Nanocomposites For Applications Research Articles

Applications of MOF-Based Nanocomposites in Heat Exchangers: Innovations, Challenges, and Future Directions

Metal–organic frameworks (MOFs) have garnered significant attention in recent years for their potential to revolutionize heat exchanger performance, thanks to their high surface area, tunable porosity, and exceptional adsorption capabilities. This review focuses on the integration of MOFs into heat exchangers to enhance heat transfer efficiency, improve moisture management, and reduce energy consumption in Heating, Ventilation and Air Conditioning (HVAC) and related systems. Recent studies demonstrate that MOF-based coatings can outperform traditional materials like silica gel, achieving superior water adsorption and desorption rates, which is crucial for applications in air conditioning and dehumidification. Innovations in synthesis techniques, such as microwave-assisted and surface functionalization methods, have enabled more cost-effective and scalable production of MOFs, while also enhancing their thermal stability and mechanical strength. However, challenges related to the high costs of MOF synthesis, stability under industrial conditions, and large-scale integration remain significant barriers. Future developments in hybrid nanocomposites and collaborative efforts between academia and industry will be key to advancing the practical adoption of MOFs in heat exchanger technologies. This review aims to provide a comprehensive understanding of current advancements, challenges, and opportunities, with the goal of guiding future research toward more sustainable and efficient thermal management solutions.

The chemical functionalization advantages of carbon nano heli-coil reinforcements for multifunctional polymeric nanocomposites

Carbon nanotubes (CNTs) have demonstrated superior mechanical, electrical, and thermal properties. Our previous studies have shown that the Heli-coil CNTs (HCNTs) perform better than the straight CNTs as nanoscale reinforcements, primarily due to their heli-coil structural configurations that can additionally provide mechanical-interlocking-mechanisms between the microfibers and resin. Pristine CNTs are inert and do not disperse well in polymers and form weak bonds with resin molecules. One of the techniques to improve the dispersion of CNTs and their bonding effectiveness is to chemically functionalize them. In this research, HCNTs that were covalently functionalized using a mixture of nitric, sulfuric, and hydrochloric acids following 16 different procedures, varying the process parameters (i.e., sonication time, acid molarity, and mixing sequence) were used. The pristine and functionalized HCNTs (FHCNTs) were incorporated into epoxy resin at very low weight percentages (i.e., 0.02, 0.04, and 0.06 wt%), processed, used to fabricate nanocomposite test specimens, and then tested according to ASTM standards. The main objective of this research was to investigate the effects of chemical functionalization process parameters and wt% of FHCNTs on the mechanical performance of polymeric nanocomposites. The test results showed improvements of up to 5.7%, 35.1%, 11.1%, 49.5%, and 60% for the tensile strength, fracture toughness, modulus, strain-to-failure, and hardness, respectively, that were mostly related to 0.02 wt% of FHCNTs reinforcements for the functionalization procedures 2, 4, and 10. Additionally, the fractured specimens were inspected and analyzed using 3D scanning-laser-confocal-microscopy and SEM imaging, and the most effective functionalization processes were recommended for structural nanocomposite applications.

Fabrication and comprehensive characterization of HPMC/PVA/CMC-MoO₃ bio-nanocomposites: Enhanced mechanical, electrical, and antibacterial properties for food packaging applications.

