Incorporation Of Graphene Oxide Research Articles

Magnetically separable and visible light-driven photocatalytic activity of graphene oxide based α-Fe2O3 nanocomposite

This work investigates the impact of graphene oxide (GO) on the structural, morphological, optical, and photocatalytic investigations of Fe2O3, an excellent photocatalyst for industrial wastewater treatment. Using the straightforward and inexpensive sol-gel auto-combustion, hummer's method and sonication method, Fe2O3 nanoparticle (NPs), GO nanosheet, and GO-based Fe2O3 (GO/Fe2O3) nanocomposite have been synthesized, respectively. The XRD patterns, Raman spectra, and FTIR spectroscopy were used for the structural analysis, which verifies the single phase hexagonal geometry of Fe2O3 NPs. The average size of the crystallites is seen to have reduced from 50 nm to 44 nm for Fe2O3 and GO/Fe2O3. The SEM along with EDS were applied to investigate the surface morphology and confirm the existence of the elements Fe and O in pure Fe2O3, and C, Fe and O in GO/Fe2O3. From UV–vis absorbance spectra, the decrease in optical band gap (2.5 eV–1.9 eV) caused by GO incorporation has been inferred, as clearly displayed in the Tauc plots. X-ray photoelectron spectroscopy (XPS) confirms the presence of Fe2+/Fe+3 ionic states and large oxygen vacancies in the GO/Fe2O3 nanocomposite. The photocatalytic properties of both materials for the toxic MB (methylene blue) dye photodegradation in an aqueous solution was evaluated while being exposed to sunlight. It makes an excellent choice for wastewater treatment due to the high photocatalytic activity of magnetically separable GO/Fe2O3 nanocomposite for decomposing the MB dye.

Preparation and sustained-release mechanism of hydroxybutyl chitosan/graphene oxide temperature-sensitive hypoglycaemic subcutaneous implants

The current situation of diabetes prevention and control is extremely severe. For instance, glimepiride (GLM), a third-generation sulfonylurea, demonstrates suboptimal clinical efficacy in oral dosage forms, which underscores the pressing need for the development of a new dosage form. Recently, in situ gel subcutaneous implants have garnered considerable attention. Hydroxybutyl chitosan (HBC) can spontaneously crosslink to form a thermosensitive hydrogel and has good biocompatibility. However, its application is hindered by its limited mechanical properties. Graphene oxide (GO), known for its stable dispersion in water, can load GLM through π–π stacking interactions. When combined with HBC, GO enhances the mechanical properties and stability of the hydrogel. Therefore, an HBC–GO@GLM hydrogel was prepared. Rheological analysis revealed that the incorporation of GO increased the critical gelation temperature of the 5 wt% HBC hydrogel from 19.1°C to 27.2°C, considerably enhancing the mechanical properties of the hydrogel. Using encapsulation efficiency as an evaluation index, the optimal encapsulation efficiency of GO@GLM was determined to be 73.53% ± 0.45% with a drug loading capacity of 27.39 ± 0.17% using the Box–Behnken design model. Computer simulation technology validated the interaction between the materials and the drug release mechanism. Pharmacokinetic results showed that compared to the HBC@GLM group, the half-life (t1/2), mean residence time and the area under the curve for the HBC–GO@GLM group were approximately 3 times those of the HBC@GLM group. Subcutaneous implantation of the HBC–GO@GLM hydrogel for drug delivery considerably extended the drug’s action time in the body, thereby maintaining blood sugar levels within a normal and stable range for an extended period.

