International Journal Of Nanoscience and Nanotechnology
Volume:17 Issue: 4, Autumn 2021

The exceptional application of nanocomposites containing polyaniline as a conductive polymer, poly (methyl methacrylate) (PMMA) as an acrylic resin and Fe3O4 nanoparticles, for corrosion protection of mild steel was reported. The synthesized nanocomposites, were characterized with different techniques. The resulting PMMA/Polyaniline/Fe3O4 nanocomposites were mixed with industrial alkyd paint to be employed as an anti-corrosion layer for mild steel in a NaCl solution. Accordingly, the potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) were applied in order to investigate the corrosion behavior of the coated mild steel. Based on the results, the nanocomposites showed outstanding anti-corrosion properties compared with other composites coating. After investigating various compositions of the nanocomposites (3, 6, 9 and 12%) in the alkyd paint, the ideal composition related to the most favorable corrosion protection was obtained for the paint mixture comprising 6% nanocomposites.

In this project, Nickel oxide nanoparticles (NiO-NPs) have been synthesized by a photolysis method and assessed for their anti-biofilm activity. It is a strategy that is simple and inexpensive. The morphology and the average particle size was investigated by scanning electron microscope (SEM), transmitted electron microscope (TEM) and the crystallite size was calculated by (XRD) analysis. The XRD studies support the existence of NiO-NPs with a high degree of crystallinity. Their nickel oxide particle size was found to be around 13-31 nm. Forty-two samples of medical waste from different hospitals in Baghdad were between 2nd to 12th of October / 2020. Bacterial isolation results recorded fifteen Staphylococcus aureus isolates. Well diffusion method was used to determine of methicillin resistance S. aureus (MRSA), in addition to using the mecA gene as a molecular method to detection of methicillin resistance gene, the results of these both methods showed that the MRSA percentage of these two methods were 53.3% and 73.4% in well diffusion method and PCR respectively. Results of MRSA biofilm formation illustrated that only four isolates (36.3%) hadn’t the ability to produce biofilm by using microtiter plate assay (MTP). In contrast, the other isolates (63.7%) could produce biofilm and they were ranging from strong to week biofilm formation. Antimicrobial activity of different concentrations of NiO-NPs (10, 20, 30, 50, and 100 µg/ml) showed ranging of inhibition zones starting from 0 to 13 mm. In comparison, the MIC concentration was 265 µg/ml (63.7%) of seven MRSA isolates and 530 µg/ml (36.4%) of four isolates. Detection of hemolysis activities of NiO-NPs against human red blood cells (RBCs) was done. The results illustrate that the hemolytic activity was 2.38%, 2.23%, 2.41%, and 2.69% corresponding to 0, 0.01, 0.1, and 1 mg/ml of NiO-NPs.

Synthesis of new natural polymers-based nanocomposites is the center of attentions for the catalyst researchers on account of their sustainability. In this regard, cellulose aerogel was hydrophobized by polysilicon to give a hydrophobic bio-support which underwent deposition of TiO2 nanoparticles afforded a catalyst with high lipophilicity, superior porosity as well as high catalytic activity. The prepared nanocomposite was structurally characterized, in which the deposition of polysilicon and TiO2 nanoparticles on an aerogel compound was recognized. The aerogel exhibited good hydrophobicity, and high selectivity in oil/water absorption with 6.3 g oil absorbed by 1 g of the absorbent. Finally, the nanocomposite was employed as a heterogeneous photocatalyst in the transformation of alcohols to aldehydes/ketones, and ethylbenzene to acetophenone with the conversions laying in the range of 81-99%. Mild conditions, high yields, excellent selectivities, and recyclability and biocompatibility of the catalyst are advantages of the reactions.

