Incorporation Of Graphene Oxide Research Articles

Dual Stimulus Responsive GO-Modified Tb-MOF toward a Smart Coating for Corrosion Detection.

Smart-sensing coatings that exhibit multistimulus response, rapid indication, and reusability are in urgent need to effectively enhance the practicability of coatings while accurately detecting metal corrosion. In this work, a reusable corrosion self-reporting coating with multiple pH and Fe3+ stimulus responses was first constructed by the integration of a composite fluorescent probe into the resin matrix. This composite sensor was constructed by combining a lanthanide metal-organic framework (Ln-MOF) based on terbium and trimeric acid (H3BTC) with graphene oxide (GO) nanosheets (GO@Tb-BTC). The incorporation of GO formed a sea-urchin-like structure, thereby increasing the specific surface area and active sites of the probe. The coatings were characterized by using electrochemical impedance spectroscopy (EIS), visual observation, and fluorescence spectrophotometry. The surface morphology, wettability, and adhesion of the coating samples were analyzed using SEM, XPS, hydrostatic contact angle test, and an adhesion test. EIS measurements in 3.5 wt % NaCl solution for 72 h demonstrated the superior corrosion protection performance of the 0.3 wt %/GO@Tb-BTC/WEP coating compared to blank coating, with the charge-transfer resistance reaching 4.33 × 107 Ω·cm2, which was 9.5 times higher than that of the pure coating. The bright green fluorescence of GO@Tb-BTC/WEP coating exhibited a turn-off response when there was an excess of OH-/H+, but it demonstrated a reversible turn-on fluorescence when the ambient pH returned to neutral. Furthermore, such Fe3+-triggered fluorescence quenching responded to concentrations as low as 1 × 10-6 M. The fluorescence quenching rate of both intact and damaged coatings surpassed that of visual and EIS detection methods. Significantly, the fluorescence in scratches was effectively quenched within 25 min using 0.3 wt %/GO@Tb-BTC/WPU coating for visual observation. GO@Tb-BTC demonstrated exceptional corrosion self-reporting capabilities in both epoxy and polyurethane systems, making it a versatile option beyond single-coating applications.

Synthesis of composite membranes modified with graphene oxide and polyethylene glycol for the removal of emerging contaminants from water

Graphene oxide (GO) incorporation of the polymer matrix of membranes can provide properties such as great durability, resistance, and reduction of fouling. In turn, polyethylene glycol (PEG) is a polymer capable of increasing the porosity and flow of membranes. The study aimed to analyze the synthesis of composite membrane polysulfone (PSF), GO and PEG, to separate caffeine, diclofenac sodium, and amoxicillin dispersed in water. It observed an increase in roughness through the incorporation of GO and its reduction with the addition of PEG. Membrane permeability increased from 0.61 L m-2 h-1 bar-1 to 4.54 L m-2 h-1 bar-1 after the addition of GO and PEG. The water permeance of the synthesized membranes reached 37.81 L m-2 h-1 bar-1. It is concluded that the structure and porosity, as well as the rejection of contaminants, were directly influenced by the incorporation of materials added to the membranes. The charge of GO contributed to structural and mechanical improvements of the membranes, reaching rejections of up to 80.61% of caffeine, 66.03% of diclofenac sodium, and 87.33% of amoxicillin with the membrane containing 1.5% of GO, being thus, it is considered promising for applications in water contaminated by emerging contaminants. The study brings real contributions to the area of membranes by developing an improved material, especially as it presents a high rejection of emerging contaminants that are still little studied.

