Functional Nanocomposite Materials Research Articles

A Simplified Method for the Preparation of Highly Conductive and Flexible Silk Nanofibrils/MXene Membrane.

Silk nanofibers (SNF) have great applications in high-performance functional nanocomposites due to their excellent mechanical properties, biocompatibility, and degradability. However, the preparation of SNF by traditional methods often requires the use of some environmentally harmful or toxic reagents, limiting its application in green chemistry. In this paper, we successfully prepared SNF using natural silk as raw material and solvent stripping technology by adjusting the solvent concentration and solution ratio (the diameter of about 120 nm). Using the above SNFs as raw materials, SNF membranes were prepared by vacuum filtration technology. In addition, we prepared an SNF/MXene nanocomposite material with excellent humidity sensitivity by simply coating MXene nanosheets with silk fibers. The conductivity of the material can approach 1400.6 S m-1 with excellent mechanical strength (51.34 MPa). The SNF/MXene nanocomposite material with high mechanical properties, high conductivity, and green degradability can be potentially applied in the field of electromagnetic interference (EMI) shielding, providing a feasible approach for the development of functional nanocomposite materials.

The Optimization of Mechanochemical Processes toward Functional Nanocomposite Materials

Mechanochemical technology is developing rapidly, judging by the scientific information in both basic and applied studies. However, many issues and points of view remain to be discussed. This review presents some new key issues for the optimization of mechanochemical processes in terms of theoretical and practical aspects. Emphasis is placed on powder technology aspects, which are not always discussed compared to functional or microscopic viewpoints. The transfer of chemical species across the interparticle interface between dissimilar species during the mechanosynthesis of nanocomposites offers many new opportunities. Since almost all material transport is preceded by charge transfer, its driving force has been sought using terminology beyond the well-established electrochemical terms. In particular, the valence state of the cationic species involved is of importance. The role of organic compounds throughout the process is emphasized, regardless of their survival in the final product. The similarity with pharmaceutical phenomena is pointed out, although its mentality is very different from that of the synthesis of nanocomposites. The rational amorphization and stabilization of molecular dispersion states with the participation of excipients are discussed. The effects of liquids, either added or formed by mechanochemical auto-liquefaction, are presented with reference to the comparison between wet and dry grinding. The mechanisms of the apparent stabilization of the mechanically activated states of the products are elucidated to investigate the practical applicability of these mechanochemically synthesized products. Finally, the most important aspects for the optimization of the mechanochemical processes of functional nanocomposites are listed.

Advanced 3D printing of graphene oxide nanocomposites: A new initiator system for improved dispersion and mechanical performance

The integration of nanoparticles, such as Graphene Oxide (GO), with photo-curable polymers in 3D printing has garnered significant interest in recent years due to the potential to create functional nanocomposite materials. This study explores the challenges of achieving optimal dispersion of GO nanoparticles within the polymer matrix and the crucial role of photoinitiators in overcoming these limitations. Traditional photoinitiators, like TPO, commonly used for GO/polymer resins, have raised concerns about high toxicity and limited sensitivity to visible light, prompting the need for alternative initiating systems. In this research, we propose a two-component initiator system based on bis-(4-t-butylphenyl)iodonium hexafluorophosphate and photosensitizer N-{4-[(E)-2-(pentafluorophenyl)ethenyl]phenyl}-2,1,3-benzothiadiazol-4-amine (IOD/PS1) as a promising solution. This new initiating system not only ensures a more environment-friendly resin but also exhibits enhanced polymerization kinetics and compatibility with GO nano fillers. This study investigated the effect of the addition of nano-GO on the kinetics of the radical photopolymerization process, 3D printing, and final mechanical and thermal properties of the received products. TPO and PEGDA/H2O were used as reference systems. In addition, a new two-component initiator system was synthesized, which is an interesting alternative to the commercial TPO initiator that is widely employed in additive techniques. This publication presents the research procedure involving various techniques: real-time FTIR and photoreology. In addition, the possibility of creating three-dimensional structures from the newly developed photo-curable resins was verified. Finally, the morphologies and mechanical properties of the resulting 3D structures were compared. Within the work, we demonstrate the advantages of the two-component initiator in achieving uniform distribution of GO and fabricating high-quality materials. By applying IOD/PS1 initiating system we facilitated a more controlled and efficient polymerization process, reducing shrinkage-induced stresses and enhancing interlayer bonding. The result was the fabrication of high-quality, well-dispersed materials with tailored properties suitable for various applications, particularly in the biomedical field.

