Nanocomposite Surface Research Articles

Dielectric Response of ZnO/PMMA Nanocomposites with Atmospheric Pressure Plasma-Modified Surfaces.

In this work, the effect of etching the surface of polymer matrix nanocomposites with atmospheric pressure plasma targeting to achieve enhanced dielectric properties was investigated. Polymer nanocomposites, with varying reinforcing phase content, were modified by atmospheric-pressure plasma resulting in an increase in the surface filler's concentration. Polymethyl methacrylate (PMMA) matrix nanocomposites reinforced with zinc oxide (ZnO) nanoparticles were prepared and dielectrically studied as a function of the nanoparticle content and the plasma modified surfaces. The electrical response of the composite systems was studied by means of Broadband Dielectric Spectroscopy (BDS) over a wide range of temperatures and frequencies. The dielectric permittivity increased with the embedded phase content and with plasma surface treatment. Energy density followed the same trend as dielectric permittivity, and the plasma-treated nanocomposite with the higher ZnO content exhibited approximately 27% higher energy density compared to the unreinforced matrix.

Adsorptive dye removal by Cu(II)-modified silica-alumina/polyaniline nanocomposite

The accelerated rate of industrial growth causes a lot of pollutants to be released into the environment. Therefore, the present work aimed at synthesizing a novel and environmentally friendly nanocomposite for eliminating dyes from wastewater. The (silica-alumina13 %)-Cu2+/polyaniline ((Si–Al)–Cu2+/PANI) nanocomposite was synthesized by the oxidative polymerization of aniline in the presence of (Si–Al)–Cu2+ composite. The nanocomposite was characterized by the FT-IR, XRD, BET, SEM, TEM, and EDX techniques. Its surface area was 287.7 m2/g and the pore diameter was 1.92 nm. The pseudo-second-order kinetic and the Langmuir isotherm models offered a satisfactory fit to the adsorption data. The removal percentage of the Acid blue 25 dye (AB25) by the nanocomposite reached 99 % within 60 min at pH 2, while the removal capacity was 135.86 mg/g. Based on the adsorption-desorption cycle results, the efficiency of the nanocomposite (99.7 %) remained unchanged up to the third cycle with a small decrease afterward. To corroborate the experimental results, a molecular modeling study was carried out using the basis function 6–311++G(d,p) and the DFT method to obtain the best molecular structure, physicochemical properties, and spectroscopic spectra of AB25 in the gas phase and water solvent. The electrostatic potential, Fuki functions, natural bond orbital, time-dependent DFT, and theoretical FT-IR were calculated. Furthermore, the adsorption of AB25 on the nanocomposite surface was verified by the Monte Carlo simulations. The computed data correlated well with the experimental results.

Hard transparent nanogradient coating for ultradurable omniphobic liquid-like surface

Omniphobic liquid-like surface (LLS) offers excellent dynamic liquid repellency owing to the highly mobile polymer chains mediating at the solid–liquid interface. These polymer chains, often achieved by surface grafting, are not durable against abrasion or oxidation, which seriously hinders their practical application. Here we report a new vapor-based approach to create transparent nanogradient coating for LLSs with unprecedented mechanical strength and durability. The nanogradient coating is composed of a sandwich structure with an ultrathin primer, a rigid bulk, and a nanocomposite surface with abundant polydimethylsiloxane-like chains, all of which achieved via sequential plasma polymerization of a linear and a cyclic siloxane. The plasma-polymerized cyclic siloxane enables coating good mechanical strength while the plasma-polymerized linear siloxane confers coating sub-nanometer roughness and excellent dynamic liquid repellency. The resultant coating exhibits contact angle hysteresis < 5° towards many low-surface-energy liquids, as well as good mechanical strength with the hardness exceeding 1 GPa and superior durability enduring 100,000 cycles of abrasion. The coating also survived industrial standard thermal and accelerated UV-aging tests without losing its liquid repellency and transparency. The reported method is facile, scalable, and substrate-independent, offering exciting new opportunities towards industrial fabrication and real-world application of LLS.

