Journal of Nano Structures
Volume:12 Issue: 1, Winter 2022

Zinc oxide was deposited on the glass substrate as a waveguide sensor by chemical vapor deposition technique. The structure, surface morphology and optical properties of ZnO thin films are characterized using X-ray diffraction, binding energy SEM , UV- spectrophotometer, Raman spectroscope and Photoluminescence (PL). The results show that the waveguide sensor of ZnO offers a good response to detect different concentrations of glucose solution. The maximum sensitivity has been determined as 1.09 dB at 560 nm thickness of ZnO layer, while the minimum sensitivity was found to be 0.79 dB, 0.87 dB and 0.96 dB at thickness 213 nm, 315 nm and 435 nm respectively. It is believed that the ZnO material has a great potential to be utilized as a sensing layer in real world applications for the detection of chemicals leakage. In this work, the ZnO was deposited on the glass substrate as waveguide sensor by CVD method. Different thickness of ZnO layers are deposited on the glass substrate. The waveguide sensor was combined with laser source and photo-detector to detect different concentrations of glucose. it was showed a good response toward the change of the glucose concentration, which will be used to detect the chemical leakage in fuel station, wells and pipeline oil.

Antifungal bioactive compounds in Thyme extract are prone to degradation by oxidation, heating or light. For preventing of this problem, encapsulation process is a valuable method to protect these natural products. The aim of this study was to encapsulate of Thyme extract via chitosan as a biodegradable polymer to keep antifungal effect and other chemical bioactive compounds. In this study, extraction of Thyme was carried out by probe ultrasonic- assisted extraction (UAE) system with total solid content (TSC) 64% and then synthesis of chitosan nanoparticles containing Thyme extract was performed by ionotropic gelation technique. Morphology of chitosan nanoparticles was identified through field emission scanning electron microscopy (FE-SEM). The related images showed a spherical shape of the nanoparticles. Particles size of the encapsulated polymers was 75.07 nm with single modal particle size distribution which was measured by dynamic light scattering (DLS) method. Infrared spectroscopy (IR) of both encapsulated with and without extract indicated that the synthesized nanoparticles could involve the bioactive compounds to their vacancies, successfully. This ecofriendly procedure could be represented as a suitable alternative for biological control of the plant pathogens instead of chemical fungicides.

The controlled formation of graphene oxide coatings in the form of the homogenous structure on stainless steel is demonstrated by scanning electron microscopy (SEM). The characterization of the material was assessed by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. The carbon content in low carbon steel is ≤ 0.3% or, to be exact around 0.1%. Problem that commonly arises with low carbon steel is that the zinc coating, known as galvanization, can easily peel off or crack when moved or transported. The objective of this study is finding alternative coatings which are more adherent and can blend with the steel by testing a mixture of galvanized coating compound (type ER-809 Zinc Rich Cold) and graphene oxide (GO). The composition of the mixture is 15% graphene oxide (GO) and 85% galvanized coating compound. The immersion times were 30 seconds, 60 seconds, and 90 seconds. Dry corrosion test was conducted by heating in a furnace at 700 0C with variations in holding time for 30 minutes, 1 hour, and 1.5 hours. Weight Loss method was used to find out the Corrosion Penetration Rate (CPR). The lowest CPR result was obtained from 30 minutes heating time. The analysis of Scanning Electron Microscope (SEM) shows that the corrosion level on low carbon steel is low. Overall, low carbon steel coated with the mixture of galvanized (type ER-809 Zinc Rich Cold) and graphene oxide (GO) has lower CPR compared to low carbon steel without coating or coated with zinc alone.

