GO Content Research Articles

The Role of Graphene Oxide in the Exothermic Mechanism of Al/CuO Nanocomposites.

Metastable intermixed composites (MICs) have received increasing attention in the field of energy materials in recent years due to their high energy and good combustion performance. The exploration of ways of improving their potential release of heat is still underway. In this study, Al-CuO/graphene oxide (GO) nanocomposites were prepared using a combination of the self-assembly and in-suit synthesis methods. The formulation and experimental conditions were also optimized to maximize the exothermic heat. The DSC analysis shows that the addition of the GO made a significant contribution to the exothermic effect of the nanothermite. Compared with the Al-CuO nanothermite, the exothermic heat of the Al-CuO/GO nanocomposites increase by 306.9-1166.3 J/g and the peak temperatures dropped by 7.9-26.4 °C with different GO content. The reaction mechanism of the nanocomposite was investigated using a DSC and thermal reaction kinetics analysis. It was found that, compared with typical thermite reactions, the addition of the GO changed the reaction pathway of the nanothermite. The reaction products included CuAlO2. Moreover, the combustion properties of nanocomposite were investigated. This work reveals the unique mechanism of GO in thermite reactions, which may promote the application of carbon materials in nanothermite.

SYNTHESIS OF GO-PEDOT:PSS NANOCOMPOSITES AND STUDY OF THEIR ELECTRICAL PROPERTIES FOR NO2 GAS SENSOR APPLICATION

In this study, GO and GO-PEDOT:PSS nanocomposite films were prepared by using the modified Hummer method and spin-coating, respectively. GO-PEDOT:PSS films with different weight ratios of GO (0.015, 0.03, 0.045 and 0.06) were prepared to study the effect of the GO additive on nitrogen dioxide (NO2) sensing performance. XRD and AFM were used to determine the crystal structure and the topography of the GO-PEDOT:PSS films. The effects of GO concentration and temperature on electrical conductivity and the change in activation energy of PEDOT:PSS films were also investigated. The findings show that as the temperature rises, the electrical resistance reduces, and as the concentration increases, the activation energy decreases.

Efficacy of Five Disinfectant Products Commonly Used in Pig Herds against a Panel of Bacteria Sensitive and Resistant to Selected Antimicrobials.

Simple SummaryAntimicrobial resistance (AMR) is a growing concern worldwide in both human and veterinary medicine. Biosecurity and the ability to limit bacterial contamination on farms are crucial in the fight against disease, including AMR bacteria. This study aimed to investigate whether the recommended concentrations of five commercial disinfectants (A to E) were sufficient to inhibit growth and inactivate a panel of bacterial strains, including some that carry multidrug resistance to selected antimicrobials. The effectiveness of each disinfectant was expressed as the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC). The results indicate that the type of disinfectant and its concentration influence the inhibitory and bactericidal efficacy. The glutaraldehyde/quaternary ammonium-compound-based (disinfectant D) and chlorocresol-based products (disinfectant B) were the most effective in this study. Varying results were observed for the other compounds, depending on the bacterial species tested. The iodine-based (disinfectant C) and potassium-peroxymonosulfate-based (disinfectant A) products were less able to inhibit or inactivate the bacteria. The disinfectant products were less effective against the strains of E. coli with different phenotypic profiles of antimicrobial resistance compared to sensitive strains.The growing threat of antimicrobial resistance worldwide has led to an increasing concern in the human, veterinary, and environmental fields, highlighting the need for strategies to effectively control bacterial contamination. Correct biosecurity practices, including the appropriate use of disinfectants, play a crucial role in controlling bacterial contamination. This study aimed to verify whether the recommended concentrations defined according to the Defra General Orders concentration (GO, published by the UK Department for Environment, Food and Rural Affairs’ disinfectant-approval scheme) of five commercial disinfectant preparations (peroxygen-based, phenol-based, two halogen-releasing agents, and glutaraldehyde/quaternary ammonium compound-based; disinfectants A to E, respectively) were sufficient to inhibit growth and inactivate selected bacterial strains, including some that carry known phenotypic patterns of multidrug resistance. The effectiveness of each disinfectant was expressed as the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values, determined by the broth-microdilution method. The results indicate that the type of disinfectant and its concentration influence the inhibitory and bactericidal efficacy. The glutaraldehyde/quaternary ammonium compound-based (disinfectant D) and chlorocresol-based products (disinfectant B) were the most effective, and the GO concentration was bactericidal in all the strains tested. The efficacy of the other compounds varied, depending on the bacterial species tested. The GO concentrations were at least able to inhibit the bacterial growth in all the products and bacterial strains tested. A greater tolerance to the compounds was observed in the strains of E. coli with multidrug-resistance profiles compared to the strains that were sensitive to the same antimicrobials.

