Physicochemical Properties Of Nanocomposites Research Articles

Halogen-doped 2D reduced graphene oxide with TiO2 nanocomposite for water remediation application

Water contamination by organic and inorganic pollutants has been a challenging problem impacting living organisms. The current study explores the photocatalytic property of nanocomposite based on iodine-doped reduced graphene oxide with titanium dioxide nanoparticles (TNPs) for methyl orange (MO) dye degradation. A nanocomposite of TNPs with iodine-doped reduced graphene oxide (TIR) is prepared using the hydrothermal technique. The physicochemical properties of nanocomposite were explored by various techniques such as an X-diffractometer (XRD), Raman spectroscopy, Fourier transforms the infrared spectrum, energy-dispersive X-ray spectroscopy spectrum (EDX), and high-resolution transmission electron microscopy (HRTEM). The XRD reveals the crystalline structure of the TIR nanocomposite. The anatase TNPs with an average particle size of 9.68 ± 2.1 nm are confirmed by HRTEM. The Raman spectrum confirms the presence of iodine molecules with a peak at 101 cm−1, and the EDX spectrum confirms the presence of iodine molecules with 15.31 % elements in the TIR nanocomposite. The MO dye degradation efficiency of 96.12 % with 120 min UV exposure for TIR suggests that the iodine-doped nanocomposite is a promising photocatalyst for water remediation.

Ti3C2Tx MXene decorated with NiMnO3 / NiMn2O4 nanoparticles for simultaneous photocatalytic degradation of mixed cationic and anionic dyes

The present report investigated the different mass ratios of Ti3C2Tx MXene decorated NiMnO3 / NiMn2O4 nanoparticles and their enhancement of photocatalytic performance. The NiMnO3 / NiMn2O4 - Ti3C2Tx MXene nanocomposites were synthesized by a simple electrostatic self-assembly method. The physicochemical properties of nanocomposites were analyzed by XRD, SEM, and FESEM with EDAX, FTIR, PL, and UV-Visible spectrometer. The rhombohedral / cubic spinel structure of NiMnO3 / NiMn2O4 was confirmed by the XRD. The SEM and FESEM morphology show that spherical NiMnO3 / NiMn2O4 nanoparticles were decorated on the Ti3C2Tx MXene sheets and also present on the inside of the Ti3C2Tx MXene sheets. The average diameter of NiMnO3 / NiMn2O4 nanoparticles (46 nm) and the interlayer spacing of Ti3C2Tx MXene sheets (56 nm) were measured from FESEM analysis. The energy bandgap of NiMnO3 / NiMn2O4 - MXene nanocomposites was determined as ranging from 1.2 eV to 0.8 eV. The Ni, Mn, O, Ti, C, and F elemental compositions of the composites were analyzed by the EDAX. The effective photo-generated electron transferring from NiMnO3 / NiMn2O4 to Ti3C2Tx MXene was established by the PL quenching of NiMnO3 / NiMn2O4. The 100 % degradation efficiency was achieved in methylene blue (MB). The mixed dye degradation rates achieved for Rhodamine B (RhB), methyl orange (MO), and methylene blue (MB) for 90 %,72 %, and 100 % after 50 min in the presence of NiMnO3 / NiMn2O4 -Ti3C2Tx MXene (20 wt %). According to a scavenger experiment, the predominant species actively involved in the photodegradation process were revealed to •OH and •O2-.

A novel nanocomposite-based zeolite for efficient remediation of Cd-contaminated industrial wastewater

Novel nanocomposite sorbent was produced by depositing nanostructured water treatment residual (nWTR) onto zeolite (Ze) using high-energy ball milling process. The physicochemical properties of nanocomposite (Ze-nWTR) prior and after Cd adsorption were analyzed by SEM–EDX, FTIR, BET and XRD. A batch study of cadmium adsorption (Ze-nWTR) was performed at various process parameters (sorbent dose, contact time, solution pH, competing ions, initial concentration and temperature). The obtained data were fitted to various equilibrium and kinetics models. The Langmuir and power function models successfully described Cd adsorption equilibrium and kinetic processes, respectively. The maximum adsorption capacity (qmax) value of Cd by Ze-nWTR nanocomposite (147 mgg−1) was 3 and 5.9 times higher than those of nWTR and zeolite sorbents, respectively. Increasing temperature from 287 to 307 K has resulted in increasing the maximum Cd adsorption capacity (qmax) of the nanocomposite from 147.9 to 270 mgg−1. The calculated thermodynamics parameters suggested physical and chemical attraction between Cd and Ze-nWTR and the association of dissociative mechanism in Cd(II) sorption process. The excellent reusability and Cd removal ability of Ze-nWTR nanocomposite (98%) from industrial wastewater confirm its potential as promising adsorbent for wastewater treatment applications.