Nanotechnology applications in breast implant manufacturing for improved durability and functionality

Breast implants are often used in restorative and cosmetic surgeries. However, the materials used for implants today could be better regarding biocompatibility and mechanical strength. It is possible to make composite biomaterials out of nanomaterials with better mechanical qualities than common implant materials like silicone elastomers and saline-filled shells. Researchers have found that adding carbon nanotubes, graphene, and hydroxyapatite nanoparticles to the shells of metal and silicone implants makes them much stronger, more flexible, and less likely to break. Researchers are also looking into polymer nanocomposites made of polycaprolactone and polylactic acid to see if they can break down better and integrate better with tissues. Changing the surface of implants at the nanoscale level can make them more biocompatible by controlling how proteins stick to the material and how cells interact with it. Animal tests with nanocoatings of polyacrylate, chitosan, and hyaluronic acid showed that they lowered the formation of capsules and inflammation. Antimicrobial nanoparticles, such as silver, zinc oxide, and antibiotics, are attached to the surfaces of implants to protect against infections and release drugs locally. Nanocontrast agents are used in high-resolution MRI and ultrasound images of implant shell integrity to get new imaging and diagnosis tools. By tracking biomarkers, nanostructured sensors could be used to find seromas, ruptures, and device failures with little to no damage. Much work has been done to show that different nanotechnologies can help breast implants in a pre-clinical setting. However, problems with regulation and standardization still need to be fixed before the implants can be used in people and made in large quantities. The process needs to be improved even more to make a lot of nanocomposite and etched surfaces. To make sure patients are safe, it is also important to do long-term biocompatibility and nanotoxicology tests. Nanotechnology has a lot of promise to change the way breast implants are made so that they look better and improve people's quality of life. This review examines nanotechnology's emerging applications for enhancing breast implants' durability and performance.

Facile Preparation of TiO2NTs/Au@MOF Nanocomposites for High-Sensitivity SERS Sensing of Gaseous VOC.

Surface-enhanced Raman spectroscopy (SERS) is a promising and highly sensitive molecular fingerprint detection technology. However, the development of SERS nanocomposites that are label-free, highly sensitive, selective, stable, and reusable for gaseous volatile organic compounds (VOCs) detection remains a challenge. Here, we report a novel TiO2NTs/AuNPs@ZIF-8 nanocomposite for the ultrasensitive SERS detection of VOCs. The three-dimensional TiO2 nanotube structure with a large specific surface area provides abundant sites for the loading of Au NPs, which possess excellent local surface plasmon resonance (LSPR) effects, further leading to the formation of a large number of SERS active hotspots. The externally wrapped porous MOF structure adsorbs more gaseous VOC molecules onto the noble metal surface. Under the synergistic mechanism of physical and chemical enhancement, a better SERS enhancement effect can be achieved. By optimizing experimental conditions, the SERS detection limit for acetophenone, a common exhaled VOC, is as low as 10-11 M. And the relative standard deviation of SERS signal intensity from different points on the same nanocomposite surface is 4.7%. The acetophenone gas achieves a 1 min response and the signal reaches stability in 4 min. Under UV irradiation, the surface-adsorbed acetophenone can be completely degraded within 40 min. The experimental results demonstrate that this nanocomposite has good detection sensitivity, repeatability, selectivity, response speed, and reusability, making it a promising sensor for gaseous VOCs.