Facile synthesis of Flower-like ZnO loading Cellulose-Chitosan nanocomposite films by biomimetic approach with enhanced performance

Flower-like ZnO composed of nanoplate was synthesized using biopolymers cellulose and chitosan via biomimetic strategy under a mild alkaline solution. In this work, we described ZnO-based cellulose/chitosan hybrid nanocomposites with enhanced mechanical, thermal, photocatalytic and antibacterial properties. Due to the uniform dispersion of ZnO nanoparticles with mean sizes of approximately 10 nm and the hydrogen bonds formed between ZnO and polysaccharides, CCZ exhibited enhanced tensile strength, which grew 1.5 times compared to neat CCF. CCZ exhibited superior antibacterial and photocatalytic activities. The width of inhibition zones around CCZ films reached 15.6–20.6 mm and 8.4–13.6 mm for S. aureus and E. coli, respectively. Furthermore, biopolymers cellulose and chitosan interacting with ZnO NPs tuned the bandgap of the semiconductor, leading to the enhancement of photocatalytic abilities. 87.1 % of methyl orange (MO) was degraded by CCZ nanocomposite within 50 min. CCZ nanocomposite remained stable after 3 cycles. The facile method extended biomimetic strategy to construct functional nanocomposite materials and provided a new route to synthesize specific morphology of ZnO NPs for various practical applications such as wastewater treatment, antibacterial materials, and solar cells.

Poly(butylene succinate) and graphene nanoplatelet–based sustainable functional nanocomposite materials: structure-properties relationship

Sustainable functional polymer nanocomposites from renewable resources are extremely promising materials that can provide the next-generation of lightweight, multifunctional materials for several applications including energy storage, automotive, construction, defense, aerospace, consumer products, biomedical and functional coatings to name few. There is limited information on the use of sustainable polymers and graphene nanoplatelets (GNs), as well as the combinations of these two can provide reduced water permeability or enhanced electrical conductivity and improved thermal properties, and so on. Building upon this hypothesis, biobased poly(butylene succinate)/few-layer GN nanocomposites were prepared via a solventless melt-blending technique. Different characterization techniques such as differential scanning calorimetery, thermogravimetric analysis, dynamic mechanical analysis, dielectric spectroscopy, X-ray diffraction (XRD) and hot stage optical microscopy were used to study the thermal and structural characteristics. The melt blending was characterized by torque and temperature curves which showed that torque was reduced by up to 15 Nm, and melt temperature was improved by up to 5 °C. The improved crystallization of the composites in low concentrations of GN was observed. Graphene has been found to increase the crystallization temperature up to 10 °C and yielded pronounced spherulite structure, whereas peak shift was observed in XRD. High filler loading from 0.5 to 6.0 wt% was used to obtain more insights for few-layer graphene applications for thermoplastic polymer processing applications.

Carbon Dots in Porous Materials: Host–Guest Synergy for Enhanced Performance

AbstractCarbon dots (CDs) are emerging as a new class of carbon nanomaterials, which have inspired growing interest for their widespread applications in anti‐counterfeiting, sensing, bioimaging, optoelectronic and energy‐related fields. In terms of the concept of host–guest assembly, immobilizing CDs into porous materials (PMs) has proven to be an effective strategy to avoid the aggregation of bare CDs in solid state, in particular, the host—guest synergy with both merits of CDs and PMs affords composites promising properties in afterglow and tunable emissions, as well as optimizes their performance in optics, catalysis, and energy storage. This Minireview summarizes the recent progress in the research of CDs@PMs, and highlights synthetic strategies of constructing composites and roles of porous matrices in boosting the applications of CDs in diverse areas. The prospect of future exploration and challenges are proposed for designing advanced CDs‐based functional nanocomposite materials.