Blood proteins self-assembly, staphylococcal enterotoxins-interaction, antibacterial synergistic activities of biogenic carbon/FeSO4/Cu/CuO nanocomposites modified with three antibiotics

IntroductionNanocomposites based on copper, iron, and carbon materials are novel nanomaterials with both antibacterial and biocompatibility properties considerable to fight against multidrug-resistant bacteria.MethodsIn this study, phytogenic carbon/FeSO4/Cu/CuO nanocomposites modified by three antibiotics including tetracycline, amoxicillin, and penicillin were employed to hinder antibiotic resistant bacteria of Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. Interaction of albumin and hemoglobin as major blood proteins with these nanocomposites were evaluated by SEM, FTIR, and AFM techniques. As in silico study, molecular docking properties of staphylococcal enterotoxin toxin A and B with (Z)-α-Bisabolene epoxide, (E)-Nerolidol, α-Cyperone, daphnauranol C, nootkatin, and nootkatone as major secondary metabolites of Daphne mucronata were obtained by AutoDock Vina program.ResultsPhysicochemical characterization of nanocomposites showed (Zeta potential (− 5.09 mV), Z-average (460.2 d.nm), polydispersity index (0.293), and size range of 44.58 ± 6.78 nm). Results of both in vitro and in silico surveys disclosed significant antibacterial activity of antibiotic functionalized carbon/FeSO4/Cu/CuO nanocomposites compared to antibiotics alone towards Gram-negative and Gram-positive bacteria.ConclusionSynergistic activity of bio-fabricated carbon/FeSO4/Cu/CuO nanocomposites with antibiotics may be affected by main parameters of concentration and ratio of antibacterial agents, physicochemical properties of nanocomposites, bacterial type (Gram-negative or Gram-positive), antibacterial mechanisms, and chemical structure of antibiotics.

Antimicrobial activity of synthesized graphene oxide-selenium nanocomposites: A mechanistic insight.

Nanoparticles have recently gained interest as an anti-bacterial agentdue to their large surface area/volume ratio and potential to compromise the integrity of bacterial cell membranes. Due to its versatility and anti-bacterial activity, graphene-based materials have drawn significant interest in biomedical applications. One of the greatest threats to life in the modern technological era is the pervasiveness of infectious diseases since bacteria cells are constantly updating themselves to resist antibiotics.In this presented study, GO-Se nanocomposite has been synthesized using polymer solution via a simple dispersion method. The structural and physicochemical properties of nanocomposite were investigated in detail. Staphylococcus aureus, Proteus vulgaris, and Bacillus subtilis bacterial strains were employed to study the anti-bacterial activity of GO-Se nanocomposite. The results show that the synthesized nanocomposites have good efficacy as an anti-bacterial agent. UV-vis spectroscopy, FTIR spectroscopy, HRTEM, XPS, and Raman spectroscopy were used to analyze the as-prepared GO and GO-Se nanocomposite.

Microstructure, morphology and physicochemical properties of nanocomposites containing hydroxyapatite/vivianite/graphene oxide for biomedical applications.