Compatibility of Molybdenum Disulfide and Magnesium Fluorinated Alkoxyaluminate Electrolytes in Rechargeable Mg Batteries

Molybdenum disulfide (MoS2)‐based cathodes have exhibited good electrochemical reactions in all phenyl complex (APC) electrolytes. However, APC electrolytes are highly corrosive and susceptible to oxidation. Alternatively, magnesium fluorinated alkoxyaluminate electrolyte (Mg[Al(HFIP)4]2) is a pioneering chloride‐free electrolyte with remarkable electrochemical activity in rechargeable Mg batteries (RMBs). This study aims to investigate the compatibility of various MoS2 nanomaterials with Mg[Al(HFIP)4]2 in RMBs. Seven MoS2 nanomaterials were synthesized under different hydro/solvothermal conditions and evaluated as cathode materials in RMBs. The results revealed that the electrochemical activity of the as‐synthesized MoS2 in RMBs significantly varied and MoS2 with high content of 1T‐phase (M5) exhibited the best specific capacity of ca. 35 mAh g−1. Heteroatom doping, graphene oxide (GO) incorporation, and dual‐salt electrolytes were employed to enhance the electrochemical performance of M5. The electrochemical tests showed that all doped‐MoS2 and GO‐MoS2 delivered poor specific capacities (< 20 mAh g−1), properly due to the disorder of the cathode material and the entrapment of Mg2+ ions. In contrast, dual‐salt electrolytes (0.3 M Mg[Al(HFIP)4]2/0.3 M LiCl) improved the initial specific capacity by 242%. This is attributed to the preferential intercalation of Li+ ions that reduces the diffusion energy barrier and facilitates the intercalation of Mg+2 ions.

Promoting Thermal Conductivity of Alumina-Based Composite Materials by Systematically Incorporating Modified Graphene Oxide

Small amounts of thermally conductive graphene oxide (GO) and modified GO are systematically introduced as a second filler to thermal interface materials (TIMs) consisting of alumina (Al2O3) particles and polydimethylsiloxane (PDMS). The surface of GO is covalently linked with an organic moiety, octadecylamine (ODA), to significantly improve the miscibility and dispersity of GO across the TIM matrix. Subsequently, two series of PDMS-Al2O3 composite TIMs are manufactured as a function of GO and ODA-GO content (0.25 wt%–2.5 wt%) to understand the effect of these second additives. The incorporation of GO into the Al2O3-PDMS composite materials generally increases the thermal conductivity (TC), ranging from 18% to 29%. Conversely, the use of ODA-GO further enhances the overall performance of TIMs (22–54%) by facilitating the dispersion degree of GO across the composite matrix. The great improvement in TC is presumably related to the formation of conductive pathways by uniformly integrating 2D-type GO flakes across spherical Al2O3 particle networks. The ability to simply regulate the polarity of the thermally conductive second filler can provide an idea for designing cost-effective and practical TIM-2-type pads that can be commercially applicable in between an integrated heat spreader and a heat sink.

Incorporating GO in PI matrix to advance nanocomposite coating: An enhancing strategy to prevent corrosion

Abstract This research endeavors to advance the anti-corrosive characteristics, mainly the physico-mechanical properties, by incorporating graphene oxide (GO) into a polyimide (PI) matrix. So, a nanocomposite coating is fabricated for an aluminum alloy substrate. Results reveal that the coating was uniformly dispersed across the surface signifying that the inclusion of GO increased the PI dispersion. The π–π stacking interactions between the aromatic rings of PI and GO contribute to their stability and improved anticorrosive properties. The incorporation of GO to PI films significantly enhances hydrophobicity, as evidenced by the increased contact angles. Assessing the corrosion resistance of the coating in a 3.5 wt% NaCl solution through electrochemical impedance spectroscopy and potentio-dynamic polarization establishes a prominent correlation between the percentage of GO and the anticorrosion efficiency of the composite coating. Precisely, the nanocomposite coating containing 5 wt% GO exhibits an impressive impedance modulus value of 107, and the corrosion current density (I cor) is drastically reduced by over three orders of magnitude, reaching 4.8 × 10−9 A cm−2, as indicated by the polarization curve. Also, prolonged immersion tests confirm the exceptional protective ability of the S5 coating (5 wt% GO), effectively shielding the metal for up to 100 h. After conducting diagnostic measurements, the hybrid nanocomposites of GO/PI examined in this study showcased their effectiveness as inhibitors in anticorrosive coatings. These composites played a vital role to hinder the oxidation of underlying aluminum alloy when exposed to oxidizing chemicals, water, or air, thereby extending the protective duration.

