Incorporation Of GO Research Articles

Chitosan/Guar gum – Graphene oxide porous scaffolds for tissue engineering applications

The present work investigates the influence of graphene oxide incorporation on the physio-chemical properties and biocompatibility of chitosan-guar gum based porous 3D scaffolds. In this study, a porous 3-dimensional chitosan/guar gum-GO scaffolds was fabricated by freeze drying method with different concentrations of GO (0, 0.5, 1 and 1.5 wt%). To improve their stability in the aqueous medium, the scaffolds was crosslinked using sodium tetraborate (Borax) resulting in borax crosslinked chitosan/guar gum-GO scaffolds (CGB) and characterized using FT-IR, XRD, Raman and TGA analysis. Crosslinking of the polymer matrix by borax was confirmed by FT-IR analysis, and XRD spectra shows that GO and borax incorporation did not affect the crystallinity of the polymer matrix. Increase in thermal stability was observed as the concentration of GO increased in the scaffolds. Porous morphology of the scaffold can be observed under scanning electron microscopy and the scaffolds exhibited around 60 % porosity. Irrespective of GO concentration, all the scaffolds exhibited good surface wettability and the degradation of the scaffolds slowed as the concentration of GO increased. In vitro cytocompatibility studies with Vero cells showed that both the CG and CGB scaffolds exhibited more than 90 % cell viability irrespective of GO concentration and the cell attached well on the scaffolds with GO when compared to control scaffolds. Overall, the prepared scaffold proved to be highly suitable for biological applications such as drug delivery and tissue engineering.

Photoconductivity of explosive percolation in conductive polymer/graphene oxide nanocomposite films

AbstractIn this study, we explored the behavior of protonated polyaniline/graphene oxide (PANI‐CSA/GO) nanocomposite films with varying GO concentrations, focusing on the novel phenomenon of explosive percolation. We observed a significant increase in electrical conductivity at the explosive percolation threshold, attributed to the emergence of a percolating metallic pathway. This discovery positions PANI‐CSA/GO films as promising materials for various electronic and electrical engineering applications. Additionally, the films demonstrated consistent and repeatable photoconductivity, showing potential for use in high‐performance UV‐photodetectors, photoactive layers in solar cells, light‐emitting diodes, and energy storage devices. Structural analyses using fourier transform infrared spectroscopy (FTIR) and x‐ray diffraction (XRD) confirmed successful GO incorporation within the PANI‐CSA matrix. Different morphological features were observed depending on the GO volume fraction, with increased GO enhancing thermal stability in the conductive zone. Our findings highlight the immense potential of PANI‐CSA/GO nanocomposite films in advanced electronic applications, emphasizing their novel conductive and photoconductive properties and improved thermal stability.

Preparation and properties of rGO-Co-NiO composite films: Low attenuation and high coloration efficiency

The study of electrochromic materials has far-reaching significance for the regulation of light and heat as well as the reduction of energy consumption. In this study, rGO-Co-NiO composite films were prepared by combining graphene oxide, which has excellent conductivity and stability, with Co-NiO films. The particle size, band gap, conductivity and response time of the electrochromic films were improved by precisely adjusting the component modulation amount of graphene oxide. The results show that with the incorporation of GO it is easy to form oxygen vacancies, which is conducive to ionic conduction and diffusion, in which the film with a GO doping concentration of 4 % has excellent performances in terms of response time and coloring efficiency, and the response time is reduced from 10.2 to 5.8 seconds, and it still possesses 57.25 % of the light modulation amplitude after 600 cycles, of which the attenuation rate is only 2 % for the period from 100 to 600 cycles, The coloring efficiency after 100 cycles is 48.21 cm2/C. In summary, the investigated rGO-Co-NiO composite films have a broad potential for future application in electrochromic devices.

Effect of Gelatin Coating and GO Incorporation on the Properties and Degradability of Electrospun PCL Scaffolds for Bone Tissue Regeneration.

