Nanographene Oxide Research Articles

Micro Ribonucleic Acid Combined with Nanoparticles in Molecular Diagnosis of Depression

This study was aimed to investigate the application of micro ribonucleic acid (miRNA) combined with nanographene particles in molecular diagnosis of depression. After the sheet-shaped graphene oxide was mixed with a solvent to form a solution, it was atomized at high temperature to form droplets and extract nanographene oxide, which was applied to an electrochemical sensor. 90 patients with depression were selected as the research objects and they were randomly divided into control group and experimental group, patients from the two groups received the miRNA molecular diagnosis and the miRNA molecular diagnosis combined with nanographene electrochemical sensor dopamine detection method, respectively. As a result, the diagnostic sensitivity (82.4%), specificity (90.3%), and accurate index (71.3%) of patients from the experimental group were higher obviously than those of the control group (54.3%, 72.8%, and 55.6%) (P <0.05). The expression levels of MiR-92b-5p and MiR-19a-3p in patients with depression were higher markedly than the levels of the normal population (P <0.05). The detection rates of mild depression, moderate depression, and severe depression in patients from the experimental group were 97.3%, 96.5%, and 91.2%, which were higher greatly than the rates of the control group (84.3%, 85.4%, and 83.2%) (P <0.05). Besides, the false positive rate (11.2%) and false negative rate (5.6%) of patients from the experimental group were sharply lower than the rates of the control group (31.5% and 16.4%) (P <0.05). In short, miRNA combined with nanographene electrochemical sensors could accurately diagnose depression with high accuracy and sensitivity, which could be applied in the clinical diagnosis.

In vitro assessments of antimicrobial potential and cytotoxicity activity of an orthodontic adhesive doped with nano-graphene oxide.

Formation of white spots and initial carious lesions are the most important complications of fixed orthodontic treatment. Preparation of orthodontic adhesives containing antimicrobial agents might be a practical solution for the prevention of the mentioned defects.

Preparation and characterization of lignin/nano graphene oxide/styrene butadiene rubber composite for automobile tyre application

Styrene butadiene rubber (SBR), is a synthetic polymer and the most abundantly used in the tire industry, which have good collaborative properties with additives and fillers. In present work, we aim to synthesize SBR composite having the properties of graphene oxide filler and made it to be biodegradable. In composite preparation, we fabricated styrene-butadiene rubber/graphene oxide/lignin composites by adding biodegradable biomolecule of lignin fillers at varying 1–3 wt% quantities amount. Those prepared SBR composites were characterized using advanced analysis techniques, and also their biodegradability was. From microscopy examination results, the morphology of pure SBR composite had been improved after the addition of graphene oxide, while the 1 wt% lignin filled SBR sample revealed well-integrated morphology with crest-and-trough-like feature, showcasing the lignin fibrils could strengthen the molecular interaction between graphene oxide nano sheet and SBR rubber. For 2 wt% lignin filled SBR sample, it exhibited large protuberants due to the aggregation effect of lignin fibrils. However, bulky and bundle structure of protuberant was more significantly formed in 3 wt% lignin filled SBR, as a result of poor interface between lignin and SBR rubber. The porosity had also been improved for 1 wt% lignin filled SBR sample, imparting it with great surface area to act as tire in automobile application. The physico-chemical analysis also detected the trace of graphene oxide and lignin functional groups in the SBR composite. In addition, the thermal analysis revealed those lignin-filled composites had stable heat tolerance behavior, which suitably used in extreme weather condition. Moreover, the 1 wt% lignin filled SBR sample exhibited good characteristics in both mechanical and biodegradable properties. Thus, the composite of 1 wt% lignin filled SBR could be regarded as a promising candidate for green tire application in the future.

Investigation of the Effect of Graphene Oxide on the Properties and Microstructure of Clay-Cement Composite Grouting Materials.