Control of Cell Adhesion and Growth on Polysaccharide-Based Multilayer Coatings by Incorporation of Graphene Oxide

Controlling cell adhesion, viability, and proliferation on solid surfaces is critical for the successful implantation and proper functioning of temporary and permanent medical devices. While, with temporary or removable implants as well as surgical instruments, even slight cellular adhesion leads to an increased risk of secondary infections, bleeding and other complications, good cellular adhesion and viability are essential for the rapid healing and successful integration of permanent implants. This work was motivated by the growing interest in the construction of biocompatible and biodegradable coatings for the biofunctionalization of medical devices. Polysaccharide-based coatings are well known for their biocompatibility, but they are non-cell-adhesive, which hinders their application as implant coatings. In this study, we demonstrate that the incorporation of one or more graphene oxide layers in hyaluronic acid/chitosan multilayers is one avenue to regulate the degree of unspecific adhesion and growth of different cells (human umbilical vein endothelial cells, HUVEC, and mouse embryonic fibroblasts, 3T3). Furthermore, we demonstrate that this approach allows cell adhesion to be regulated across the entire range between completely prevented and highly promoted cell adhesion without introducing systemic cytotoxicity. These findings may contribute to the establishment of a new approach to adapt medical devices to cells and tissues.

Influence of graphene oxide additives on the NF separation of triazine-based H2S scavenging compounds using advanced membrane technology

This work proposes an innovative approach for the membrane separation of spent and unspent H2S scavengers (SUS) derived from the application of MEA-triazine in offshore oil and gas production. Modified nanofiltration membranes were fabricated by incorporating graphene oxide (GO) and polyvinyl alcohol (PVA) into a thin film composite (TFC) to obtain a thin film nanocomposite (TFN) with enhanced permeability. In addition, various immobilization strategies for GO were investigated. The performance of the membranes and the effect of the GO loading were evaluated in terms of permeability, fouling propensity, and rejection of key components of the SUS, i.e., MEA-triazine (unspent scavenger), dithiazine (spent scavenger), and monoethanolamine, operating on a sample of SUS wastewater obtained from an offshore oil and gas platform. Various characterization techniques, such as contact angle, FTIR, XRD, SEM, TGA, and AFM, were employed to evaluate the structure, composition, and hydrophilicity of the membrane. The results show a remarkable increase in permeability (from 0.22 Lm-2 h-1 bar-1 for the TFC to 5.8 Lm-2 h-1 bar-1 for the TFN membranes), due to the enhanced hydrophilicity from GO incorporation. The strong interfacial interaction between GO and PVA within the TFN membrane results in negligible nanofiller leaching. The incorporation of GO moderately increases the rejection of the unspent scavenger (63% to 73%, 62% to 79%, 62% to 80%, and 68% to 76%), while drastically increasing the rejection of the spent scavenger, which is approximately null for the TFC membrane without GO and increases up to 58% in the TFN membrane with GO. Therefore, while the proposed membranes cannot be used for the selective separation of the unspent form the spent scavenger, they can achieve substantial recovery of all the key components contained in the SUS to avoid their discharge into the sea.