Polymer-based nanocomposites such as polycaprolactone/graphene oxide (PCL/GO) have emerged as alternatives for bone tissue engineering (BTE) applications. The objective of this research was to investigate the impact of a gelatin (Gt) coating on the degradability and different properties of PCL nanofibrous scaffolds fabricated by an electrospinning technique with 1 and 2 wt% GO. Uniform PCL/GO fibers were obtained with a beadless structure and rough surface. PCL/GO scaffolds exhibited an increase in their crystallization temperature (Tc), attributed to GO, which acted as a nucleation agent. Young's modulus increased by 32 and 63% for the incorporation of 1 and 2 wt% GO, respectively, in comparison with neat PCL. A homogeneous Gt coating was further applied to these fibers, with incorporations as high as 24.7 wt%. The introduction of the Gt coating improved the hydrophilicity and degradability of the scaffolds. Bioactivity analysis revealed that the hydroxyapatite crystals were deposited on the Gt-coated scaffolds, which made them different from their uncoated counterparts. Our results showed the synergic effect of Gt and GO in enhancing the multifunctionality of the PCL, in particular the degradability rate, bioactivity, and cell adhesion and proliferation of hGMSC cells, making it an interesting biomaterial for BTE.

Fe-MOFs/graphene oxide-derived magnetic nanocomposite for enhanced adsorption of As(V) in aqueous solution

The urgent need to remove arsenic from groundwater stems from the irreversible damage it causes to aquatic systems and biological health. In this study, unique magnetic Fe3O4/graphene oxide (GO) nanocomposites derived from MIL-100(Fe)/GO precursor were rationally and precisely developed by combination of solvothermal synthesis and pyrolysis methods. The optimized MIL-100(Fe)/1%GO-400 magnetic nanocomposite (where 1% and 400 represent the mass ratio of GO to MIL-100(Fe) and pyrolysis temperature, respectively) exhibited exceptional adsorption capacity for As(V) and possessed magnetic separation properties. The novel nanocomposite had complete MOF morphology and crystal structure, as well as good resistance to interference from ions and could be used effectively over a wide pH range (2–9) for adsorption of As(V). The As(V) adsorption on the nanocomposite was found to follow the pseudo-second-order (PSO) kinetic model and Temkin adsorption isotherm model, as well as a spontaneous endothermic process dominated by chemisorption. The incorporation of GO and pyrolysis of the Fe-MOFs was proven to enhance the adsorption capacity of nanocomposite, water stability, and magnetic recovery ability. The adsorption mechanism was attributed to the synergistic effect of chemical complexation, hydrogen binding and electrostatic interaction. This work not only presents a feasible strategy for the development of Fe-MOFs-based derivatives, but also offers a promising approach to expanding the application of functional Fe-MOFs-based derivatives in arsenic-contaminated wastewater treatment.

Comprehensive anti-corrosion study of electrodeposited graphene oxide-alumina composite with nickel matrix in NaCl solution

In this work, a matrix of nickel composite coating is embedded with graphene oxide and alumina. This work developed a matrix of nickel composite coating embedded with graphene oxide and alumina (GO-Al2O3) at various concentrations using an electrodeposition process. Fourier transforms infrared spectroscopy (FTIR) and Energy-dispersive X-ray spectroscopy (EDAX) confirmed further incorporation of GO and GO-Al2O3 within nickel coating. The calculated crystal size of the nickel coating was 19.46 nm; however, it reduced to 11.58 nm in the Ni-GO-Al2O3 (1.5 g/L) coating. The surface morphology of Ni-GO-Al2O3 coating using Field emission Scanning electron microscopy (FE-SEM) showed fine grain size; however, nickel had cubic-shaped crystals and was significantly larger. Contact angle measurements reveal the hydrophobic characteristic of the Ni-GO-Al2O3 coating, which was 110.8° compared to nickel (71.4°). Tafel and electrochemical impedance showed maximum polarization resistance for Ni-GO-Al2O3 (1.5 g/L) coating. The developed Ni-GO-Al2O3 coating was put through short, long-term immersion tests and showed less weight loss than Ni and Ni-GO coating. pH change was the least for Ni-GO-Al2O3 coating due to its compact shape, which prevented the transport of corrosion-causing ions to the metal and consequently reduced metal oxidation. Ni-GO-Al2O3 coating shows the least blue spot, indicating negligible rupture after immersion. Atomic force microscopy study revealed that Ni-GO-Al2O3 has a smoother surface, which did not significantly change even after immersion. Nickel coating showed cracks, producing high corrosion products and more pits, showing its inability for long-term inhibition; however, Ni-GO-Al2O3 coating with the least cracks and pits showed negligible corrosion products on its surface even after one month of exposure. Fe and O are higher in Ni and Ni-GO after immersion and least in Ni-GO-Al2O3, making it more protective. Compared to pure Ni coatings, the composite coating electrode containing 1.5 g/L of GO-Al2O3 had the best corrosion resistance due to the abovementioned characteristics.