Reductions in bleeding rates and bulk shrinkage of grouting repair materials comprise the key to solving the leakage of earth–rock dams. In this paper, an anti-seepage grouting material for earth–rock dam was developed by introducing mineral admixtures and graphene oxide (GO) nano sheets into low-cost clay–cement grouting materials and by adding polycarboxylate superplasticizers (PCs) to improve slurry viscosity. The experimental results show that the shear stress and viscosity of the slurry increase with the increase in GO concentration, and the slurry has a certain thixotropy. GO can provide a platform to promote the formation of hydration products and fill the pores of clay particles due to its high specific surface area and low volume; in this paper, the microstructure of clay–cement–graphene oxide (CCGO) grouting materials were improved. Therefore, the bleeding rate, bulk shrinkage rate, setting time and unconfined compressive strength (UCS) of the sample were macroscopically improved. In particular, the bleeding rate and bulk shrinkage rate were shown to be 0% when the content of GO reached 1.08 g/kg. Thus, the grouting anti-seepage and reinforcement performance of CCGO grouting materials were improved.

Development of nano structured graphene oxide incorporated dexamethasone with enhanced dissolution

We present the development of nanographene oxide (nGO) incorporated dexamethasone (DXM) composites (DXM-nGO) with enhanced aqueous solubility. Antisolvent precipitation was used for successful incorporation of nGO into DXM, a popular COVID-19 drug. The study focuses on morphology and dissolution performance of the formulated DXM-nGO, which were characterized using scanning electron microscopy (SEM), Raman spectroscopy, X-ray diffraction (XRD), Differential scanning calorimetry (DSC) and Thermogravimetric analysis (TGA). In vitro dissolution profile showed that for a DXM-nGO containing 0.5% nGO showed that time for 50% dissolution (T50) dropped from 39 min to 24 min, while time for 80% dissolution (T80) went from not dissolved state to 56 min for the same composite. In general, the nGO incorporation into DXM showed enhanced solubility, and in vitro dissolution data suggest that the nGO may be a candidate for successful bioavailability improvement.

Study of the tribological properties of nano lubricating oil blends for diesel engines

The aim of this paper is to evaluate and compare the tribological properties of lubricating oil blends with added nano graphene and nano cerium oxide (CeO2) on the key friction pairs of diesel engines. Dispersion stability is the premise of the study of tribological properties. In this paper, nano CeO2 particles were self-made and high-quality nano graphene was purchased. The dispersion stability of the two nanomaterials in lubricating oil was studied after the same modification. According to the working conditions of the cylinder liner and piston ring, friction and wear tests of the lubricating oil blends containing the modified nanomaterials were carried out at different temperatures. The results showed that both nanomaterials were successfully modified with oleic acid and stearic acid. The dispersion stability of the modified nanomaterials in lubricating oil was improved. The dispersion stability of the lubricating oil blends with graphene before and after modification was slightly higher than that of lubricating oil blends with CeO2 before and after modification. At high temperature, the anti-friction properties of the two nano lubricating oil blends were similar. At ambient temperature, lubricating oil blends containing modified CeO2 did not play a role in reducing friction, while lubricating oil blends with modified graphene had the effect of reducing friction. Whether at ambient temperature or high temperature, the anti-wear property when lubricated with lubricating oil blends with modified CeO2 within the right concentration range was better than that when lubricated with lubricating oil blends containing modified graphene.

Surface conjugation of titanium dioxide nanoparticles on nano-graphene oxide enhances photocatalytic degradation of azo dyes under sunlight.

Here, conjugate of nano-graphene oxide (GO) and titanium dioxide nanoparticle (nTiO2) was proposed for the photocatalytic degradation of two toxic azo dyes, Congo red (CR) and Methylene blue (MB), under sunlight irradiation. Furthermore, the optimized weight ratio between GO and nTiO2 of 1:5 demonstrated the highest degradation efficiency. The nanoconjugate induced 85% degradation of 40ppm of CR in 60min and a complete degradation within 70min, while it degraded more than 90% of 20ppm of MB in 80min. The photocatalyst can be reused for five cycles of photocatalysis. Thus, the photocatalytic potential of GO/nTiO2 under visible light may be used as a very suitable and cost-effective photocatalyst industrially for the removal of toxic dyes from water.

