Oxide Polymer Composites Research Articles

Harnessing PbZrO3-Polymer composites for enhanced electron collection through advanced interfacial engineering

The integration of metal oxide-polymer composites into energy conversion devices presents a promising strategy for improving electron collection efficiency. This study addresses the performance challenges faced by Dye-Sensitized Solar Cells (DSSCs), particularly in enhancing light absorption and charge carrier transport. The investigate the use of hybrid PbZrO3-Polymer composites, specifically PbZrO3 Perovskite combined with PNMPy-PoA conducting polymers, to optimize electron collection in these devices. Utilizing advanced characterization techniques, including structural analysis, morphological studies, and electrochemical measurements, Author explore the synergistic interactions between the metal oxides and polymers. By incorporating PbZrO3 nanoparticles with conducting polymers (poly-o-anisidine and poly-N-methyl pyrrole) and organic DTTCY dyes, synergetic achieves a significant improvement in the power conversion efficiency (PCE) of DSSCs. Our results reveal that the optimized PNMPy-PoA-PbZrO3 counter electrode exhibits a photoelectric conversion efficiency of 3.46 % under ideal conditions, with reduced charge transfer resistance at the electrolyte-counter electrode interface. These findings highlight the effectiveness of hybrid metal oxide-polymer composites in enhancing electron collection and stability, offering substantial improvements in the performance of energy conversion devices.

Effects of high-temperature thermal reduction on thermal conductivity of reduced graphene oxide polymer composites

The graphitic crystalline structure of reduced graphene oxide (rGO) can be improved by high-temperature thermal reduction at various heat-treatment temperatures ranging from 1000 to 2500 °C. The crystallinity significantly increased with increasing heat-treatment temperature. The electrical conductivities of the rGOs heat-treated at 2000 and 2500 °C (h-rGO-2000 and h-rGO-2500, respectively) were similar to those of commercial graphite. The isotropic thermal conductivity of rGO/epoxy composite with 10 wt% h-rGO-2500 (2.56 W/mK) was 11.6 times higher than that of pristine rGO (p-rGO; 0.22 W/mK) and significantly superior to those of epoxy composites with commercial graphite (0.82 W/mK) and mesophase pitch-based carbon fibers (MPCFs; 1.29 W/mK). Moreover, owing to the synergistic effect operating in the MPCF–h-rGO hybrid filler in epoxy composites, this combination of fillers increased the thermal conductivity to a greater extent than the MPCF–p-rGO hybrid filler. Optimum synergistic effects on the isotropic and in-plane thermal conductivities were achieved with an MPCF:h-rGO-2000 weight ratio of 49:1 (11.90 and 17.93 W/mK, 1.48 and 1.85 times higher than 8.02 and 9.69 W/mK for MPCF–p-rGO, respectively). Finally, a machine learning method that could predict and optimize the properties of rGOs based on their heat-treatment temperatures and material compositions was developed.

The use of low‐density polyethylene‐molybdenum oxide polymer composites as radiation shielding laminates in dental radiology physical structures

AbstractRadiation protection is crucial in the protection of humans from the harmful effects of ionizing radiation. One of the most reliable ways of reducing the risk of occupationally exposed workers and the public in dental radiology is the installation of an effective radiation shielding barrier at the facility. Concrete barriers are predominantly used for dental shielding, however there is need to consider the use of lighter, ready‐made, and lower half value layer (HVL) materials as shielding materials in dental radiology facilities. In this work, low‐density polyethylene‐molybdenum oxide polymer composites were prepared (85C2H4‐15MoO3, 90C2H4‐10MoO3, and 95C2H4‐5MoO3), and the radiation attenuation measurements were carried out experimentally. The composites displayed acceptable x‐ray absorbing capabilities. 85C2H4‐15MoO3 polymer composite (DT1) showed optimal shielding in comparison with concrete. DT1 has an approximate HVL like concrete while it is 54.3% lighter than concrete. 85C2H4‐15MoO3 polymer composite is 1.5%, 0.8%, and 6.3% higher in linear attenuation coefficient than concrete at 60, 70, and 80 kVps, respectively. This implies that DT1 can effectively replace concrete at dental diagnostic energies.