Designing a nanocomposite that accumulates biocompatibility and antimicrobial behaviour is an essential requirement for biomedical applications. Hydroxyapatite (HAP), graphene oxide, and vivianite in one ternary nanocomposite with three phases and shapes led to an increase in cell viability to 97.6% ± 4 for the osteoblast cells in vitro. The obtained nanocomposites were investigated for their structural features using X-ray diffraction, while the microstructure features were analyzed using a scanning electron microscope (SEM) and a transmission electron microscope. The analysis showed a decrease in the crystal size to 13 nm, while the HAP grains reached 30 nm. The elongated shape of vivianite reached 200 nm on SEM micrographs. The monoclinic and hexagonal crystal systems of HAP and vivianite were presented in the ternary nanocomposite. The maximum roughness peak height reached 236.1 nm for the ternary nanocomposite from 203.3 nm, while the maximum height of the roughness parameter reached 440.7 nm for the di-nanocomposite of HAP/graphene oxide from 419.7 nm. The corrosion current density reached 0.004 μA/cm2 . The ferrous (Fe2+ ) and calcium (Ca2+ ) ions released were measured and confirmed. Therefore, the morphology of the nanocomposites affected bacterial activity. This was estimated as an inhibition zone and reached 14.5 ± 0.9 and 13.4 ± 1.1 mm for Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) after 24 h. The increase in viability and the antibacterial activity refer to the compatibility of the nanocomposite in different medical applications.

Decomposition of dye pigment via photocatalysis process using CuO-TiO2 nanocomposite

In the present work, the degradation efficiency of dye pigment was enhanced by using of CuO-TiO2 nanocomposite. It was synthesized via sol–gel method under various ratios of CuO:TiO2 including 0.001:1 (as named 0.1%CuO-TiO2), 0.005:1 (as named 0.5%CuO-TiO2), 0.01:1 (as named 1.0%CuO-TiO2). The physico-chemical properties of nanocomposite were characterized by X-ray diffractometer (XRD), scanning electron microscopy (FE-SEM) and energy dispersive spectroscopy (EDS). The degradation efficiency was tested with methylene blue (MB) as a dye pigment and compared to pure synthesized TiO2 and P25. The 0.10%CuO-TiO2 obtained the best MB degradation efficiency (approximately 100% under 30 min UV-A irradiation) as similar as P25. The pure synthesized TiO2 obtained the lowest MB degradation efficiency of 70%.

Silver/Chitosan Nanocomposites: Preparation and Characterization and Their Fungicidal Activity against Dairy Cattle Toxicosis Penicillium expansum.

This work aimed to evaluate the fungicide activity of chitosan-silver nanocomposites (Ag-Chit-NCs) against Penicillium expansum from feed samples. The physicochemical properties of nanocomposites were characterized by X-ray fluorescence analysis (XRF), small-angle X-ray scattering (SAXS), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). The morphological integrity of the nanohybrid was confirmed by electron transmission. By the data of RFA (X-ray fluorescent analysis), the contents of Ag in Ag-chitosan composite were 5.9 w/w%. The size distribution of the Ag nanoparticles incorporated in the chitosan matrix was investigated by SAXS. The main part of the size heterogeneity distribution in the chitosan matrix corresponds to the portion of small particles (3–4 nm). TEM analysis revealed a spherical morphology in the form of non-agglomerated caps, and 72% of the nanoparticles measured up to 4 nm. The minimum inhibitory concentration of NCs was evaluated in petri dishes. Three different concentrations were tested for antifungal activity against the mycotoxigenic P. expansum strain. Changes in the mycelium structure of P. expansum fungi by scanning electron microscopy (SEM) were observed to obtain information about the mode of action of Ag-Chit-NCs. It was shown that NC-Chit-NCs with sizes in the range from 4 to 10 nm have internalized sizes in cells, form agglomerates in the cytoplasm, and bind to cell organelles. Besides, their ability to influence protein and DNA fragmentation was examined in P. expansum. SDS-PAGE explains the apparent cellular protein response to the presence of various Ag-Chit-NCs. The intensity of P. expansum hyphal cell protein lines treated with Ag-Chit-NCs was very thin, indicating that high molecular weight proteins are largely prevented from entering the electrophoretic gel, which reflects cellular protein modification and possible damage caused by the binding of several protein fragments to Ag-Chit-NCs. The current results indicate that Ag-Chit-NCs <10 nm in size have significant antifungal activity against P. expansum, the causative agent of blue mold-contaminated dairy cattle feed.

