Poly(ethylene oxide)/graphene oxide nanocomposites: structure, properties and shape memory behavior

ABSTRACTNanofiller‐reinforced polymer nanocomposites can be used to improve the mechanical, thermal, electrical, and barrier properties of neat polymers. In this study, two‐dimensional graphene oxide (GO) nanosheets were successfully incorporated into hydrophilic crosslinked poly(ethylene oxide) (XPEG) hydrogels. Change in the gas permeability and mechanical strength were monitored as functions of the GO content and average GO flake size. The experimental results are discussed with two theoretical models (i.e., the modified Nielsen and Halpin‐Tsai models) to predict the effect of two‐dimensional GO nanofillers (e.g., loading content and alignment) on the gas permeability and mechanical properties of the GO‐embedded XPEG hydrogels (GO–XPEGs). When the GO sheets were fully exfoliated and homogeneously dispersed in the XPEG matrix, their significant reduction in gas permeability and improvement in mechanical strength were in good agreement with those theoretical models. In particular, the incorporation of 4 wt % GO into the XPEG hydrogel matrix resulted in an 80–90% reduction in the gas permeability for various gases, including He, H2, O2, N2, CH4, and CO2. Also, with increasing GO content, both the Young's modulus and tensile strength of the GO–XPEG nanocomposite hydrogels increased significantly compared to those of the neat XPEG hydrogel. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45417.

Polymer nanocomposites offer enhancement in thermomechanical and physicochemical properties of polymers with the presence of a little amount of nanostructured fillers such as carbon nanotubes, graphene, and layered silicates. A facile and rapid preparation of hytrel (HTL)-graphene oxide (GO) nanocomposites is done via a solution mixing method. The influence of GO content (0.1, 0.5, 1, 2, and 5 wt%) on mechanical and thermal properties of GO/HTL nanocomposites has been evaluated by using various techniques such as tensile testing, thermogravimetric analysis, differential scanning calorimetry, and dynamic mechanical analysis. The thermal stability and mechanical properties of GO/HTL nanocomposites were increased with increasing GO content. The composites have valuable improvement in tensile strength (139%) and storage modulus (72%) for HTL composite containing 5 wt% GO. The incorporation of GO into HTL polymer shows enhancement in thermal and mechanical properties due to the presence of strongest noncovalent interaction (π–π stacking) between the interface of nanocomposites. These enhanced physical properties of GO/HTL composites show its potential use in structural application.

Development of three-dimensional piezoelectric polyvinylidene fluoride-graphene oxide scaffold by non-solvent induced phase separation method for nerve tissue engineering

The properties of cassava starch based bioplastic have been successfully enhanced by additioning of graphene oxide (GO) filler. The composite was synthesized via starch intercalation method using glycerol plasticizer with variation of 5 – 15 % v/v GO filler and mixing time of 30 and 60 minutes. The effects of GO content and the mixing time to the mechanical, water uptake and biodegradation were studied. The synthesis of GO and its integration in the bioplastic composite were also elucidated. The increasing of the GO content and mixing time improved the mechanical properties of composite mainly due to of good homogeneity among the constituents in the composite as indicated by scanning electron microscopy (SEM) and Fourier Transfom Infrared (FTIR) spectroscopy. The bioplastic produced using 15% of GO and 60 minutes mixing time had the highest mechanical properties with tensile strenght of 3,92 Mpa, elongation of 13,22% and modulus young of 29,66 MPa. The water uptake and biodegradation increased as the increase of GO content and decreased as the increase of the mixing time. Graphene oxide is the promissing filler for further development of cassava starch based bioplastics.

The stable flower-like layered structure of molybdenum disulfide (MoS2)–graphene oxide (GO) nanocomposites was synthesized by a one-pot hydrothermal process. The novel nanoarchitecture of MoS2–GO nanocomposites acts as an electrocatalyst in multifunctional electrochemical performance. The distribution and morphological studies for MoS2–GO nanocomposites were analyzed via X-ray diffraction, energy-dispersive X-ray analysis, scanning electron microscopy, Brunauer–Emmett–Teller, and X-ray photoelectron spectroscopy analysis. Modified graphite felt (MGF) electrodes were developed using a spray-coating process to uniformly distribute MoS2–GO nanocomposites on graphite felt. The 1 mg cm–2 MGF electrode showed the best electrochemical activity and electrochemical reversibility toward the redox couples of the iron(II) electrolyte, as indicated in electrochemical impedance spectroscopy, cyclic voltammetry, and Tafel plots; this may be due to the presence of sulfur and oxygen heteroatom layers of the MoS2–GO nanocomposites, which are more actively participated in the charge transfer redox reactions of the iron(II) electrolyte. Iron redox flow battery performance with an active area of 132 cm2 was found to be 99.95% of coulombic efficiency (ηc), with a corresponding peak power density of 75.60 mW cm–2. Furthermore, in 1.0 M KOH, MoS2–GO nanocomposites demonstrate effective electrocatalysis for the oxygen evolution reaction (OER). The complete catalytic impact of MoS2–GO nanocomposites toward the OER was investigated. The MoS2–GO nanocomposites show an overpotential of 1.49 V (recorded at η of 10) and a Tafel slope of 381 mV dec–1 and remain stable after 20 h of chronoamperometry in 1.0 M KOH. The OER activity of MoS2–GO nanocomposites was found to be significantly higher than that of the bare screen-printed electrode and MoS2.