In this study, the nanostructures of Zn1-xCuxO with x=0.000, 0.025, 0.050 and 0.075 were successfully synthesized by sol-gel auto combustion method using glycine as a fuel. The prepared powders were calcined at 300 °C. The effect of Cu doping on structural and optical properties of powders was studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-visible absorption spectroscopy (UV- vis) and photoluminescence (PL). The XRD patterns showed all samples have wurtzite structure. There is an extra peak belong to CuO at 2θ=38o in the XRD pattern of the sample with x=0.075. The average crystal size of the prepared powders is about 29-47 nm. The SEM micrographs revealed that all doped nanostructures have Leaf-like structure with the thickness about 15-20 nm. Absorption spectra showed a red shift and decrease in the band gap in the Zn1-xCuxO system. The PL spectra showed that the maximum Emission wavelength increases with dopant concentration.

This study sought to identify the effect of adding zirconium oxide and titanium dioxide nanoparticles on some mechanical and physical properties (hardness, roughness, and spectrophotometer UV-light absorption) of soft denture lining materials. For 3 experiments of this study, 315 specimens were prepared from soft liner by conventional methods (n of each experiment=105) and then divided into three groups as stated by the tests (roughness, hardness, and spectrophotometer color absorption); 15 specimens as a control group (pure soft liner), 45 specimens for nanoparticles as a two test group (reinforced with 2 wt %, 3 wt %, and 5wt % of Zirconium oxide and Titanium dioxide nanoparticles respectively.   The mean hardness and surface roughness values of the soft-lining denture in the experimental groups of 2 %, 3%, and 5% of TiNPs and ZrNPs were significantly lower than the control group (P< 0.001). The hardness and surface roughness decreased significantly after adding nanoparticles, and the most decrease was seen in the 5% of both TiNPs and ZrNPs groups. The UV- light absorption values of the experimental groups were significantly higher than those of the control group (P< 0.001), and the maximum increase was seen was in the 5% of both TiNPs and ZrNPs groups.Incorporating the TiO2 and ZrO2 nanoparticles into soft liner improve the mechanical and physical properties; decrease surface roughness, hardness, and increased opacity of the liner material. This improvement was directly proportional to the concentrations of the nanoparticle.

Eight eco-friendly, and magnetically-separable heterogeneous photocatalysts including five Au nanoparticles (NPs) modified magnetic TiO2@Fe3O4 NPs and three Ag-Au bi-plasmonic NPs-decorated TiO2@Fe3O4 NPs with enhanced photocatalytic performance under visible light were synthesized and used for photodegradation of methyl orange (MO) as a model pollutant in textile wastewater samples. The photocatalytic activity was assessed using two radiation sources namely, an intense linear 532-nm laser and a continuous solar-simulated xenon lamp. Compared to the TiO2 alone, the prepared photocatalysts revealed efficient photocatalytic activity in visible region due to the presence of two localized surface plasmon resonance (LSPR)-generated hot electrons from excited Au and Ag NPs and reached to about 98% in 60 min. In addition, the results demonstrated that the photocatalysts have different degradation performance with respect to the type of applied light sources and also to the composition/shell thickness of plasmonic layer. The Langmuir-Hinshelwood adsorption model was used for evaluation of kinetics, degradation rate and half-life time of the reaction and it was concluded that the mechanism of MO degradation involves charge transfer and plasmon resonance energy transfer (PRET) from these plasmonic NPs to the TiO2. On the other hand, the reusability studies revealed that the photocatalysts can be re-used for several cycles without losing its performance with a convenient magnetic separability. Finally, it is shown that the prepared photocatalysts is successfully applied for degradation of organic pollutant in real textile wastewater.

Technique of sol-gel was utilized to make Cu0.6Zn0.4Fe2O4 spinel ferrite, then ( 400 nm and 800 nm) ± 2 0thin films on substrates of Al were precipitated through technique of plasticizer and vacuum as thermal evaporation (TE) through thermal plasma (TP). Tests of diffraction of X-ray (XRD) exposed the thin maked filmsare of polycrystalline nano-structure and the micro-strain occurrence in the crystals because of sintering temperature (ST) influence. Topography images of AFM revealed surfaces as smooth and roughness being low for samples that deposited. Images of surface of SEM thin films present spherical nano-composite grains and the images of cross-sections illustrate agglomerated particles shaped regularly. Influence of thickness on characters of microwave for samples with no any adhesive or fixative addition was revealed and examined through the system of Ne2rk (VNA) Analyzer in X- band width of (8 -12.5) GHz frequency range which illustrates very good stability for the reflectance and very high absorptance proportions.