Enhanced lysosome escape mediated by 1,2-dicarboxylic-cyclohexene anhydride-modified poly-l-lysine dendrimer as a gene delivery system

Antisense oligodeoxynucleotide (ASODN) can directly interfere a series of biological events of the target RNA derived from tumor cells through Watson-Crick base pairing, in turn, plays antitumor therapeutic roles. In the study, a novel HIF-1α ASODN-loaded nanocomposite was formulated to efficiently deliver gene to the target RNA. The physicochemical properties of nanocomposite were characterized using TEM, FTIR, DLS and zeta potentials. The mean diameter of resulting GEL-DGL-FA-ASODN-DCA nanocomposite was about 170–192 nm, and according to the agarose gel retardation assay, the loading amount of ASODN accounted for 166.7 mg/g. The results of cellular uptake showed that the nanocomposite could specifically target to HepG2 and Hela cells. The cytotoxicity assay demonstrated that the toxicity of vectors was greatly reduced by using DCA to reversibly block the cationic DGL. The subcellular distribution images clearly displayed the lysosomal escape ability of the DCA-modified nanocomposite. In vitro exploration of molecular mechanism indicated that the nanocomposite could inhibit mRNA expression and HIF-1α protein translation at different levels. In vivo optical images and quantitative assay testified that the formulation accumulated preferentially in the tumor tissue. In vivo antitumor efficacy research confirmed that this nanocomposite had significant antitumor activity and the tumor inhibitory rate was 77.99%. These results manifested that the GEL-DGL-FA-ASODN-DCA nanocomposite was promising in gene therapeutics for antitumor by interacting directly with target RNA.

Composite nanomaterials based on 1-butyl-3-methylimidazolium dicianamide and clays

Nanocomposites of ionic liquids with layered aluminosilicates represent a new class of functional materials that are promising when creating electrochemical devices, in environmental protection, in biomedicine, etc. Such nanocomposites contain environmentally friendly (clay) and easily regenerable components (ionic liquids), which makes them promising objects of green chemistry. In this paper, the interaction of 1-butyl-3-methylimidazolium dicyanamide ionic liquid with clays such as montmorillonite K10 (MMT K10), bentonite (Bent) and halloysite (Hal), which have a different molecular and mesoporous structure, as well as particles of different size and shape, was studied for the first time. Physicochemical methods such as FT-IR, TG, DSC, electron microscopy, viscosimetry and conductometry were used. The effect of the confinement of ionic liquid in the pores and immobilization on the surface of clays on the physicochemical properties of nanocomposites has been revealed. It was found that the interaction of ionic liquid with clays depends on the type of nanoclay, and the interaction strength changes in the following order: MMT K10 ≈ Bent >> Hal. The resulting materials have the properties of pseudoplasticity, high ionic conductivity, which is promising when creating electrochemical devices. At low temperature, the electrical conductivity of the halloysite-based composite is higher than that of a pure ionic liquid. The conductivity of the studied materials obeys to a general trend, which depends on the specific interactions and the properties of the clay-filled ionic liquid.

Endotoxin removal from aqueous solutions with dimethylamine-functionalized graphene oxide: Modeling study and optimization of adsorption parameters.

Novel graphene oxide (GO)-based adsorbent embedded with epichlorohydrin (ECH) as a coupling agent and dimethylamine (DMA) as a ligand (GO-ECH-DMA) were prepared and employed for endotoxin removal from aqueous solutions. The physicochemical properties of nanocomposite were fully characterized. The model attributed to batch adsorption process was optimized employing response surface methodology (RSM) via various parameters such as pH, GO-ECH-DMA dosage, and contact time and endotoxin concentration. The p-value with low probability (<0.00001), determination coefficient (R2=0.99) and the non-significant lack of fit (p > 0.05) showed a quadratic model with a good fit with experimental terms. The synergistic effects of the linear term of contact time and GO-ECH-DMA dosage on endotoxin removal were significant. The optimum condition for endotoxin removal was obtained at pH of 5.52, GO-ECH-DMA dosage of 21 mgL-1, contact time of 56 min and endotoxin concentration of 51.3 endotoxin units per milliliter (EUmL-1). The equilibrium was the better explained by Langmuir isotherm with the maximum monolayer adsorption capacity of 121.47 EUmg-1, while the kinetics of the endotoxin adsorption process was followed by the pseudo-second-order model. The adsorbent could be recycled with NaOH. The possible mechanisms of endotoxin adsorption were proposed by hydrogen-bonding, π-π stacking, and electrostatic interaction.