Perovskite Type B-CaTiO3 Coupled with Graphene Oxide as Efficient Bifunctional Composites for Environmental Remediation

To prepare boron doped perovskite CaTiO3 nanocubes coupled with graphene oxide (B-CaTiO3/GO), B-CaTiO3 photocatalyst was initially synthesized by the solvothermal method and subsequently attached on GO by a simple hydrothermal process. The phase structure and optical features of the prepared materials were efficiently characterized by several techniques. The XRD patterns indicated that boron doping could not give rise to lattice disruption of CaTiO3. The results of XPS, HRTEM and Raman measurements revealed that the presence of B-CaTiO3 is anchored on the surface of GO effectively. The morphology of the B-CaTiO3/5GO was nanocube particles. The photocatalytic capacity of B-CaTiO3/GO nanocomposites was determined by investigating the degradation of a model dye, methylene blue (MB). Their degradation performance could be enhanced by altering the ratio between B-CaTiO3 and GO. The most effective GO incorporation is 5 wt%, and at this loading percentage, B-CaTiO3/GO nanocomposite showed improved photocatalytic activity compared with CaTiO3 and B-CaTiO3 photocatalyst, which could be attributed to the synergistic efficacy of the adsorbed MB molecule on the GO followed by their degradation after 180 min of visible light. Additionally, the active species trapping tests confirm the dominant role performed by ·OH and O2·− during the degradation of MB. The presence of HCO3− and Cl− indicated moderate prohibitive effect on the degradation of MB, while NO3− and SO42− negatively affected the catalytic activity in a non-significant way. In brief, the results of this study show that boron doped perovskite-type semiconductor catalysts by combining with graphene has significant efficiency in the removal of MB from aqueous solution, which can be employed as effective photocatalyst materials for the treatment of other organic pollutants.

Fabrication and characterization of biomimetic plant cuticles from pullulan - graphene oxide (PU-GO) and beeswax - stearic acid (BW-SA) for Citrus Limon Rosso preservation

Inspired by the natural plant cuticles, a novel strategy was proposed for the fabrication of biomimetic plant cuticles from pullulan-graphene oxide (PU-GO) and beeswax-stearic acid (BW-SA), which could serve as hydrophilic polysaccharides and hydrophobic waxes, respectively. PU-GO and PU-GO/BW-SA in different GO concentrations (0, 10, 30 and 50 μg/mL) were prepared, and their structural characteristics and basic properties were investigated. Results showed that PU-GO/BW-SA possessed a hydrophilic layer and a hydrophobic structure similar to the structure of natural plant cuticles. The incorporation of GO enhanced the barrier properties of the films and PU-GO/BW-SA showed a higher contact angle, lower tensile strength and higher barrier properties compared with PU-GO. In addition, PU-GO/BW-SA in 10 μg/mL GO concentration (PU-GO10/BW-SA) possessed the lowest WVP (7.2 × 10−7 g/(m h Pa)) and a contact angle (93.78°) similar to natural plant cuticles. Applications in Citrus Limon Rosso further proved the potential of PU-GO10/BW-SA as a biomimetic plant cuticle in fruit preservation.