Greener approach using Citrus sinensis fruit towards the rapid in vivo eco-synthesis of natural supported bioactive NCs: Ag@Xanthan, CuO@Fe3O4@nanoclay and TiO2@CeO2@montmorinent NCs

For the first time, an economic, highly efficient, simple, fast and in vivo protocol by the Citrus sinensis fruit was employed for biosynthesis of some bioactive Ag@Xanthan, CuO@Fe3O4@nanoclay and TiO@CeO2@Montmorinent Nanocomposites (NCs). The RP-HPLC-DAD fingerprint record of the fruit demonstrated the presence of potent antioxidants such as oxalic acid, tannic acid, mallic acid, ascorbic acid, and citric acid. The NCs were structurally characterized through the spectroscopic (Uv–vis and FT-IR methods) and surface analysis techniques (TEM, XRD, EDS methods). Furthermore, the impact of the in vivo method was studied using FT-IR spectroscopy on the hyper-accumulation of phytochemicals on the surface of green nanocomposites and their bioactivity. The antioxidant and antibacterial properties of green synthesized NCs demonstrated very well results against some dangerous bacteria of Pseudomonas aeruginosa (P. aureus), Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) compared to ascorbic acid and chloramphenicol as positive controls of antioxidant and antibacterial activities, respectively.

Exploring the sustainable elimination of dye using cellulose nanofibrils- vinyl resin based nanofiltration membranes

This study focuses on the development of a novel self-cleaning nanofiltration membrane for the efficient removal of the cationic dye methylene blue (MB) from industrial wastewater. The membrane is composed of vinyl resin (VR), cellulose nanofibrils (CNF), and titanium alpha aluminate (TAAL) nanoparticles.The TAAL loading ranged from 1 to 5 wt%, the pH varied from 5 to 10, and the initial MB concentration ranged from 10 to 50 ppm. Using a dead-end filtration system, the (VR/CNF@TAAL) membrane with 5 wt% TAAL at pH 10 demonstrated excellent performances. It achieved a remarkable 98.6% removal efficiency for 30 ppm MB dye, with a maximum adsorption capacity of 125.8 mg/g. The adsorption kinetics analysis revealed that the process followed the pseudo-second-order model, indicating a chemisorption mechanism. The rate constant was determined to be 1.2732 × 10–3 g mg−1 min−1. The Freundlich isotherm model provided a better fit (R2 = 0.996) than the Langmuir model, suggesting multilayer adsorption on the nanocomposite membrane surface. In addition to its high adsorption and filtration capabilities, the (VR/CNF@TAAL) nanocomposite membrane exhibited cost-effectiveness and environmental friendliness as an adsorbent for MB removal from industrial wastewater. The membrane’s self-cleaning property further contributes to sustainability by reducing the need for additional chemical treatments.

Formulation of biodegradable alginate-based nano-carriers for in-vitro drug delivery and antibacterial activity

Evaluation of the controlled release of ciprofloxacin (CIP.HCl) and the antibacterial efficacy of alginate (ALG)-based nanocarriers constitute the primary objectives of the current work. Herein, ALG-based nano-structures were prepared by the co-precipitation method and thoroughly analyzed using different characterization techniques, i.e., fourier transform infrared (FT-IR), powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) and zeta potential (ZP). The intense peaks emerged at 500, 545, and 750 cm−1 due to the CeO bond. Peaks that appeared at 550–600 cm−1 and 525 cm−1 are due to the stretching vibrations of FeO and ZnO bonds, respectively. Lowering of the peaks from 1640 to 1630 cm−1 and 1420 to 1384 cm−1 were observed in ALG-based nanocomposite (NC) due to the interaction of ALG with metal oxides (MO), which confirmed the formulation of CeO2/ZnFe2O4/ALG nanocomposite. The diffraction peaks at 28.6°, 56.6°, 76.5°, 37°, 47.9°, 62.3°, 74°, 13°, 21° confirmed the synthesis of MO (crystallite size 15.74 nm) and CeO2/ZnFe2O4/ALG (12 nm). In accordance with morphological studies, CeO2/ZnFe2O4 oxides had a uniform distribution throughout the relatively smooth and permeable surface of the ALG-based NC. Ciprofloxacin (CIP) was used as a model drug. Negative values of ZP revealed that CIP-loaded nanocomposite (CeO2/ZnFe2O4/ALG/CIP) had more stability than CeO2/ZnFe2O4/ALG. The maximum percentage of loading around 25 % on ALG NC was examined using the optical density (OD) method at pH 5.5. Correlation coefficients from the first order (0.971), Korsmeyer (0.9858), and Hixson (0.9021) models show the best-fitted models of the release profile in all circumstances. The release mechanism was investigated using various kinetics models. The controlled drug released was observed around 17 % at 40 °C after 3 h at pH 7.4, which is almost identical to the body temperature of a human, which is 37 °C. Similarly, after 24 h, sustained and controlled in-vitro release of the drug was studied, and it was 37, 72, and 74 % at pH 2.2, 7.4, and 9.4, respectively. Thus, prepared ALG-based NC is suitable for the controlled in-vitro release of (CIP.HCl). Metal oxides (CeO2/ZnFe2O4) and ALG-based nanocomposite (CeO2/ZnFe2O4/ALG) showed great antibacterial activity against Staphylococcus aureus (S. aureus) like 15 mm and 14 mm than Escherichia coli (E. coli).