Electrochemically based targeted metabolomics for uric acid, xanthine, and hypoxanthine in plasma samples for early diagnosis of acute renal failure after cardiopulmonary bypass using rGO-GCE

Cardiopulmonary bypass (CPB) may cause a systemic inflammatory reaction in patients during cardiac surgery due to the interaction of blood with heart-lung machine circuits. This inflammation may lead to organ failure. One of the most severe complications of cardiac surgery is the development of acute renal failure (ARF). Early diagnosis of ARF using fast, accurate, and sensitive methods may prevent ARF development. Therefore, we developed and validated an electroanalytical method for simultaneous analysis of three biomarker candidates, uric acid (UA), hypoxanthine (HXA), and xanthine (XA), from plasma samples. Their quantification was performed using reduced graphene oxide modified glassy carbon electrode (rGO-GCE) synthesized through rapid one-step electropolymerization. The characterization studies of rGO-GCE with cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and scanning electron microscope (SEM) analyses showed a successful surface modification of GCE with rGO. The electrochemical oxidations of the biomarkers were examined using square wave voltammetry (SWV) with the rGO sensor in 0.1 M phosphate-borate (PB) buffer (pH 7). Various operational parameters, including pH and type of supporting electrolyte, instrumental parameters, electro polymerization cycles, and GO concentration, were optimized. Under optimum conditions, good linear responses were obtained for three metabolites (R2 > 0.99). The LOQ of the method was 0.12 μM for UA, 0.13 μM for XA, and 0.43 μM for HXA. The developed method was successfully applied to patient plasma samples of ARF (n = 9) and control (n = 17) collected at five-time points of CPB. The UA, HXA, and XA levels were significantly altered in ARF patients. The results showed the applicability of the developed method for early diagnosis of ARF developed after CPB.

Experimental Study on Mechanism of Graphene Oxide-Modified Coral Sand Cement Mortar to Resist Sulfate Erosion

Coral sand particles with low strength and rich pores affect the mechanical properties and durability of their cement-based materials. This paper investigates the mechanical properties and internal pore evolution of graphene oxide-modified coral sand cement mortar under sulfate erosion environment, aiming to better understand the effect of graphene oxide on the mechanical properties of coral sand cement mortar under an erosion environment, especially in wet and dry cycles. Mechanical properties of coral sand cement mortar were tested with different amounts of graphene oxide and different erosion cycles to understand the relationship between the change of flexural and compressive strength and the content and erosion cycle. The microscopic parameters of hydration products and internal dissolution pores were analyzed by XRD and SEM. The results showed that the degree of erosion performance improvement is related to the content of GO, and the two are positively correlated at first and then negatively correlated. At 0.03 wt% content, the retardation effect is the best. There were more orderly pore arrangement with less morphological complexity, when the dissolution amount of Ca(OH)2, porosity, total pore area, pore number, probability entropy, average form factor, and fractal dimension decreased. Coral sand cement mortar increases resistance to sulfate attack, which graphene oxide inhibits the formation of new dissolution pores and the expansion of original pores.

Enhancing the optical properties of chitosan, carboxymethyl cellulose, sodium alginate modified with nano metal oxide and graphene oxide

The solution casting method was utilized to synthesize nanocomposite films of chitosan (Cs)/CuO, Cs/graphene oxide (GO), carboxymethyl cellulose (CMC)/TiO2, CMC/GO, sodium alginate (Na-Alg)/TiO2, and Na-Alg/GO owing to their various applications. The influence of CuO, TiO2 and GO concentration on the optical properties of Cs, CMC and Na-Alg films was studied by UV-Vis Spectroscopy. The absorbance of Cs, CMC and Na-Alg increased with increasing the filler's content, thus reflecting the dependence of Cs, CMC, and Na-Alg properties on the nanofiller's content, and confirming the interactions between individual polymers and CuO, TiO2 and GO nanoparticles. The obtained absorbance values were then used to calculate the absorption coefficient and, hence, the optical band gap values. The characteristic absorption bands of CuO and TiO2 underwent a redshift by increasing the filler's content. The results showed that the optical band gap of Cs, CMC, and Na-Alg decreased with filler's content, and they possessed 1, 2 and 2 band gaps respectively. The obtained results recommended that Cs, CMC, and Na-Alg nanocomposites can be used in optoelectronic devices.