Incorporation of graphene oxide in the layer-by-layer self-assembly of polyacrylic acid and poly(diallyldimethylammonium chloride) to fabricate nanocomposite membrane for forward osmosis

In this study, polyacrylic acid (PAA) and poly (diallyldimethylammonium chloride) (PDDA) were self-assembly on the surface of hydrolyzed polyacrylonitrile membrane. Graphene oxide (GO) was embedded on the membrane through dispersing it on either PAA or PDDA solution. The presence of GO in the composite membrane made the surface morphology become rougher than that of the pristine membrane. In addition, the membrane maintained hydrophilic with improved surface electronegativity. During the performance evaluation (1 M Na2SO4 as draw solution, and pure water as feed), the membrane prepared with GO in PAA solution had the highest separation efficiency. Because GO facilitates the strong electrostatic interaction between PAA + GO with PDDA, resulting in a dense selective layer. At optimum concentration of GO in PAA with a bilayer, the composite membrane exhibited a water permeation flux of 16 LMH and a salt reverse diffusion of 22.3 gMH. Using different types of salts (Na2SO4, NaCl, MgSO4, MgCl as draw solution), the composite membrane confirmed that it was a nanofiltration-forward osmosis like type of membrane, giving a high separation efficiency for a draw solution of Na2SO4.

Rheological and Flexural Strength Characteristics of Cement Mixtures through the Synergistic Effects of Graphene Oxide and PVA Fibers.

This study investigates the synergistic effects of incorporating graphene oxide (GO) and polyvinyl alcohol (PVA) fibers into cement paste mixtures, aiming to modify their rheological properties and flexural behaviors with resistance to crack formation. The relationship between static yield stress and critical shear strain was examined in ten cement paste mixtures with varying concentrations of 6 mm and 12 mm PVA fibers and 0.05% GO. Additionally, viscosity analyses were performed. For the specimens fabricated from these mixtures, flexural strength tests were conducted using the Digital Image Correlation (DIC) technique for precise strain analysis under load history. The results indicated a significant increase in static yield stress, viscosity, and critical shear strain due to the combined addition of GO and PVA fibers, more so than when added individually. Notably, in PVA fiber-reinforced cement mixtures, the integration of GO increased the crack initiation load by up to 23% and enhanced pre-crack strain by 30 to 50%, demonstrating a notable delay in crack initiation and a reduction in crack propagation. Microstructural analyses using Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS) revealed a concentrated presence of GO around and on the PVA fibers. This promotes increased C-S-H gel formation, resulting in a denser microstructure. Additionally, GO effectively interacts with PVA fibers, enhancing the adherence of hydration products at their interface.

Carbonation of Shale Ceramsite High-Strength Lightweight Concrete Incorporating Graphene Oxide

The growing demand of concrete for improving durability has stimulated extensive research on graphene oxide (GO). Carbonization, as an irreversible deterioration, should be paid more attention to high-strength lightweight concrete (HSLWC) with the characteristics of porous structure. In this study, the effect of different low content of GO on the carbonation depth of HSLWC made from shale ceramsite was experimentally investigated. Subsequently, the effect of GO on pore distribution of HSLWC was analyzed. Four groups of grade 60 HSLWC were designed for comparative experiments, in which 0.00%, 0.01%, 0.03% and 0.05% (by weight of cement) GO were added, respectively. The results indicated that GO could effectively reduce the carbonization depth of HSLWC. When GO content was 0.05%, the carbonization depth was reduced by approximately 23%. The main reason was that GO not only reduce the total porosity but also refine the pores, thus improving the carbonization resistance of HSLWC.

Study of mechanical property and biocompatibility of graphene oxide/MEO2MA hydrogel scaffold for wound healing application.

Wound healing is a complex biological process crucial for restoring tissue integrity and preventing infections. The development of advanced materials that facilitate and expedite the wound-healing process has been a focal point in biomedical research. In this study, we aimed to enhance the wound-healing potential of hydrogel scaffolds by incorporating graphene oxide and poly (ethylene glycol) methyl ether methacrylate (MEO2MA). Various masses of graphene oxide were added to MEO2MA hydrogels via free radical polymerisation. Comprehensive characterizations, encompassing mechanical properties, and biocompatibility assays, were conducted to evaluate the hydrogels' suitability for wound healing. In vitro experiments demonstrated that the graphene oxide-based hydrogels exhibited a proper swelling degree and tensile strength, responding effectively to moisture conditions and adhesiveness for wound healing. Notably, the tensile strength significantly increased to 626 kPa in the graphene oxide hydrogels. Biocompatibility assessments revealed that the graphene oxide/MEO2MA hydrogels were non-toxic to human dermal fibroblast cell growth, with no significant difference in cell viability observed in the graphene oxide/MEO2MA hydrogel (H-HG) group. In a rat skin experiment, the wound-healing rate of the hydrogel incorporating graphene oxide surpassed that of the pristine hydrogel after a 15-day treatment, achieving over 95% wound closure in the H-HG group. The histopathological analysis further supported the efficacy of the H-HG hydrogel dressing in promoting more effective tissue regeneration. These results collectively highlight the potential of the graphene oxide/MEO2MA hydrogel scaffold as a promising dressing for medical applications.

