Advanced Nanocomposites Research Articles

Characterization of nanocellulose isolated from bamboo fibers

Nanocellulose is a prominent reinforcing material for the production of advanced nanocomposites owing to its high specific strength, low cost, good thermal and mechanical properties and biodegradability. The current study aims to extract nanocellulose from bamboo fiber by chemical treatment and mechanical grinding. The nanocellulose was extracted by acetic acid and sodium chlorite treatment followed by a mechanical grinding process. Particle size analysis of extracted nanocellulose was performed by dynamic light scattering (DLS). The average size of nanocellulose was observed approximately 25.40 nm. FTIR characterization was performed to observe the change in structural properties of the fibers after each treatment. In addition, optical and morphological analyses were also investigated by UV–Vis spectrometer and FESEM, respectively. The nanocellulose extracted from bamboo fibers can be used as reinforcement for the fabrication of bionanocomposites for several applications such as food packaging, automobile, construction, and electrical Industries.

A review on advanced nanocomposites materials based smart textile biosensor for healthcare monitoring from human sweat

A review on advanced nanocomposites materials based smart textile biosensor for healthcare monitoring from human sweat

Scalable hierarchical wood/ZnO nanohybrids for efficient mechanical energy conversion

Owing to the hierarchical structure, easy multi-functionalization and favorable mechanical properties, wood could harvest electricity from mechanical energy through piezoelectric behavior. In this work, a scalable method to synthesize wood/ZnO composite with multilayered ZnO morphologies is reported for efficient mechanical energy conversion. The synthesis includes charged wood template fabrication, precursor infiltration, and ZnO hydrothermal growth, resulting in controlled ZnO morphologies and distributions while maintaining the hierarchical structure of the wood. Stereo-digital image correlation (stereo-DIC) investigated the relationship between deformation and piezoelectric performance, which revealed the homogeneous distribution of multilayered ZnO enhance piezoelectric performance. The output voltage of wood/ZnO was 1.5 V under periodic mechanical compression (8–10 N) for 300 cycles, while the output current was 2.91 nA. The scalable synthesis strategy and piezoelectric performance are significant for the design of advanced wood nanocomposites for sustainable and efficient energy conversion systems.

Recent advances in Metal Organic Framework (MOF)-based hierarchical composites for water treatment by adsorptional photocatalysis: A review

Architecting a desirable and highly efficient nanocomposite for applications like adsorption, catalysis, etc. has always been a challenge. Metal Organic Framework (MOF)-based hierarchical composite has perceived popularity as an advanced adsorbent and catalyst. Hierarchically structured MOF material can be modulated to allow the surface interaction (external or internal) of MOF with the molecules of interest. They are well endowed with tunable functionality, high porosity, and increased surface area epitomizing mass transfer and mechanical stability of the fabricated nanostructure. Additionally, the anticipated optimization of nanocomposite can only be acquired by a thorough understanding of the synthesis techniques. This review starts with a brief introduction to MOF and the requirement for advanced nanocomposites after the setback faced by conventional MOF structures. Further, we discussed the background of MOF-based hierarchical composites followed by synthetic techniques including chemical and thermal treatment. It is important to rationally validate the successful nanocomposite fabrication by characterization techniques, an overview of challenges, and future perspectives associated with MOF-based hierarchically structured nanocomposite.

Advances in the Physico-Chemical, Antimicrobial and Angiogenic Properties of Graphene-Oxide/Cellulose Nanocomposites for Wound Healing