In2O3-ZnO nanoporous photocatalyst modified with CuOx cocatalyst for enhanced photocatalytic bacterial inactivation and dye degradation

In this study, CuOx surface passivated In2O3 loaded porous ZnO, (CuOx/In2O3(x%)-ZnO)), were synthesized utilizing a solvothermally produced organic–inorganic ZnS(en)0.5 hybrid material. The high-resolution scanning electron microscopy (HR-SEM) and transmission electron microscopy (TEM) images of the CuOx/In2O3(2.5%)-ZnO nanocomposite reveal a macrosheet-shaped morphology comprising nanosized grains. The photocatalytic behavior of all the synthesized CuOx/In2O3(x = 0,1,2.5, and 5%)-ZnO nanocomposites were examined against aqueous dye solutions of orange II, and bisphenol A, E. coli bacteria under one sun illumination. The CuOx/In2O3(2.5%)-ZnO nanocomposite exhibits enhanced photoactivity for cationic dyes (eosin Y) than that for anionic (orange II). The results indicate that cationic dyes undergo photocatalytic degradation, whereas the anionic dyes adsorb on the CuOx/In2O3(2.5%)-ZnO nanocomposite surface, reducing the removal of organic pollutants. The optimal nanocomposites, CuOx/In2O3(2.5%)-ZnO photocatalyst exhibit maximum photodegradation performance of 99%, 94%, 27% for orange II dye, eosin dye, BPA, and 98% for E. coli inactivation within 180 min, respectively. The CuOx/In2O3(2.5%)-ZnO nanocomposite was successfully demonstrated to be an effective photocatalyst and excellent antibacterial agent. Finally, the charge transfer mechanism during photocatalytic organic decomposition and bacterial inactivation was studied.

RGO-SiO2-Fe2O3 nanocomposites pave the way for efficient cadmium ion remediation and electrochemical detection

Our investigation introduces a straightforward methodology for fabricating RGO-SiO2-Fe2O3 nanocomposites tailored for dual-purpose adsorption and electrochemical sensing of Cd2+ ions from aqueous environments. A comprehensive exploration of adsorption parameters encompassing initial pH levels (2−9), interaction duration (2–210 min), temperature (303–333 K), initial concentrations (20–100 mg/L) and adsorbent dosage (0.2–1 g/L) was conducted to ascertain optimal conditions. Results indicate a remarkable removal efficiency of Cd(II) at 95.82% under pH 6 within 180 minutes. Elaborate adsorption isotherm and kinetic analyses reveal adherence to the Langmuir isotherm and pseudo-second-order kinetic model, with RGO-SiO2-Fe2O3 NCs exhibiting a maximum adsorption capacity of 145.28 mg/g for Cd(II). For electrochemical detection, cyclic voltammetry (CV) utilizing a glassy carbon electrode modified with RGO-SiO2-Fe2O3 NCs exhibited distinct responses attributed to the interaction between Cd(II) ions and the nanocomposite surface. Optimized sensing conditions employing RGO-SiO2-Fe2O3 NCs were identified as a pH 6, and concentration of 90 ppb with a sensitivity of 0.0754 mA/ppb cm2 and a limit of detection (LOD) of 0.8893 ppb for Cd(II) ions. Notably, negligible interference from co-existing ions was observed, with a marginal current change of approximately 7.4%. The exceptional attributes of RGO-SiO2-Fe2O3 NCs underscore their potential for dual-purpose applications in detecting and mitigating Cd2+ ions in water system.