Anisotropic and Lightweight Carbon/Graphene Composite Aerogels for Efficient Thermal Insulation and Electromagnetic Interference Shielding.

High-performance and lightweight carbon aerogels (CAs) have attracted considerable attention in various fields such as electrochemistry, catalysis, adsorption, energy storage, and so on. However, finding an environmentally friendly and efficient preparation method and achieving a controllable performance of CAs are still a challenge. Herein, a series of anisotropic carbon/graphene composite aerogels were synthesized by unidirectional freezing of polyamic acid ammonium salt/graphene oxide (PAS/GO) suspension followed by lyophilization, thermal imidization, and carbonization. The prepared aerogels presented a tubular pore structure oriented along the freezing direction. The GO dispersed in the polymer matrix reinforced the skeleton of aerogels, which significantly inhibited the volume shrinkage during the preparation process, thus giving low densities of 0.074-0.185 g cm-3. In addition, the oriented pore structure endowed the composite aerogels with obviously anisotropic heat insulation performance. The radial thermal conductivity was as low as 0.038 W m-1 K-1 at the density of 0.074 g cm-3. When the initial content of GO rose to 20 phr, the resultant aerogels exhibited a high electrical conductivity of about 0.77 S cm-1 in the radial direction and the electromagnetic interference shielding effectiveness (EMI SE) reached 54.6 dB at the same time. Therefore, this study provided a facile and environmentally friendly method to prepare lightweight and anisotropic carbon aerogels.

Polyurethane Elastomer Layered Nanocomposite Material for Sports Grounds and the Preparation Method Thereof.

Polyurethane, as a rubber material, can relieve the load on the ground and provide seismic design for the venue, which is of great significance for sports venues. In order to improve the seismic resistance and abrasion resistance of materials for sports fields and reduce accidents in sports, this article has carried out research on the polyurethane elastomer layered nanocomposites for sports fields and their preparation. Today's world is a challenging era of science and technology. The fields of biotechnology, information, medicine, energy, environment, and national defense and security are closely related to the development of high tech, and the requirements for materials are becoming increasingly diversified. Polymer nanocomposite coating has the dual characteristics of organic and inorganic components. It not only retains the advantages of a polymer but also endows it with versatility. It meets the current application needs. It is a hot spot in today's research. Among them, there are two major problems in the composite process of nanomaterials and polymers: dispersion and compatibility. How to improve the dispersion of nanoparticles and enhance the compatibility between nanoparticles and polymers is an urgent problem to be solved. In the method part, this article introduces a small amount of polyurethane and polyurethane elastomers formed after polyurethane modification and introduces layered compounds and nanocomposites and introduces several models involved in nanomaterials in terms of algorithms. In the analysis part, this paper conducts a comprehensive analysis of the hard segment mass fraction, mechanical properties, thermal decomposition behavior, degradation mechanism, and dynamic mechanical properties. With the increase of GO content, the tensile strength increases significantly and the elongation at break becomes smaller and smaller. When the GO content increases from 0% to 2%, the tensile properties of the WPU film increase from 2.6 MPa to 7.9 MPa and the fracture of the elongation decreased from 201.7% to 62.8%. This shows that the increase in GO content will make the composite material harder and brittle. It can be seen from the experimental results that the preparation of the polyurethane elastomer layered nanocomposite material designed in this paper has a good application effect on sports venues.