Carbon Dots in Porous Materials: Host-Guest Synergy for Enhanced Performance.

Carbon dots (CDs) are emerging as a new class of carbon nanomaterials, which have inspired growing interest for their widespread applications in anti-counterfeiting, sensing, bioimaging, optoelectronic and energy-related fields. In terms of the concept of host-guest assembly, immobilizing CDs into porous materials (PMs) has proven to be an effective strategy to avoid the aggregation of bare CDs in solid state, in particular, the host-guest synergy with both merits of CDs and PMs affords composites promising properties in afterglow and tunable emissions, as well as optimizes their performance in optics, catalysis, and energy storage. This Minireview summarizes the recent progress in the research of CDs@PMs, and highlights synthetic strategies of constructing composites and roles of porous matrices in boosting the applications of CDs in diverse areas. The prospect of future exploration and challenges are proposed for designing advanced CDs-based functional nanocomposite materials.

Thermostable and Redispersible Cellulose Nanocrystals with Thixotropic Gelation Behavior by a Facile Desulfation Process

As a ecofriendly and promising nanomaterial, cellulose nanocrystals (CNCs) have attracted significant interest. However, the intrinsic sulfate-modified surface and self-aggregation behavior of the most common acid-hydrolyzed CNCs with sulfuric acid lead to the low thermostability and poor redispersion of solid-state CNCs materials, which limit their practical applications. In this work, we propose a simple and effective strategy to not only remove the sulfates in CNCs but also resuscitate their dispersibility by a facile post-treatment process, including an acid-triggering gelation, solvent exchange with ethanol, and supercritical CO2 drying. The resultant CNC powder exhibits a high thermostability, much higher than that of the common acid-hydrolyzed CNCs and similar to that of the pristine cellulose. Moreover, the CNC powder can be readily redispersed in various solvents by a short ultrasonic treatment. Subsequently, as the CNC concentration increases, CNC gels spontaneously form and exhibit thixotropic behaviors. Taking advantage of these characteristics of the above desulfated CNC powder, we fabricated a CNC/Ag nanoparticle gel, magnetic CNC/Fe3O4 nanoparticle gel, pressure-sensitive polymer/CNC composite gel, and colorless and transparent poly(lactic acid)/CNC thermoplastic films. Therefore, the highly thermostable, redispersible, and easy-to-gel CNC powder has a huge potential as a building block for various stable, well-dispersed, and functional nanocomposite materials.

Potential of bioinspired cellulose nanomaterials and nanocomposite membranes thereof for water treatment and fuel cell applications

Bio derived nanocellulose possesses versatile properties, which are very worthwhile for advanced functional applications. Nanocellulose i.e. nanofibers and nanocrystals can be applied in the form of solution, suspension, ink or nanomaterials in composites, nanocomposites, coatings and films. These forms of nancellulose are found for the development of hydrogels, aerogels, electrodes, adsorbents, packaging films, membranes, nanopapers, filters, supercapacitors, electrodes, electrolytes, rheology modifiers, food additives, scaffolds, and biomaterials/formulations for biomedical and tissue engineering. This paper, categorically reviews and discusses the potential of composite, nanocomposite and hybrid materials obtained from nanocellulose for water treatment and purification. It reviews the extraction of nanocellulose such as cellulose nanofibers, cellulose nanocrystals and bacterials nanocellulose and their physicochemical properties. The emphasis has been given on the nanocellulose based adsorbents, absorbents, flocculants, nanopapers, membranes, photocatalysts etc. It is seen that nanocellulose based various functional nanocomposite and hybrid materials have huge potential for the extraction of metal ions and organic dyes from water, removal of organic contaminants, virus, bacteria, turbidy and chemical oxygen demand from wastewater stream, separation of oil/water mixture, and photocatalytic degradation of organic contaminants in water. The comparative analysis of cellulose nanomaterials for all the above applications are presented graphically to understand the relation between types of materials and their potential for water purification by removing different contaminant; as well as its proton conductivity for prospective application in fuel cells.