Evaluation of the mechanical properties and degradation behavior of chitosan-PVA-graphene oxide nanocomposite scaffolds in vitro

ObjectivesChitosan (CTS) has been a popular option for scaffold fabrication because of its biocompatibility, biodegradability, antimicrobial and nonimmunogenic effects. However, it is of limited function, due to its low mechanical strength and its solubility in acidified media. These limitations could be overcome by its blending with PVA and incorporation with bioactive materials to improve its mechanical properties and tissue regeneration capability. MethodsCarbon based nanomaterials, such as graphene oxide (GO) incorporated with CTS/PVA blend to improve composite-scaffold stability. GO nanoparticles were chemically prepared and fully characterized. Different concentrations of both CTS and nano-GO were used for the fabrication of CTS/PVA/GO nanocomposite films through the solvent-casting method. The mechanical properties, thermal stability biodegradation, and swelling of the nanocomposite films were evaluated after characterization by XRD, FTIR and SEM, to detect the effect of GO incorporation in the scaffold to select the suitable dental application. ResultsA better performance was observed in thermal stability, biodegradation, and water resistance after GO addition into CTS/PVA scaffolds. Regarding mechanical properties, groups were assessed by Kruskal Wallis test afterward Dunn’s post hoc test. There was no significant difference in tensile strength between the nanocomposite films of CTS (2%) and CTS (3%). The tensile strength decreased after addition of nano-GO at different concentrations. The elastic modulus significantly increased when (1%) GO was added into the 1CTS (2%):1PVA. ConclusionsCTS/PVA/GO nanocomposite can be used in dental hard tissue engineering, as the incorporation of GO into the CTS/PVA polymer blend improves its properties which is regarded as the critical concentrations of CTS and GO.

Green and Heavy-Duty Anticorrosion Coatings: Waterborne Epoxy Thermoset Composites Modified through Variation of Zinc Dust Loading and Incorporation of Amine-Capped Aniline Trimer and Graphene Oxide.

In this study, an array of environmentally friendly and heavy-duty anticorrosion composite coatings were prepared. The synthesis involved amine-capped aniline trimer (ACAT) produced by an oxidative coupling reaction and graphene oxide (GO) prepared based on Hummer's method, and later, the waterborne epoxy thermoset composite (WETC) coatings were prepared by thermal ring-opening polymerization of EP 147w, a commercial waterborne epoxy resin, in the presence of ACAT and/or GO with zinc dust (ZD). A synergistic effect was observed by replacing a significant amount of the ZD loading in the WETC by simultaneously incorporating a small amount of ACAT and GO. The electrochemical corrosion measurements of the as-prepared WETC coatings indicated that incorporating 5% w/w ACAT or 0.5% w/w GO separately replaced approximately 30% w/w or 15% w/w of the ZD, respectively. Moreover, the WETC coatings containing 5% w/w ACAT and 0.5% w/w GO simultaneously were found to replace 45% w/w of the ZD. A salt spray test based on ASTM B-117 also showed a consistent trend with the electrochemical results. Incorporating small amounts of ACAT and GO in WETC coatings instead of ZD not only maintains the anticorrosion performance but also enhances adhesion and abrasion resistance, as demonstrated by the adhesion and abrasion tests.

Electrospun polycaprolactone/graphene oxide scaffolds with secondary surface porosity and gelatin-coating

Polycaprolactone (PCL) is a versatile and biodegradable synthetic polymer widely used in tissue regeneration applications owing to its versatility and mechanical properties. In this study, we employed a three-level strategy to develop innovative PCL-based scaffold biomaterials using electrospinning. First, we incorporated graphene oxide (GO); second, we introduced secondary surface porosity (SSP) through non-solvent induced phase separation (NIPS) with a diameter of approximately 2 μm; and third, we applied a gelatin coating (Gt). The inclusion of GO resulted in both a reduction in fiber size and a decrease in the size of the secondary surface pores formed on the fibers. Additionally, the incorporation of GO led to a noteworthy 20-fold increase in gelatin adhesion compared to pure SSP-PCL scaffolds. However, the mechanical properties of the gelatin-coated scaffolds exhibited a decrease compared to the uncoated scaffolds. This reduction is primarily attributed to the decrease in crystallinity in coating gelatin scaffold. Furthermore, GO and gelatin played critical roles in enhancing biodegradation and bioactivity, promoting hydroxyapatite formation on the surface of SSP-PCL scaffolds. In vitro cell viability tests demonstrated the cytocompatibility of PCL, PCL/Gt, and PCL/Gt/GO electrospun SSP scaffolds, facilitating the adhesion of human mesenchymal stem cells. Our study introduces an innovative strategy for fabricating PCL scaffolds through electrospinning, incorporating SSP for improved gelatin adsorption, and holds great promise for tissue engineering applications.