The main objective of this research is to develop efficient and environmentally benign heterogeneous catalysts for synthesis of 1,5-benzodiazepine derivatives. For this purpose, for the first time, heterogeneous BaTi0.85Zr0.15O3 (BTZ) catalyst was prepared by hydrothermal synthesis in the presence of hexadecylamine (HAD) as surfactant, followed by solvothermal method, and the prepared catalyst was characterized by various techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), N2 adsorption-desorption, Fourier-transform infrared  (FTIR),Thermogravimetric  (TG-DTG) and Temperature programmed desorption  (NH3-TPD) analysis. BTZ is easily used as a heterogonous, reusable and efficient catalyst for synthesis of 1,5-benzodiazepine by reaction of o-phenylenediamine with different ketones under various conditions. The advantages of this catalytic system is mild reaction conditions, short reaction times, high product yields, easy preparation of the catalysts, non-toxicity of the catalysts, simple and clean work-up of the desired products. Furthermore, the solid catalyst demonstrates long durability for synthesis of 1,5-benzodiazepine derivatives consecutively for at least four cycles under mild conditions.

In the late ages, many diseases were discovered, and newly innovative drugs became resistant to the treatment of these diseases, the development in nanoscience and nanotechnology in the field of medicine will cause great progress in diagnosing the disease and its treatment. Newly developed drugs are available in the form of two oral and intravenous doses cannot be a good combination for each product. Trials to increase the solubility to improve bioavailability are illustrated by size reduction and increasing surface area through nanoparticles. It was found that   proteins or nucleic acids like structure products may require a more convenient carrier system to support their efficacy and avoid degradation while a new disease has been found and needs new drugs. The choice of nanoparticles determines the physical and chemical constants that can be used in various ways to prepare nanoparticles as needed. This brief introduction explains the different types of lipids, the drug delivery system based on lipids and nanoparticles, their preparation and applications to pharmaceutical drugs products and possible aspects in the future. A comparison showed that nano lipid carrier is the best choice among other lipid - based formulation like solid lipid nano particles due to more stability and high loading capacity. This article will focus on silico methods adopted in lipid-based-drug-delivery-systems (LBDDS)  development and choosing the optimum lipid - based invention, computational modelling for nanostructure formulation design, computational modelling of drug solubility in variety of lipid-based formulation and molecular dynamics as an approach to analyse the loading capacity of poorly water-soluble drugs in lipids nanoparticles.

Biosynthesis of nanoparticles (NPs) by plant extracts as a one-pot, cost-effective and rapid method has attracted the great attention due to the controllable properties of nanoparticles. Herein, for the first time we report a method for synthesis of a polyphenol modified magnetically separable Fe3O4 NPs by aqueous extract of Achillea wilhelmsii C. Koch (Aw) leaves as a natural capping and reducing agent for water remediation purposes. Aw is the native plant of Iran with high amount of polyphenol compound that its aqueous leaf extract offers several advantages, including modification of structures and improving the physical and chemical properties of the Fe3O4. The prepared nanoparticles possessed great magnetism (~60), pure crystalline structure, and high adsorption capacity toward cationic dye like methylene blue (MB) (~8 mg/g). The Aw-Fe3O4 nanoparticles displayed pH-responsive behavior. With an increase in pH value, the phenolic compounds were deprotonated and revealed enhanced electrostatic interactions with high MB removal efficiency (73%). The intra-particle diffusion and pseudo-second-order kinetic model were suitable to illustrate the adsorption processes of MB.  Moreover, the obtained nanoparticles showed efficient reusability after three cycles. Altogether, the finding of this study demonstrates that Aw-Fe3O4 NPs can be considered as a suitable adsorbent to purify dye wastewater.

