Nanocomposite Of Nanoparticles Research Articles

Palladium doped tungsten oxide nanoparticle nanocomposite for sensitive detection of CO2 and LPG gases

According to the results from paleoclimate data, long-term variations in climate change were affected by the concentration levels of carbon dioxide (CO2), besides the liquid petroleum gases (LPG) as a gas product of petroleum during the refining treatment. Herein, CO2 and LPG sensing device was fabricated by hydrothermally treated WO3 nanoparticles achieving significant responses of 89% and 82% towards CO2 and LPG gases. The synthesis approach was enhanced by incorporating palladium (Pd) with a doping level. The Physico-chemical properties of Pd-doped WO3 specimens with different contents from Pd (0.3, 0.6, 0.9, and 1.2wt.%) were evaluated using various tools such as XRD, FESEM, HRTEM, EDX, TGA, FTIR, Raman spectroscopy, and UV–Vis spectrophotometry. At WO3/(0.9wt.%) Pd, the device demonstrated a tremendous high response rate against the CO2 to be 164%. While the sensitivity of LPG recorded a higher response of 125% with WO3/(0.6wt.%) Pd nanocomposite. The resistance of the two platinum electrode sensors for different gases at different temperatures is used to measure and figure out how the sensors work electrically when exposed to other gases. This research proposes a method for enhancing the sensing performance of nanomaterials based on metal oxides.

Synthesis, characterization, and catalytic activity of platinum nanoparticles

According to the Creative Commons Attribution License, open access articles such as this one may be freely used, distributed, and reproduced in any form as long as the original work is properly attributed. A normal calcination step in catalyst synthesis is avoided from this process. A platinum nanoparticle nanocomposite was discovered using transmission electron microscopy (TEM) with an average particle size of 2.2 nm–0.6 nm. It was found that 63% of the Pt and 37% of the PtO were found in the XPS investigations.

Simultaneous and individual determination of seven biochemical species using a glassy carbon electrode modified with a nanocomposite of Pt nanoparticle and graphene by a one-step electrochemical process

We propose a sensitive and selective electrochemical approach for simultaneous and individual determination of seven electroactive biochemical species using a modified electrode with a nanocomposite of Pt nanoparticles and reduced graphene oxides (PtNP/rGO). The PtNP/rGO nanocomposite was synthesized and deposited on a glassy carbon electrode (GCE) from Pt4+ precursors and GO by one-pot electrochemical synthesis, forming PtNP/rGO-GCE. As-prepared PtNP/rGO electrode was characterized by Raman spectroscopy, contact angle measurements, SEM-EDS analysis, and cyclic voltammetry. Compared with bare GCE, Pt electrode, PtNP-GCE, the modified electrode exhibited excellent catalytic activity and large surface area, and rGO-GCE, which enabled sensitive and selective detection of seven biochemical species such as ascorbic acid (AA), dopamine (DA), uric acid (UA), acetaminophen (AP), xanthine (XA), nitrite (NO2−), and hypoxanthine (HX) with good voltammetric resolution in differential pulse voltammetric (DPV) measurements. In addition, the electroanalytical performance of the PtNP/rGO-GCE sensor displayed satisfactory reproducibility and stability. Finally, the sensor could be applied for the detection of the seven biochemical species in real samples like human blood serum. Therefore, the PtNP/rGO-GCE can provide one promising platform for the simultaneous detection of redox-active biochemical species in environmental, food, and clinical samples.

PEG-mesoporous material modified by superparamagnetic nanoparticles as a delivery system of cefotaxime.

The fight against infectious bacterial diseases has been taking major steps forward by designing new nanodrugs and nanoscale biological carriers with unique physicochemical properties. Here, polyethylene glycol (PEG)-silica mesoporous material/superparamagnetic CuFe2O4 nanoparticle nanocomposite was synthesized using a facile chemical approach, and proposed as a carrier for the delivery of cefotaxime (CTX) drug. The resulting nanocomposite material and nanocomposite CTX drug carrier were characterized by different techniques. Antibacterial activity of the nanocomposite drug carrier was investigated against E.coli and S. aureus bacteria, and compared with that of commercial CTX drug. It was found that the minimum inhibitory concentrations of the nanocomposite drug carrier (1.25 and 5μg/mL) were significantly less than those of the commercial drug (10 and 80μg/mL) against the bacteria. Furthermore, enhanced performance of the nanocomposite CTX carrier for both the Gram-negative and Gram-positive bacteria was evidenced.