This study explores the synthesis and characterization of bio-nanocomposite films composed of HPMC/PVA/CMC blends with molybdenum trioxide (MoO₃) nanofillers at varying concentrations. X-ray diffraction (XRD) analysis confirms the structural integrity of the polymer matrix, with MoO₃ enhancing crystallinity as its concentration increases. Fourier-transform infrared spectroscopy (FTIR) reveals strong hydrogen bonding between MoO₃ and the polymer matrix, leading to improved interfacial compatibility. Ultraviolet-Visible (UV-Vis) spectroscopy indicates enhanced optical properties, with increased UV absorption correlating with higher MoO₃ content. As the MoO₃ concentration increased, the indirect energy gap decreased from 3.96 eV to 2.94 eV. Mechanical testing demonstrates significant improvements in tensile properties, including Young's modulus, ultimate tensile strength, and toughness, attributed to MoO₃'s electrostatic and hydrogen bonding effects on the polymer network. Electrical and dielectric analyses further show that higher MoO₃ levels boost conductivity, interfacial polarization, and charge storage, particularly at low frequencies. Additionally, the addition of MoO₃ reduces the contact angle, enhancing hydrophilicity, and significantly increases cell viability, achieving a peak value of 93.33 ± 1.73 % at 2.0 % MoO₃ loading. Antibacterial assays confirm strong inhibition of both gram-positive and gram-negative bacterial growth, with greater efficacy observed against gram-positive strains. These results underscore the potential of HPMC/PVA/CMC-MoO₃ nanocomposites for applications in bio-compatible, mechanically robust, and antibacterial materials.

Recent developments and advanced applications of promising functional nanocomposites for green buildings: A review

Recent developments and advanced applications of promising functional nanocomposites for green buildings: A review

CHARACTERIZATION OF GRAPHENE/H-BNNS REINFORCED HIGH-PERFORMANCE POLYURETHANE NANOCOMPOSITES PRODUCED USING SOLVENT CASTING METHOD

Polyurethane (PU) is a popular material for nanocomposites application in polymer science and technology. In pure form, PU is not suitable for engineering applications that require additional processing to improve the mechanical and thermal properties. High-performance PU nanocomposites with superior properties may be obtained by reinforcement with nanostructures such as graphene (Gr) and hexagonal boron nitride nanosheets (h-BNNS). In the present research, h-BNNS and Gr are used as a reinforcement into the PU matrix. Solvent casting method has been used to obtain PU/Gr, PU/h-BNNS, and PU/Gr + h-BNNS (hybrid) nanocomposites. Gr and h-BNNS are reinforced into the PU matrix at weight % (wt.%) of 0.3, 0.5, and 0.7, respectively. In hybrid PU nanocomposite the combination of both Gr and h-BNNS has been used in the wt.% of 0.3, 0.5, and 0.7. Characterization techniques such as Fourier transform infrared spectrometer (FTIR), field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), and dynamic mechanical analysis (DMA) were employed to elucidate the morphological and structural changes within the PU nanocomposite matrix. Results revealed the establishment of polymerization in all three types of reinforcement and the presence of hard segments in the h-BNNS reinforced PU nanocomposites, which indicates the presence of hydrogen bonding. h-BNNS reinforced PU nanocomposites revealed the formation of strong interfacial interaction between the h-BNNS and the PU matrix. Significant changes in the storage modulus (E') were observed with the various types of reinforcing agents. Reinforcement of 0.5 wt.% of h-BNNS yields better results compared to Gr and hybrid reinforcement.