Graphene oxide (GO) and its reduced form (rGO) have recently attracted a fascinating interest due to their physico-chemical properties, which have opened up new and interesting opportunities in a wide range of biomedical applications, such as wound healing. It is worth noting that GO and rGO may offer a convenient access to its ready dispersion within various polymeric matrices (such as cellulose and its derivative forms), owing to their large surface area, based on a carbon skeleton with many functional groups (i.e., hydroxyl, carboxyl, epoxy bridge, and carbonyl moieties). This results in new synergic properties due to the presence of both components (GO or rGO and polymers), acting at different length-scales. Furthermore, they have shown efficient antimicrobial and angiogenic properties, mostly related to the intracellular formation of reactive oxygen species (ROS), which are advantageous in wound care management. For this reason, GO or rGO integration in cellulose-based matrixes have allowed for designing highly advanced multifunctional hybrid nanocomposites with tailored properties. The current review aims to discuss a potential relationship between structural and physico-chemical properties (i.e., size, edge density, surface chemistry, hydrophilicity) of the nanocomposites with antimicrobials and angiogenic mechanisms that synergically influence the wound healing phenomenon, by paying particular attention to recent findings of GO or rGO/cellulose nanocomposites. Accordingly, after providing a general overview of cellulose and its derivatives, the production methods used for GO and rGO synthesis, the mechanisms that guide antimicrobial and angiogenic processes of tissue repair, as well as the most recent and remarkable outcomes on GO/cellulose scaffolds in wound healing applications, will be presented.

Sonochemical Approach of Highly Thermal, Mechanical, and Corrosion Inhibition Performance of Metal–Organic Framework (ZIF‐8)‐Decorated Waterborne Polyurethane Nanocomposite

Herein, highly porous metal–organic framework (ZIF‐8)‐decorated environmental friendly waterborne polyurethane (WPU) (ZIF‐8@WPU) nanocomposites via facile sonochemical technique are synthesized. The ZIF‐8@WPU shows threefold excellent mechanical performance (tensile strength ≈23 MPa and elongation 670%) at a very low 2.5 wt% filler loading compared to pristine WPU. In addition, the synthesized ZIF‐8@WPU exhibits high thermal stability and water vapor permeability properties with increasing nanofiller concentration. Interestingly, the incorporation of ZIF‐8 into WPU potentially improves the corrosion inhibition performance with a superior corrosion rate (υcorr) 1.7 × 10−2 mm year−1 and ≈94% protection efficiency (PE) at lower filler (2.5 wt%) loading, attributing to the facile synthesis methods, internal structural arrangement, well interaction of filler and matrix, high surface area, and tuneable pore size of filler material. The crystallinity of ZIF‐8 and ZIF‐8@WPU is analyzed by powder X‐ray diffraction, morphology by scanning electron microscopy, thermal properties by thermogravimetric analysis, and mechanical properties by the universal testing machine. This new insight has potential toward the green approach for synthesizing and structural engineering high‐performance advanced nanocomposites in the coating, breathable devices, and food packaging industrial utilization.

TEM characterization and reaction mechanism of composite coating fabricated by plasma spraying Nb–SiC composite powder

Niobium carbide composite coatings with Nb2C, NbC, Nb3Si as the main phases were prepared in situ on the surface of TC4 titanium alloy by plasma spraying Nb–SiC composite powder. The microstructure of the coating was characterized in detail by TEM, and the reaction mechanism of Nb–SiC was revealed. Sub-micron and nano-scale NbC grains dispersed in Nb3Si region, nano-Nb/Nb3Si cellular eutectic region, and equiaxed Nb2C nanograins region were formed in the coating. The research results show that Nb and SiC reacted firstly to form cubic NbC and Nb3Si phases during the plasma spraying process. Then, NbC with a higher melting point took the lead in crystallization during the cooling process of the coating, forming sub-micron and nano-scale NbC granular fine grains. Nb3Si with a lower melting point crystallized around the sub-micron and nano-scale NbC granular fine grains in the subsequent cooling process. In the plasma spraying process, the molten droplets formed Nb/Nb3Si cellular eutectic structure under large temperature gradient and extremely fast cooling rate. The remaining Nb in the raw material powder formed a diffusion couple with NbC to generate fine and dispersed nano-equiaxed Nb2C with cubic structure. The present investigation provides a reference for the reaction synthesis of advanced nanocomposites using Nb–SiC system.

Molecular assembly of carbon nitride-based composite membranes for photocatalytic sterilization and wound healing.