The sluggish reaction kinetics and aggregation of volume during lithiation/delithiation process are the main obstacles of anode for li-ion capacitors (LICs). Here, we use the “three bird one stone” strategy to design the anode of phosphorus abundant Co2P nanoparticles encapsulated by N-doped CNTs rationally. The Co2P nanoparticles contribute to shorten the Li+ diffusion length, while abundant phosphorus guaranteeing the high electrical conductivity and N-CNTs providing stable structure protecting layers. Hence, Co2P/N-CNTs electrode reveals a large specific capacity of 807 mAh g-1 at 0.1 A g-1 over 200 cycles and excellent rate performance of 395 mAh g-1 at 3.2 A g-1. Extraordinary, the capacitive contribution of Co2P/N-CNTs electrode at 1 mV s-1 is 80.73%, contributing to the enhanced reaction kinetics and rate capacity. The LICs comprising of Co2P/N-CNTs anode and activated carbon (AC) cathode demonstrate an outstanding energy density of 130 Wh kg-1 at 625 W kg-1 along with 90.24% capacity retention over 10000 cycles at 5 A g-1 within 4.5 V. The proposed strategy can be applied to develop promising electrode materials for promising energy storage systems.

Nowadays, due to bacterial antibiotic resistance, the design of new high-performance antibiotics to maintain human health has been a significant challenge. Accordingly, photothermal antibiotics have been developed based on semiconductor materials such as graphene. Herein, copper sulfide (CuS) nanoplates and graphitic carbon nitride (g-C3N4)/CuS were synthesized as salient antibacterial agents and their antibacterial features were assessed using polymethyl methacrylate (PMMA) as a practical matrix. The morphology and structure of nanostructures were characterized by X-ray diffraction (XRD), ultraviolet (UV)-visible (Vis) diffuse reflectance spectroscopy (DRS), and field emission scanning electron microscopy (FESEM). Based on the results obtained by the UV-Vis light absorption, the g-C3N4, CuS, and g-C3N4/CuS nanostructures illustrated strong absorptions in the visible light region while demonstrated 2.92, 1.20, and 0.27 eV band gaps, respectively. Eventually, the study of the antibacterial properties of the nanostructures exhibited that the zone of inhibition is augmented by anchoring the CuS nanoplates onto the g-C3N4 surface. Interestingly, g-C3N4/CuS nanocomposite brought 12 and 17 mm zone of inhibitions for Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), respectively. More significantly, the results attested that inserting the g-C3N4 nanostructures promote the antibacterial features of CuS nanoplates, originated from its nucleation effect boosting surface area to volume ratio of the sulfides, amplifying interfacial interaction, and elevating established reactive oxidative species (ROS) killing the bacteria. The presented research opens new windows toward augmenting the antibacterial features of biomedical polymers.

Mint, a medicinal plant has gained immense attention from food and pharmaceutical industries because of its numerous health benefits while treating Vitamin D (Vit D) deficiency via recommended fortified food always remains the primary objective of nutritionists. We aimed to evaluate the biocompatible nature of our mint oil-Vit D encapsulated β-Cyclodextrin carbon-based nanoparticles before establishing their potential application in the medicine and food industry. The repercussion of different concentrations of nanoparticles was evaluated on various model systems (microbes, cell lines, erythrocytes, plant seeds and zebrafish embryos) and result obtained was subjected to statistical analysis. In our study, synthesized nanoparticles revealed no antimicrobial activity. The cytotoxicity and anticancer potential of the nanoparticles were studied using L929 and HeLa cell lines respectively at various concentrations and divulged the fact that these nanoparticles induce significant cell death at higher concentrations but remain non-detrimental at lower concentrations. Further, exposure of nanoparticles to RBCs presented a dose-dependent induction of hemolysis and lipid peroxide production. A similar trend of toxicity was evident in the zebrafish embryo as well at higher concentrations. Phytotoxicity analysis revealed no effect of nanoparticles on germination of seeds albeit the root and shoot length of seedlings were affected significantly. Overall, our results indicate high biocompatibility of these nanoparticles only at lower concentrations and their further applications in various industries should strictly consider minimal doses.