A novel self-supportive thin film based on graphene oxide reinforced chitosan nano-biocomposite for thin film microextraction of fluoxetine in biological and environmental samples

In this research, for the first time, graphene oxide doped chitosan (GO/CS) nano-biocomposite (NBC) is designed and prepared as a novel self-supportive thin layer for thin film microextraction (TFME) of fluoxetine (FLX) followed by determination applying HPLC-UV-Vis. The properties of the prepared self-supportive thin film were characterized applying ATR-FTIR, FESEM, and XRD techniques. The extraction capability of GO/CS NBC toward FLX has been evaluated, and the obtained results revealed that incorporation of GO into CS has led to higher extraction efficiency in comparison to the CS thin film. After optimizing the effective factors on the extraction efficiency, the figures of merit for the developed method have been evaluated for determination of FLX in various samples. Accordingly, the method’s linearity is in the range of 0.4–800 ng mL−1 (R2 = 0.996), 4–1000 ng mL−1 (R2 = 0.994), 4–1000 ng mL−1 (R2 = 0.990), and 6–1000 ng mL−1 (R2 = 0.993) for deionized water, wastewater, urine and plasma samples, respectively. The limits of detection based on 3 S/N definition was 0.1, 1, 1 and 1.6 ng mL−1 for deionized water, wastewater, urine, and plasma samples, respectively. The repeatability of the developed method has been investigated in the term of intra-day, inter-day and inter-thin film precision and RSD% values for six replicate experiments were obtained 8.6%, 8.4% and 5.7%, respectively. The accuracy of the developed method has been investigated by extraction of FLX from spiked wastewater, plasma and urine samples and the relative recoveries of 104.4%, 87.3% and 82.4% have been resulted, respectively.

A sustainable route for production of graphene oxide-contained nanostructured carbons from rice husk waste and its application in wastewater treatment

Agricultural biomass, such as rice husk (RH), is a renewable source of bioenergy. However, a large amount of RH ash (RHA) is generated after the thermal conversion of RH. The main component of RHA is silica (>85 wt%). This study used recyclable RHA as a mesoporous SBA-15 template source. Next, ordered mesoporous carbon/ graphene oxide (RH-CMK-3/GO) composites were synthesized through the direct carbonization of GO, sucrose, and an SBA-15 template. Experimental data demonstrated that GO was successfully conjugated on the surface of CMK-3. The RH-CMK-3/GO exhibited a highly ordered mesostructure, which was not affected by the incorporation of GO. Compared with bare RH-CMK-3, the RH-CMK-3/GO had an enhanced surface area and pore volume. The composite exhibited a highest pore volume of 1.143 cm 3/g, a surface area of 1138 m2/g, and a pore diameter of 3.68 nm. The RH-CMK-3/GO revealed a higher ability for the adsorption of rhodamine B (RhB) than did the SBA-15, SBA-15/GO, and pure CMK-3 materials. The removal of RhB increased with increases in the composite dosage, solution pH and temperature, and carbonization temperature and time and a decrease in the initial RhB concentration. Moreover, the RH-CMK-3/GO exhibited a highest removal efficiency of 100%. The thermodynamics, kinetics, and isotherm adsorption data for the RH-CMK-3/GO composite exhibited satisfactory fitting for the endothermic, pseudo-second-order, and Langmuir models, respectively. Moreover, the composite exhibited good reusability. These results suggest that RHA can be effective for the fabrication of valuable mesoporous carbon nanocomposites and the elimination of organic contaminants from wastewater.

Development of chitosan-graphene oxide blend nanoparticles for controlled flurbiprofen delivery

The use of natural polymeric nanoparticles (Nps) as drug carriers is a highly promising area of research in the field of drug delivery systems because of their high efficiency. In this study, flurbiprofen (FB) loaded chitosan-graphene oxide (CS-GO) blend Nps were synthesized as a controlled delivery system using the emulsion method. The crystalline, molecular, and morphological structures of the prepared CS-GO Nps were characterized using a variety of analytical methods, including Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-Ray diffractometry (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM). It was found that the introduction of GO into the CS nanoparticle formulation increased its thermal stability. The range of the average particle size was between 362 ± 5.06 and 718 ± 2.21 nm, with negative zeta potential values between −7.67 ± 4.16 and − 27.93 ± 2.26 mV. The effects of the CS/GO ratio, the FB/polymer ratio, the amount of span 80, and the cross-linker concentration were assessed on FB release profiles. In vitro release studies displayed a two-stage release behaviour with a fast initial release of the FB, followed by sustained and extended release, and the incorporation of GO into the CS Nps made the FB release more sustained and controlled manner. Besides, the cytotoxicity test of the FB-loaded CS-GO Nps was studied through MTT assay, and it was found that they were biocompatible. Based on these findings, it can be inferred that the prepared CS-GO Nps might be a promising candidate drug carrier system for FB.