Polymeric carbon nitride (pCN) has attracted increasing interest as a metal-free photocatalyst because of its high efficiency in reactive oxygen species (ROS) generation. However, due to poor solubility, compounding pCN at the molecular level into more advanced nanocomposites remains a challenge. Herein, we report the dissolution of pCN in polyphosphoric acid (PPA) for the first time and fluid-phase assembly with carbon nanotubes (CNTs) into a flexible free-standing membrane. Mechanism and generality studies disclosed that the coordination of the acidity, viscosity, and adsorption energy of the solvents led to the successful dissolution of pCN. Interestingly, the pCN/CNTs molecular composite membrane exhibited not only superior mechanical properties and cycling performance as a result of strengthened π-π interfacial interaction, but also outstanding inactivation of E. coli and S. aureus in sterilization and wound healing for laboratory mice via photogenerated oxygen radicals. It would open a new era of pCN for biomedical applications in molecular composite membranes, beyond the traditional solar fuel applications in powders.

How weak hydration interfaces simultaneously strengthen and toughen nanocellulose materials

Hygroscopicity and the resulting pronounced structural deformation and mechanical attenuation limit the applications of wood and nanocellulose materials. Understanding the micromechanical mechanisms of interfibrillar hydration from the perspective of interfacial hygromechanics is a prerequisite for achieving tailored macroscopic properties. Here, we demonstrated a counterintuitive mechanism that weak hydration interfaces can simultaneously strengthen and toughen nanocellulose materials due to the transition of interfacial deformation mode. The interfibrillar sliding barrier and shear strength are undoubtedly reduced by increasing interfacial hydration and shift from stick–slip motion at low humidity to more continuous slip at high moisture content. These transitions in the shear response suppress local deformation at the interface, facilitate the homogenization of fibril deformation, and ultimately enhance the interfacial load transfer capability of long fibrils through the cooperativity of hydrogen bonds. The redistribution of local stress across the interface also reduces the strain concentration in fibrils, promoting fibril pullout and bridging. This novel mechanism is applicable to other hydrogen bond-dominated building blocks for the bottom-up design of advanced nanocomposites that are both strong and tough.

Synthesis and Characterization of Multifunctional Metal‐Organic Framework (Ni‐ZIF‐67) Decorated Waterborne Polyurethane (Ni‐ZIF‐67/WPU) Nanocomposites: Sonochemical Approach

AbstractThis work investigates the effect of a modified nickel‐doped metal‐organic framework (Ni‐ZIF‐67) as a filler on thermal, mechanical, and water vapor permeability properties of environmentally friendly waterborne polyurethane (WPU). The facile and greener ultrasound (sonochemical) technique is developed to prepare multifunctional Ni‐ZIF‐67@WPU nanocomposites, exhibiting superior crystallinity and uniform distribution. The resultant Ni‐ZIF‐67 nanoparticles and Ni‐ZIF‐67@WPU films are characterized by various techniques, including powder XRD, FE‐SEM, FTIR, TGA, UTM, contact angle, and antibacterial properties. Ni‐ZIF‐67@WPU nanocomposites exhibited excellent three‐fold mechanical performance (tensile strength ≈22 MPa) at a very low 5 wt.% filler loading and high thermal stability compared to pristine WPU. In addition, Ni‐ZIF‐67@WPU exhibited optimum water vapor permeability performance at 5.0 wt.% filler with the potential antibacterial application. Demonstrate that the rapid and facile synthesis approach can enhance the interaction of filler and matrix, high surface area, and tuneable pore size of filler material. This new insight has a new green approach for fabricating advanced nanocomposites toward practical utilization.