Development of biodegradable nanofiber filters based on surface-modified cellulose nanofibers with graphene oxide for high removal of airborne particulate matter

Airborne particulate matter is a pressing environmental and public health concern globally. This study aimed to develop sustainable filtration materials from cellulose nanofibers (CNFs) modified with graphene oxide (GO) to capture fine particulates from air effectively. CNFs were extracted from α-cellulose via mechanical grinding and modified with 0.5–1.5 wt% GO solution by ultrasonication to produce CNF-GO nanocomposites. These were freeze-dried into highly porous, lightweight aerogels for air filtration applications. Fourier transform infrared spectroscopy (FT-IR) confirmed GO incorporation through hydroxyl group interactions. Field emission scanning electron microscopy (FE-SEM) revealed a porous 3D network with reduced porosity after GO addition due to pore blocking. X-ray diffraction analysis showed the cellulose I crystal structure was retained after modification. Brunauer-Emmett-Teller (BET) measurements indicated increased density but decreased surface area and pore volume with GO loading. The thermogravimetric analysis demonstrated improved thermal stability with GO incorporation due to oxidative reactions and a barrier effect. The particulate absorption efficiency markedly increased from 86.37 % to 99.98 % for CNFs modified with 1.5 wt% GO due to the high surface area, surface oxygen functionalities, and nanoplatelet morphology of GO. The nanofiber filters with 1.5 wt% GO exhibited a maximum absorption efficiency of 99.98 % and a quality factor of 0.0912 Pa−1. Although GO reduced biodegradability, substantial degradation occurred under soil conditions. Overall, the sustainable, high-efficiency CNF-GO air filters developed in this work demonstrate immense promise for controlling air pollution and protecting human health.

Electron beam radiation constructed and improved bone repairing performance based on hierarchical thermoplastic polyurethane/graphene oxide/hydroxyapatite hot melt adhesive with high flow ductility

AbstractThe aging population increased the demand for the development and utilization of bone filling materials. In this study, hydroxyapatite (HAP) and graphene oxide (GO) were introduced into thermoplastic polyurethane (TPU) by melt mixing and electron beam radiation to obtain the new hot melt adhesive (TPU/HAP/GO). The structures and morphologies of the TPU/HAP/GO were analyzed using FTIR, XRD, SEM, BET, DSC. The mechanical properties of the TPU/HAP/GO were evaluated using a universal testing machine. TPU/HAP/GO was demonstrated to have good bacterial inhibition by the zone of inhibition test and plate method. The good biocompatibility of the hot melt adhesive was demonstrated using the MTT method and the Hoechst 33342/PI double staining method. The osteogenic differentiation of mouse osteoblasts (MC3T3‐E1) treated with TPU/HAP/GO was detected by alkaline phosphatase (ALP) staining. ALP staining showed that the hot melt adhesive promoted the differentiation of MC3T3‐E1 cells into osteoblasts. This hot melt adhesive had great application potential in bone tissue engineering.Highlights Green electron beam radiation method for synthesizing hot melt adhesives. Enhanced mechanical properties of composites by incorporation of graphene oxide. Improvement of antimicrobial and osteogenic capacities for polyurethane.

Nanofabrication of chitosan-based dressing to treat the infected wounds: in vitro and in vivo evaluations.