Efficient removal of crystal violet dye from water using zinc ferrite-polyaniline nanocomposites.

Nanomaterials are widely employed in wastewater treatment, among which nanoferrites and their composites hold significant prominence. This study adopts a green approach to synthesize zinc ferrite nanoparticles, subsequently integrating them with polyaniline (PANI) to fabricate the ZnFe2O4-PANI nanocomposite. Characterization of the prepared ZnFe2O4-PANI nanocomposite was conducted using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopic (SEM) techniques. Using Scherrer's equation, the crystallite size of the synthesized zinc ferrite nanoparticles was found to be 17.67nm. SEM micrographs of the ZnFe2O4-PANI nanocomposite revealed that in situ polymerization of ZnFe2O4 with polyaniline transforms the amorphous surface morphology of the polymer into a homogeneous nanoparticle structure. The adsorption of crystal violet (CV) dye onto the surface of the ZnFe2O4-PANI nanocomposite depends on pH, adsorbent dosage, temperature, concentration levels and duration. The Langmuir adsorption model fitted the data well, indicating adherence to a pseudo-second-order kinetic pattern. Thermodynamic values ΔG°, ΔH° and ΔS° indicated that the adsorption process occurred spontaneously. Advantages and disadvantages of the technique have also been highlighted. Mechanism of adsorption is discussed. From the obtained results, it is evident that the ZnFe2O4-PANI nanocomposite holds promise as a sorbent for the removal of dye from wastewater.

Characterization of surface and bulk properties of α-Tocopherol blended and γ irradiated UHMWPE sandwich nanocomposites

In the present study, an unconventional approach in compression molding is chosen to fabricate Ultra High Molecular Weight Polyethylene (UHMWPE) sandwich composites with Graphene (Gr) and Nano-diamond (ND) as fillers. A unique comparison is done between the surface and bulk properties of UHMWPE nano-composites and UHMWPE sandwich composites. Influence of gamma irradiation at doses of 50, 100 kGy doses and vitamin E (vit-E) on crystal structure, mechanical, thermal and tribological characteristics of UHMWPE composites were studied through x-ray diffraction (XRD), raman spectroscopy, dynamic mechanical analysis (DMA), rheology, differential scanning calorimetry (DSC), tensile, nano-indentation and wear characterization techniques. Fracture regions and surface wear of the samples were analysed through scanning electron microscopy (SEM) to understand the dispersion behavior of fillers in matrix. The concentration of vit-E content in UHMWPE greatly influenced the crosslinks and surface properties in gamma irradiated composites. Gamma irradiation have shown significant improvement in crystallinity, viscous behavior and bulk properties of UHMWPE composites. Irradiated UHMWPE nano-composites have shown better tensile results when compared with sandwich composites, with 22 % increase in young's modulus and 16 % increase in yield stress. Wear rate has been reduced by 25 % for irradiated sandwich UHMWPE composites when compared with UHMWPE nano-composites.