Urea electrooxidation-boosted hydrogen production on nitrogen-doped porous carbon nanorod-supported nickel phosphide nanoparticles

Urea electro-oxidation reaction (UEOR)-boosted water electrolysis can supplant the kinetics-restricted oxygen evolution reaction (OER) and provide an energy-saving method of hydrogen generation. However, low UEOR activity and the poisoning issue of the catalyst limit its practical application. Herein, a simple coordination reaction is used to synthesize the dimethylglyoxime-NiⅡ complex (DMG-NiⅡ), which efficiently serves as the initial precursor to synthesize nitrogen-doped carbon nanorod-supported nickel phosphide nanoparticle (Ni2P/N-Cnanorods) nanocomposites. The density functional theory calculations and electrochemical results reveal that nitrogen doping can weaken the adsorption of hydrogen and the generated CO2, resulting in an enhancement of hydrogen evolution reaction (HER) and UEOR activity. In addition, N-doping can also promote the generation of Ni3+, which can further promote the UEOR and HER performance. Concretely, the overpotential for the HER on Ni2P/N-Cnanorods-2h nanocomposites is only 201 mV at 10 mA cm−2, and the onset potential of the UEOR on Ni2P/N-Cnanorods-2h nanocomposites is only 1.34 V. Additionally, the Ni2P/N-Cnanorods nanocomposites also show excellent long-term stability due to the introduction of nitrogen-doped carbon material. Consequently, the symmetric Ni2P/N-Cnanorods-2h||Ni2P/N-Cnanorods-2h urea electrolyzer requires 1.41 V of electrolysis voltage for urea electrolysis, which can be applied in energy-saving H2 production and environment purification.

Nanocomposite of Ag nanoparticles and deep eutectic solvent-derived carbon dots with oxidase mimicking activity as synergistic bactericidal agent.

A new type of nitrogen and chloride co-doped carbon dots (N/Cl-CDs) based on choline chloride-urea-glycine ternary deep eutectic solvents (DESs) was synthesized using a one-step hydrothermal method. The prepared N/Cl-CDs exhibited oxidase-like activity and excellent antibacterial activity against Escherichia coli, Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA). The addition of silver nanoparticles (Ag NPs) (i.e. N/Cl-CDs + Ag NPs) to the N/Cl-CDs also significantly enhanced the oxidase and antibacterial activities. The nanocomposite (1·8 mg ml-1 ) completely inactivated 105 CFU per ml of MRSA in 90 min. E.coli and S. aureus were labelled with the N/Cl-CDs, enabling multicolour fluorescence imaging at different excitation wavelengths. The nanocomposites have high antibacterial efficiency as a new bactericidal agent, as well as application potential with good biocompatibility and low toxicity.

In-situ synthesis of reduced graphene oxide/silver nanoparticles (rGO/AgNPs) nanocomposites for high loading capacity of acetylsalicylic acid

Graphene has excellent properties which can be a promising material as nanocomposites for application in a drug delivery system (DDS). In this study, reduced graphene oxide/silver nanoparticles (rGO/AgNPs) nanocomposites was synthesized using a facile in-situ method for drug loading application of acetylsalicylic acid (ASA). The synthesis results were characterized by FESEM, EDX, UV-Vis, XRD, and Raman spectrophotometers analyses. The results showed that rGO/AgNPs nanocomposites was synthesized successfully. Drug loading application was performed using UV-Vis measurements. The loading results depicted that rGO/AgNPs is successfully created in high-capacity loading for ASA. Drug loading performances enhanced with the increasing loading time of ASA on rGO/AgNPs. The optimum percentage of drug loading capacity for ASA by rGO/AgNPs was ∼83% in a contact time of 30 hrs.

A Co-Doped Carbon Dot/Silver Nanoparticle Nanocomposite-Based Fluorescence Sensor for Metformin Hydrochloride Detection.