Influence of graphene oxide properties, superplasticiser type, and dispersion technique on mechanical performance of graphene oxide-added concrete

The incorporation of Graphene Oxide (GO) nanomaterial into concrete has gained significant attention due to its potential to enhance mechanical and durability properties. The addition of GO to concrete creates considerable changes in the morphology of the concrete matrix, creating a densified microstructure. Critical parameters significantly affect these microstructural enhancements and, consequently, the final performance in GO-added concrete. These parameters include GO material properties, superplasticiser (PS) type, and dispersion techniques. Therefore, this study investigates the influence of GO on the mechanical performance of concrete, focusing on these critical factors. Unlike existing studies concentrating on a single parameter's effect, this research comprehensively compares how these parameters impact GO-added concrete. Two commercially available GO types (GO-A and GO-B) and two PS types (PS-A and PS-B) are utilised. At the same time, three commonly used mixing techniques, such as mechanical, high-speed, and ultrasonic mixing techniques, are considered for GO dispersion. GO-A is added to concrete in percentages ranging from 0.02% to 0.14% by weight of cement (bwoc), while GO-B ranges from 0.04% to 0.20% bwoc. Based on compressive strength test results, the optimum GO dosages are 0.08% for GO-A and 0.12% for GO-B. The highest strength results are achieved for GO-B added concrete with PS-A addition and following the ultrasonic dispersion method, highlighting these parameters as optimal for maximising GO-added concrete performance. The optimum concrete mix exhibits 33%, 24%, 25%, and 30% increments for compressive strength, indirect tensile strength, flexural strength, and elastic modulus properties at 28 days. This paper provides a deep theoretical explanation of the effects of GO material properties, dispersion techniques, and PS type on GO-added concrete performance. The findings provide valuable insights into selecting suitable parameters for optimising the mechanical properties of GO-added concrete, contributing to the advancement and effectiveness of construction materials.

Environmentally Friendly Photothermal Membranes for Halite Recovery from Reverse Osmosis Brine via Solar-Driven Membrane Crystallization.

Modern society and industrial development rely heavily on the availability of freshwater and minerals. Seawater reverse osmosis (SWRO) has been widely adopted for freshwater supply, although many questions have arisen about its environmental sustainability owing to the disposal of hypersaline rejected solutions (brine). This scenario has accelerated significant developments towards the hybridization of SWRO with membrane distillation-crystallization (MD-MCr), which can extract water and minerals from spent brine. Nevertheless, the substantial specific energy consumption associated with MD-MCr remains a significant limitation. In this work, energy harvesting was secured from renewables by hotspots embodied in the membranes, implementing the revolutionary approach of brine mining via photothermal membrane crystallization (PhMCr). This method employs self-heating nanostructured interfaces under solar radiation to enhance water evaporation, creating a carefully controlled supersaturated environment responsible for the extraction of minerals. Photothermal mixed matrix photothermal membranes (MMMs) were developed by incorporating graphene oxide (GO) or carbon black (CB) into polyvinylidene fluoride (PVDF) solubilized in an eco-friendly solvent (i.e., triethyl phosphate (TEP)). MMMs were prepared using non-solvent-induced phase separation (NIPS). The effect of GO or GB on the morphology of MMMs and the photothermal behavior was examined. Light-to-heat conversion was used in PhMCr experiments to facilitate the evaporation of water from the SWRO brine to supersaturation, leading to sodium chloride (NaCl) nucleation and crystallization. Overall, the results indicate exciting perspectives of PhMCr in brine valorization for a sustainable desalination industry.