Aim: Here, an innovative kind of antibacterial nanocomposite film is developed by incorporating graphene oxide and zinc oxide into chitosan matrix. Materials & methods: Our dressing was fabricated using the solution casting method. Fourier transform infrared spectra and TGA-DTG clearly confirmed the structure of film dressing. Results & conclusion: Our results showed the tensile strength and elongation at the break of the films were 20.1±0.7MPa and 36±10%, respectively. Our fabricated film could absorb at least three-times thefluid of its dry weight while being biocompatible, antibacterial, non-irritant and non-allergic. In addition, it accelerated the healing process of infected wounds by regulating epithelium thickness and the number of inflammatory cells, thus it may be useful for direct application to damaged infected wounds.

Design and development of graphene oxide/shape memory nanocomposite based on hexamethylene diisocyanate mixing segment

AbstractShape memory polymers are remarkable materials renowned for their distinctive ability to fix and recover their original shape in response to specific stimuli. However, the lower shape fixity (SF) of conventional thermally triggered shape memory polyurethane (SMPU) has limited its broad application potential. This study investigates the transformative influence of graphene oxide (GO) nanofillers when incorporated into a linear diisocyanate‐based mixing segment SMPU (SMPU‐GO). The lower SF issue of SMPU is ingeniously addressed by leveraging the interactive properties of GO with the 4,4′‐methylene bis‐phenyl diisocyanate hard segment and the introduction of additional physical cross‐links via hexamethylene diisocyanate mixing segment. At 1 wt.% GO incorporation, the modulus increased by 178%, an 8% increase in tensile strength, while the elasticity was maintained. Excellent improvement in SF and shape recovery (SR) was attained at 1 wt.% GO incorporated SMPU, and the SMPU nanocomposite showed the highest SF (65%) and SR (100%) at 70°C temperature and 50% strain.

Thermal and power performance optimization of cost-effective solar cells using eco-friendly perovskite materials

In this paper, a novel solar cell is proposed that utilizes a Sn-based perovskite (CH3NH3SnI3) absorber layer and a graphene oxide (GO) hole transport layer. The proposed device demonstrates exceptional power conversion efficiency (PCE), fill factor (FF), temperature stability, and environmental sustainability, all while maintaining low cost. Through simulations and analysis using 1D SCAPS, it is shown that the proposed perovskite solar cell (PSC) achieves a PCE of 22.24% and an FF of 83% at 45 °C, with a quantum efficiency exceeding 85% in the visible spectrum. Furthermore, the proposed PSC maintains its performance at high temperatures ranging from 85 °C to 95 °C, in the wake of incorporation of GO and mesoporous carbon. The optimized value of the proposed PSC is then simulated with the inclusion of the microstructural properties in COMSOL Multiphysics and 20.92% PCE is observed. By avoiding toxic Pb-based materials and incorporating Sn-based materials as well as low-cost and scalable elements such as ZnO, GO, and mesoporous carbon, the proposed device minimizes its environmental impact and processing cost. Overall, this proposed PSC shows great promise as a viable option for large-scale solar energy applications.

Ugradnja grafenova oksida u sloj vodljivog polimera i naknadna elektrokemijska redukcija

U ovom radu provedena je elektrokemijska sinteza poli(3,4-etilendioksitiofena) (PEDOT) sloja i kompozitnog sloja PEDOT/grafenov oksid (GO). Sinteza je provedena iz elektrolita koji je sadržavao 3,4-etilendiokstiofen (EDOT) u otopini poli(natrij 4-stirensulfonata) (PSS) ili smjesi PSS/GO. Rezultati su pokazali da se dobra pseudokapacitivna svojstva PEDOT slojeva postižu elektrokemijskom sintezom kod 1,00 V te pri trajanju sinteze do 600 s. Za optimalnu koncentraciju PSS određena je vrijednost od 0,01 mol dm<sup>–3</sup>. Ugradnja GO-a u strukturu vodljivog polimera dokazana je rezultatima UV/Vis spektrofotometrije. Radna elektroda sa slojem PEDOT/GO negativno je polarizirana pri −1,4 V u 0,1 mol dm<sup>–3</sup> otopini KCl. Tim postupkom GO je preveden u vodljivi oblik odnosno reducirani grafenov oksid. Poboljšana pseudokapacitivna svojstva ukazala su na uspješno provedenu elektrokemijsku redukciju GO-a u sloju vodljivog polimera. Sintetizirani vodljivi polimeri ispitani su metodom cikličke voltametrije.