Computational Study on Production Mechanism of Nano-Graphene Oxide/Poly Diallyl Dimethyl Ammonium Chloride (NGO/PDADMAC) Nanocomposite

Nanographene oxide (NGO) is one of the most attractive carbon nanomaterials, which due to its high surface-to-mass ratio and epoxy functional groups on the plate, carboxy and hydroxy on the edges, is easily dispersed in water and is one of the most effective materials for the surface adsorbent. Poly diallyl dimethyl ammonium chloride (PDADMAC) nanocomposite with nano-graphene oxide (NGO/PDADMAC) is used to treat pollutions of negatively charged colloidal materials in water. To form nano-composite with diallyl dimethyl ammonium chloride monomer in the form of live radical polymerization, are used two intermediates of 2-bromopropyl bromide (BPB) and potassium ethyl xanthate (EX). In this study, nano-graphene oxide is exposed to 2-bromopropionyl bromide (NGO/BPB), is investigated the possibility of interacting with three functional groups (carboxy, hydroxy, and proxy) of the graphene oxide nano-sphere. Potassium ethyl xanthate (EX) and Poly diallyl dimethyl ammonium chloride are then added to their nano-complex (NGO/BPB). Thermodynamic and structural parameters based on B3LYP/6-31 + G** show that the structure of the complex created in the carboxy and hydroxy positions has better structural properties than the epoxy group, with comparing of the groups in the IR spectra of experimental and computational, is more the probability of overlap the hydroxy agent. The thermodynamic, structural, and computational parameters indicate the possibility of forming a composite with the hydroxy agent group to be used as filler.

Coal-Derived Functionalized Nano-Graphene Oxide for Bleach Washable, Durable Antiviral Fabric Coatings

Coal-Derived Functionalized Nano-Graphene Oxide for Bleach Washable, Durable Antiviral Fabric Coatings

Investigation of photocatalytic and DNA interaction of novel heterostructured GO/Bi2O3/ZnO nanocomposite

In the present work, we synthesize novel heterostructured nanocomposites of GO/Bi2O3/ZnO (GBZ), GO/Bi2O3 and GO/ZnO adopting by solid state method and using nano graphene oxide (GO), Bismuth oxide (Bi2O3) and Zinc oxide (ZnO). The desire synthesized nanocomposites were characterized and established by UV–visible spectroscopy, X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopic (TEM) and Furrier transform infrared spectroscopy (FT-IR) techniques. The average grain, particle and crystallite sizes of GBZ were found to be 100 ± 5, 50 ± 2 and 48 ± 2 nm, respectively. The most exciting feature of the compositions is that the nanoparticles were distinctly shaped with effective photocatalytic activity against crystal violet (CV) degradation in the presence of sunlight under normal conditions. Among all the composites, GBZ has more catalytic degradation efficiency (85 %) than other catalysts, including different dyes and its rate constant (k) is 17.8 × 10−3min−1 against CV. This study also includes the common ion effect of the catalysts. The GBZ was easily recoverable by a simple filtration method and recycled without significant loss of photocatalytic activity. In the present work we first time report the DNA interactions with GBZ and show good binding results with a distinctly red shift from 258.34 to 269.32 nm. The advantages of these nanocomposites were synthetic process, high yield, solvent-free condition, reusable, cost-effective, nontoxic, short-time reaction and less hazardous materials under a green context.

Experimental Study on Bonding CFRP to Fiber Concrete Beam Considering the Effect of using Nanographene Oxide in Improving the Mechanical Properties of Polyamine Resin

This research examined the effect of nanographene oxide in enhancing the mechanical properties of polyamine resin for better adhesion of carbon-fiber-reinforced polymer (CFRP) to a fiber-reinforced concrete beam. To this purpose, 33 fiber-reinforced concrete beams retrofitted with CFRP of lengths 50 cm, 35 cm, and 20 cm and widths 3 cm, 6 cm, and 10 cm were experimentally studied. Graphene oxide weight percentages of 1, 2, and 3 percent were considered, and the corresponding cases were compared with the case of a retrofitted beam without graphene oxide. According to the results of experiments on 12 of the beams, as the nanomaterial in the adhesive increases from 1 to 2 and 3%, the values of maximum load-carrying capacity, maximum mid-span deflection, beam stiffness, and beam toughness exhibited 46,19, 27, and 5 %, respectively, relative to the case of the beam reinforced with CFRP and without graphene oxide. Subsequently, given the close results of the beams reinforced with 2 and 3% graphene oxide. The 2% graphene oxide was used in the rest of the samples to investigate the effect changes in the number of layers, length, and width of the CFRP on the mechanical properties of the concrete beam. The results indicated that an increase in the number of layers, length, and width of CFRP results in an increase in the load-carrying capacity and deformability of the fiber-reinforced concrete beam