Graphene oxide incorporation in Ag-doped ZnO nanocomposite as efficient electron extraction material for planar perovskite solar cells

The hybrid metal halide perovskite solar cells have emerged as potential contenders in the photovoltaic market owing to their exceptional optoelectronic properties. Zinc oxide (ZnO) is a reasonable option for an electron extraction layer (EEL) in perovskite solar cells due to its wide band gap, energy band alignment with the absorber layer, and ease of production. Spincoating suspensions of ZnO nanocomposites EELs at lower temperatures (110 °C) employed in regular planar triple cation perovskite solar cells. The impact of Ag doping and GO incorporation in ZnO was studied in detail to get insights into the photovoltaic performance of PSC. Due to the inclusion of GO and Ag in ZnO, a significant enhancement in photovoltaic performance was observed and the target GO-Ag-ZnO EEL-based PSC exhibited PCE of 8.72 % which was found almost 16 % higher than pristine ZnO EEL-based PSC. We attribute the enhanced photovoltaic performance to the superior electron transport/extraction facilitated by the inclusion of graphene layers. This improvement can also be linked to the superior quality of the perovskite thin film employed in the study.

Preparation of hydrophobic and fire-retarding poly(lactic acid)/graphene oxide foams for oil/organic solvents absorption

Petroleum leakage, oil spill and toxic organic solvent emissions have become a global water contamination issue. To solve this problem, it is a promising solution to develop a simple and green strategy to prepare environmentally friendly and high absorption capacity absorbents from biodegradable polymers. Herein, in this work, PLA was used as the matrix to prepare the foam absorbent. Firstly, the flame retardant methoxy-phosphonitrilic trimer (HEPCP, FR) was synthesized. Then PLA composite foams were produced by melting PLA with FR, and mixing with GO through a freezing-dry method. The results showed that FR-PLA/5GO foam self-extinguished immediately when removing the ignition source, due to the fact that the incorporation of GO further improve the fire retardancy of FR-PLA foam. The porosity and the water contact angle of FR-PLA/5GO were gradually increased up to 94.0% and 127.4°, showing a lightweight, highly hydrophobic and homogeneous pore structure. Then the FR-PLA/5GO foam was used as the oil/organic solvent absorbent, which reached the saturated adsorption capacity within 10 s due to the high hydrophobicity and porosity. Meanwhile, the absorbent showed good recyclability, and the FR-PLA/5GO foam still maintained > 75.0% of its original capacity after 10 cycles of the evaporation−adsorption procedure. This work provides a method for developing a biodegradable absorbent for the oil/organic contaminant.

Tin Oxide-Graphene Oxide (SnO2/GO) Nanocomposite: A Promising Photocatalyst for Rhodamine-B Dye Degradation

Appropriate wastewater treatment methods for effectual and practical decontamination of wastewater bodies is the prime goal of today’s environmentalists and industrialists. Herein, sunlight driven photocatalytic degradation of rhodamine-B (RhB) has been investigated by employing hydrothermally synthesized tin oxide-graphene oxide (SnO2/GO) nanocomposite. Physiochemical characterization of composite has been accomplished via X-ray diffraction (XRD) analysis, ultraviolet (UV) spectroscopy, diffused reflectance spectroscopy (DRS) and photoluminescence (PL). Photocatalytic degradation of RhB is studied using UV light and spectrophotometer. SnO2-GO nanocomposite degraded the RhB dye in 120 min comparatively in quite lesser time than separate SnO2 and GO degradation performances. The incorporation of GO into SnO2 decreases the rate of electron–hole recombination, increases the oxidation of carriers as well as the rate of carrier separation owing to the synergistic impact of GO and SnO2. Therefore, an affordable graphene oxide supported SnO2 nanocomposite can be implicated as efficacious real wastewater treatment method at industrial scale.