Sustainable pervious concrete incorporated with graphene oxide: a comprehensive analysis of mechanical, infiltration and microstructure performance

ABSTRACT This study is a novel coalescence of using laboratory-based self-synthesised Graphene Oxide (GO) in pervious concrete (PC). The study aims to determine the effect of GO on the workability, paste drain down, porosity using CT scanning, hardened density, mechanical, infiltration and microstructural properties of previous concrete. Six mixes were designed with GO incorporation by cement weight (0, 0.02, 0.04, 0.06, 0.08 and 0.1 wt%). At 0.1 wt% of GO, the compressive strength of PC was 31.03 and 32.89 MPa at 28 and 56 days, respectively. Regarding splitting tensile strength, values were 3.68 and 3.9 MPa, and shear strength measured 4.88 and 5.12 MPa for the corresponding periods. Significant increment of 52.1% and 57% in compressive strength was observed at 28 and 56 days. The infiltration rate of all the mixes has shown a declining trend with an increase in GO percentage, and the maximum decrement was observed in the mix containing 0.1% of GO with 11.67% reduction of infiltration compared to control PC, but was within the standard permeable range as per American Concrete Institute (ACI 522R-10). Microstructural analysis revealed improved GO-modified PC performance, enhancing mechanical strength and infiltration characteristics, offering a promising and innovative solution for sustainable pavement development.

Enhanced mechanical properties of polyphenylene sulfide and liquid crystal polymer composites by interfacial bonding capacity of graft‐modified graphene oxide and glass fibers

AbstractThe aim of this study is to broaden the potential applications of polyphenylene sulfide (PPS) by incorporating graphene oxide (GO)‐grafted glass fiber (GF) to enhance the mechanical properties of liquid crystal polymer (LCP)/PPS composites. The surface of GF was modified using γ‐Aminopropyltriethoxysilane (KH550), allowing for the grafting of GO. Subsequently, GO‐GF/LCP/PPS composites were prepared through extrusion injection molding. The properties of the composites were evaluated using scanning electron microscopy, differential scanning calorimetry, and thermogravimetric analysis. The findings indicate that the interfacial adhesion between GF and composites is significantly improved with the addition of GO, The mass fractions of GO used were 0.1%, 0.5%, and 0.7%. The incorporation of GO‐grafted GF proves to be an effective approach in enhancing the tensile and flexural strengths of LCP/PPS composites. Additionally, a reduction in wear volume and tribological coefficient is observed compared to composites without GO‐treated GF. Notably, when the GO content is 0.5 wt%, the mechanical properties of the composites show significant improvement, with a 50% increase in impact strength compared to the composite without GO, and a decrease in friction coefficient from 0.28 to 0.22.

Enhanced physiochemical, antibacterial, and hemostatic performance of collagen-quaternized chitosan-graphene oxide sponges for promoting infectious wound healing

Bacteria-infected wound healing has attracted widespread attention in biomedical engineering. Wound dressing is a potential strategy for repairing infectious wounds. However, the development of wound dressing with appropriate physiochemical, antibacterial, and hemostatic properties, remains challenging. Hence, there is a motivation to develop new synthetic dressings to improve bacteria-infected wound healing. Here, we fabricate a biocompatible sponge through the covalent crosslinking of collagen (Col), quaternized chitosan (QCS), and graphene oxide (GO). The resulting Col-QCS-GO sponge shows an elastic modulus of 1.93-fold higher than Col sponge due to enhanced crosslinking degree by GO incorporation. Moreover, the fabricated Col-QCS-GO sponge shows favorable porosity (84.30 ± 3.12 %), water absorption/retention (2658.0 ± 113.4 %/1114.0 ± 65.7 %), and hemostasis capacities (blood loss <50.0 mg). Furthermore, the antibacterial property of the Col-QCS-GO sponge under near-infrared (NIR) irradiation is significantly enhanced (the inhibition rates are 99.9 % for S. aureus and 99.9 % for E. coli) due to the inherent antibacterial properties of QCS and the photothermal antibacterial capabilities of GO. Finally, the Col-QCS-GO+NIR sponge exhibits the lowest percentage of wound area (9.05 ± 1.42 %) at day 14 compared to the control group (31.61 ± 1.76 %). This study provides new insights for developing innovative sponges for bacteria-infected wound healing.