The research paper describes the synthesis of silver, copper doped (LaXFeO3) nano lanthanum ferrites (where X = Ag, Cu, both Ag and Cu) by using the sol-gel method. Their dielectric properties, magnetic properties, and catalytic applications were studied by LCR tester and VSM (Vibrating Sample Magnetometer), UV-Vis Spectroscopy respectively. The dielectric properties were studied as a function of frequency and applied field at room temperature and also in a temperature range of 313 K to 673 K. These results confirmed that the doping of silver and copper decreases the dielectric properties due to their conducting behavior. Room temperature magnetic properties revealed the doping of copper influenced the magnetic properties. It was noticed that the magnetism of bare LaFeO3 is very low and the magnetism of La0.5Ag0.25Cu0.25FeO3 and La0.5Cu0.5FeO3 has increased almost 100 times. This may be attributed to the size and shape of the nano ferrites. Also, the catalytic performance of the doped LaFeO3 nanomaterials showed better catalytic performance. The results indicated that the developed nanostructures will find applications in telecommunications.

Over the past decades, the growing industrialization caused continuously increased release of heavy metal into environment. Through the food chain, heavy metals can be enriched in the body, causing serious harm. The removal and recycling of heavy metals are of great significance to environment protection, health concern as well as resource reuse. Pectic materials are available from a variety of natural sources and can be used as versatile adsorbents for heavy metal. Enzyme-based biocatalysts are one of the largest and commercially successful groups ofcatalysts. Integration of nanomaterials in the applications results in significant improvement of sensitivity, stability and other analytical characteristics. Thus, new functional nanomaterials are key components of numerous biosensors. However, due to the great variety of available nanomaterials, they should be carefully selected according to the desired effects. For the correction of pathological conditions of the human body, the prevention and rehabilitation of intoxication, the development of enterosorbents is necessary, one of which is various pectin products. Based on the conducted experiments, the regime parameters of obtaining pumpkin pectin-containing extract by the enzymatic method were established.

In the present study, the pH responsive electrospun carboxymethyl chitosan nanofibers were prepared via electrospinning method and cross-linked with glutaraldehyde vapor for various times up to 48 h. The controlled release of 5-Fluorouracil (5-FU) from single layer and tri-layered nanofibers (5-FU in the middle layer) was compared to obtain a sustained delivery system of 5-FU anticancer drug. The release of 5-FU from nanofibers was investigated at 37 °C under acidic pH (pH 5.5) and physiological pH (pH 7.4). The release data were fitted by zero-order, Higuchi and Korsmeyer-Peppas pharmacokinetic equations to determine the 5-FU release mechanism from nanofibers. Tri-layered nanofibers exhibited the sustained delivery of 5-FU without initial burst release during 168 and 216 h at pH=5.5 and 7.4, respectively. The initial burst release followed by sustained release of 5-FU from single layer cross-linked carboxymethyl chitosan nanofibers occurred during 48 and 60 h. The “n” constant of Korsmeyer-Peppas equation indicated the non Fickian diffusion of 5-FU from single layer nanofibers at both pH values of 5.5, pH 7.4 and tri-layered nanofibers at pH 5.5. Whereas, the Fickian diffusion of 5-FU was occurred from tri-layered nanofibers at pH 7.4. The obtained results indicated the high capability of tri-layered nanofibers for controlled release of 5-FU compared to single layer nanofibers.