In this study, a fluorescence sensor based on nitrogen and phosphorus co-doped carbon dot/silver nanoparticle (NPCD/AgNP) nanocomposites was developed for metformin hydrochloride (MFH) detection. We first utilized the reducing nature of the NPCDs to prepare AgNPs from Ag+ and subsequently prepare NPCD/AgNP nanocomposites. The nanocomposite material was characterized by various methods, including electron microscopic methods (SEM and TEM), spectroscopic methods (UV-Vis, PL, FTIR, and XPS spectroscopy), light scattering (ELS), and XRD. Further, we utilized the enhanced fluorescence of the NPCDs as well as the overlap between the fluorescence emission spectrum of the NPCDs and the absorption spectrum of the AgNPs to use the NPCD/AgNP nanocomposites as an effective inner filter effect (IFE) pair for sensing MFH. The IFE between NPCDs and AgNPs in the nanocomposite material resulted in a significant quenching of the fluorescence intensity of the nanocomposites compared to that of the pure NPCDs. However, the fluorescence was recovered when MFH was introduced into the nanocomposite solution. The fluorescence intensity of the nanocomposites increased linearly as the MFH concentration increased from 2 to 100 µg/L. This detection method showed good sensitivity compared to other methods. It also showed high selectivity and high sensing potential for MFH in human serum and yielded acceptable results.

Industrial molasses waste in the performant synthesis of few-layer graphene and its Au/Ag nanoparticles nanocomposites. Photocatalytic and supercapacitance applications

In view of clean environment, the industry needs to address multiple demands at different levels of production and processes via the sustainable approach including recycling or smart use of produced waste. On the other hand, a development and success of green energy requires the crucial materials synthesized via efficient, sustainable methodology. Herein, the green, simple, easily scalable, fast, and highly efficient synthesis of few-layer graphene (FLG) and its composites with Au and Ag nanoparticles using a waste is presented. The FLG synthesis based on the exfoliation of graphite runs in water in the presence of industrial co-product, molasses, which next also shows performant reductive properties during Ag and Au NPs formation. The decreased size of NPs deposited on FLG indicates the synergetic effect of molasses and FLG, exhibiting the add role of FLG/molasses as metal stabilizer species. The NPs/FLG composites are efficient photocatalysts of bisphenol (BisA) degradation in the presence of peroxy-monosulfate (PMS) activator. The Au/FLG (PVDF) and Ag/FLG (PVDF) based electrodes reveal as well relatively high gravimetric capacitance, 205 Fg-1 and 729 Fg-1. The presented approach is much worthy to be further applied in the synthesis of other layered materials as well as other non-noble supported metallic systems.

A novel ZIF-8@ZIF-67/Au core–shell metal organic framework nanocomposite as a highly sensitive electrochemical sensor for nitrite determination

A novel electrochemical sensor has been introduced in the present work. The proposed sensor is a nanocomposite of imidazole zeolites and gold metal nanoparticles that was easily designed and synthesized (core-shell ZIF-8@ZIF-67/Au NPs). This sensor was used to determine nitrite using the differential pulse voltammetry (DPV) technique. Nanocomposites have been characterized using transmission electron microscopy (TEM), Fourier transform (FT-IR), field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), ultraviolet spectroscopy, scattered X-ray spectroscopy Energy (EDX) and electrochemical element maps and electrochemical techniques. After the plotted the calibration diagram with the differential pulse voltammetry technique, the detection limit was 2 nM and the linear range was obtained 0.64×10−8-22.14×10−3 M for nitrite oxidation. Therefore the method is simple, sensitive, and specific, with a short analysis time, and the main advantages of this purpose sensor are the easy synthesis method, low limit of detection, and good selectivity, excellent stability, reproducibility, and good repeatability in nitrite determination. One of the successes of this sensor is in determining nitrite in water, sausage, and deli meat samples.

Tuning Interparticle Contacts and Transport Properties of Maghemite-Thermoset Nanocomposites by Applying Oscillating Magnetic Fields.