Correlations between the anti-corrosion properties and the photocatalytic behavior of epoxy coatings incorporating modified graphene oxide deposited on a zinc substrate.

This research aimed to create a substrate-coating system based on zinc and an epoxy resin incorporating modified graphene oxide, which possesses two key characteristics: effective resistance against corrosion and the ability to harness photocatalytic properties. Furthermore, correlations between the anti-corrosion properties and the photocatalytic behaviour of the coatings were made. Thin epoxy (EP) layers embedding 0.1 wt% graphene oxide (GO), reduced graphene oxide (rGO), and modified graphene oxide with (3-aminopropyl)-triethoxysilane (APTES) or poly(amidoamine) (PAMAM) dendrimer were applied on a zinc (Zn) substrate using the dip-coating method. Anti-corrosion properties of coated Zn samples were investigated through electrochemical impedance spectroscopy (EIS) measurements. They showed that the corrosion protection effect is more prominent for EP containing functionalized GO, the highest in the case of GO-PAMAM. The results of the EIS measurements indicated also that the corrosion protection provided by EP-rGO is smaller than that of EP. The photocatalytic properties of the coatings were studied by exposure of the samples to Methylene Blue (MB) solution followed by monitoring the model dye degradation through UV-Vis measurements. To determine the changes in the anti-corrosion properties due to photocatalysis, the coated Zn samples were put through additional EIS measurements. The same coatings applied to a glass substrate lacked photocatalytic properties, indicating that the Zn substrate is accountable for the degradation of MB. Furthermore, the incorporation of GO or functionalized GO into the coating amplifies this effect. From EIS spectra, it was determined that the protective properties loss observed after 3 days is due to coating delamination during exposure to MB solution, the EP-GO-APTES retaining the best adhesion of the coating, 98% remaining on Zn after a cross-hatch test. The corrosion measurements were complemented by examining the morphology and structure of the coatings and the modified GO particles. All things considered, the Zn/EP-GO-APTES system shows the best ability to break down organic pollutants, keeping a good anti-corrosive property and adhesion.

Facile synthesis of a 3D magnetic graphene oxide/Fe3O4/banana peel-derived cellulose composite aerogel for the efficient removal of tetracycline.

Many initiatives have incorporated graphene oxide (GO) and biomass into aerogels for wastewater treatment. We report on the facile fabrication of a magnetic GO/Fe3O4/banana peel-derived cellulose (bio-cellulose) aerogel using an ultrasound-assisted mechanical mixing method and freeze-drying technique for the removal of tetracycline (TC). The component materials and composite aerogel were characterized using Fourier-transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), Raman spectroscopy, field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), nitrogen adsorption-desorption analysis, and vibrating sample magnetometry (VSM). The effects of solution pH and adsorbent dose on the adsorption performance of the synthesized adsorbents were investigated. The adsorption behavior at the equilibrium of the GO/Fe3O4/bio-cellulose aerogel was studied and analyzed using four well-known non-linear models: Langmuir, Freundlich, Sips, and Temkin. The results showed that the experimental data fitted well with the Freundlich and Sips isotherm models. The maximum adsorption capacity achieved from the Sips model was 238.7 mg g-1. The adsorption kinetics were studied and proved to follow the Elovich kinetic model with an initial rate of 0.89 g g-1 min-1. These results confirm the favorable adsorption of TC on the heterogeneous surface that exhibits a wide range distribution of adsorption energies of the desired GO/Fe3O4/bio-cellulose aerogel. The experimental findings demonstrate that the aerogel possesses the notable features of environmental friendliness, cost-effectiveness, and comparatively high TC adsorption capacity. Therefore, utilizing biomass to develop the structure of the magnetic GO-based composite aerogel is significantly promising for antibiotic-containing wastewater treatments.