Graphene oxide-titanium oxide-polyaniline hybrid materials for high-performance dye-sensitized solar cells

A new solar cell that comprises a graphene oxide and titanium oxide nanoparticle (NP) composite with graphitized polyaniline (PANI) has been tested in polymer solar cells (PSCs). In this study, a series of conjugated polymers were synthesized and evaluated as the absorber and hole-transport layer materials in organic solar cells, demonstrating the significant impact of the chemical structure of the polymers on solar cell performance. The incorporation of graphene oxide (GOX) and titanium oxide TiO2 NP in conjugated polymers, particularly when graphitized within the PANI layer, led to improved open-circuit voltages compared to structurally similar polymers without NP. The morphology of the composite films was analyzed and related to the photovoltaic performance of polymers synthesized with polyaniline PANI-base and PANI-salt. Optimal NP addition in PANI-salt, PANI-base, PANI-base-TiO2, and PANI-base-GOX resulted in open-circuit voltages and efficiencies of 433 mV and 3.67%, 250 mV and 0.595%, 310 mV and 1.358%, and 520 mV and 2.366%, respectively. This study underscores the importance of polymer film uniformity in the performance of PSCs, with the highest efficiency obtained using a conjugated polymer with the best PANI-salt and PANI-base-GOX films. The research sheds light on the relationship between polymer structure and device photovoltaic performance, which is crucial for the design of new polymeric materials for efficient use and stable OSCs and PSCs.

Photothermal Hydrogel Composites Featuring G4-Carbon Nanomaterial Networks for Staphylococcus aureus Inhibition.

Microbial infections represent a significant health risk, often leading to severe complications and, in some cases, even fatalities. As a result, there is an urgent need to explore innovative drug delivery systems and alternative therapeutic techniques. The photothermal therapy has emerged as a promising antibacterial approach and is the focus of this study. Herein, we report the successful synthesis of two distinct supramolecular composite hydrogels by incorporating graphene oxide (GO) and single-walled carbon nanotubes (SWNTs) into guanosine quadruplex (G4) based hydrogels containing covalently bound β-cyclodextrin (β-CD). The G4 matrix was synthesized through a two-step process, establishing a robust network between G4 and β-CDs, followed by the encapsulation of either GO or SWNTs. Comprehensive characterization of these composite hydrogels were conducted using analytical techniques, including circular dichroism, Raman spectroscopy, rheological investigations, X-ray diffraction, and scanning electron microscopy. A notable discovery from the conducted research is the differential photothermal responses exhibited by the hydrogels when exposed to near-infrared laser irradiation. Specifically, SWNT-based hydrogels demonstrated superior photothermal performance, achieving a remarkable temperature increase of up to 52 °C, in contrast to GO-based hydrogels, which reached a maximum of 34 °C. These composite hydrogels showed good cytotoxicity evaluation results and displayed synergistic antibacterial activity against Staphylococcus aureus, positioning them as promising candidates for antibacterial photothermic platforms, particularly in the context of wound treatment. This study offers a valuable contribution to the development of advanced and combined therapeutic strategies for combating microbial infections and highlights the potential of carbon nanomaterial-enhanced supramolecular hydrogels in photothermal therapy applications.