Effect of graphite oxide content on shape memory performance of graphite oxide‐carbon fiber hybrid reinforced shape memory polymer composites by VIHPS

AbstractGraphite oxide (GO)‐carbon fiber (CF) hybrid reinforced shape memory polymer composites (SMPC) with different GO content were prepared by vacuum infiltration hot‐press forming experimental system (VIHPS). By studying the wettability and adhesion characteristics between the shape memory matrix and CF, it was found that the addition of GO could improve the ability of the matrix to wet the CF surface and enhance the interface bonding. The shape memory performance of the composite with GO was better than that of CF reinforced epoxy matrix composite. The shape fixed rate increased by nearly 8%, and the shape recovery rate increased by nearly 13%. Combined with the test results and the characterization analysis of microstructure, the strengthening effect of GO was mainly reflected in the following aspects. Firstly, the surface folds of GO and its two‐dimensional grid structure increased the surface roughness and wettability of CF, forming a mechanical interlock among GO, reinforcement and matrix. The mechanical interlock promoted the reinforcement and matrix to have an ideal interfacial bonding strength. Secondly, the addition of GO was conducive to the transfer of deformation force and heat to prevent stress concentration in the composite and significantly improved the shape memory performance of the composite.

Soft computing and statistical approach for sensitivity analysis of heat transfer through the hybrid nanoliquid film in rotating heat pipe

In this paper, the numerical solution for heat transfer through a rotating heat pipe is studied and a sensitivity analysis is presented by using statistical experimental design technique. Graphene oxide-molybdenum disulfide (GO-MoS2) hybrid nanofluid is taken as working fluid inside the pipe. The impact of the heat pipe parameters (rotation speed, initial mass, temperature difference) on the heat transfer and liquid film thickness is investigated. The mathematical model coupling the fluid mass flow rate and liquid film evolution equations in evaporator, adiabatic, and condenser zones of the heat pipe is constructed. The mathematical model is solved by implementation of “Particle Swarm Optimization” along with the finite difference method. The outcomes demonstrate that hybrid nanoparticles help to improve the heat transfer through the heat pipe and reduce liquid film thickness. The heat transfer rises with increasing temperature difference and reducing inlet mass, and it reduces slightly with rising rotation speed. The difference in liquid film thickness between the evaporator and condenser zones increases with increasing temperature difference and decreasing rotation speed. The impact of increasing the volume fraction of GO on the liquid film thickness is higher than that in the case of the MoS2 nanoparticles. However, an increase of the heat transfer is noticed in case of increasing the volume fraction of GO relative to increasing MoS2 concentration. Statistical analysis of the computed numerical data and the identification of significant parameters for total heat transfer are found using the response surface method. At 95% level of significance, the GO concentration in the hybrid nanofluid, inlet mass of the hybrid nanofluid and the temperature difference inside the evaporator zone of the pipe are found to be significant linear parameters for increasing heat transfer.

Voltammetric sensor for COVID-19 drug Molnupiravir on modified glassy carbon electrode with electrochemically reduced graphene oxide

• There are no published reports for electrochemical determination of Molnupiravir in any matrix. • The first electrochemical validated, sensitive, cheap, easy and fast method for determination of Molnupiravir in pharmaceutical preparations. • Reduced GO has excellent conductivity, thermal and chemical stability for sensor application. A direct, simple, and sensitive method based on electrochemical deposition of reduced graphene oxide (rGO) on a glassy carbon electrode (GCE) using cyclic voltammetry (CV) was developed for Molnupiravir (MOL) quantitative analysis. Here, the electrochemical oxidation of MOL was examined using square wave voltammetry (SWV) and a well-defined peak at 0.2 V was measured against the Ag/AgCl reference electrode with the rGO sensor in Britton-Robinson pH 9 buffer. Various operational parameters for MOL analysis such as pH of supporting electrolyte, instrumental parameters, electropolymerization cycles, and GO concentration were optimized. The sensor exhibited a linear range from 0.09 to 4.57 μM with a detection limit of 0.03 µM. The electrochemical response of the rGO sensor was characterized by electrochemical impedance spectroscopy and CV. The character of current and reversibility of the electrode reaction, the number of electrons and protons transferred were studied by the CV method. The developed sensor was validated according to the International Council for Harmonisation (ICH) guidelines. Validation parameters, such as stability, linearity, sensitivity, accuracy, precision, recovery, robustness and ruggedness were evaluated according to the ICH requirements. The developed sensor was successfully applied for the quantification of MOL in capsule formulations.