Conductive nanofillers, if integrated in an organized manner, can improve the transport properties of polymer matrices without compromising on their light weight. However, the relationship between the particle assemblies and transport properties of such nanocomposites, especially the competing effects of connected nanofiller pathways compared to resistances at interparticle contacts, has not been quantitatively studied. In this work, with the model nanocomposite of maghemite nanoparticles in epoxy, a novel fabrication method has been demonstrated to align nanofillers and control the interparticle contact amount within such a nanofiller assembly, using nanoparticle surface functionalization and oscillating magnetic field application. The nanofiller assembly cross-sectional areas were measured by processing micro-CT images and compared with the measured electrical and thermal properties of the nanocomposites. In terms of thermal transport, when the nanofiller assembly cross-sectional area was small, the dominance of conductivity pathways was observed up to ∼4.7 vol %, while interfacial thermal resistance began to dominate when the nanofiller assembly cross-sectional area became larger than 2700 μm2.

Green synthesis of CuO nanocomposite from watermelon (Citrullus lanatus) rind for the treatment of aquaculture effluent

Aquaculture can generate toxic effluent that have a deleterious effect on the aqueous environment. The aim of this study was to synthesise a nano-composite of copper oxide nanoparticles (CuO-NP) and kaolin (CuO-NC) for the regulation of some physico-chemical parameters of aquaculture effluent before being discharged into the environment. CuO-NP was obtained from a green synthesis route from watermelon (Citrullus lanatus) rind. The synthesised nanoparticles (NPs) were characterised by particle size analyser, BET, DTA/TGA and FTIR. The green synthesis technique was successfully able to achieve nano-sized particles. BET by computational analysis revealed that CuO-NC has 174.2 m2/g specific surface area, 0.2108 cm 3/g pore volume, and 2.647 nm pore size. CuO-NC was thermally stable up to 270 °C. Also, CuO-NC in addition to the CuO-NP had some hydroxide salt moieties. The utilisation of CuO-NC in treating aquaculture effluent was able to successfully regulate the pH, colour, odour, dissolved oxygen, total alkalinity, chemical oxygen demand Copper and Lead in line with permissible limits. Based on the discussions, the process was considered technically feasible for scale-up and implementation as a sustainable water resource management technology.

Electrophoretic deposition of chitosan reinforced baghdadite ceramic nano-particles on the stainless steel 316L substrate to improve biological and physical characteristics

Despite the low cost and high mechanical properties of stainless steel (SS 316L) as orthopedic implants, it shows poor bioactivity and biocompatibility due to various corrosion mechanisms occurring in a biological environment. Therefore, this study is aimed at developing a novel nano-composite of chitosan-baghdadite nano-particles by electrophoretic technique to enhance the corrosion resistance, biocompatibility, and bioactivity properties of SS 316L implants. The results demonstrated that the applied Chitosan coating including 1 wt% baghdadite nano-particles at 15 V and 10 min was hydrophobic (44.26° ± 1.34) and it increased the roughness of SS 316L from 0.20 ± 0.01 μm to 1.47 ± 0.22 μm. Furthermore, increasing the baghdadite percentage affected coating adhesion. The evaluation of MG63 cell viability, spreading, and attachment verified no cytotoxicity, and well spreading and suitable attachment of MG63 cells on the coatings (optimum sample = coating with 1 wt% baghdadite nano-particles). This type of coating could provide appropriate biological properties for orthopedic implants based on the observed results.

Insight of microencapsulation and fluorescence efficacy of chitosan based nanocomposite for photocatalytic performance

Hydrogel based microencapsulation of metal oxide nanoparticles have been found to be more practical commencement for the functional materials in current research scenario. Here, in situ development of microencapsulated ZnO nanoparticles (NPs) using functionalized chitosan based hydrogel has been achieved. Fluorescent NPs are shielded by organic moieties in a specific chiral backbone of polysaccharide; thus, electrons and holes can be moved across the interface of NPs/Organic framework in hydrogel. The enhanced mechanical strength, compactness, stability in buffer solution, adsorption, positive ζ-potential, and photocatalytic effect of the nanocomposite has been thoroughly investigated with various instrumental analyses. Inherent fluorescence efficacy from NPs in nanocomposite has been monitored for the sequential photocatalytic degradation using two model organic pollutants. The catalytic efficiency for visible-light induced degradation has been established utilizing absorbance, kinetics, equilibrium and thermodynamic point of view. Microencapsulation protects NPs from open air oxidation, retains their activity and reduces toxicity. Degradation process has been monitored through real time and time dependent fluorescence efficacy study of the nanocomposite. Insolubility of hydrogel based nanocomposite facilitates a very convenient recovery and removal of unused nanocomposite without generating further harmful wastage.