Recent Advancements in Metallic Au- and Ag-Based Chitosan Nanocomposite Derivatives for Enhanced Anticancer Drug Delivery

The rapid advancements in nanotechnology in the field of nanomedicine have the potential to significantly enhance therapeutic strategies for cancer treatment. There is considerable promise for enhancing the efficacy of cancer therapy through the manufacture of innovative nanocomposite materials. Metallic nanoparticles have been found to enhance the release of anticancer medications that are loaded onto them, resulting in a sustained release, hence reducing the dosage required for drug administration and preventing their buildup in healthy cells. The combination of nanotechnology with biocompatible materials offers new prospects for the development of advanced therapies that exhibit enhanced selectivity, reduced adverse effects, and improved patient outcomes. Chitosan (CS), a polysaccharide possessing distinct physicochemical properties, exhibits favorable attributes for controlled drug delivery due to its biocompatibility and biodegradability. Chitosan nanocomposites exhibit heightened stability, improved biocompatibility, and prolonged release characteristics for anticancer medicines. The incorporation of gold (Au) nanoparticles into the chitosan nanocomposite results in the manifestation of photothermal characteristics, whereas the inclusion of silver (Ag) nanoparticles boosts the antibacterial capabilities of the synthesized nanocomposite. The objective of this review is to investigate the recent progress in the utilization of Ag and Au nanoparticles, or a combination thereof, within a chitosan matrix or its modified derivatives for the purpose of anticancer drug delivery. The research findings for the potential of a chitosan nanocomposite to deliver various anticancer drugs, such as doxorubicin, 5-Fluroacil, curcumin, paclitaxel, and 6-mercaptopurine, were investigated. Moreover, various modifications carried out on the chitosan matrix phase and the nanocomposite surfaces to enhance targeting selectivity, loading efficiency, and pH sensitivity were highlighted. In addition, challenges and perspectives that could motivate further research related to the applications of chitosan nanocomposites in cancer therapy were summarized.

Functionalized boron nitride nanosheets and their polypropylene nanocomposites: influence on thermal, mechanical, rheological and wear behaviour

ABSTRACT The few-layer hexagonal boron nitride (hBN) nanosheets with hydroxyl (−OH) functional group at edges are synthesized using heat treatment of micron size hBN powder followed by sonication. These nanosheets are modified with a silane coupling agent, 3-Aminopropyl,triethoxysilane (APTES). The synthesized hBN nanosheets are mixed with the PP matrix using twin-screw extrusion followed by injection moulding. In case of APTES-modified hBN nanosheets incorporation in the PP matrix with PP-grafted maleic anhydride (PP-g-MA) shows the formation of an imide bond between the MA functional group of PP-g-MA and the amine group of APTES modified hBN nanosheets revealing compatibilization. The flow behaviour index values are lower for hBN nanosheets filled PP nanocomposites showing the improved processability from Rheological characterization. The few-layered – OH and APTES modified hBN nanosheet incorporation in the PP matrix improves the tensile and thermal properties. The incorporation of APTES modified hBN nanosheet in the PP matrix shows an increase in tensile modulus (18.1%) and tensile strength (8.1%) respectively. Wear studies show the incorporation of – OH and APTES modified hBN nanosheets in the PP matrix decreases the coefficient of friction and wear rate significantly. The wear rate at 4 min of wear testing for modified hBN nanosheet in the PP nanocomposites is ~ 96% less in comparison with neat PP. The wear mechanism is established from wear measurements and scanning electron microscopy (SEM) of worn-out wear surfaces of PP nanocomposites.

Evaluating the antibacterial efficacy of a silver nanocomposite surface coating against nosocomial pathogens as an antibiofilm strategy to prevent hospital infections