Physical characterization of PVP/PEO modified by graphene Oxide for optical and electrical applications

GO@PVP/PEO polymeric blend-based nano-composites has been prepared by the LASER irradiation technique. GO content is changed by LASER irradiation time alteration. XRD showed the decline of crystallinity with growing GO content. FT-IR analysis approved the interaction between the PVP/PEO and GO sheets. UV/Vis. spectra show Lessening in band-gap by raising GO content upon the blend, in agree with XRD analysis. For illustration, allowed direct bandgap at t = 0.0 min records 4.6 e.V, while at t = 20 min 3.8 e.V.in brief, optical gaps are affected by the crystal structure alterations. The surface morphology altered from slight rough to rougher (t = 0.0 min (Ra = 13.21 nm); t = 10 min (Ra = 31.42 nm); t = 20 min (Ra = 38.30 nm)), revealing increasing in amorphous region within the polymeric matrix. Regarding FESEM micrographs, composition with t = 10 min displays big and small GO clumps, the large aggregate shows a width of around 100 μm, while at t = 20 min clumps size diminishes to 70 μm. Additionally, the activation energy declined to owe to the density of the polymeric/graphene oxide H- bond (according to the CR model, activation energy = 25.39 kJ mol−1at t = 0.0 min, while it becomes 1.11 kJ mol−1 at t = 15 min). Such a thermal and optical development could lead to promising results in optical and electrical devices industries.

Viscosity‐curing time behavior, viscoelastic properties, and phase separation of graphene oxide/epoxy asphalt composites

AbstractGraphene oxide (GO) with 0.2, 0.5, and 1.0 wt% loading was used to modify warm‐mix epoxy asphalt binders (WEABs). The thermal stability, structure of GO, rotational viscosity‐curing time performance, dynamic moduli, glass transitions, damping ability, mechanical performance, and phase‐separated morphology of GO/epoxy asphalt composites were investigated in the laboratory. GO significantly enhanced the thermal stability of the pure WEAB. X‐ray scattering analysis revealed that GO layers were delaminated in the epoxy asphalt binder. GO accelerated the cure reaction of the pure WEAB and thus resulted in higher rotational viscosity of GO/epoxy asphalt composites. Furthermore, the viscosity of the modified WEABs slightly increased in the GO content. GO increased the dynamic moduli and Tgs of both epoxy and asphalt for the pure WEAB. However, the damping ability of GO/epoxy asphalt composites was similar to that of the pure WEAB. Confocal microscopy observations revealed that GO was dispersed in both asphalt and epoxy phases of the phase‐separated WEAB. The asphalt domains in the continuous epoxy phase became more spherical and uniform with the existence of GO. Moreover, the dispersion of epoxy in the discontinuous asphalt phase became more evident. The mechanical properties of the pure WEAB were greatly improved with the addition of GO. The tensile toughness and strength of the pure WEAB increased by 31% and 33%, respectively, with the addition of 0.2 wt% GO.

The effects of graphene oxide load on the optical, structural and electrical properties of ternary nanocomposites (Polyvinyl alcohol/copper/graphene oxide) for electronic and photovoltaic application

Polyvinyl alcohol/copper/graphene oxide (PVA/Cu/GO) ternary nanocomposites films on fluorine doped tin oxide (FTO) substrate were synthesized via electrochemical deposition technique. The structural, morphological and compositional properties of the films were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Energy dispersive X-ray spectroscopy (EDX), while the Optical absorption and conductivity measurements were studied by using ultraviolet–visible (UV–vis) spectrophotometry and four-point probe techniques respectively. The XRD results revealed that the GO was dispersed uniformly in the composites. The results also revealed that the presence of GO enhanced the crystallinity of the nanocomposite films with visible characteristic peaks corresponding to indexed miller indices. Clusters of spherical shaped particles were visible in the SEM micrograph while the EDX confirmed the presences of carbon, copper, and oxygen as the major constituents of the deposited films. UV–visible analysis revealed a decrease in band gap values from 3.89 to 2.51 eV with increasing GO loading. Good absorbance in the UV region was observed at within the range of 350 to 400 nm. The nanocomposite films were found to show an increase in conductivity at low GO content as ascertained by Four-point probe analysis. The obtained results herein shows that the PVA/Cu/GO nanocomposites posses attractive physiochemical properties suitable for photovoltaic and organic electronic applications.

