANFs into macroscale fiber using a simultaneous protonation and wet‐spinning process is studied to reduce defects and control disorder. The ANF‐assembled fibers consist of hierarchically aligned nanofibers that behave as a defective law structure, making it possible to reach a Young's modulus of 53.15 ± 8.98 GPa, a tensile strength of 1,353.64 ± 92.98 MPa, and toughness of 128.66 ± 14.13 MJ m−3. Compared to commercial aramid fibers, the fibers exhibit ≈1.6 times greater toughness while also providing specific energy to break as 93 J g−1. Furthermore, this shows recyclability of the ANF assembly by retaining ≈94% of the initial mechanical properties. This study demonstrates a facile process to produce high stiffness and strength fibers composed of ANFs that possess significantly greater toughness than commercial synthetic fibers.

Bridging hollow carbon nanostructures to hierarchically pomegranate-like microspheres for efficient oil adsorption and catalysis applications

Hierarchical carbon superstructures that built from primary nanoscale objects and featured with a micro- or macroscopic architecture are highly desired, as credited by the synergistically integrated specialties. Here, we present a simple “microconfined-assembly-locking” approach to achieve pomegranate-like mesoporous carbon microspheres (PMCMs), in which the Pickering droplet-confined colloidal particle assembly and surfactant-directed interfacial locking are coupled. The formed PMCMs possess a unique micro-nano-hierarchical structure that consisting numerous mesoporous hollow carbon nanospheres within a permeable crust. Benefitting from this hierarchical arrangement, such a peculiar architecture not only preserves high surface area, large pore volume and good accessibility of the nano-building blocks, but also upgrades in mechanical strength and easy handling ability. In addition, this strategy allows the interior microstructures to be manipulated through combinatorial varying the assembled colloidal particles and interfacial chemical locking processes. Notably, the PMCMs show superior sorption capacity and cyclability for organics or oils from water in a fixed-bed system, which could also be applied to enhance the catalytic performance in hydrogenation of aromatic compounds after loading with Ru nanoparticles. This synthetic method provides a powerful bridge between nanoscale objects and microscale patterning, and paves a way to access other novel superstructures for expanding their potential applications.