First principles insights into oxide/polymer composites: SrTiO3/polyaniline/graphene

A detailed computational investigation, based on density functional theory, of the interaction of polyaniline (PANI) and graphene nanoribbons (GNRs) with SrTiO3 is presented. The adsorption of PANI in various oxidation states and co-adsorption with GNRs is found to be thermodynamically favourable. Adsorbed PANI introduces N and C 2p states into the SrTiO3 bandgap, while co-adsorption of PANI and GNRs leads to a bridging of the gap and semi-metallic behaviour, thus rendering the electrical properties highly sensitive to the loading of the GNRs/PANI in the composites. Modelling the lattice dynamics of the composites predicts a 68–88% reduction in the lattice thermal conductivity due to reduced phonon group velocities. Taken together, these findings provide insight into the growing number of experimental studies highlighting the enhanced thermoelectric performance of oxide-polymer composites and indicate co-adsorption with graphene as a facile direction for future research.

Biosynthesis-Based Al2O3 Nanofiller from Cymbopogon citratus Leaf/Jute/Hemp/Epoxy-Based Hybrid Composites with Superior Mechanical Properties.

Metallic nanoparticles (NPs) manufactured by ecofriendly strategies have also received much interest because of their elastic scattering properties and performance in nanomaterials. Aluminium oxide nanomaterials stand out among nanomaterials due to their tremendous uses in ceramic products, fabrics, therapeutic agents, catalyst supports, sewage sludge, and biosensors. The current paper investigates the effect of the nanoparticle composition and layer sequential on the mechanical characteristics of jute (J)-hemp (H) incorporated with an aluminium oxide polymer composite. NaOH is used to change the physical aspects of both plant fibres. A total of 20 specimens were tested with varying stacking sequences and padding weight ratios. Mechanical properties like a nanocomposite's tension, bending, and ILSS was measured. Stacked series and flowability substantially impact the nanocomposite. The Group 3 nanocomposite with 2% Al2O3 has the highest tensile strength, 54.28% of the Group 1 and 2 combinations. The stack series significantly influences the material properties of nanomaterials. Because of the alternating layers of natural fabrics, Group 4 specimens have the maximum flexural strength. Group 3 composite materials have the highest ILSS because they have hemp on the outermost surface. It has been discovered that Group 4 material with a 2% Al2O3 concentration is possibly the most substantial material. The existence of Al2O3 nanoparticles in the green synthesis was confirmed by XRD analysis.

Characterization of Solar Absorber Coated by Reduced Graphene Oxide Polymer Composite on Metal Sheets

This paper presents the characterization of solar heat absorber coatings on metal sheets using reduced graphene oxide polymer composites. The reduced graphene oxide (rGO) polymer composite material was evenly coated by the silk-screen method on three types of metal sheets. The thickness of the coated sheet samples was 0.25 mm which were exposed under solar radiation and the variations in temperatures versus time were recorded. The influence of solar radiation and angle of incidence during peak hours was recorded. The results show that stainless steel coated by rGO absorber gain more heat than other metal sheet absorbers. These coatings have a promising scope in solar thermal applications and the technique is cost-effective to characterize efficient solar absorber coatings.

All 3D Printed Stretchable Piezoelectric Nanogenerator for Self-Powered Sensor Application.

With the rapid development of wearable electronic systems, the need for stretchable nanogenerators becomes increasingly important for autonomous applications such as the Internet-of-Things. Piezoelectric nanogenerators are of interest for their ability to harvest mechanical energy from the environment with its inherent polarization arising from crystal structures or molecular arrangements of the piezoelectric materials. In this work, 3D printing is used to fabricate a stretchable piezoelectric nanogenerator which can serve as a self-powered sensor based on synthesized oxide–polymer composites.

Redox mechanisms of conversion of Cr(VI) to Cr(III) by graphene oxide-polymer composite

Alternative methods of aqueous chromium removal have been of great research interest in recent years as Cr (VI) is a highly toxic compound causing severe human health effects. To achieve better removal of Cr (VI), it is essential to understand the chemical reactions that lead to the successful removal of Cr species from the solution. Recent studies have demonstrated that graphene oxide (GO) based polymer beads cannot only adsorb Cr (VI) via electrostatic attractions but also reduce it to Cr (III), which is a much less toxic form of chromium. This conversion and the functional groups involved in this conversion, until now, were not elucidated. In the present study, we employed X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy to investigate the conversion pathway of Cr (VI) to Cr (III) in graphene-based polymer beads. The results showed that alcoholic groups are converted to carboxylic groups while reducing Cr (VI) to Cr (III). The inclusion of GO in the polymer beads dramatically increased the potential of Cr (VI) uptake and conversion to Cr (III), indicating polymers and nanomaterials containing alcohol groups can remove and convert chromium in water. Other functional groups present in the polymer bead play an important role in adsorption but are not involved in the conversion of Cr (VI) to Cr (III).