To explore the effects of the replacement rate of recycled aggregate, the content of graphene oxide (GO) and GO oxygen content on the fracture performance of recycled concrete (RC). In this paper, three point bending method was used to study the fracture property of GO-RC. The results show that the use of recycled aggregate will reduce the fracture property of RC, and the fracture property of RC will gradually improve with the increase of GO content. With the same amount of GO, the strengthening effect of 20% GO with oxygen is better than 40% GO with oxygen. The fracture energy and fracture toughness increase with the addition of GO, so GO plays an important role in improving the fracture performance of RC.

Tunable photoluminescence of water-soluble AgInZnS–graphene oxide (GO) nanocomposites and their application in-vivo bioimaging

Crystallization, mechanical performance and hydrolytic degradation of poly(butylene succinate)/graphene oxide nanocomposites obtained via in situ polymerization

Neural regeneration requires an optimal environment, including structural, chemical, mechanical, and electrical properties. Alginate (Alg) and graphene oxide (GO) are promising biomaterials for nerve tissue engineering, as Alg provides biocompatibility and hydrogel formation, while GO enhances mechanical strength and conductivity. For this study, GO was synthesized using the modified Hummer’s method, and Alg–GO scaffolds with varying GO concentrations were developed. FTIR spectroscopy confirmed the successful incorporation of GO into the Alg matrix, while UV–Vis and photoluminescence analyses demonstrated GO-induced modifications of the optical properties. Thermal analysis revealed improved stability with increasing GO content, whereas swelling tests showed enhanced water uptake and retention. Conductivity measurements indicated a clear improvement in electrical conductivity, particularly at moderate GO concentrations. SEM imaging confirmed a homogeneous distribution of GO within the Alg matrix, with structural uniformity across all samples. Cytocompatibility was assessed using SH–SY5Y neuroblastoma cells through MTT, LDH, and LIVE/DEAD assays. All composites supported cell attachment, viability, and proliferation, with GO concentrations up to 6% promoting optimal cell growth without inducing cytotoxicity. In contrast, excessive GO content (9%) resulted in reduced proliferation, although biocompatibility was maintained. These results highlight the potential of Alg–GO scaffolds as promising candidates for neural tissue engineering. The findings demonstrate the potential of Alg–GO scaffolds as advanced biomaterials for regenerative medicine. Future research should focus on in vivo evaluations to confirm their therapeutic applicability.

The hydrothermal process was used to prepare Mn3O4/x%GO nanocomposites (NC’s) having different ratios of the Mn3O4 nanoparticles (NP’s) on the surface of graphene oxide (GO) sheet. SEM image showed that the Mn3O4 NP’s were distributed over the surface of GO sheet. HRTEM images exhibited the lattice fringe arising from the (101) plane of the Mn3O4 NP’s having the interplanar d-spacing of 0.49 nm decorating on the surface of GO. The electronic absorption spectra of Mn3O4/x%GO NC’s also show broad bands from 250 to 550 nm. These bands arise from the d–d crystal field transitions of the tetrahedral Mn3+ species and indicate a distortion in the crystal structure. Photo-catalytic activity of spinel ferrite Mn3O4 NP’s by themselves was low but photo-catalytic activity is enhanced when the NP’s are decorating the GO sheet. Moreover, the Mn3O4/10%GO NC’s showed the best photo-catalytic activity. This result comes from the formation of Mn–O–C bond that confirm by FT-IR. This bond would facilitate the transfer of the photoelectrons from the surfaces of the NP’s to the GO sheets. PL emission which is in the violet–red luminescent region shows the creation of defects in the fabricated Mn3O4 NP’s nanostructures. These defects create the defect states to which electrons in the VB can be excited to when the CB. The best degradation efficiency was achieved by the Mn3O4 NP’s when they were used to decorate the GO sheets in the Mn3O4/10%GO NC’s solution.HighlightsLattice fringe of Mn3O4 with an interplanar d-spacing of 0.49 nm for (101) plane.Photocatalytic activity of spinel ferrite Mn3O4 nanoparticles by itself is low.Number of photoelectrons created depends on number of Mn3O4 on a given area of GOThe bonding of the Mn3O4 to the GO sheet would be though a Mn–O–C junction.The degradation processes were accelerated by Mn3O4/10%GO nanocompositesGraphic abstract