Antibacterial, biocompatible, hemostatic, and tissue adhesive hydrogels based on fungal-derived carboxymethyl chitosan-reduced graphene oxide-polydopamine for wound healing applications

In this study, we developed biocompatible, fungus-derived carboxymethyl chitosan (FCMCS)–reduced graphene oxide (rGO)-polydopamine (PDA)-polyacrylamide (PAM) (FC-rGO-PDA) hydrogels with excellent antibacterial, hemostatic, and tissue adhesive properties for wound healing applications. FC-rGO-PDA hydrogels were prepared by the alkali-induced polymerization of DA followed by the incorporation of GO and its reduction during the polymerization AM to form a homogeneously dispersed PAM network structure in FCMCS solution. The formation of rGO was verified using UV–Vis spectra. The physicochemical properties of hydrogels were characterized by FTIR, and SEM, water contact angle measurements, and compressive studies. SEM and contact angle measurements showed that hydrogels were hydrophilic with interconnected pores and a fibrous topology. In addition, hydrogels adhered well to porcine skin with an adhesion strength of 32.6 ± 1.3 kPa, . The hydrogels exhibited viscoelastic, good compressive (77.5 kPa), swelling, and biodegradation properties. An in vitro study using skin fibroblasts and keratinocytes cells showed the hydrogel had good biocompatibility. Testing against two model bacteria, viz. Staphylococcus aureus and E. coli revealed that the FC-rGO-PDA hydrogel has antibacterial activity. Furthermore, the hydrogel exhibited hemostasis properties. Overall, the developed FC-rGO-PDA hydrogel has antibacterial and hemostasis properties, high water holding capacity, and excellent tissue adhesive properties, which make it a promising candidate for wound healing applications.

Hydrothermal synthesis of GO/ZnO composites and their micromorphology and electrochemical performance

In this study, a graphene oxide/zinc oxide (GO/ZnO) composite was synthesized by the one-pot hydrothermal technique using various GO/ZnO ratio compositions. These were characterised by scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) and Raman spectroscopy. The findings reveal that the GO/ZnO composite has three different micromorphologies: ZnO-nanorods (ZnO-NRs) were embedded and agglomerated over the GO surface; ZnO-microrods (ZnO-uRs) adhered to and separated on the GO surface; and GO was coated by ZnO at 1:1, 1:2 and 1:8 ratios. In addition, the electrochemical performance of the synthesized GO/ZnO composites was investigated using cyclic voltammetry (CV). The results show that the embedded and agglomerate of ZnO-NRs over the GO surface have the best performance, indicated by a larger CV curve area and higher specific capacitance than the GO and other GO/ZnO composites. The results indicate that the incorporation and insertion of GO and ZnO NRs have an effective reversible nature and are promising electrode materials for supercapacitor applications.

Microwave-induced growth of {[formula omitted]} faceted zinc oxide/graphene 2D/2D nanostructures for visible-light photocatalysis and hydrogen evolution reaction

The future hydrogen economy urges to replace platinum-based catalysts since large-scale production of hydrogen using platinum is not economically viable to deal with the influx of interest. Developing cost-effective, durable, and efficient catalysts is one of the most relevant research frontiers. Herein, interconnected and {101̅0} faceted 2D zinc oxide decorated on graphene sheets was effectively fabricated by a simple CTAB-assisted microwave technique and has been intensively investigated for photocatalytic dye degradation and electrocatalytic hydrogen evolution. The XRD and Raman spectra confirm the in-situ reduction of GO to rGO and successful synthesis of ZnO/rGO hybrids. Compared with the pure ZnO, as-obtained ZnO/rGO hybrids exhibited good stability and superior photocatalytic efficiency under visible-light irradiation, owing to reduced electron-hole pair recombination upon GO incorporation, as affirmed by PL spectra, TRPL lifetime measurements, and photocurrent responses. The 2D/2D ZnO/rGO hybrid nanostructure showed optimised material properties for exceptional electrochemical H2 evolution, producing a current density of − 10 mA/cm2 at a significantly reduced overpotential of − 810 mV vs. RHE, and a Tafel slope of 157 mV/dec in 0.5 M H2SO4. The enhanced catalytic activity can be attributed to the introduction of rGO sheets, which improved the surface area and electrical conductivity of the sample. The multifunctional nature of ZnO/rGO hybrids in both photocatalysis and electrocatalysis sheds light upon environmental pollution and the energy crisis.