Electrochemical synthesis and characterization of aromatic decorated graphene nanosheet and reduced graphene nanosheet

In this study, four different derivatives of graphene oxide or reduced graphene oxide nanosheets (A1–A4) were synthesized by electrochemical method. The synthesized compounds were characterized using melting point, Fourier Transform infrared (FT-IR), Field Emission Scanning Electron Microscopy (FESEM), X-Ray Powder Diffraction (XRD), and Transmission electron microscopy (TEM). The results of x- ray diffraction prove that the prepared nano graphene or graphene oxide derivatives are chemically or physically occurred as the added aromatic systems were decorated physically or formed a covalent bond to the nanosheets. The field emission scanning electron microscopy and transmission electron microscopy prove the formation of sheet-like nano structures. The results proved that the electrochemical method was feasible in preparing these compounds understudy as it is cheap and does not include the use of solvents harmful to the environment as well as fast. All prepared compounds were stable at room temperature and could be isolated easily from the reaction mixture.

Preparation of rGO-Cu2S for quantum dot sensitized solar cells application and investigation of its properties

This paper presents the results of fabrication of reduced graphene oxide - Cu2S cathode to replace the Pt, CuS, PbS and Cu2S cathode electrodes in an quantum dot sensitized solar cell. The rGO-Cu2S material was fabricated by hydrolysis and printed onto the surface of the FTO substrate with a proportional change in the mass of graphene oxide and Cu2S nano, and then the film was calcined at 350 oC. The electrode structure after calcination was analyzed by X-ray diffraction spectroscopy, the particle size was determined by transmission electron microscopy, and the surface morphology was determined by scanning electron microscopy, semiconductor type is determined by Mott-Schottky measurement and the redox ability of the electrode in the polysulfide electrolyte system is evaluated by electrochemical equipment. The results show that the performance of the rGO-Cu2S cathode is better than that of the Cu2S electrode, which has been proven through the C-V measurement. This is a very positive signal for the team to continue researching to fabricate quantum dot sensitized solar cells and determining photovoltaic efficiency in further studies.

Preparation and characterization studies of nano graphene oxide

Recently, graphene oxide has received a lot of attention due to its unique chemical and physical properties. In this work, graphene oxide nanoparticles were produced using a chemical peeling technique. Graphene Oxide (GO) films with two-dimensional structure were successfully prepared via the modified hummer method. X-ray diffraction was chosen to measure the crystal structure of the graphene oxide nano powder. A Fourier transform infrared (FTIR) spectrum analyzer was used to confirm the presence of oxygenated functional groups. The thermal stability of graphene oxide nanomaterial was estimated to be 450 °C from TGA. This exceptional thermal stability of these graphene oxides is important in the application in the areas related to the solar energy conditions of transparent film composite materials and biomedical applications.

Separation and determination of lithium and manganese ions in healthy humans and multiple sclerosis patients based on Nano graphene oxide by Ultrasound assisted-dispersive -micro solid-phase extraction