NANOCOMPOSITES BASED ON A HEAT RESISTANT POLYCYANURATE MATRIX

The review article is devoted to a promising and rapidly developing class of thermosetting polymers – polycyanurates created from cyanate ester resins (CER), in particular, to the synthesis and characterization of the structure and physical properties of their nanocomposites obtained by in situ method using inorganic nanoparticles with an organo-functionalized surface. Cyanate ester resins are very easy to use, and the technology of their processing is close to the technology of manufacturing materials based on traditional epoxy resins. Due to their high heat resistance, cyanate ester resins are increasingly replacing epoxy materials, especially in high-tech industries. An important feature of the synthesis of nanocomposites based on polycyanurates is that almost all functionalized nanoparticles used in the published studies catalyze the high-temperature polycyclotrimerization of dicyanates into polycyanurates. Nanoparticles with reactive groups on a surface, such as hydroxy, phenolic, amine, epoxy, etc. are covalently embedded in the forming polymer network during the synthesis process due to their easy chemical interaction with cyanate groups of the cyanate ester resin. The chemical reactions to such hybridization have been thoroughly studied. This phenomenon prevents an aggregation of nanoparticles and leads to their effective distribution in a polymer matrix, which in turn ensures high performance of the resulting nanocomposites. A specific effect of ultra-low (<1 wt.%) nanofiller concentrations on the glass transition temperature, heat resistance and mechanical strength of the resulting nanocomposites has been established: the glass transition temperature of polycyanurate increases by 40–60 °C with the introduction of 0.01 to 1.00 wt.% of epoxy-functionalized polyhedral oligomeric silsesquioxane (POSS), amino-SiO2, amino-POSS or amino-functionalized montmorillonite (MMT). Increasing the content of nanoparticles above ~2 wt.% usually leads to the opposite effect due to the formation of their aggregates. The areas of industrial application of nanocomposites based on polycyanurates are described. It has been shown that the valuable complex of thermal, dielectric, mechanical, and chemical properties of polycyanurates, as well as their ability for nanostructuring and all kinds of chemical modifications, due to the high reactivity of the cyanate groups of CER, contribute to the wide application of CER, polycyanurates and nanocomposites based on them in various fields of industry instead of traditional epoxy resins. In recent years, the use of CER, its composites and nanocomposites has increased significantly in the aerospace and defense industries, in the manufacture of electrical products and electronics, etc. CER-based products are used as potting resins, binders for carbon, glass and organic plastics, coatings, adhesives in aircraft, helicopters, satellites, antennas, gas turbines, microchips, etc.

Synthesis of Cu-GPNs/Polyvinyl chloride (Cu-GPNs/PVC) nanocomposite for application as an electromagnetic wave reflecting material

This article presents a method for synthesizing Cu-GPNs/PVC nanocomposite materials. Cu is synthesized from CuCl2 salt using ascorbic acid as a reducing agent. Graphene nano sheet (GPNs) was synthesized using the oxidation method of graphite, then reducing it at high temperatures. The characteristics of Cu nanoparticles, graphene were determined using Field Emission Scanning Electron Microscopy (FE-SEM), Transmission Electron Microscopy (TEM), Energy-dispersive X-ray spectroscopy (EDX), and X-ray diffaction (XRD). With a mass ratio of 5% nano Cu and 10% graphene, the Cu-GNPs/PVC nanocomposite film with a thickness of 0.6 mm can reflect from 86.89% to 90.78% at a frequency of 8-12 GHz.

Molecular Modeling Analysis of rGO/Fe<sub>3</sub>O<sub>4 </sub>Nanocomposite Molecules

Nanocomposites, comprising reduced graphene oxide (rGO) and iron oxide nanoparticles (Fe3O4) have emerged as promising materials for various applications due to their exceptional properties. However, a critical research gap exists in understanding the electrostatic potential distribution within these complex molecular structures. This study aims to address this gap by employing advanced computational techniques to visualize the electrostatic potential within rGO/ Fe3O4 nanocomposites at the molecular level. The primary objective of this study is to map the spatial distribution of the electrostatic potential within rGO/Fe3O4 nanocomposites. This will provide molecular-level insights into the electrostatic environment and its influence on electronic structure, reactivity, and intermolecular interactions. By correlating the electrostatic potential with material properties, such as reactivity and stability, we aim to enable the rational design of improved nanocomposites. The novelty of this research lies in its interdisciplinary approach, bridging materials science, chemistry, and physics. The outcomes are expected to have significant implications for optimizing the performance of rGO/Fe3O4 nanocomposites in applications ranging from energy storage to catalysis and beyond. This study contributes to our fundamental understanding of nanocomposite behavior and paves the way for enhanced materials design.

Thermal Degradation Study of Hydrogel Nanocomposites Based on Polyacrylamide and Nanosilica Used for Conformance Control and Water Shutoff.