An investigation on thermo-mechanical performance of graphene-oxide-reinforced shape memory polymer

Abstract Based on micro morphology, a thermo-mechanical coupling model of shape memory graphene oxide/epoxy resin (SMGO/EP) was proposed. The heat transfer capability, mechanical property and shape memory ability of shape memory polymer (SMP) were further investigated. The reliability of the modeling was verified by comparing the heat transfer and shape fixation rate of the experimental and simulation data. The results showed that the maximum error of heat transfer was 6.04%, and shape fixing rate error was 2.33%. When the volume fraction of GO was 1.50 vol%, the maximum stress can reach 158.39 MPa, 46.52% higher than that of pure shape memory EP. With the increase in the volume fraction of GO in the SMGO/EP composites, the heat transfer enhancement and recovery rate of SMGO/EP were directly affected by the doping content of GO. The surface temperature of the composites with GO doping content of 1.50 vol% was 20.26°C higher than that of pure SMEP after heating for 300 s. Under the coupling effect of heat transfer and stress characteristics, the mechanism of shape memory effect of SMGO/EP composites was revealed. The thermo-mechanical coupling modeling of SMGO/EP can effectively predict the shape memory characteristics of the SMGO/EP composites.

Improvement of osteogenic properties using a 3D-printed graphene oxide/hyaluronic acid/chitosan composite scaffold

Oral and maxillofacial tumors, trauma and infections are the main causes of jaw defects, whose clinical treatment is very complicated. With the development of biological tissue engineering, many biological materials have been widely used in various fields of stomatology, and they play a very important role in the repair and replacement of maxillofacial bone defects. In this study, we intended to prepare a graphene oxide/hyaluronic acid/chitosan (GO/HA/CS) composite hydrogel with different mass ratios of GO: 0.1% (0.1% GO/HA/CS), 0.25% (0.25% GO/HA/CS), 0.5% (0.5% GO/HA/CS), and 1% (1% GO/HA/CS), prepare it into a multilayered and stable composite scaffold through 3D-printing technology, observe the surface morphology of the composite scaffold through scanning electron microscopy (SEM), and then test its physical and chemical properties, mechanical properties, water swelling rate, in vitro degradation and other material properties. Moreover, the biological performance of the GO/HA/CS composite scaffold was studied through experiments, such as cell morphology observation, cell adhesion, cell proliferation, and live-dead cell staining. The results showed that through chemical cross-linking and 3D-printing technology, a porous (pore size: 450–580 μm) and multilayered GO/HA/CS biological scaffold could be successfully constructed, and its surface was an interconnected microporous structure, and the porosity decreased (94%−40%) gradually with the increase of GO. Meanwhile, with the change in GO concentration, some mechanical properties of the scaffold could be improved, such as water swelling rate, degradation rate, and elastic modulus. In addition, the composite scaffold with the appropriate amount of GO had almost no cytotoxicity and could promote cell growth and proliferation, especially 0.25% GO/HA/CS composite scaffold. Consequently, the 0.25% GO/HA/CS composite scaffold had excellent biological material properties and good biocompatibility with osteoblasts, which may provide a new idea for the repair of jaw defects.

Electrodeposition of chitosan/graphene oxide conduit to enhance peripheral nerve regeneration

Currently available commercial nerve guidance conduits have been applied in the repair of peripheral nerve defects. However, a conduit exhibiting good biocompatibility remains to be developed. In this work, a series of chitosan/graphene oxide (GO) films with concentrations of GO varying from 0-1 wt% (collectively referred to as CHGF-n) were prepared by an electrodeposition technique. The effects of CHGF-n on proliferation and adhesion abilities of Schwann cells were evaluated. The results showed that Schwann cells exhibited elongated spindle shapes and upregulated expression of nerve regeneration-related factors such as Krox20 (a key myelination factor), Zeb2 (essential for Schwann cell differentiation, myelination, and nerve repair), and transforming growth factor β (a cytokine with regenerative functions). In addition, a nerve guidance conduit with a GO content of 0.25% (CHGFC-0.25) was implanted to repair a 10-mm sciatic nerve defect in rats. The results indicated improvements in sciatic functional index, electrophysiology, and sciatic nerve and gastrocnemius muscle histology compared with the CHGFC-0 group, and similar outcomes to the autograft group. In conclusion, we provide a candidate method for the repair of peripheral nerve defects using free-standing chitosan/GO nerve conduits produced by electrodeposition.