Study of electromagnetic shielding effectiveness of metal oxide polymer composite in their bulk and layered forms.

In this paper, we present the studies on electromagnetic interference (EMI) shielding effectiveness (SE) of K2CrO4-PMMA composites developed by two different methods: one in bulk form of thickness 1.2mm and another by stacking twelve layers of thin films each of thickness 100μm. The EMI SE of stacked twelve layers of 1.2-mm-thick composite films has been achieved until 23.2dB in the frequency range 8.0-12.0GHz. This is remarkably higher than the 17dB achieved for the bulk composites of 1.2mm thickness. The characteristic EMI SE graphs obtained using Agilent E82B Vector Network Analyzer in the X band frequency range have been depicted, and the shielding mechanism in these composites has been analyzed. It is found that the SE in this frequency range is dominated by absorption. The study suggests these composites to be a potentially promising material for EMI shielding purpose.

Saturable absorber incorporating graphene oxide polymer composite through dip coating for mode-locked fiber laser

Fabrication of microfiber saturable absorbers (SA) is a tedious process. This work demonstrates a simplified method of microfiber SA fabrication by integrating graphene oxide/polymethylsiloxane (GO/PDMS) using dip-coating technique. The idea is to enhance light-matter interaction between graphene and propagating light modes within the microfiber by enhancing the binding strength and proximity of the graphene-polymer composite to the microfiber. The implementation of GO/PDMS SA in an erbium-doped fiber laser cavity has successfully generated ultrashort pulses with pulse duration of 629 fs in the C-band emission region. The success of this work contributes to better insight towards simplifying the fabrication technique of microfiber SAs.

Exclusively Proton Conductive Membranes Based on Reduced Graphene Oxide Polymer Composites.

Proton exchange membranes are at the heart of various technologies utilizing electrochemical storage of intermittent energy sources and powering electrical devices. Current state of the art membranes are based on perfluorosulfonic acid, introduced more than a half century ago. Low specificity to protons accompanied by permeance by other species is one of the main impediments for various promising applications in green technologies in an energy sustainable economy. Here we present composite membranes that are exclusively proton selective and do not allow crossover of any ionic or molecular species other than protons. Membranes have high proton conductivity and exceptional mechanical and chemical stability and thus may significantly improve performance of hydrogen-based technologies such as electrolyzers, various kinds of fuel cells, and flow batteries in the future.

Nanoscale toughening of ultrathin graphene oxide-polymer composites: mechanochemical insights into hydrogen-bonding/van der Waals interactions, polymer chain alignment, and steric parameters.

This paper describes a systematic study on the nanoscale toughening of monolayer graphene oxide (GO) by an ultra-thin polymer adlayer, which impedes the propagation of cracks during intraplanar fracture. Using molecular dynamics simulations, the crack-bridging capabilities of a library of five hydrogen-bonding-capable polymers are explored against an epoxide-rich GO substrate. The best crack-bridging effect is found in polymers with functional groups that can both donate/accept hydrogen atoms and have better capability to form cooperative hydrogen bonds. Aligning the chains of poly(acrylic acid) orthogonally to the crack propagation direction significantly enhances the fracture toughness of monolayer GO (by 310%) in comparison to that for an adlayer with randomly arranged chains (180% enhancement). Notably, van der Waals interactions, which are seldom highlighted in the fabrication of strong GO-polymer interfaces, are found to also provide significant crack-bridging capabilities when the polymers possess large side groups. These results pave the way for a set of design criteria that can help in remediating the intrinsically brittle mechanical behavior of two-dimensional materials, a barrier that currently restricts their potential applications.

Synthesis and application of polymer-grafted nanocellulose/graphene oxide nano composite for the selective recovery of radionuclides from aqueous media

ABSTRACTA series of batch adsorption experiments under optimized conditions were performed and also to evaluate the reliability and feasibility of prepared adsorbent, carboxylate functionalized ethylene glycol dimethacrylate (EGDMA) crosslinked nanocellulose/graphene oxide polymer composite (EGDMA-g-nCell/GO) for Th(IV) recovery from aqueous media. The material was well characterized by using FTIR, XRD, XPS, SEM-EDS, TG-DTA and zeta potential analysis. The equilibrium adsorption capacity (Q0) among the various models was 141.21 mg/g at 30 °C and was well correlated with Langmuir isotherm model with reduced χ2 and R2 values. The spent adsorbent was undergone four cycles of regeneration process without any significant loss in adsorption capacity using 0.1 M HNO3 as desorbing agent, with up to 98.0 % recovery.