The synthesis method of nanomaterials, their shape, and sizes, is essential in improving the efficiency of the dye-sensitized solar cell by increasing energy absorption and conversion. In this work, metal oxide nanoparticles included: copper oxide (CuO), nickel oxide (NiO), and binary CuNiO2, were successfully synthesized via a photolysis method using UV lamb. Morphological, structural, optical, and electrical characterization were done using various techniques such as X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), transmitted electron microscope (TEM), Energy-dispersive X-ray spectroscope (EDX) and, photoluminescence spectroscopy (PL). X-ray diffraction analysis confirmed that the synthesized metal oxide nanoparticles were formed. The average particle size copper oxide (CuO), nickel oxide (NiO), and binary CuNiO2 were rang 4-17 nm estimated by TEM. The optical properties were analyzed using photoluminescence spectroscopy (PL), and the bandgaps of CuO, NiO, and CuNiO2 nanoparticles were determined to be 2.83 eV, 3.4 eV and 2.04 eV Sequentially. We used photochemically synthesized CuO, NiO, and CuNiO2 nanoparticles to make dye-sensitized solar cells (DSSCs). In this research, two counter electrodes have been used: Graphene oxide Nano-Sheets and Graphene oxidesilver nanocomposite were synthesized by Modifying Hummers presses. Cibacron Brilliant Red B is one of the dyes used at the Wasit Governorate textile factory. The remainder is mostly discarded as wastewater used as a photosensitizer in our research. From the J -V curves, where efficiency ranged from 0.231  to 9.61 %, to 100 mW/cm2, the opening circuit voltage (Voc), the short t current density (Jsc), the fill factor (FF) and efficiency (h) was calculated. Finally, CuO, NiO, and CuNiO2 nanoparticles can be proven to increase the efficiency of dye-sensitized Solar Cells with brilliant B-dye cibacrons.

The principal aim of this research is the green synthesis and application of Fe3O4/CaO magnetic nanoparticles (MNPs) for heterocyclic reactions. Fe3O4/CaO MNPs have been prepared using FeSO4 and quail eggshell waste powder in solvent-free conditions. Morphology and structure of Fe3O4/CaO MNPs were determined by FT-IR, X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). It was used as a highly efficient catalyst for the synthesis of triazole carbohydrate derivatives. (1S, 2R, 3R, 4R)-1-(4-amino-5-mercapto-4H-1,2,4-triazol-3-yl) pentane-1,2,3,4,5-pentanol (3) was synthesized by the reaction of thiocarbohydrazide and D-gluconic acid-δ-lactone in the presence of Fe3O4/CaO MNPs (7% mol) in ethanol under reflux conditions. Compound (3) was used as an intermediate for the synthesis of [1,2,4]triazolo[3,4-b][1,3,4]thiadiazin and thiadiazol derivatives. The assigned structure was further established by CHN analyses, NMR, and FT-IR spectra. Because of excellent capacity, the exceedingly simple workup, and good yield, eco-friendly catalyst Fe3O4/CaO MNPs were proved to be a good catalyst for this reaction.

The eye has many barriers with specific anatomies that make it difficult to deliver drugs to targeted ocular tissues, and topical administration using eye drops or ointments usually needs multiple instillations to maintain the drugs’ therapeutic concentration because of their low bioavailability. A drug-eluting contact lens is one of the more promising platforms for controllable ocular drug delivery, and, among various manufacturing methods for drug-eluting contact lenses, incorporation of novel polymeric vehicles with versatile features makes it possible to deliver the drugs in a sustained and extended manner. Contact lenses for ophthalmic drug delivery have become very popular, due to their unique advantages like extended wear and more than 50% bioavailability. To achieve controlled and sustained drug delivery from contact lenses, researchers are working on various systems like polymeric nanoparticles, etc. This article reveals the recent achievements in the field of alternative drug delivery in ophthalmology to treat glaucoma combined with myopia. During in vitro experiments it was demonstrated that lossless and prolonged drug delivery is feasible if soft contact lenses of various materials are utilized as drug carriers. However, among two studied model solutions, only one of them passed all drug release tests with all five types soft contact lenses materials.