A portable and sensitive dopamine sensor based on AuNPs functionalized ZnO-rGO nanocomposites modified screen-printed electrode

Dopamine (DA) is an important neurotransmitter and one of the biomarkers of psychiatric diseases such as Parkinson's disease and schizophrenia. Therefore, it is urgent to explore an effective method to realize rapid and sensitive detection of DA. In this paper, porous zinc oxide microspheres-functional reduced graphene oxide composites (ZnO-rGO) were successfully prepared by a simple solution method, then gold nanoparticles (AuNPs) were combined by electrodeposition. Zinc oxide porous microspheres-reduced graphene oxide-gold nanoparticles nanocomposites were used to modify the screen-printed electrode ([email protected]) to fabricate a fast and efficient non-enzymatic electrochemical sensing platform for detecting DA in biological samples. The sensor obtained a good linear range of 0.5 μM to 100 μM and a low detection limit of 0.294 μM at S/N = 3. Additionally, a sensor was applied to the determination of DA in human biological samples, and it showed good stability and reproducibility, making it an excellent candidate material in the field of biosensors.

Influence of photooxidation on ionic reversible interactions of ionic poly(ether urethane)/silica hybrids

Organic-inorganic hybrids that combine the reversible nature of electrostatic interactions present in ionic systems with the reinforcement ability of nanoparticles in nanocomposites have the potential to revolutionize a wide spectrum of technologies. However, the prediction of their service lifetime under photooxidative conditions has remained elusive. In this paper, the accelerated environmental ageing of ionic hybrid materials made by combining imidazolium-functionalized poly(ethylene glycol)-based polyurethane (im-PU) and surface-modified sulfonate silica nanoparticles (SiO2-SO3H) is addressed. Since the resulting ionic nanocomposites are dynamic, the present contribution aims to elucidate their temporal behavior and precisely distinguish the contribution of the nanoparticles addition to the photochemical behavior. Although the addition of SiO2-SO3H nanoparticles within im-PU matrix led to faster photooxidative degradation, the ionic imidazolium-sulfonate crosslinks are thought to be sustained under photooxidative conditions. The results further suggest that the molecular weight loss and the resulting ductile-to-brittle transition for the ionic hybrid under atmospheric ageing conditions are attributed to severe chain scissions into the im-PU backbone in the presence of SiO2-SO3H nanoparticles. Overall, the present investigation suggests that the silica nanoparticles addition is responsible for the prodegradant effect rather than the presence of reversible ionic interactions in the system. The present work thus provides a deeper understanding about the crucial role of the incorporation of dynamic linkages within ionic nanocomposites during photochemical ageing and can aid the future design and use of these systems.

Cytotoxic and molecular assessment with copper and iron nanocomposite, act as a soft eradicator against cancer cells

The composites are the materials, which have either one or more combination with other material and exhibit extraordinary chemical characteristics. The present work describes the formation of composite of copper and iron metal oxide (CuFeO2). The synthesized powder materials are in nanorange. The nanocomposite nanoparticles (NCsNPs) were synthesized via solution process with using copper nitrate hexahydrate, iron nitrate non hydrate as a main precursor material whereas sodium hydroxide was utilized as a salt reducing agent. The formed NCsNPs were characterized with X-ray diffraction pattern (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and Fourier Transform infra-red spectroscopy (FTIR) were used for the structural and chemical characteristic in detail. It reveals that the NCNP is ∼45 nm in size with clear spherical shaped morphology with good chemical characteristics. The NCsNPs were utilized against cancer cells (C2C12 myoblast) for to reduce the growth rate with different incubation (24 & 48 h) periods. The % cells death was examined through MTT assay at different concentration (0.5 µg/mL, 1 µg/mL, 2 µg/mL, 5 µg/mL, 10 µg/mL, 25 µg/mL, 50 µg/mL, 100 µg/mL) of NCs with different (24 & 48 h) incubations respectively. The apoptosis in cells were analyzed with quantitative polymerase chain reaction (qPCR) study with apoptotic marker gens caspase 3 and 7 with control and the obtained data reveals that with the exposure of NCs, upregulated in gene expression at fixed concentration in 24 h incubation period. Based on acquired results a possible relation between the NCs and cancer cells were also discussed.