Two birds with one stone: Simultaneous fabrication of HfC nanowires and CNTs through efficient utilization of polymer-derived ceramics

• Carbon nanotubes (CNTs) were fabricated by using the waste gasses when preparing hafnium carbide nanowires (HfC NWs ) through thermal pyrolysis of Hf-containing precursor. • The CO and CH 4 released by Hf-containing precursor are the main carbon source for the growth of CNTs. • The in situ growth of HfC NWs increased the flexural strength of carbon/carbon (C/C) composites, and CNTs/carbon cloth displayed enhanced electrochemical performance. Carbon nanotubes (CNTs) are fabricated in carbon cloth by ultilizing the waste gasses when fabricating hafnium carbide nanowires (HfC NWs ) through thermal pyrolysis of Hf-containing polymer precursor. The formed HfC NWs are distributed uniformly on the surface of the carbon fibers in carbon/carbon (C/C) composites and display perfect single crystal appearance. The pyrolysis of the Hf-containing organic precursor provides hafnium and carbon source for the growth of HfC NWs . The released waste gasses containing CO, CH 4 and CO 2 are the main carbon source for the growth of CNTs. Specifically, the flexural strength of HfC NWs reinforced carbon/carbon (HfC NWs -C/C) composites is enhanced by ∼105% compared with pure C/C, and the CNTs/carbon cloth also displays improved electrochemical performance with respect to capacitor applications. The present study introduces a novel sustainable and eco-friendly process related to polymer-derived ceramics to form advanced ceramic nanocomposites and proposes a deep understanding of the growth mechanism of CNTs.

An atomistic study of deformation mechanisms in metal matrix nanocomposite materials

With nanoscale reinforcements resulting in a high density of matrix/reinforcer interfaces, metal matrix nanocomposite (MMNC) materials behave differently from their micro-composite counterparts. An atomistic level understanding of the fundamental deformation mechanisms is necessary to link the nanoscale reinforcement attributes with the strengthening and fracture properties of the nanocomposite. Using the Aluminum-(Silicon Carbide), Al-SiC, nanocomposite as an example, we conducted classical Molecular Dynamics simulations of uniaxial tensile deformation for the composite. By varying nanocomposite design parameters, including the SiC particle size, and the particle volume fraction, we revealed the deformation mechanisms and defects evolution in nanocomposite materials. The deformation mechanisms are characterized into three subsequent mechanisms, which are (I) defect-free deformation driven by lattice distortion of the matrix, (II) dislocation-based deformation driven by dislocation nucleation and growth, and (III) failure-based deformation driven by interface separation and void growth. The nanoparticle volume fraction was found to have a major effect on dislocation-based deformation, whereas the particle size had a greater impact on the failure-based deformation. This work sheds light on the fundamental deformation mechanisms of MMNCs which may facilitate the future design of advanced nanocomposites with broader applications. • Atomistic deformation mechanisms of metal matrix nanocomposite (MMNC) materials • Molecular dynamics simulations of tensile deformation of the Al-SiC nanocomposites with varying size and volume fraction of the SiC nanoparticles • Three subsequent deformation mechanisms of MMNCs are identified as (I) defect-free mechanism, (II) dislocation nucleation & growth mechanism, and (III) interface separation mechanism

MXene-Based Ceramic Nanocomposites Enabled by Pressure-Assisted Sintering.

As MXenes become increasingly widespread, approaches to utilize this versatile class of 2D materials are sought. Recently, there has been growing interest in incorporating MXenes into metal or ceramic matrices to create advanced nanocomposites. This study presents a facile approach of mixing MXene with ceramic particles followed by pressure-assisted sintering to produce bulk MXene/ceramic nanocomposites. The effect of MXene addition on the densification behavior and properties of nanocomposites was explored through the Ti3C2Tz/alumina model system. We discovered that the presence of MXene altered the densification behavior and significantly enhanced the densification rate at low temperatures. In-depth microstructural characterization showed a homogeneous distribution of Ti3C2Tz MXene at the alumina grain boundaries. The Ti3C2Tz/alumina nanocomposites exhibited electrical conductivity but reduced hardness. We also demonstrated that using multilayered Ti3C2Tz as a precursor can produce composites with plate-like TiCx morphology. This work provides a conceptual approach for utilizing the diversity and versatility of MXenes in creating tunable advanced nanocomposites.