Nanocrystalline Calcium Carbonate Hydroxyapatites Containing Multiwall Carbon Nanotubes: Synthesis and Physicochemical Characterization

Nanocomposites (NCs) based on carbonated calcium hydroxyapatite (CHA) (bioapatite, an analogue of the inorganic component of mammalian bone tissue), carbonate apatite (Ca10(PO4)6CO3, CA), and multiwall carbon nanotubes (CNTs) are prepared in the system CaCl2–(NH4)2HPO4–NH4HCO3–NH3–CNT–H2O (25°C) by coprecipitation of calcium and phosphorus salts with CNTs from aqueous solutions. The physicochemical properties of nanocomposites are studied as dependent on their formation conditions and composition using the solubility (residual concentrations) method and pH measurements. The composition, crystal structure, morphology, spectroscopic and thermal characteristics of the synthesized CHA/CNT and CA/CNT NCs are determined using chemical analysis, X-ray powder diffraction, thermal analysis, and IR spectroscopy. Either CHA/CNT NCs of composition Ca10(PO4)6(CO3)x(OH)2–2х · yCNT · zH2O, where х = 0.2; 0.5; 0.8; y = 1, 2, 3; z = 6.8–10.8, or (when х = 1) CA/CNT NCs of composition Ca10(PO4)6CO3 · yCNT · zH2O, where y = 1–3; z = 6.9–10.8, are formed as the carbonate and CNT contents of the NC increase. Our results favor the understanding of the effect of carbonization and CNTs on the metabolic formation of native bone tissue apatite and can be used for the design of efficient ceramics for bone implants.

One-pot synthesis of novel silver-polyaniline-polyvinylpyrrolidone electrocatalysts for efficient oxygen reduction reaction

A facile and fast aqueous phase-based strategy to synthesize silver-polyaniline-polyvinylpyrrolidone (Ag-PANI-PVP) nanocomposites, via chemical oxidative polymerization method is presented. In the presence of polyvinylpyrrolidone (PVP), which has an accelerating effect on the oxidation of aniline with silver nitrate, Ag nanoparticles (AgNPs) were in situ generated in aqueous solution during simultaneous formation of polyaniline (PANI), without any additional reducing agent or complicated treatment. We have demonstrated synthesis of three stabile Ag-PANI-PVP nanocomposites with different content, size, and morphology of Ag nanoparticles by varying the experimental parameters, such as pH and PVP concentration. As a result, this led to different Ag nanostructures (spherical and polyhedral NPs), and, consequently, different morphology of formed nanocomposites (granular and nanosheets). The physicochemical properties of nanocomposites were examined by using different analytical techniques (UV–Vis, TEM, FESEM, FT-IR, XRD, and Raman). It is found that optical properties, electrical conductivity and the content of Ag in the composites vary depending on the synthetic conditions. The electrocatalytic behavior of Ag-PANI-PVP nanocomposites was examined towards the oxygen reduction reaction in acidic and alkaline media. All tested nanocomposites showed high electrocatalytic activity, while the most active catalyst is the one with the highest electrical conductivity (≈0.6 S cm−1) and the lowest Ag content (3.4 wt%), synthesized in the solution without added acid. The simplicity of synthesis and good electrocatalytic efficiency of prepared nanocomposites combined with large-scale availability make them attractive as Pt-free electrocatalysts.