In the present study, an impedimetric aptasensor was designed based on a glassy carbon modified with nano composite of graphene oxide-chitosan along with 1-Pyrenebutyric acid–N-hydroxysuccinimide ester (Pry) linker to detect tetracycline antibiotic. After the modification of the electrode surface, the aptamer strands were immobilized on it, and it was then used for determination tetracycline concentration. Under optimum conditions, aptamer revealed a linear range of 1.0 × 10-15 - 3.2 × 10-7 with a detection limit of 3.2 × 10-16 M for determination of tetracycline. Some advantages of this biosensor are being highly selective and sensitive for detection of tetracycline, not expensive and easy preparation. Also, this designed aptasensor was applied in the real samples of drug and serum solutions successfully. Moreover, it can be implied that this creates a basis for improvement in graphene oxide-based impedimetric biosensors.

This research intends to propose a new approach to improve the performance of aluminium composites made of chips with the addition of ZrO2 nanoparticles. Moreover, the chip-based composite-reinforced ZrO2 contents offer alternative sources to manufacturing automotive industries to recycle, reuse the machined materials as a secondary source of metal, and protect our earth from greenhouse gas for a sustainable life. This study focused on examining the effects of preheating time (t), preheating temperature (T), and volume fraction (VF) on the mechanical and physical properties of a ZrO2 aluminium chips nanocomposite. This nanocomposite was produced through the hot extrusion method followed by ECAP to compare the result with heat treatment. The influence of each factor was analysed using the factorial design, followed by RSM. The microstructure and theaverage grain sizes of the extrudates were also investigated. Direct solid-states, such as hot extrusion and equal channel angular pressing (ECAP), are alternative and efficient solid-state processes for use in recycling aluminium scrap. These processes utilise less energy and are eco-friendly. Ceramic nanoparticles such as ZrO2 are suggested as alternatives in the production of metal composites. Nanocomposites made of aluminum AA6061 chips reinforced with 5%, 10%, and 15% volume fraction of ZrO2 powder were produced under different processing temperature of 450°C, 500°C and 550°C. The results were analyzed using analysis of experiments (DOE) principle, and assisted by Minitab 18 software. Maximum yield strength and hardness increased to 119.26 MPa and 65.25 VH compared to 100.26 MPa and 50 VH (as-received AA6061), respectively.

[(Cured epoxy resin- lignin) nanomagnetic interpenetrating polymer network (IPN)] (NM - IPN’s) derived from cured epoxy with amine hardener and Lignin was synthesized by sequential polymerization in the presence of Fe3O4 nanomagnetic particles. The chemical structure and surface morphology of NM semi IPNS resin nanoparticles were characterized by Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). The thermal properties of (NM semi IPNS) have been evaluated by Thermogravimetric analysis (TGA) and Differential Scanning Calorimetric (DSC). Adsorption of Cu+2, Pb+2, Co+2 and Cd+2 was investigated under different conditions such as pH and time using flameless atomic absorption spectroscopy. The adsorption studies were evaluated by using Langmuir and Freundlich isotherms.

In the present study, an impedimetric aptasensor was designed based on a glassy carbon modified with nano composite of graphene oxide-chitosan along with 1-Pyrenebutyric acid–N-hydroxysuccinimide ester (Pry) linker to detect tetracycline antibiotic. After the modification of the electrode surface, the aptamer strands were immobilized on it, and it was then used for determination tetracycline concentration. Under optimum conditions, aptamer revealed a linear range of 1.0 × 10-15 - 3.2 × 10-7 with a detection limit of 3.2 × 10-16 M for determination of tetracycline. Some advantages of this biosensor are being highly selective and sensitive for detection of tetracycline, not expensive and easy preparation. Also, this designed aptasensor was applied in the real samples of drug and serum solutions successfully. Moreover, it can be implied that this creates a basis for improvement in graphene oxide-based impedimetric biosensors.