Tailoring an engineered cementitious composite with enhanced mechanical performance at ambient and elevated temperatures using graphene oxide and crumb rubber

With the increased use of engineered cementitious composite (ECC) in closed environments and as a structural material, it is necessary to fully understand its performance under elevated temperatures. This research investigates the response of ECC to ambient and elevated temperatures and addresses the issue of explosive spalling by incorporating graphene oxide (GO) and crumb rubber (CR). Twenty GO-modified rubberized ECC mixes were designed using Response surface methodology (RSM), considering GO content, GO concentration for CR pretreatment, CR replacement of fine aggregate, and elevated temperature as the input variables. Results show that mixes with GO and GO-treated CR outperform those without GO or untreated CR at ambient and elevated temperatures. Response predictive models exhibited high coefficient of determination (R2) values ranging from 84 % to 96 %. Multi-objective optimization yielded optimum input factors, resulting in improved mechanical properties that were experimentally validated to confirm the accuracy of the developed models.

Ethylene Glycol-water Based Graphene Oxide Nanofluid as Corrosion Inhibitor in Automotive Radiator

A rapid cooling process is essential to maintain an optimal working temperature in a vehicle, which directly impacts its efficiency. Corrosion is a persistent and inevitable damage in cooling systems that use water-based fluids. The current challenge is to explore water-based fluids that not only exhibit excellent corrosion resistance but also possess superior heat conduction properties to improve vehicle efficiency. This study investigated the incorporation of Graphene Oxide, renowned for its corrosion inhibition properties, into ethylene glycol/water solution to assess its protective efficacy on Al6061 material. A series of analytical methods, including Optical Emission Spectroscopy (OES), pH, conductivity, Fourier-Transform Infrared Spectroscopy (FTIR), and polarization techniques, are used to evaluate the corrosion inhibition performance of graphene oxide at various concentrations and under different ambient temperatures. The results showed a decrease in pH value and conductivity with increasing concentration of graphene oxide. FTIR analysis confirmed the formation of a protective layer on the surface of Al6061. Corrosion rate assessment was performed on Al6061 samples immersed in ethylene glycol/water mixture with graphene oxide concentrations of 0, 0.03%, 0.05%, and 0.10%. There was a significant decrease in corrosion rate with the addition of graphene oxide to the cooling system: at 30°C, the rate decreased to 4.620, 3.308, 2.565, and 1.006 mpy; at 40°C, up to 4,728, 2,541, 1,503, and 1,270 mpy; and at 50°C, up to 5.629, 1.146, 2.947, and 1.441 mpy, corresponding graphene oxide concentrations of 0.03%, 0.05%, and 0.1%, respectively. Experimental data confirmed that graphene oxide effectively reduces the corrosion rate of Al6061 in ethylene glycol/water mixtures. The study concluded that the use of graphene oxide as a corrosion inhibitor markedly improved the resistance and performance of Al6061 in ethylene glycol/water, with graphene oxide contributing to this protective mechanism through the process of physisorption.

Fabrication of poly (quinine-co-itaconic acid) incorporated reduced graphene oxide nanocomposite and its application for electrochemical sensing and photocatalysis of hydroquinone.