Hybrid polypyrrole/copper/graphene oxide nanocomposite films synthesized via potentiostatic deposition with enhanced photovoltaic properties

Novel ternary nanocomposites films of Polypyrrole/copper/graphene oxide (PPy/Cu/GO) showed enhanced optical and electronic properties. In this study, PPy/Cu/GO films were synthesized with different GO load (0.0, 0.4, 0.6, and 0.8 wt%) using electrochemical deposition technique. The structural, optical and electrical properties of the composites were evaluated using X-Ray Diffraction (XRD) spectroscopy, UV–visible spectroscopy, Scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX), and four-point probe methods. XRD results reveal that the GO was completely intercalated and dispersed uniformly in the nanocomposites. The results also revealed that the nanocomposite films are crystalline in nature, with distinct peaks corresponding to indexed miller indices. UV-visible analysis revealed that all of the nanocomposites showed good UV absorbance which was significant in the UV–Vis region of ≈450 nm. The energy band gap decreased with increase in GO load and was found within 3.46 to 2.25 eV, across the range of GO load which fall within the range of energy band gap for photovoltaic applications. The SEM results revealed that the nanocomposite films showed unevenly shaped structures with porous surface which increases with increasing GO loading, while the EDX result revealed the presence of carbon, oxygen nitrogen and copper as fundamental elements deposited. The nanocomposites' four-point probe analysis revealed slight increase in conductivity with low GO content. The incorporation of Cu and GO nanoparticles in PPy matrix provides a better balance and thus improved the photovoltaic properties of PPy/Cu/GO making them suitable for photovoltaic applications.

Synergistic effect of reduced graphene oxide and carbon black as hybrid light absorber for efficient and antifouling texture-based solar steam generator

Efficient utilization of solar energy as the cleanest and most plentiful natural resource for drinking water is a water is as sustianble and environmental friendly approach to obviate long-standing water scarcity. Carbon-based photothermal absorbers due to broadband light absorption are very interesting in interfacial solar steam generation systems. Herein, we investigate the convenient application of reduced graphene oxide (rGO) nanosheets with carbon black (CB) nanoparticles on the cotton fabric as a flexible texture-based photothermal absorber. Polyurethane (PU) as a self-floating insulator foam was selected to manage the energy loss and preserve light converted to heat on the fabric surface. The pristine cotton fabric around the foam provides continuous water supply through the capillary forces via cellulose fibers. Our reported system exhibits maximum evaporation rates and solar-thermal conversion efficiencies of 2.05, 2.09 kg.m-2h−1 and ∼ 98, 96 % for fresh and saline water, respectively. It was observed that the synergistic effect of rGO and CB caused to a reduction in the required GO concentration as a cost effective aspect. Proper washability of the treated fabrics without any visible carbonic material emersion was confirmed owing to the acceptable recyclability of more than ten cycles. The suggested platform can be used on large scale because of the simplicity in both preparation and regeneration approaches.

Bioinspired lotus fiber-based graphene electronic textile for gas sensing

Graphene electronic textiles (e-textiles) have attracted significant attention in various sensing applications owing to their strong advantages. During the fabrication of these textiles, there are factors to consider, such as electrical conductivity, mechanical flexibility, weight, and applicability in other practical applications. Bioinspired lotus fiber has appropriate advantages to be used as graphene e-textiles, including lightweight (< 1 mg), eco-friendliness, crease-resistant, pilling resistance, and flexibility. However, lotus fiber-based graphene e-textiles have not yet been reported. In this study, we developed a reduced graphene oxide‒coated lotus fiber (RGOLF) which was successfully fabricated by the hydrogen interaction between graphene flakes and cellulose fiber. The higher the GO concentration (~ 3 g/L) and fiber diameter (~ 300 μm), the higher the electrical conductivity of the RGOLF was measured. The RGOLF exhibited a higher electrical conductivity (4.63 ± 0.22 μS) and a remarkable sensing performance for hazardous NO2 gas molecules within a short exposure time (~ 3 min), including a low detection limit (~ 1 ppm), selectivity, and resistance to relative humidity. Moreover, we verified the mechanical flexibility and elasticity of RGOLF through a 1,000-cycle bending test, and tensile test, respectively. These results suggest that the bioinspired RGOLF could be used as a gas sensor in environmental air with a strong potential for use in various wearable applications.