The application of nanocomposites based on polyacrylamide hydrogels as well as silica nanoparticles in various tasks related to the petroleum industry has been rapidly developing in the last 10-15 years. Analysis of the literature has shown that the introduction of nanoparticles into hydrogels significantly increases their structural and mechanical characteristics and improves their thermal stability. Nanocomposites based on hydrogels are used in different technological processes of oil production: for conformance control, water shutoff in production wells, and well killing with loss circulation control. In all these processes, hydrogels crosslinked with different crosslinkers are used, with the addition of different amounts of nanoparticles. The highest nanoparticle content, from 5 to 9 wt%, was observed in hydrogels for well killing. This is explained by the fact that the volumes of injection of block packs are counted only in tens of cubic meters, and for the sake of trouble-free workover, it is very important to preserve the structural and mechanical properties of block packs during the entire repair of the well. For water shutoff, the volumes of nanocomposite injection, depending on the well design, are from 50 to 150 m3. For conformance control, it is required to inject from one to several thousand cubic meters of hydrogel with nanoparticles. Naturally, for such operations, service companies try to select compositions with the minimum required nanoparticle content, which would ensure injection efficiency but at the same time would not lose economic attractiveness. The aim of the present work is to develop formulations of nanocomposites with increased structural and mechanical characteristics based on hydrogels made of partially hydrolyzed polyacrylamide crosslinked with resorcinol and paraform, with the addition of commercially available nanosilica, as well as to study their thermal degradation, which is necessary to predict the lifetime of gel shields in reservoir conditions. Hydrogels with additives of pyrogenic (HCSIL200, HCSIL300, RX380) and hydrated (white carbon black grades: 'BS-50', 'BS-120 NU', 'BS-120 U') nanosilica have been studied. The best samples in terms of their structural and mechanical properties have been established: nanocomposites with HCSIL200, HCSIL300, and BS-120 NU. The addition of hydrophilic nanosilica HCSIL200 in the amount of 0.4 wt% to a hydrogel consisting of partially hydrolyzed polyacrylamide (1%), resorcinol (0.04%), and paraform (0.09%) increased its elastic modulus by almost two times and its USS by almost three times. The thermal degradation of hydrogels was studied at 140 °C, and the experimental time was converted to the exposure time at 80 °C using Van't Hoff's rule. It was found that the nanocomposite with HCSIL200 retains its properties at a satisfactory level for 19 months. Filtration studies on water-saturated fractured reservoir models showed that the residual resistance factor and selectivity of the effect of nanocomposites with HCSIL200 on fractures are very high (226.4 and 91.6 for fracture with an opening of 0.05 cm and 11.0 for porous medium with a permeability of 332.3 mD). The selectivity of the isolating action on fractured intervals of the porous formation was noted.

Multipurpose adsorption applications of boron-doped and amino-functionalized magnetic mesoporous silica nanocomposite.

In this study, boron-doped magnetic mesoporous silica nanocomposite was prepared through the hydrothermal synthesis procedure followed by post modification with -NH2 groups. The higher surface area, more ordered mesoporous structure, and higher surface charge density obtained by boron doping and amino functionalization contributed to the use of nanocomposite for multipurpose application functions. When used as an adsorbent for light green (LG) anionic dye, boron-doped nanocomposite exhibited higher adsorption capacity (105.80mg/g) compared to undoped nanocomposite (72.23mg/g), while when used as a drug carrier for Doxorubicin (DOX), a sufficient drug loading capacity (48.0mg/g) was obtained, which is also higher than that of undoped nanocomposite (30.3mg/g). In terms of LG adsorption, the effects such as initial concentration, adsorbent dosage, time, pH, and temperature on the adsorption properties were investigated in detail. Adsorption kinetics, isotherms, thermodynamics, and reusability are discussed. The existence of small quantity of boron doping enhanced the surface charge density from 0.0393 to 0.2854 C/m2, which resulted in higher adsorption capacity for LG adsorption dominated by electrostatic attraction, and led to formation of silanol holes together with the -OH and -NH2 functional groups, which resulted in higher drug loading capacity for DOX adsorption dominated by hydrogen bonding. This promising result provides that boron-doped and -NH2 grafted magnetic mesoporous silica material can function as multipurpose adsorbent for various environmental applications.