Synthesis and properties of nanocomposites in the system of potassium polytitanate - layered double hydroxide

An experimental method to produce a new kind of functional nanocomposite materials is proposed. The synthesis involved the treatment of layered potassium polytitanate with ternary aqueous solutions of Me2+(Zn) and Me3+(Al, Cr) nitrates and K2CO3; the products were characterized by XRD, SEM, TEM and laser diffraction methods. The structure of the particles produced is formed by platy quasi-amorphous lepidocrocite-like flakes of potassium polytitanate with incrusted nanoparticles of layered double hydroxides of Zn4Cr2(OH)12CO3∙3H2O or Zn0.66Al0.34(OH)2(CO3)0.17∙H2O. The measured physico-chemical, tribological and electrical properties of the nanocomposites are discussed taking into account their potential application as antifriction and antiscuff additives of lubricating compositions or functional materials in the manufacture of electronic devices, emphasizing the influence of their structural features on the tribological and electrical properties.

The interaction effect of bacterial cellulose with gold nanoparticles obtained by metal-vapor synthesis

In the present work, a promising method was proposed for the formation of new functional nanocomposite materials based on bacterial cellulose and Au nanoparticles obtained by a biocompatible and environmentally friendly metal vapor synthesis. The structure and composition of the composite films surface were studied by XPS, SEM, and IR spectroscopy. It was determined that Au nanoparticles effectively chemisorb the bacterial cellulose nanofibrils forming nanoparticles with a size of about 25 nm with a metal core-hydrocarbon shell structure.

Effect of Interaction of Bacterial Cellulose with Gold Nanoparticles Obtained by Metal Vapor Synthesis

A promising method for preparation of new functional nanocomposite materials based on bacterial cellulose and Au nanoparticles was proposed for the first time. The Au nanoparticles were obtained by biocompatible and environmentally friendly metal vapor synthesis. The structure and composition of the surface of composite films were studied by XPS, SEM, and IR spectroscopy. Gold nanoparticles were found to efficiently chemisorb nanofibrils of bacterial cellulose, which gave nanoparticles of approximately 25 nm in size with a “metal core–hydrocarbon shell” structure.

Carbon dots as building blocks for the construction of functional nanocomposite materials

Carbon dots (CDs) are carbon-based quasi-spherical fluorescent nanoparticles with unique physical and chemical properties. Due to their complexity and diversity, CDs are applied in analytics, sensors, bio-imaging and diagnostics. Stabilizing CDs as well as improving their performances can extend their range of applications; it is desirable to combine them in an appropriate solid matrix or prepare solid-state nanocomposites. In this review, a summary of the research of CD nanocomposites is given. Describes the loading methods of CDs on polymers, metals and their compounds, non-metals and their compounds, and metal organic frameworks, which including electrostatic interactions, covalent bonds, non-covalent bonds or hydrogen bonds. In addition, the working mechanism and application of CD nanomaterials are also introduced. The challenges encountered, potential and prospects with CD nanocomposite are discussed at the end of the article.

Mesoporous and Nanocomposite Fibrous Materials Based on Poly(ethylene terephthalate) Fibers with High Craze Density via Environmental Crazing: Preparation, Structure, and Applied Properties.