Recent Studies on Thermally Conductive 3D Aerogels/Foams with the Segregated Nanofiller Framework.

As technology advances toward ongoing circuit miniaturization and device size reduction followed by improved power density, heat dissipation is becoming a key challenge for electronic equipment. Heat accumulation can be prevented if the heat from electrical equipment is efficiently exported, ensuring a device's lifespan and dependability and preventing otherwise possible mishaps or even explosions. Hence, thermal management applications, which include altering the role of aerogels from thermally insulative to thermally conductive, have recently been a hot topic for 3D-aerogel-based thermal interface materials. To completely comprehend three-dimensional (3D) networks, we categorized and comparatively analyzed aerogels based on carbon nanomaterials, namely fibers, nanotubes, graphene, and graphene oxide, which have capabilities that may be fused with boron nitride and impregnated for better thermal performance and mechanical stability by polymers, including epoxy, cellulose, and polydimethylsiloxane (PDMS). An alternative route is presented in the comparative analysis by carbonized cellulose. As a result, the development of structurally robust and stiff thermally conductive aerogels for electronic packaging has been predicted to increase polymer thermal management capabilities. The latest trends include the self-organization of an anisotropic structure on several hierarchical levels within a 3D framework. In this study, we highlight and analyze the recent advances in 3D-structured thermally conductive aerogels, their potential impact on the next generation of electronic components based on advanced nanocomposites, and their future prospects.

Antimicrobial studies in rubber nanocomposites—A mini review

Infectious diseases are considered as a significant threat to human health as well as environment. Due to the increasing microbial diseases, researchers are trying to find out new materials with superior antimicrobial properties. Insertion of various nanofillers into rubber matrices will result in the production of advanced rubber nanocomposites with improved mechanical, electrical, thermal and barrier properties. However, improvement in antimicrobial properties of rubber nanocomposites is still remaining as an unexplored area. But the existing studies show that, the addition of antimicrobial nanofillers can introduce antimicrobial properties into the final rubber nanocomposites and thus can be used in various biomedical applications. Thus the present review tries to bring together all the available antimicrobial works in the area of rubber nanocompositses.

Dielectric relaxation of α-Fe2O3/Gd2O3 core-shell nanoparticle obtained through the polyol method

The design of core-shell nanostructures is a potential approach to obtaining advanced dielectric nanocomposites. The frequency-dependent dielectric dispersion of gadolinium oxide (Gd2O3) encapsulated iron oxide (Fe2O3) core-shell nanoparticles (Fe2O3/Gd2O3 CSNPs) synthesized by the polyol route is investigated in the temperature range from 303 K to 553 K and in the frequency range from 42 Hz to 1.1 MHz. The phase formation of the materials is evaluated by X-ray diffraction analysis. Synthesized Fe2O3/Gd2O3 CSNPs have multi-core nature are found by Transmission electron microscopy (TEM). Relaxation time corresponding to dielectric loss is found to obey Arrhenius law with an activation energy of 0.26 eV. Dielectric relaxation is analyzed in the electric modulus formalism. The frequency-dependent conductivity spectra follow the Jonscher power law.

Recent progress in nanocomposites of carbon dioxide fixation derived reproducible biomedical polymers.

In recent years, the environmental problems accompanying the extensive application of biomedical polymer materials produced from fossil fuels have attracted more and more attentions. As many biomedical polymer products are disposable, their life cycle is relatively short. Most of the used or overdue biomedical polymer products need to be burned after destruction, which increases the emission of carbon dioxide (CO2). Developing biomedical products based on CO2 fixation derived polymers with reproducible sources, and gradually replacing their unsustainable fossil-based counterparts, will promote the recycling of CO2 in this field and do good to control the greenhouse effect. Unfortunately, most of the existing polymer materials from renewable raw materials have some property shortages, which make them unable to meet the gradually improved quality and property requirements of biomedical products. In order to overcome these shortages, much time and effort has been dedicated to applying nanotechnology in this field. The present paper reviews recent advances in nanocomposites of CO2 fixation derived reproducible polymers for biomedical applications, and several promising strategies for further research directions in this field are highlighted.