Antimicrobial nanocoatings may be a means of preventing nosocomial infections, which account for significant morbidity and mortality. The role of hospital sink traps in these infections is also increasingly appreciated. We describe the preparation, material characterization and antibacterial activity of a pipe cement-based silver nanocoating applied to unplasticized polyvinyl chloride, a material widely used in wastewater plumbing. Three-dimensional surface topography imaging and scanning electron microscopy showed increased roughness in all surface finishes versus control, with grinding producing the roughest surfaces. Silver stability within nanocoatings was >99.89% in deionized water and bacteriological media seeded with bacteria. The nanocoating exhibited potent antibiofilm (99.82–100% inhibition) and antiplanktonic (99.59–99.99% killing) activity against three representative bacterial species and a microbial community recovered from hospital sink traps. Hospital sink trap microbiota were characterized by sequencing the 16S rRNA gene, revealing the presence of opportunistic pathogens from genera including Pseudomonas, Enterobacter and Clostridioides. In a benchtop model sink trap system, nanocoating antibiofilm activity against this community remained significant after 11 days but waned following 25 days. Silver nanocoated disks in real-world sink traps in two university buildings had a limited antibiofilm effect, even though in vitro experiments using microbial communities recovered from the same traps demonstrated that the nanocoating was effective, reducing biofilm formation by >99.6% and killing >98% of planktonic bacteria. We propose that conditioning films forming in the complex conditions of real-world sink traps negatively impact nanocoating performance, which may have wider relevance to development of antimicrobial nanocoatings that are not tested in the real-world.

Deep insight into physical properties of carboxymethyl cellulose-barium oxide nanocomposites

Nanocomposites, blending the unique properties of inorganic nanoparticles with polymers, are gaining momentum in various industries. This study delves into the synthesis and characterization of barium oxide (BaO)-doped carboxymethyl cellulose (CMC) nanocomposites, focusing on their structural, optical, electrical, and dielectric properties. Using an in-situ polymerization method, CMC films were doped with 5 % and 10 % BaO nanoparticles. X-ray diffraction analysis revealed that the doped samples exhibited enhanced crystallinity compared to pure CMC, with crystallinity percentages measured at 37.95 % and 28.86 % for 5 % and 10 % BaO, respectively, indicating the successful incorporation of BaO. Scanning electron microscopy illustrated the distribution of BaO nanoparticles, showing spherical agglomerations on the film surface. SEM analysis reveals emergence of spherical agglomerations and bright spots on nanocomposite film surface upon BaO introduction, indicating BaO nanoparticles presence. Further, the BaO nanoparticles act as catalytic and nucleating agents, influencing crystalline structure nucleation and growth, potentially enhancing film homogeneity and structural integrity. In addition, UV–visible spectroscopy elucidated the optical properties, indicating a shift in the bandgap from indirect to direct with BaO addition. The bandgap values decrease upon the addition of BaO, indicating a transition from an amorphous to a nanocrystalline structure, with respective reduction percentages of 22.73 % and 10.71 % for the 5%BaO/CMC and 10 %BaO/CMC samples compared to CMC. Electrical conductivity measurements showed enhanced conductivity in 10 % BaO/CMC due to improved charge carrier mobility, supported by dielectric studies demonstrating increased dielectric. The introduction of 5 % and 10 % BaO resulted in reductions of approximately 62.06 % and 65.77 %, respectively, compared to the pure CMC sample. This decrease in dielectric loss indicates an enhancement in the electrical properties of the nanocomposites. This comprehensive investigation could give further insights into the different properties of BaO-doped CMC nanocomposites, offering insights into their potential applications in various fields such as electronics, energy storage, and optoelectronics.

Quaternary branched polyethylenimine‐based nanocomposite for removal of NO3− ions from aqueous solutions

AbstractThis study synthesized a nanocomposite based on quaternary branched polyethyleneimine containing sodium alginate and graphene oxide and characterized by FE‐SEM, EDX‐MAP, XRD, FT‐IR, and TGA and used as an efficient sorbent for the removal of nitrate ions. The maximum ion exchange in optimized conditions was discovered to be 75%. The experimental studies showed that nitrate removal follows the pseudo‐first‐order model due to more consonance. Also, Weber–Morris and Boyd models suggested that the nitrate ions adsorption on the surface of nanocomposite is not controlled only by the intraparticle diffusion step. Moreover, Langmuir, Redlich–Peterson, and Hill models exhibited high regression coefficients of 0.991, 0.993, and 0.992, respectively. Thermodynamic studies confirmed the adsorption system was spontaneous and exothermic. Recovery assay showed that more than 98% of the nitrate ion exchanged by the nanocomposite was regenerated and nanocomposite could be reused seven cycles without efficacy reducing significantly. The nanocomposite showed excellent antibacterial activity against Staphylococcus aureus and Escherichia coli cells, with minimum inhibitory concentrations of 62.5 and 125 μg mL−1, and zone of growth inhibition of 17.5 ± 0.5 and 10.5 ± 0.5 mm, respectively. The results represented that the introduced nanocomposite is a useful material for the removal of nitrate ions from aqueous solution and has antibacterial properties.