Comparative capacitive performance of MnSe encapsulated GO based nanocomposites for advanced electrochemical capacitor with rapid charge transport channels

Graphene oxide (GO) nanostructures are systems with many fascinating novel properties that can be used to study new science and have significant promise for applications. In this study, graphene oxide was prepared using the modified Hummer’s method. In addition, potassium ferrite is a good candidate for biomedical application, as iron and potassium are biocompatible and non-toxic materials. Mg0.85K0.3Fe2O4/GO nanocomposites were prepared by the citrate auto-combustion method. The effect of adding GO to Mg0.85K0.3Fe2O4 on structure, morphology, electrical, and magnetic properties was discussed. Samples under investigation were characterized using XRD, infrared spectroscopy (IR), high-resolution transmission electron microscopy (HRTEM), and atomic force microscopy (AFM). The crystallite size of prepared samples was decreased from 28.098 to18.148 nm by increasing GO content. Scanning electron microscope (SEM) confirms the successful adhesion of Mg0.85K0.3Fe2O4 nanoparticles on graphene oxide sheets, which are dispersed in a metal oxide matrix. EDAX analysis confirms the existence of C, O, K, Mg, and Fe elements present in the samples. Magnetic properties were studied by VSM and Faraday's method. GO has a significant effect on the magnetic properties of nanocomposites. For instance, the saturation magnetization and Curie temperature have diverse values, which will be appropriate for numerous applications.

The current research aimed to investigate the different aspects of novel nanocomposites based on carboxylated acrylonitrile butadiene rubber (XNBR), carboxylated styrene butadiene rubber (XSBR), graphene oxide (GO), and glycidyl methacrylate-grafted XNBR compatibilizer (XNBR-g-GMAC) blend. For this purpose, the novel nanocomposites of GO-XNBR-g-GMAC/XNBR/XSBR with different XNBR, XSBR, and GO composition and with and without XNBR-g-GMAC were synthesized. The related characteristics including curing properties, swelling behavior, morphological, electrical and mechanical characteristics were studied through rheometry, swelling test, transmission electron microscopy (TEM) and scanning electron microscopy (SEM) observation, electrical resistivity, mechanical test, dynamic mechanical thermal analysis (DMTA), etc. Results of rheometric tests revealed that the addition of XNBR-g-GMAC and increasing GO content reduces the scorch time (t 5) and optimum cure time (t 90) and increases the crosslink density (CLD). So that the addition of 5 phr of compatibilizer and 1 phr of GO to the XNBR75/XSBR25 blend reduced the t 5 and t 90 by 29% and 34%, respectively. TEM micrograph confirms the GO dispersion in rubber matrix and SEM observation shows that incorporation of XNBR-g-GMAC and GO reduces dispersed-phase droplet size due to the improved compatibility of XNBR and XSBR. According to the DMTA result, all the samples except XNBR/XSBR (without XNBR-g-GMAC) show one glass transition temperature (T g) which means XNBR-g-GMAC successfully enhanced the compatibility of XNBR/XSBR. The mechanical properties of samples showed that by the increase of GO concentration tensile strength, elongation at break, modulus, fatigue life, and hardness increased. Testing surface temperature changes in constant voltage (75 V) showed that the addition of 0.3 phr GO showed the best result and the further increase of GO up to the value of 1 phr revealed the opposite result and caused a decrease of about 54%. The results of practical tests also confirm the theories.

Polyacrylamide (PAAm) hydrogels have been proposed for use as promising biomaterials in biomedical and tissue engineering but their poor mechanical and water-retention properties have hindered their development. Graphene oxide (GO), an excellent nanofiller, was added to PAAm to produce mechanically strong GO–PAAm composites. The free radical crosslinking copolymerization method was used with GO content varying in the range between 5 and 50 µl of GO. The mechanical properties of the GO–PAAm composites are measured by compressive test, revealing a decrease in the shear modulus and toughness of the composites above 8 µl of GO by increasing GO content.

Rheology of graphene oxide suspended in yield stress fluid