Electrochemical Detection of Ascorbic Acid in Oranges at MWCNT-AONP Nanocomposite Fabricated Electrode.

Ascorbic acid (AA) is an essential vitamin in the body, influencing collagen formation, as well as norepinephrine, folic acids, tryptophan, tyrosine, lysine, and neuronal hormone metabolism. This work reports on electrochemical detection of ascorbic acid (AA) in oranges using screen-print carbon electrodes (SPCEs) fabricated with multi-walled carbon nanotube- antimony oxide nanoparticle (MWCNT-AONP) nanocomposite. The nanocomposite-modified electrode displayed enhanced electron transfer and a better electrocatalytic reaction towards AA compared to other fabricated electrodes. The current response at the nanocomposite-modified electrode was four times bigger than the bare electrode. The sensitivity and limit of detection (LOD) at the nanocomposite modified electrode was 0.3663 [AA]/µM and 140 nM, respectively, with linearity from 0.16–0.640 μM and regression value R2 = 0.985, using square wave voltammetry (SWV) for AA detection. Two well-separated oxidation peaks were observed in a mixed system containing AA and serotonin (5-HT); and the sensitivity and LOD were 0.0224 [AA]/µA, and 5.85 µΜ, respectively, with a concentration range from 23 to 100 µM (R2 = 0.9969) for AA detection. The proposed sensor outperformed other AA sensors reported in the literature. The fabricated electrode showed great applicability with excellent recoveries ranging from 99 to 107 %, with a mean relative standard deviation (RSD) value of 3.52 % (n = 3) towards detecting AA in fresh oranges.

Testing the Dispersion of Nanoparticles in a Nanocomposite with an Ultra-Low Fill Content Using a Novel Non-Destructive Evaluation Technique.

A non-destructive evaluation (NDE) technique capable of testing the dispersion of nanoparticles in a nanocomposite would be of great use to the industry to check the quality of the products made and to ensure compliance with their specifications. Very few NDE techniques found in the literature can evaluate the level of dispersion of the nanoparticles in the whole nanocomposite. Here, a recently developed NDE technique based on pulsed phase thermography (PPT) in transmission mode was used to assess the particle dispersion in ultra-low, less than 0.05 wt%, Ag enriched polymeric based nanocomposite manufactured with an innovative nano-coating fragmentation technique. The phasegrams obtained with the presented technique clearly showed clusters or bundles of Ag nanoparticles when present, down to the size of 6 µm. Therefore, the new NDE approach can be applied to verify that the expected levels of dispersion are met in the production process.

Polydopamine nanoparticles and hyaluronic acid hydrogels for mussel-inspired tissue adhesive nanocomposites

Bioadhesives are intended to facilitate the fast and efficient reconnection of tissues to restore their functionality after surgery or injury. The use of mussel-inspired hydrogel systems containing pendant catechol moieties is promising for tissue attachment under wet conditions. However, the adhesion strength is not yet ideal. One way to overcome these limitations is to add polymeric nanoparticles to create nanocomposites with improved adhesion characteristics. To further enhance adhesiveness, polydopamine nanoparticles with controlled size prepared using an optimized process, were combined with a mussel-inspired hyaluronic acid (HA) hydrogel to form a nanocomposite. The effects of sizes and concentrations of polydopamine nanoparticles on the adhesive profiles of mussel-inspired HA hydrogels were investigated. Results show that the inclusion of polydopamine nanoparticles in nanocomposites increased adhesion strength, as compared to the addition of poly (lactic-co-glycolic acid) (PLGA), and PLGA-(N-hydroxysuccinimide) (PLGA-NHS) nanoparticles. A nanocomposite with demonstrated cytocompatibility and an optimal lap shear strength (47 ± 3 kPa) was achieved by combining polydopamine nanoparticles of 200 nm (12.5% w/v) with a HA hydrogel (40% w/v). This nanocomposite adhesive shows its potential as a tissue glue for biomedical applications.