Giant Room-Temperature Electrocaloric Effect of Polymer-Ceramic Composites with Orientated BaSrTiO3 Nanofibers.

Cooling based on the electrocaloric effect (ECE) is a promising solution to environmental and energy efficiency problems of vapor-compression refrigeration. Ferroelectric polymer-ceramics nanocomposites, integrating high electric breakdown of organic ferroelectrics and large EC strength of ceramics, are attractive EC materials. Here, we tuned the orientation of Ba0.67Sr0.33TiO3 nanofibers (BST nfs) in the P(VDF-TrFE-CFE) polymer. When the nfs were aligned parallel to the field, a ΔT of 11.3 K with an EC strength of 0.16 K·m/MV was achieved in the blends. The EC strength not only surpasses advanced nanocomposites but also is comparable to ferroelectric ceramics. The simulation indicates that a significantly higher electric field is concentrated in polymer regions around the ends of the orientated nfs, contributing to easier flipping of polymer chains for large ECE. This work provides a new method to obtain large ECE in composites for next-generation refrigeration.

Carbon nanofilm stabilized twisty V2O3 nanorods with enhanced multiple polarization behavior for electromagnetic wave absorption application

• Core-shell V 2 O 3 @C nanocomposite was constructed by a two-step strategy. • V 2 O 3 @C shows enhanced electrical conductivity and abundant defects. • Effective absorption bandwidth (EAB) gets to 7.21 GHz at ultra-low thickness. • Multiple polarization and conductance loss are used to analyze the absorbing mechanism. Vanadium (V) oxides exhibit low electrical conductivity and poor polarization properties, especially in that V 2 O 3 has low stability and is easily oxidized to higher valence V oxides. To solve this problem, we herein provide a two-step strategy for the synthesis of carbon nanofilm stabilized twisty V 2 O 3 nanorods (V 2 O 3 @C), including a hydrothermal reaction and a controlled pyrolysis process. Conductivity tests and electron-spin resonance (ESR) spectra indicate that the coating of carbon nanofilm not only enhances the electrical conductivity but also generates abundant defects. The electromagnetic waves absorption (EMA) results suggest that V 2 O 3 @C exhibits excellent EMA performance at ultra-low thickness, where the effective absorption bandwidth gets to 7.21 GHz at 1.7 mm and the maximal absorption reaches –56 dB. Enhanced conductivity loss and improved multiple polarization relaxation were used to illustrate the absorbing mechanism of V 2 O 3 @C. This work provides new insights into the design of advanced nanocomposites for EMA applications.

Trends in Layered Double Hydroxides‐Based Advanced Nanocomposites: Recent Progress and Latest Advancements

AbstractRecently, layered double hydroxides (LDHs) have gathered vast interest due to overall positive charge, unique crystallinity, and biocompatibility for diverse applications. Despite the advantageous attributes, these hydrotalcites often result in several limitations concerning the application requirements, such as aggregation, as well as poor chemical and thermal stabilities, hindering their scale‐up progress and practical utilization. In addressing these issues, the recent advancements in the fabrication of intelligent LDHs nanocomposites based on organically (polymer/polyelectrolyte)‐modified and inorganic (metal)‐composited architectures are systematically presented. Initially, a brief note on the shortcomings in various fields and the chemistry of these pristine LDHs is given. Then, various synthetic strategies used to fabricate these emerging LDH nanocomposites are comprehensively emphasized, focusing on the advancements in their structure and applicability. In addition, the effects of various attractive physicochemical attributes of LDHs and their nanocomposite forms are discussed, including their applicability in adsorption, biomedicine, catalysis, energy, and environment‐related applications. In summary, this article is concluded with an outlook concerning the positioning of LDH‐based nanocomposites compared to other innovative materials, as well as the current challenges and future requirements for scale‐up.