Preparation of mesoporous and nanocomposite fibrous polymer materials based on commercial poly(ethylene terephthalate) (PET) fibers with high density of crazes (HCD fibers) via environmental crazing (EC) is described. Multiple crazes in pristine PET fibers were initiated by the precrazing procedure, and the density of the initiated crazes in the starting HCD fibers is equal to ∼200 crazes per mm. The scenario of environmental crazing of the HCD PET fibers was studied by online microscopic observations. The mechanism of environmental crazing of the HCD fibers is found to be different from the classical well-known scheme: new crazes are initiated over a broad interval of tensile strains of up to 250%, splitting of thin craze walls takes place, and the collapse of the fibrillar-porous structure of crazes is prevented. The HCD fibers preserve their porosity even upon the complete removal of the physically active liquid environment from the volume of crazes. As a result, the overall porosity of the HCD fibers can reach ∼60 vol % and pore dimensions are estimated to be below ∼6 nm. Applied properties of the mesoporous HCD fibers (gas storage potential, sorption, insulating properties) are studied. The bottom-up synthesis of silver nanoparticles in the mesoporous HCD fibers via reduction of silver ions is described, and the resultant silver-containing nanocomposite fibers are characterized by a uniform distribution of silver nanoparticles with an average size of 3 nm. The silver content in the HCD fibers is 6 times higher than that in the pristine PET fibers with the same tensile strain. The silver-loaded fibers show high bactericidal activity against Gram-positive ( Staphylococcus aureus) and Gram-negative bacteria ( Escherichia coli) and antifungal activity against Candida guilliermondii. The proposed EC approach allows preparation of sustainable mesoporous polymeric fibers and related functional nanocomposite materials with valuable functional properties for diverse applications.

Interface modification of titanium dioxide nanoparticles by titanium-substituted polyoxometalate doping for improvement of photoconductivity and gas sensing applications

TiO2 nanoparticles are commonly used as versatile precursors to make functional nanocomposite materials. However, the surface defects at grain boundaries of TiO2 nanoparticles significantly affect the photoelectric properties of TiO2 nanomaterials. In this work, we firstly prepared nanocomposites of TiO2 and polyoxometalates (POMs) in which different POMs, including titanium-substituted POMs K5 [PW11TiO40] and K7 [PW10Ti2O40], are incorporated with TiO2 nanoparticles so as to make an interface modification on grain boundaries of TiO2 nanoparticles. Then the photoconductivities of the TiO2/POM nanocomposites were investigated through measurement of photocurrent responses, current-voltage curves, Mott-Schottky plots and surface photocurrent spectra. Compared with pure TiO2 nanoparticles, TiO2/POM nanocomposites exhibit superior photoelectric properties, benefitting from the interface modification from different POMs. The gas sensing performance for acetone was also explored by use of the as-prepared photoconductive devices, and TiO2/PW11Ti exhibited a high gas sensing performance.

Recent advances in catalytic properties of LDHs/carbon composite materials

As a family of highly ordered two-dimensional anionic clay materials, layered double hydroxides (LDHs) can be used as catalyst, catalyst supported, or precursors for the synthesis of low-cost and highly dispersed supported metal catalysts with excellent catalytic activity and stability. Due to the excellent mechanical, electrical, and physicochemical properties, carbon nanomaterials can work as ideal functional components to fabricate LDHs/carbon composite catalysts with enhanced catalytic performance. This review summarizes the recent development in the controlled fabrication of functional nanocomposite materials based on layered double hydroxides and carbon-based materials, and their applications as the heterogeneous catalyst such as photocatalyst, electrocatalyst, hydrogenation and oxidation catalyst, etc. Furthermore, current challenges and prospects of LDHs/carbon composite catalysts are discussed from the viewpoint of material design and application.

A Development of Micro strip Patch Antenna from synthesized Nanocomposites materials for Defence Applications.

Wide varieties of functional nanocomposite materials have been analyzed and have attracted considerable attention from both academia and industries for their application in chemical, biomedical and microelectronic devices. However the successful implementation of such type of materials in RF, microwave devices and defense applications is relatively limited. In this paper, Magneto-Metal-Dielectric-Polymer Nanocomposites will be introduced as new functional materials well suited for RF/microwave device application. The nanoparticle with sub 5-10 nm diameters and tight size distribution, are synthesized and homogeneously dispersed to enhance the microwave properties of the engineered RF substrate by increasing the relative permeability and relative permittivity. This work not only presents the experimental implementation of magneto-metal-dielectric-nanocomposite engineered substrates for RF antenna with 2-4 GHz (S-band) Operational frequencies, but also correlates the unique magneto dielectric properties to the key antenna performance parameters such as gain,bandwith,efficiency,return loss, and directivity. The paper will be concluded with brief implementations of several other ongoing activities within the RF MEMS/NEMS of a variety of several nanostructure materials in the form of ultra thin films in RF/MW/defense devices.