Graphene-Reinforced Metal and Polymer Matrix Composites

Composites have tremendous applicability due to their excellent capabilities. The performance of composites mainly depends on the reinforcing material applied. Graphene is successful as an efficient reinforcing material due to its versatile as well as superior properties. Even at very low content, graphene can dramatically improve the properties of polymer and metal matrix composites. This article reviews the fabrication followed by mechanical and tribological properties of metal and polymer matrix composites filled with different kinds of graphene, including single-layer, multilayer, and functionalized graphene. Results reported to date in literature indicate that functionalized graphene or graphene oxide-polymer composites are promising materials offering significantly improved strength and frictional properties. A similar trend of improved properties has been observed in case of graphene-metal matrix composites. However, achieving higher graphene loading with uniform dispersion in metal matrix composites remains a challenge. Although graphene-reinforced composites face some challenges, such as understanding the graphene-matrix interaction or fabrication techniques, graphene-reinforced polymer and metal matrix composites have great potential for application in various fields due to their outstanding properties.

Carbon foams from emulsion-templated reduced graphene oxide polymer composites: electrodes for supercapacitor devices

Amphiphilic reduced graphene oxide (rGO) is an efficient emulsifier for water-in-divinylbenzene (DVB) high internal phase emulsions.

Evaluation of Radiation Shielding Properties of the Polyvinyl Alcohol/Iron Oxide Polymer Composite.

Context:Lead is the conventional shielding material against gamma/X-rays. It has some limitations such as toxic, high density, nonflexibility, and also bremsstrahlung production during electron interaction. It may affect the accuracy of radiotherapy outcome.Aims:To theoretically analyze the radiation shielding properties of flexible polyvinyl alcohol/iron oxide polymer composite with five different concentrations of magnetite over the energy range of 15 KeV–20 MeV.Subjects and Methods:Radiological properties were calculated based on the published literature. Attenuation coefficients of pure elements are generated with the help of WinXCOM database.Results:Effective atomic numbers and electron density are increased with the concentration of magnetite. On the other hand, the number of electrons per gram decreased. Mass attenuation coefficient (μ/ϼ) and linear attenuation coefficients (μ) are higher in the lower energy <100 KeV, and their values decreased when the energy increased. Computed tomography numbers (CT) show the significant variation between the concentrations in <60 KeV. Half-value layer and tenth-value layers are directly proportional to the energy and indirectly proportional to the concentration of magnetite. Transmission curve, relaxation length (ƛ), kinetic energy released in the matter, and elemental weight fraction are also calculated and the results are discussed.Conclusions:0.5% of the magnetite gives superior shielding properties compared with other concentrations. It may be due to the presence of 0.3617% of Fe. Elemental weight fraction, atomic number, photon energy, and mass densities are the important parameters to understand the shielding behavior of any material.

Synthesis and Solid‐State NMR Studies of Proton‐Conducting Mesoporous Niobium Oxide Polymer Composites with Nafion‐Like Thermal Durability

AbstractProton conductivity and thermal durability studies were performed on a series of mesoporous Nb2O5 composites with naphthalene sulfonate formaldehyde resin polymerized within the pores. The proximity of the sulfonate groups of the polymer to the walls of the oxide mesostructure was deliberately tailored to ensure superior dehydration resistance crucial to proton conductivity. Initially characterized by nitrogen adsorption, XRD, TGA and STEM, subsequent study using impedance spectroscopy over a temperature range of 20–150 °C established their proton conductivity performance. The most promising sample displayed a conductivity of 21.77 mS cm−1 at 80 °C surpassing the literature value for Nafion 117 (8 mS cm−1) as measured in our labs using the same setup. Subsequent thermal durability tests demonstrated that this composite maintains superior conductivity to Nafion 117 at 80 °C for the length of the study (24 h). These observations were rationalized by in depth solid‐state NMR studies.