In this work, we report the synthesis of poly (quinine-co-itaconic acid) incorporated graphene oxide composite that is electro-active and photo-active simultaneously. The poly (quinine-co-itaconic acid)@rGO composite was successfully utilized for electrochemical detection and photocatalytic degradation of hydroquinone (HQ). HQ is recognized as an environmental pollutant because of its high toxicity to human health even at low concentrations. The synthesized composite was characterized using different characterization techniques i.e. Fourier Transform Infrared Spectroscopy (FTIR), Energy Dispersive X-ray Spectroscopy (EDX), Scanning Electron Microscopy (SEM), X-ray Diffractometry (XRD), Brunauer-Emmett-Teller (BET) and zeta potential. The characterization studies revealed the net negative surface charge of -17.6 mV for poly (quinine-co-itaconic acid)@rGO composite that confirms its stability. Moreover, the XRD and FTIR studies confirmed the fabrication of poly (quinine-co-itaconic acid)@rGO composite. The electrochemical properties of synthesized composite were determined via cyclic voltammetry and electrochemical impedance spectroscopy which showed high conductivity and charge transfer kinetics. Under optimized condition, the sensor showed excellent response for hydroquinone i.e. potential window from -0.6 to 0.6 V at scan rate 50 mV s-1 and borate buffer of pH 8 as supporting electrolyte. The developed method was comprehensively validated and found linear between 0.1 to 40 μM of HQ, with limit of detection 0.03 μM and limit of quantification 0.1 μM, respectively. The real water and personal care products samples were used to check the applicability of developed sensor and good percent recovery was achieved. The synthesized poly (quinine-co-itaconic acid)@rGO composite was also utilized for photocatalytic degradation of HQ and the degradation efficiency was obtained as 99% with dosage of 0.5 g L-1 under optimized conditions such as solution pH 7, initial concentration of HQ 10 mg L-1, catalyst dosage of 5 mg and irradiation time of 40 min, respectively. The degradation efficiency of poly (quinine-co-itaconic acid)@rGO composite was also evaluated in real water samples from industry and river.

Improved corrosion protection performance of electrophoretic epoxy coatings with the incorporation of amino-functionalized graphene oxide

Improved corrosion protection performance of electrophoretic epoxy coatings with the incorporation of amino-functionalized graphene oxide

Investigating the Antibacterial Activities of Graphene Oxide Loaded Spiky Gold Nanocomposites via Chitosan linker

The graphene oxide (GO) loaded spiky gold (AuNS) nanocomposites were prepared by electrostatic interaction between negatively-charged GO nanosheets and positively-charged AuNS by the assistance of chitosan as linker molecules. The AuNS/GO nanocomposites exhibit a red-shift in the extinction spectra and a reduction in the zeta potential compared to those of the pristine AuNS due to the presence of oxygen-containing functional groups in GO. The bactericidal analysis demonstrates that the incorporation of GO greatly enhances the intrinsic antibacterial activities of AuNS. Besides, the AuNS with smaller size exhibit better bactericidal efficiency compared to that of AuNS with bigger size. Upon light irradiation, the AuNS/GO with the absorption peak close to the wavelength of excitation light (900 vs. 904 nm) demonstrates a noticeable improvement in the bactericidal efficiency which is attributed to the plasmon-induced photothermal effect. All these results suggest that the AuNS/GO nanocomposites can work as a promising functional material for both intrinsic and plasmon-induced antibacterial materials.

Rough‐Endoplasmic‐Reticulum‐Like Hierarchical Composite Structures for Efficient Mechanical‐Electromagnetic Wave‐Energy Attenuation

AbstractInspired by a critical organelle called rough endoplasmic reticulum (RER), a wave‐energy attenuation nano‐carbon foam (WANF) with a unique hierarchical composite structure consisting of 3D‐lamelle, 2D‐perforations and 1D‐microspheres is constructed by incorporating graphene oxide (GO) and polydimethylsiloxane (PDMS) into a carbon nanotubes (CNTs)‐based aerogel. Benefiting by unusual mechanisms like vortex shedding, secondary reflection and resonance, WANF displays excellent acoustic wave absorption, achieving a sound absorption coefficient of over 0.9 with a bandwidth of 4.75 kHz at a thickness of 20 mm. Significantly, it features obvious acoustic absorption intensity in medium‐low frequency range. Moreover, the nano‐carbon aerogel skeleton (NCAS) of WANF endows it with good electromagnetic wave absorption through dielectric loss, exhibiting a minimum reflection loss of −48.61 dB and an efficient electromagnetic absorption with a bandwidth of 5.35 GHz. The excellent wave‐energy attenuation performance of WANF indicates an attracting double‐stealth effect in sonic and electromagnetic area, which shows great potential in integrate protection of advanced military equipment and sensitive electronic infrastructures.