The Role of Phenol and Flavonoid in the Synthesis and Application of Nano Graphene Oxide

The unique properties of graphene oxide have generated significant interest in recent years. Many potent aromatic drugs are water-insoluble, complicating their administration. Nano graphene oxide, a potential drug carrier, is typically synthesized through environmentally harmful chemical methods. This review emphasizes the need for more sustainable approaches to address these challenges while maintaining graphene oxide's effectiveness in drug delivery. Plant extracts are rich in bioactive compounds known as phytochemicals which have the ability to synthesize nano graphene oxide. A large and most intricate class of these phytochemicals are Phenolic compounds which have an aromatic ring and one or more hydroxyl groups in their structural conformations. Based on their structural composition, they are divided into subgroups that include phenolic acids, flavonoids, tannins, coumarins, lignans, quinones, stilbenes, and carotenoids. Plant polyphenols are gaining increasing attention because of their potent antioxidant properties and important roles in preventing oxidative stress-related diseases. The extraction, identification, and characterization of phenolic compounds from a range of plant sources has become a major area of study in the health and medical fields in recent years. The role of phenol and flavonoid in the synthesis and application of nano composites are also covered in this review.

Metal‐organic Framework‐derived NiO/ZnO Composites for Photoelectrocatalytic Reduction of Cr(VI)

AbstractNi/Zn‐MOF composites with photoelectrocatalytic (PEC) performance for Cr(VI) reduction were prepared via hydrothermal method and calcinating method. The as‐prepared NiO/ZnO composites exhibited uniform morphology. When being subjected to an external voltage of 0.7 V and irradiated with visible light for 120 min, the NiO/ZnO composite exhibited a Cr (VI) reduction efficiency of almost 100 %, outperforming ZnO and NiO counterparts. The effects of the content of NiO to ZnO and different calcination temperatures on PEC performance were also investigated. Additionally, elimination experiments results indicated that photo‐generated electrons (e−) play a crucial role in the catalytic reduction of Cr(VI). The notable enhancement in the photoelectrocatalytic performance can be credited to the applied bias voltage and the formation of a p‐n heterojunction between NiO and ZnO. Consequently, the NiO/ZnO nanocomposites exhibit significant potential for the PEC reduction of Cr(VI). This capability underscores the promise of NiO/ZnO nanocomposites for applications in the photoelectrocatalytic reduction of Cr(VI) and related environmental remediation processes.

Solvent-free synthesis of covalent-framework 2D crown ether and its application for polylactic acid nanocomposites having antibacterial property

This study showed the synthesis of a covalent-frameworked 2D crown ether, named C2O, consisting of carbon and oxygen in a 2:1 mol ratio, using solvent-free synthesis for the first time. The synthesized C2O is distinguished by its structure, which includes numerous phenol groups akin to phlorotannins, conferring high antibacterial property through contact-based mechanisms and biocompatibility. The inherent crown ether structure of C2O facilitates efficient metal adsorption, allowing for the easy facile preparation of C2O containing Cu atom (Cu@C2O). Cu@C2O exhibits enhanced antibacterial property at much lower concentrations compared to the native C2O. For practical application, polylactic acid (PLA) nanocomposite films were prepared using C2O as a filler, achieving 99.99 % of antibacterial property at just 0.1 wt% concentration. When the PLA nanocomposite films were prepared using Cu@C2O as the filler, the required concentration was further reduced to 0.03 wt%, while still demonstrating 99.99 % of antibacterial property. Additionally, the excellent copper ion adsorption capacity of Cu@C2O ensures minimal leaching, thus mitigating cytotoxicity concerns. Given their high and long-term antibacterial properties, biocompatibility, these materials represent promising candidates for various biomedical, packaging and antifouling paint applications, demonstrating significant potential across diverse domains.