Development and sensitivity analysis of MWCNTs coated D-shaped plastic optical fiber sensor for the detection of mercury

Heavy metal pollutants in rivers and water catchments are one of the problems faced by many developing countries as they may result in health issues among their people. A proper sensing mechanism is required to ensure the quality of water. In this research, we propose a simple, low cost, and highly sensitive D-shaped plastic optical fiber (POF) sensor layered with functionalized multi-walled carbon nanotubes (MWCNTs) for the detection of mercury in water. The sensor underwent interrogation across a range of mercury concentrations at room temperature. Numerous methods of characterization have been employed to explore the intricate structural attributes of the sensing layer to verify that the nanocomposite surface layer is functionalized with minimal disruption to the nanotubes. The experimental results revealed that the coated sensor displayed swift response and recovery time of 6.3 s and 13 s respectively when tested with the dynamic mercury concentration range (0 to 5 ppm). Moreover, it exhibited a relative absorbance of 7.33 %/ppm, which is approximately four times higher than the plain sensor and a limit of detection (LOD) of 0.1 ppm. The sensor has the potential to be transformed into an on-site, portable, real-time optical sensor for the detection of mercury ions in drinking water, offering high sensitivity and fast data acquisition.

Impact of ZrO2 Content on the Formation of Sr-Enriched Phosphates in Al2O3/ZrO2 Nanocomposites for Bone Tissue Engineering.

This study investigates the profound impact of the ZrO2 inclusion volume on the characteristics of Al2O3/ZrO2 nanocomposites, particularly influencing the formation of calcium phosphates on the surface. This research, aimed at advancing tissue engineering, prepared nanocomposites with 5, 10, and 15 vol% ZrO2, subjecting them to chemical surface treatment for enhanced calcium phosphate deposition sites. Biomimetic coating with Sr-enriched simulated body fluid (SBF) further enhanced the bioactivity of nanocomposites. While the ZrO2 concentration heightened the oxygen availability on nanocomposite surfaces, the quantity of Sr-containing phosphate was comparatively less influenced than the formation of calcium phosphate phases. Notably, the coated nanocomposites exhibited a high cell viability and no toxicity, signifying their potential in bone tissue engineering. Overall, these findings contribute to the development of regenerative biomaterials, holding promise for enhancing bone regeneration therapies.

Dependence of the M choice on the properties of Hf(M)SiCN (M = Nb, Ta, Ti, Zr) ceramic coatings: ab-initio and experimental study

The HfMSiCN coatings (M = Nb, Ta, Ti, Zr) are researched using ab-initio theoretical method and double glow plasma surface alloying. The aim is to enhance the high temperature stability and wear resistance of these coatings, alongside optimizing mechanical and thermodynamic properties. Firstly, the calculated mechanical properties for Hf0.5M0.5CN correlate with those experimental measurement for HfMSiCN. Secondly, the thermodynamic parameters exhibit that the Hf0.5Zr0.5CN has the lowest thermal expansion coefficient and higher bulk modulus at high-temperatures. Moreover, the wear rate of HfZrSiCN at 500 ℃ is less than 60% of its wear rate at 300 ℃. The superior wear resistance of HfZrSiCN coating is attributed to a friction-induced composite layer including a dense amorphous nanocomposite surface layer and a nano-friction glaze layer supported by nanograins.