Lithium regulates the concentration of nitric oxide in the human body and a high dose of nitric oxide causes multiple sclerosis (MS). Also, the amount of manganese in the cerebrospinal fluid alters the metabolic reactions associated with MS. In this study, the mixture of the ammonium pyrrolidine dithiocarbonate (APDC), the hydrophobic ionic liquid [HMIM][PF6] and acetone coated on the surface of graphene oxide nanoparticles (GONPs) and used for separation Li and Mn in human samples by ultrasound assisted-dispersive-ionic liquid-micro-solid phase extraction technique (USA-DIL-μ-SPE) at pH 6.0. After extraction and back-extraction, the amount of lithium and manganese in the blood, serum and urine samples was determined by the flame and the graphite furnace atomic absorption spectroscopy (F-AAS, GF-AAS), respectively. By optimizing parameters, the LOD, Linear ranges (LR) and preconcentration factor (PF) for Li and Mn ions were obtained (0.03 mg L-1, 0.25 μg L-1), (0.1-0.4 mg L-1, 0.08-1.5 μg L-1) and 10, respectively (%RSD<5). The capacity adsorption of APDC/IL/GONPs and GONPs was achieved (148.5 mg g-1, 122.3 mg g-1) and (41.3 mg g-1, 33.7 mg g-1) for Li and Mn ions in a static system, respectively. This method was successfully validated by spiking samples and certified reference materials (CRM).

Antimicrobial Properties and Shear Bond Strength of Composite Used in Orthodontics Following the Addition of Curcumin-Reduced Nanographene Oxide

Background: Composites used in the direct bonding of brackets in fixed orthodontics are considered a suitable environment for the multiplication of cariogenic bacteria and the establishment of microbial plaques by creating a distance between the bracket, tooth surface, and surface properties such as porosity. In the present study, we decided to combine curcumin-reduced nano-graphene oxide (rGO-NCUR) with a composite resin used in orthodontics to achieve a composite with optimal shear bond strength (SBS) and antimicrobial properties against Streptococcus mutans as a main cariogenic bacterium. Methods: In the present study, nanoparticle of graphene oxide (NGO) was synthesized by the modified Hummers’ method using graphite powder and reacted by NCUR to regenerate reduced-NGO (rGO-NCUR). Scanning electron microscopy (SEM) was used to confirm the synthesis of NGO, NCUR, and rGO-NCUR. SBS and antimicrobial activity of Transbond XT composite containing 5% rGO-NCUR were performed against S. mutans biofilms. SPSS software, one-way ANOVA test, and Tukey post hoc test with a significance level equal to or less than 0.05 were used to analyze the data. Results: The synthesis of NGO, NCUR, and rGO-NCUR in nanoscale was confirmed by SEM. The amount of SBS in the composite sample with 5% w/w rGO-NCUR was 12.30 ± 0.65 MPa. The optical density of S. mutans in the biofilm structure formed on composite containing 5% w/w rGO-NCUR was significantly reduced (62.10%) compared with the control group, namely, original composites used in orthodontics (P<0.05). Conclusions: Based on the data of the present study, it can be concluded that composite containing 5% w/w rGO-CUR, without adverse effect on the physical-mechanical properties of composites, can be used as an antimicrobial additive of composites used in orthodontics to control biofilm formation and caries around orthodontic brackets.

Adsorption of methylene blue dye on nano graphene oxide-thermodynamics and kinetic studies

Wastewater effluents contain synthetic dyes which cause a potential hazard to the environment. Hence, these dyes need to be removed from the water bodies. In the present study, Nano graphene oxide was used as an adsorbent to remove Methylene Blue dye from synthetic wastewater. Graphene Oxide used in the experiment was prepared in the laboratory by Hummer’s method. The effect of dosage, time of contact, initial concentration, temperature, and pH has been investigated. The equilibrium time of contact turned out to be 15 min, the optimum dosage of Graphene Oxide turned out to be 10 mg, the optimum temperature turned out to be 313 K and the optimum pH turned out to be 8pH. The coefficient value for adsorption capacity qmax obtained in Langmuir isotherm was 429.485 mg/g with a significant value of regression R2 = 0.974. The value of the Kf coefficient obtained in Freundlich isotherm was about 117.209 mg/g with a regression, R2 = 0.944. Kinetic study of the adsorption process followed the Pseudo second-order kinetic model. The adsorption process is found to be endothermic and spontaneous. Thus experimental results favor the removal of Methylene Blue dye using nano graphene oxide as an adsorbent.