Design and fabrication of polyvinylidene fluoride-graphene oxide/gelatine nanofibrous scaffold for cardiac tissue engineering

Polyvinylidene fluoride (PVDF) electrospun scaffolds have recently been developed for cardiac tissue engineering applications thanks to their piezoelectricity. However, PVDFs’ hydrophobic nature requires modifications by incorporating natural polymers. In this study, we focussed on the hybrid electrospinning of PVDF and gelatine and the further introduction of graphene oxide nanoparticles to investigate either hydrophilicity or piezoelectricity enhancement and its impact on mouse embryonic cardiomyocytes. The results revealed a nanofibre diameter of 379 ± 73 nm for the PVDF/gelatine/graphene oxide (PVDF-GO-CG) platform, providing excellent tensile strength. Additionally, hydrophilicity was improved by gelatine and GO incorporation compared with pure PVDF. Cellular studies also showed an elongated morphology of cardiomyocytes, similar to the myocardial tissue, as well as high viability and non-toxicity in the PVDF-GO-CG scaffold according to the average survival rate. Furthermore, the expression of connexin 43 and troponin T genes underwent an increment of 41 and 35% in the PVDF-GO-CG compared with the PVDF-CG sample. This study proves the applicability of the PVDF-GO-CG scaffold as an alternative substrate for developing engineered cardiac tissues by providing an environment to re-establish their synchronised communications.

An experimental study on micro-structure and hardened properties of ultra-high strength self-compacting concrete by incorporating Graphene Oxide

The modern material in the rapidly expanding building sector is ultra high strength self-compacting concrete (UHSSC). There are several ways to make UHSSC, but one of the best ways is by employing graphene oxide to improve the microstructure of cement (GO). GO is a cutting-edge nanomaterial that excelled in a number of disciplines. This study examines the microstructure and toughened characteristics of UHSSC with GO incorporation. Improved GO dispersion in the concrete is achieved by using silica fume (10% cement weight), while better pore structure and resistance to chloride penetration are achieved by using GGBS (30% cement weight). To achieve UHSSC, GO is added to cement at concentrations of 0.25, 0.5, 0.75, 1.0, and 1.25% by weight of cement. EDS (Energy dispersive x-ray spectroscopy) technique is used to determine the crystalline properties of GO nanomaterial and SEM (Scanning electron microscope) is used to determine the microstructure of the GO incorporated UHSSC.

Photoelectrical and thermal sensing measurement of spin coated ZnO and ZnO-RGO thin film

This research reported the synthesis of ZnO and ZnO-RGO as well as their photo sensing and thermal sensing properties. This is with a view to reducing the electron hole recombination in ZnO and improving the sensing properties. ZnO and ZnO-RGO were synthesized by the hydrothermal method and spin coated on glass to obtain the thin film. The SEM micrograph of ZnO-RGO showed mini ZnO nanorods decorated and formed on the RGO sheet. The adherence of the nanorods were improved as the loading mass of GO increased in the hybrid. Though ZnO and ZnO-RGO had comparable thermal sensing response of 2.8 and 3.1 respectively at 573 K, ZnO-RGO showed improved electrical conductivity as temperature increased. ZnO sensors logged a negative temperature coefficient (NTC) value of 0.00236/K and a sensitivity value of 0.0139 Ω/K while ZnO-RGO had a NTC value of 0.00248/K (which is higher than values obtained in literature for silver and palladium based graphene hybrids) and a sensitivity value of 0.00769 Ω/K. A value of 0.0561eV was obtained for the activation energy of ZnO sensor while 0.0615eV was obtained for ZnO-RGO. For the photo sensing, incorporation of GO into ZnO decreased the band gap at peak wavelength of ZnO-RGO to 2.48 eV from 3.1 eV for ZnO and improved the photoconductivity to the order of 106 Ω. This research has confirmed that incorporating GO in ZnO increased the activation energy of ZnO-RGO thermistor, and consequently increased the thermal sensing response thus resulting in improved thermal and photo sensing properties of ZnO. With an improved NTC, sensor response and activation energy, ZnO-RGO can replace Pd based RGO and Ag nanoparticles based RGO as thermistors.