Abstract 376: Capture and release of circulating tumor cells by temperature-sensitive graphene oxide-polymer composite

Abstract Introduction and Objective: Recently, various microfluidics-based circulating tumor cells (CTC) isolation technologies have been developed to isolate, enumerate, and characterize CTCs, but there are few studies reporting CTC release after selective capture. Existing devices face impediments to the easy release of captured cells due to the conjugation of antibodies to permanent structures within the devices. Here we present a tunable microfluidic polymer graphene oxide (GO) Chip based on a temperature-sensitive graphene oxide-polymer composite for selective capture and efficient subsequent release of CTCs. Methods: A blend film of GO sheets and thermo-responsive polymers serves as a platform enabling cell capture and release in our microfluidic devices. The polymers with a tunable lower critical solution temperature (LCST) allow for stimulated release of the captured cells when the device temperature is below the LCST. The GO sheets serve as a carrier for phosophlipid-PEG-amine, which is used for the immobilization of an antibody against the epithelial-cell-adhesion-molecule (EpCAM). To investigate the capture efficiency, MCF-7 cells labeled with cell tracker dye were spiked into 1 mL of whole blood and flowed through the microfluidic device. After thoroughly washing the device with PBS at 25 °C to remove any non-specifically bound cells, we dissolved the thermo-responsive composite with 1 mL of PBS at 5 °C in a cold room and collected released cells from the device outlet. The released cells were cytospun and stained to identify CTCs as cytokeratin positive, DAPI positive, and CD45 negative cells. We also tested peripheral blood samples obtained from patients with metastatic breast cancer in a similar manner. Results: The graphene oxide-polymer based CTC-chip showed a capture efficiency of 95.21% at 95.21% and a release efficiency of 92.45% for MCF-7 breast cancer cells. This new GO Chip was also able to isolate viable CTCs from blood samples of metastatic breast cancer patients for further molecular characterizations. Conclusion: We present a sensitive and tunable microfluidic chip based on a GO-polymer composite to capture, release, identify, and characterize extremely rare CTCs. The CTCs released from the chip are viable, suggesting that this polymer based GO Chip offers great potential for clinical applications due to its high-affinity cell capture and the ability to enable various downstream analyses of captured CTCs. Citation Format: Hyeun Joong Yoon, Apoorv Shanker, Yang Wang, Molly Kozminsky, Shamileh Fouladdel, Monika L. Burness, Ebrahim Azizi, Max S. Wicha, Jinsang Kim, Sunitha Nagrath. Capture and release of circulating tumor cells by temperature-sensitive graphene oxide-polymer composite. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 376. doi:10.1158/1538-7445.AM2015-376

Synthesis and characterization of reduced graphite oxide–polymer composites and their application in adsorption of lead

Herein, we report the in situ polymerization of 1,5-diaminonaphthalene (15DAN) and 1,4-diaminoanthraquinone (14DAA) on the surface of reduced graphite oxide (RGO). Synthesized RGO-P15DAN and RGO-P14DAA were characterized by FTIR, Raman, SEM, TGA and XRD. The adsorption capacity and adsorptivity of the synthesized composites were investigated by Atomic Absorption Spectroscopy (AAS) using 100ppm aqueous solution of Pb2+ ions. Further, we compared the results of the composites with those of poly 1,5-(diaminonaphthalene) (P15DAN), poly 1,4-(diaminoanthraquinone) (P14DAA), RGO, graphite oxide (GO) and graphite. Among the tested adsorbents, RGO-P15DAN demonstrated the high adsorptivity.

Interfacial shear strength of reduced graphene oxide polymer composites

Interfacial shear strength (IFSS) between particle and matrix in particulate polymer composites is a critical property in determining the mechanical behaviors since it is directly related to not only their Young’s modulus or specific strength, but also energy absorbing capability. However, the conventional techniques often present a technical challenge to accurately measure the IFSS between fillers and matrix in the composites. This is more apparent in graphene particulate composites due to their nano-scale dimensions as well as the platelet-shaped geometry. Here, the focus of this study is to use a semi-empirical approach to determine the IFSS of graphene particulate composites by combining experiments with finite element (FE) modeling. The materials of interest are reduced graphene oxide (RGO) and polycarbonate (PC). The tensile testing was performed to characterize the mechanical properties, while simultaneously monitoring the acoustic emission events in order to measure the global debonding stress (GDS) in the composites. By coupling thermal stress analysis and deformation analysis with the GDS as input to a FE model, the IFSS of the RGO particulate PC composites was successfully estimated by about 136MPa, avoiding unnecessary assumptions and uncertainties which are seem to be inevitable with the conventional techniques for the IFSS measurement.