Magnetic SiO2@CoFe2O4 nanoparticles decorated on graphene oxide as efficient adsorbents for the removal of anionic pollutants from water

In this study, magnetic nanocomposites viz. SiO2@CoFe2O4 nanoparticles decorated on graphene oxide were synthesized using solvothermal and sol-gel processes. The prepared nanocomposite materials were used as magnetic adsorbents for the removal of organic and inorganic pollutants (acid black 1 dye and Cr(VI) ions as model pollutants) from aqueous solution. The structure, morphology and other physico-chemical properties of nanocomposites were characterized by X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM), high resolution-transmission electron microscopy (HR-TEM), vibrating sample magnetometer (VSM), X-ray photo spectroscopy (XPS), zeta potential and Fourier transform infrared (FT-IR) spectroscopy. Batch mode adsorption studies were conducted with the prepared nanocomposites to determine the maximum adsorption capacity of acid black 1 dye and Cr(VI) ions as a function of contact time, pH, adsorbent dosage and initial adsorbate concentrations. Different kinetic and isotherm models were tested to describe and elucidate the adsorption mechanisms. Based on the experimental results obtained, the synthesized materials proved to exhibit considerable potential for the removal of acid black 1 and Cr(VI) ions from aqueous solution.

Synthesis and Characterization of PVA/GO Nanocomposite Films

SummaryNanocomposite films of PVA (polyvinyl alcohol) with GO (graphene oxide) as organic filler have been synthesized successfully. GO was prepared through modified Hummers method and confirmed by SEM and XRD. Nanocomposites were prepared containing various weight amount of GO (0.1, 0.2 and 0.5%) within PVA matrix. Filmss are casted on clean glass plate through solution casting method and dried followed by. Further the investigation of thermal and mechanical as well as physicochemical properties of nanocomposites are done using respective analysis techniques. Electronic conductivity of the prepared Films are also measured. The value of electronic conductivity enhances as the GO content increases within polymer matrix. Thermal and mechanical analysis shows increment in stability with increasing GO content. Maximum electronic conductivity e.g. 1.95 × 10−2 Scm−1 was found for G‐5 (0.5%) films.

Synthesis of multifunctional nanocomposites and their application in imaging and targeting tumor cells in vitro

The labeling of cells with nanomaterials for tumor detection is a very important part of various biomedical applications. In this study, multilayer nanocomposites were synthesized to achieve the multiple functions of fluorescence, magnetism, and bioaffinity. Firstly, superparamagnetic Fe3O4 nanoparticles were prepared as a magnetic core. Then, fluorescein isothiocyanate (FITC) was covalently linked to the surface of the silica-coated Fe3O4 core (designated FMNPs). Finally, bovine serum albumin (BSA) was conjugated onto the FMNPs (designated FMNPs-BSA). We also evaluated the feasibility and efficiency of labeling the human liver cancer cell line SMMC-7721 (SMMC-7721) with nanocomposites. SEM, hysteresis loop, EDS, FTIR, fluorescence spectra, and fluorescence microscopy were used to determine the physicochemical properties of nanocomposites. Fluorescence microscopy, SEM-EDS, and TEM were used to determine fluorescence labeling, absorption, and uptake respectively. The results showed that the nanocomposites obtained exhibited fine superparamagnetism, strong fluorescence, and good biological affinity. We succeeded in using the new multilayer nanocomposites to label cells, which had properties of magnetic targeting and fluorescent tracing.

Antibacterial Silicone-Urea/Organoclay Nanocomposites

Montmorillonite modified with distearyldimethyl ammonium chloride (C18-QAC) (Nanofil-15) (NF15) was incorporated into polydimethylsiloxane-urea (silicone-urea, PSU) copolymers. PSU was obtained by the reaction of equimolar amounts of aminopropyl terminated polydimethylsiloxane (PDMS) oligomer ( = 3,200 g/mol) and bis(4-isocyanatohexyl)methane (HMDI). A series of PSU/NF15 nanocomposites were prepared by solution blending with organoclay loadings ranging from 0.80 to 9.60% by weight, corresponding to 0.30 to 3.60% C18-QAC. Colloidal dispersions of organophilic clay (NF15) in isopropanol were mixed with the PSU solution in isopropanol and were subjected to ultrasonic treatment. Composite films were obtained by solution casting. FTIR spectroscopy confirmed that the organoclay mainly interacted with the urea groups but not with PDMS. XRD analysis showed that nanocomposites containing up to 6.40% by weight of organoclay had fully exfoliated silicate layers in the polymer matrix, whereas 9.60% loading had an intercalated structure. Physicochemical properties of nanocomposites were determined. PSU/NF15 nanocomposites displayed excellent long-term antibacterial properties against E. coli.