An experimental investigation and comprehensive modelling of thermal and rheological behaviour of graphene oxide nano platelets suspended mineral oil nano lubricant

Suspension of nano additives in lubricants enhances its thermo-physical behaviour and prolongs the compressor durability in eco-friendly refrigeration systems. Therefore, this study investigates the influence of graphene oxide (GO) nano platelet concentration range of 0.05 – 0.75 vol%, temperature range of 30 – 90 °C and shear rate range of 5.48 s−1 to 190 s−1 on the thermal and rheological behaviour of mineral oil lubricant. Field Emission Scanning Electron Microscopy (FESEM) analysis confirms the platelet structure of GO with a maximum sheet thickness of 5 nm. FT-IR result confirms the pure physical interaction of GO with lubricant. Thermal conductivity and dynamic viscosity of nano lubricants ascended with increasing GO concentration and descended with increasing temperature. The maximum thermal conductivity enhancement of 70% was achieved for the nano lubricant with 0.75 vol% at 30 °C with respect to pure oil. Non - Newtonian shear thinning behaviour was possessed by both pure and nano lubricants at all temperatures. The Artificial Neural Networking (ANN) and mathematical correlation were developed to predict the thermo physical properties of nano lubricants. The maximum R-square value of 0.99998 and 0.9988 was achieved for ANN models of thermal conductivity ratio and relative viscosity of nano lubricants. The ANN model outperforms mathematical correlation by achieving maximum R-square and minimum mean square error (MSE).

Formulation of nano-graphene doped with nano silver modified dentin bonding agents with enhanced interfacial stability and antibiofilm properties

ObjectiveThe aim of this study was to synthesize and characterize reduced nano graphene oxide (RGO) and graphene nanoplatelets (GNPs) doped with silver nanoparticles (nAg) and to prepare an experimental dentin adhesive modified with RGO/nAg and GNP/nAg nanofillers for studying various biological and mechanical properties after bonding to tooth dentin. MethodsNanoparticles were characterized for their morphology and chemical structure using electron microscopy and infrared spectroscopy. Experimental dentin adhesive was modified using two weight percentage (0.25% and 0.5%) of RGO/nAg and GNP/nAg to study its degree of conversion (DC), antimicrobial potential, and cytotoxicity. The effect and significance of these modified bonding agents on resin-dentin bonded interface were investigated by evaluating interfacial nanoleakage, micropermeability, nanodynamic mechanical analysis, micro-tensile bond strength (µTBS), and four-point bending strength (BS), ResultsBoth 0.25% and 0.5% GNP/nAg graphene-modified adhesives showed comparable DC values to the commercial and experimental adhesive (range: 42–46%). The bacterial viability of the groups 0.25% and 0.5% GNP-Ag remained very low under 25% compared to RGO/nAg groups with low cytotoxicity profiles (cell viability>85%). Resin-bonded dentin interface created with GNP/nAg showed homogenous, well-defined hybrid layer and regularly formed long resin tags devoid of any microporosity as evidenced by SEM and confocal microscopy. The lowest nanoleakage and highest bending strength and µTBS was recorded for 0.25% GNP/nAg after 12 months of ageing. A significantly increased nanoelasticity was seen for all experimental groups except for control groups. SignificanceThe addition of 0.25% GNP/nAg showed optimized anti-biofilm properties without affecting the standard adhesion characteristics.

Preparation and adsorption properties of nano-graphene oxide/tourmaline composites

Abstract This research addresses the asphalt smoke emission in the process of asphalt pavement construction. The nano-graphene oxide (GO)/tourmaline composites were prepared to alleviate the asphalt smoke emission and improve the construction environment. The macrocharacteristics and micromorphology of the composites were analyzed, and their optimal preparation process was determined. Using material microanalysis methods, such as X-ray diffractometer, Raman spectroscopy, and Fourier transform infrared spectrometer, the structural characteristics and material composition of the composites were studied. The adsorption properties of the composites on asphalt smoke were clarified. It will provide technical support for the improvement of infrastructure construction environment. The results show that 3-aminopropyl triethoxysilane is superior than hexadecyl trimethyl ammonium bromide in surface modification of tourmaline. During the composite process, surface modifiers and GO had no significant effect on the structure of tourmaline. GO could enhance the adsorption properties of tourmaline on asphalt smoke. When the GO content was 1.5 wt%, the improvement was the largest, which is 17.42%. At that time, the emission-reduction rate of asphalt smoke reached 41.11%.