Mechanism and Applications of Biochar Carbon Dots and Nanocomposites in Heavy Metal Ion Sensing and Adsorption

Biochar is a carbonaceous material produced by the pyrolysis of biomass. Biochar has been embraced due to its various properties as well as its broad utility in soil and water pollution. Biochar technology is the answer to all the numerous problems concerning the environment. There has also been a lot of interest in biochar nanotechnology because of the improvements, especially in the physical, chemical, and surface characteristics of biochar. The biochar is further transformable into a number of forms of nanomaterials too, such as carbon dots (CDs) and nanocomposites. The modification of the biochar affects the mechanisms in the adsorption of pollutants from wastewater. CDs attract attention because of their unique properties, such as optical, biological, surface, and solubility properties among others. Due to their unique architecture and interesting properties, numerous disciplines have shown considerable interest in them. CDs are suitable as fluorescence probes. The fluorescence of CDs was reduced by all metal ions but to different extents. From the current review, we derive some relevant information on biochar and biochar nanotechnology and the factors that determine its properties and its mechanism in metal sensing and adsorption. . KEYWORDS :Biochar nanocomposites, Carbon dot, Fluorescence probes, Heavy metal, Sustainability

Application of Nanocomposites in Covalent Organic Framework-Based Electrocatalysts.

In recent years, the development of high-performance electrocatalysts for energy conversion and environmental remediation has become a topic of great interest. Covalent organic frameworks (COFs), linked by covalent bonds, have emerged as promising materials in the field of electrocatalysis due to their well-defined structures, high specific surface areas, tunable pore structures, and excellent acid-base stability. However, the low conductivity of COF materials often limits their intrinsic electrocatalytic activity. To enhance the catalytic performance of COF-based catalysts, various nanomaterials are integrated into COFs to form composite catalysts. The stable and tunable porous structure of COFs provides an ideal platform for these nanomaterials, leading to improved electrocatalytic activity. Through rational design, COF-based composite electrocatalysts can achieve synergistic effects between nanomaterials and the COF carrier, enabling efficient targeted electrocatalysis. This review summarizes the applications of nanomaterial-incorporated COF-based catalysts in hydrogen evolution, oxygen evolution, oxygen reduction, carbon dioxide reduction, and nitrogen reduction. Additionally, it outlines design principles for COF-based composite electrocatalysis, focusing on structure-activity relationships and synergistic effects in COF composite nanomaterial electrocatalysts, as well as challenges and future perspectives for next-generation composite electrocatalysts.

Poly(vinyl alcohol)-Assisted Exfoliation and Grafting Modification of Boron Nitride Nanosheets with a High Aspect Ratio via a Continuous Production Method for Energy Storage and Thermal Management.

Hexagonal boron nitride nanosheets (BNNS) integrating many extraordinary properties are usually combined with polymers to fabricate multifunctional dielectric materials for energy storage and thermal management. Unfortunately, the existing technologies for producing BNNS generally have the disadvantages of inefficiency and low product quality, which significantly hinder the wide application of high-value nanocomposites. Herein, a novel poly(vinyl alcohol) (PVA)-assisted pan-milling method based on the innovative solid-state shear milling (S3 M) technology is reported for the production of high-quality BNNS. The uniform three-dimensional (3D) shear force field generated by pan milling not only ensured the high aspect ratio of BNNS (the average lateral size of ∼954 nm and the average thickness of ∼3.7 nm) but also induced the mechanochemical reaction between PVA and BNNS to achieve in situ grafting modification on the BNNS surface. The simultaneous high-quality exfoliation and surface modification of BNNS positively contributed to the mechanical, dielectric, and thermal conduction properties of BNNS/PVA nanocomposites. At the BNNS content of 10 wt %, the BNNS/PVA composite film exhibited excellent robustness (Young's modulus of 5305 MPa and the tensile strength of 83 MPa), with a satisfactory breakdown strength (Eb of 134.7 MV/m) and dielectric constant (∼5 at 1000 Hz). In addition, the substantial improvement of thermal conductivity (from 0.88 to 5.59 W·m-1·K-1) guaranteed the stability of the dielectric properties of the nanocomposites at high temperatures. This pan-milling method characterized by green and efficiency is highly scalable to other two-dimensional (2D) layered materials, providing a practical strategy for the industrial fabrication of nanocomposites in elevated-temperature energy storage.