Effect of graphene oxide and carbon black on the thermoelectric performance of niobium doped strontium titanate

Strontium titanate-based ceramics are promising n-type thermoelectrics due to their low cost and high thermal and chemical stability. Here, SrTi0.85Nb0.15O3 was prepared with carbon additions of electrochemically produced graphene oxide (eGO) and commercially available carbon black (CB). Ceramic samples were sintered at 1700 K under a reducing atmosphere. XRD, HR-TEM and Raman spectra confirmed the matrix phase was cubic perovskite; there were no carbon residues. By incorporating graphene oxide, the electrical conductivity increased nine-fold to 2818 S cm−1 at 300 K as a result of enhanced carrier mobility. In contrast, the carbon black samples exhibited low density and a small average grain size of ∼1 μm. High-resolution X-ray photoelectron spectroscopy revealed the presence of a large number of ionised impurities in the carbon black samples, which significantly enhanced scattering effects; low thermal conductivities of 1.7 W m−1 K−1 were achieved at 873 K. The work reveals that eGO promotes charge transport in SrTiO3, while CB significantly suppresses phonon transport. Both effects are relevant to the development of other thermoelectrics.

Does the Incorporation of Graphene Oxide into PMMA Influence its Antimicrobial Activity?

The increase in infectious diseases mediated by oral bacteria has been one of the most potent threats to human health, specifically to the elderly. Researchers seek to incorporate antimicrobial nanomaterials into PMMA to control the colonization of microorganisms and reduce deadly diseases. To conduct a systematic review to answer the question: "Does graphene oxide incorporated into polymethylmethacrylate influence its antimicrobial activity?" The electronic search was performed in PubMed, Embase, Web of Science, Scopus, and Google Scholar databases, and articles published until October 2021 were selected. The search terms were: ("acrylic resin" OR PMMA) AND (graphene OR "oxide graphene") AND (antimicrobial OR antibacterial OR "anti-infective agent"). The risk of bias analysis of the articles was performed using the quasi-experimental study assessment tool adapted from the JBI. Two hundred and fifty-nine articles were found in the databases. After removing the duplicates, 245 were analyzed by title and abstract. Of these, 06 were selected for full reading, of which 03 met the eligibility criteria and were included in this systematic review. This systematic review's findings can infer that the incorporation of graphene in the form of graphene-based coatings to PMMA showed antimicrobial effectiveness.

Synthesis of chitosan-graphene oxide thermosensitive in situ hydrogel for nasal delivery of rasagiline mesylate: In-vitro-ex vivo characterization

Intranasal administration of a drug offers a way to bypass the blood-brain barrier, allowing for an increased drug concentration in the brain and improved bioavailability. In this context, the preference for polymeric thermoresponsive intranasal hydrogels has been widely documented. Here, there is a need to enhance the physical properties of the hydrogel and improve control over the release of the drug. In this work, we propose the incorporation of graphene oxide (GO) into a thermosensitive in situ hydrogel (RM@CS/B-GP-GO) based on chitosan (CS) and beta-glycerophosphate (B-GP) for intranasal delivery of rasagiline mesylate (RM). The prepared in situ hydrogel formulations were characterized using gelation temperature, gelation time, swelling, porosity, gel strength, mucoadhesive strength, pH, morphological features, spectral analysis, drug release, permeation study, and so on. In this work, the incorporation of GO showed a significant concentration-dependent effect on the properties of the thermosensitive CS hydrogel. In brief, the addition of GO in RM@CS/B-GP decreased the gelation time, porosity, and swelling of the hydrogel. Additionally, CS-hydrogel strength increased with higher concentrations of GO. The RM@CS/B-GP-GO hydrogel (1 mg/mL of GO) showed the customized release of RM almost 68.41 ± 2.01 % in 8 h than the RM@CS/B-GP hydrogel (log p < 0.05). Based on these findings, the physical and mechanical properties of the RM@CS/B-GP-GO thermosensitive hydrogel were improved by the addition of optimized concentration GO. Moreover, RM@CS/B-GP-GO hydrogel shows good biocompatibility with nasal mucosa. Overall, the design of RM@CS/B-GP-GO can open new options for the delivery of RM through the nasal route.