Preparation of the Multi-Walled Carbon Nanotubes/Nickel Composite Coating with Superior Wear and Corrosion Resistance

The multi-walled carbon nanotubes/nickel (MWCNTs/Ni) nanocomposite coatings were prepared on Cu substrate by electro-deposition method in the electrolyte with well-dispersed MWCNTs. Surface morphologies of the composite coatings with protrusion structures were confirmed by scanning electron microscopy. X-ray diffraction, fourier transform infrared spectroscopy, and energy-dispersive x-ray spectrometer were used to characterize the phase structures, functional groups, and elements distribution of the coatings as well as the incorporated MWCNTs. In addition, the effect of MWCNTs percentage on thickness, hardness, wear, and corrosion resistance of the coatings was also investigated. Results indicated that the incorporation of MWCNTs positively affected the hardness of coatings for their strengthening skeletons effect. Meanwhile, the coating with the MWCNTs concentration of 0.2 g/L could achieve the lowest friction coefficient, wear rate as well as the mass loss in the tribological test by a ball-on-disk tribometer. And also, the optimal corrosion resistance with the highest corrosion potential (Ecorr) and the lowest corrosion current density (Icorr) of the composite coating was finally proved after the potentiodynamic polarization evaluation, which could promote the potential applications in preparing the functional nanocomposite materials.

Phase Tuning of Nanostructured Gallium Oxide via Hybridization with Reduced Graphene Oxide for Superior Anode Performance in Li-Ion Battery: An Experimental and Theoretical Study.

The crystal phase of nanostructured metal oxide can be effectively controlled by the hybridization of gallium oxide with reduced graphene oxide (rGO) at variable concentrations. The change of the ratio of Ga2O3/rGO is quite effective in tailoring the crystal structure and morphology of nanostructured gallium oxide hybridized with rGO. This is the first example of the phase control of metal oxide through a change of the content of rGO hybridized. The calculations based on density functional theory (DFT) clearly demonstrate that the different surface formation energy and Ga local symmetry of Ga2O3 phases are responsible for the phase transition induced by the change of rGO content. The resulting Ga2O3-rGO nanocomposites show promising electrode performance for lithium ion batteries. The intermediate Li-Ga alloy phases formed during the electrochemical cycling are identified with the DFT calculations. Among the present Ga2O3-rGO nanocomposites, the material with mixed α-Ga2O3/β-Ga2O3/γ-Ga2O3 phase can deliver the largest discharge capacity with the best cyclability and rate characteristics, highlighting the importance of the control of Ga2O3/rGO ratio in optimizing the electrode activity of the composite materials. The present study underscores the usefulness of the phase-control of nanostructured metal oxides achieved by the change of rGO content in exploring novel functional nanocomposite materials.

Fuel Flexible and Efficient Semionics Single Layer Fuel Cell

Fuel cells are traditionally based on a three-layer configuration - anode, electrolyte and cathode –leading to a complex structure, not least since the three layers have to be chemically stable and mutually compatible. Our new electrolyte-free, single layer fuel cell represents a radically new approach to fuel cell research and design. An advanced fuel flexible single layer/electrolyte free fuel cell with a functional nanocomposite was developed. Several different types of fuel, for example, gaseous (hydrogen and biogas) and liquid fuels (bio-ethanol and bio-methanol), were used in the experiments. Maximum power densities of 800, 300, 500, 400 mW cm-2 were achieved using hydrogen, bio-gas, bio-methanol, and bio-ethanol, respectively. These results show that single layer/electrolyte free fuel cell systems with functional nanocomposite offer significant advantages in reducing the operational and capital costs for the production of power and heat with a multi-fuel flexibility. This system might be the one of the promising solutions for sustainable energy development. This study is based on nanocomposites for advanced fuel cell technology (NANOCOFC) to develop functional nanocomposite materials for next generation marketable products. References B.Zhu, Rizwan Raza, Q.Liu, H.Qin, L.Fan, “Fuel cells based on the electrolyte and non-electrolyte separator” Energy and Environmental Sciences , 2011, 4 (8), 2986 - 2992.