Haptic In‐Sensor Computing Device Based on CNT/PDMS Nanocomposite Physical Reservoir

The importance of haptic in‐sensor computing devices has been increasing. Herein, a haptic sensor with a hierarchical structure is successfully fabricated via the sacrificial template method, using carbon nanotube‐polydimethylsiloxane (CNT‐PDMS) nanocomposites for in‐sensor computing applications. The CNT‐PDMS nanocomposite sensors, with different sensitivities, are obtained by varying the amount of CNTs. The input stimuli are transformed into higher‐dimensional information, enabling a new path for the CNT‐PDMS nanocomposite application, which is implemented on a robotic hand as an in‐sensor computing device by applying a reservoir computing paradigm. The nonlinear output data obtained from the sensors are trained using linear regression and used to classify nine different objects used in everyday life with an object recognition accuracy of >80% for each object. This approach can enable tactile sensation in robots while reducing the computational cost.

Investigation of Antibacterial Activities of Copper based Multinary Sulfide Alloys

One of the nanomaterial-based antimicrobials, CuS, has emerged as a potential active therapeutic agent to combat biofilm infections, showing superior antibacterial activity with both photothermal and photodynamic effects under NIR illumination. To investigate the influence of transition metals on the antibacterial activity of CuxS, the antibacterial properties of shape- and phase- controlled copper-based multinary sulfide (M: CuxS (M: Mn, Zn and Ni)) nanostructures prepared by hot injection method were investigated against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli under NIR light irradiation. It has been shown that CuxS-based nanomaterials suppress bacterial growth under NIR light irradiation and that, in addition to their antibacterial activity, they also exhibit a remarkable ability to form biofilms. The antibiofilm efficacy of the M:CuxS (M: Mn, Zn and Ni) nanocomposites was significantly higher than that of bare CuS, resulting in biofilm inhibition with rates of 52.53%, 62.24% and 74.48% on E. coli for Mn:CuxS, Zn:CuxS and Ni:CuxS, respectively. In addition, the biofilm of S. aureus was more affected by treatment with M:CuxS (M: Mn, Zn and Ni) nanocomposites, with biofilm activity of 64.15%, 68.42% and 87.35% for Mn:CuxS, Zn:CuxS and Ni:CuxS, respectively. Ni:CuxS showed the highest antibacterial activity, which is attributed to smaller crystal and particle size and energy band gap, resulting in a larger number of nanoparticles per unit volume, a larger surface area and a stronger tendency to electrostatically bind to bacterial cell membranes, a faster ability to penetrate channels and stronger absorption in the NIR range. This work points the way for a broad application of CuS-based biocompatible synergistic antibacterial nanocomposites and can also serve as a guide for antibacterial/antibiofilm approaches as an alternative to conventional antibiotic treatments.

Energy systems and green sourced nanomaterials—A today’s outlook

Owing to current growing demands of environmental friendly energy devices, innumerable green materials/nanomaterials have been applied to design the desired high tech devices. Amongst energy devices, supercapacitors have been ranked distinctively for efficient energy storage competence. Principally, green nanocomposites derived from green or ecological polymers and green nanoparticles have been scrutinized for supercapacitor components. Concerning this, current review has been planned to sketch the energy storage application of green nanocomposites, predominantly for supercapacitors. In this concern, mostly synthetic green polymers (such as polyaniline, polypyrrole, etc.) and their blends with natural polymers (like chitosan) having fine biodegradability, non-toxicity, low cost, and superior device end performance have been found as the noteworthy materials. Additionally, green nanofillers like carbon nanoparticles (carbon nanotube, graphene, etc.) and metal nanoparticles have been processed with green polymers via ecological techniques, like in situ, solution, sonication, mixing, hydrothermal, exfoliation, reduction, etc., to form the anticipated energy device components. In consequence, the designed ecological nanocomposites expectedly had the advantages of low price/weight, superior mechanical/heat resilience, electron transference, capacitance, power/charge density, charge-discharge, sustainability as well as environmentally friendliness for energy related methodological systems. Incidentally, the design and performance challenges towards the application of ecological nanocomposites in energy storage devices have been conversed.

Retraction Note: Design, development, and drug delivery applications of graphene polymeric nanocomposites and bionanocomposites

Retraction Note: Design, development, and drug delivery applications of graphene polymeric nanocomposites and bionanocomposites