Organic-inorganic Nanocomposites Research Articles

Biosustainable Multiscale Transparent Nanocomposite Films for Sensitive Pressure and Humidity Sensors.

Light weight, thinness, transparency, flexibility, and insulation are the key indicators for flexible electronic device substrates. The common flexible substrates are usually polymer materials, but their recycling is an overwhelming challenge. Meanwhile, paper substrates are limited in practical applications because of their poor mechanical and thermal stability. However, natural biomaterials have excellent mechanical properties and versatility thanks to their organic-inorganic multiscale structures, which inspired us to design an organic-inorganic nanocomposite film. For this purpose, a bio-inspired multiscale film was developed using cellulose nanofibers with abundant hydrophilic functional groups to assist in dispersing hydroxyapatite nanowires. The thickness of the biosustainable film is only 40 μm, and it incorporates distinctive mechanical properties (strength: 52.8 MPa; toughness: 0.88 MJ m-3) and excellent optical properties (transmittance: 80.0%; haze: 71.2%). Consequently, this film is optimal as a substrate employed for flexible sensors, which can transmit capacitance and resistance signals through wireless Bluetooth, showing an ultrasensitive response to pressure and humidity (for example, responding to finger pressing with 5000% signal change and exhaled water vapor with 4000% signal change). Therefore, the comprehensive performance of the biomimetic multiscale organic-inorganic composite film confers a prominent prospect in flexible electronics devices, food packaging, and plastic substitution.

Synthesis of organic-inorganic hybrid nanocomposites modified by catalase-like catalytic sites for the controlling of kiwifruit bacterial canker.

Kiwifruit bacterial canker, caused by Pseudomonas syringae pv. Actinidiae (Psa), is one of the most important diseases in kiwifruit, creating huge economic losses to kiwifruit-growing countries around the world. Metal-based nanomaterials offer a promising alternative strategy to combat plant diseases induced by bacterial infection. However, it is still challenging to design highly active nanomaterials for controlling kiwifruit bacterial canker. Here, a novel multifunctional nanocomposite (ZnO@PDA-Mn) is designed that integrates the antibacterial activity of zinc oxide nanoparticles (ZnO NPs) with the plant reactive oxygen species scavenging ability of catalase (CAT) enzyme-like active sites through introducing manganese modified polydopamine (PDA) coating. The results reveal that ZnO@PDA-Mn nanocomposites can efficiently catalyze the conversion of H2O2 to O2 and H2O to achieve excellent CAT-like activity. In vitro experiments demonstrate that ZnO@PDA-Mn nanocomposites maintain the antibacterial activity of ZnO NPs and induce significant damage to bacterial cell membranes. Importantly, ZnO@PDA-Mn nanocomposites display outstanding curative and protective efficiencies of 47.7% and 53.8% at a dose of 200 μg mL-1 against Psa in vivo, which are superior to those of zinc thiozole (20.6% and 8.8%) and ZnO (38.7% and 33.8%). The nanocomposites offer improved in vivo control efficacy through direct bactericidal effects and decreasing oxidative damage in plants induced by bacterial infection. Our research underscores the potential of nanocomposites containing CAT-like active sites in plant protection, offering a promising strategy for sustainable disease management in agriculture.

Physicochemical and structural characteristics of hybrid nanocomposites based on branched polyimide with a low content of inorganic component

The series of organic-inorganic hybrid nanocomposites based on branched polyimide matrix and with different amounts of tetraethoxysilane (TEOS) (5, 20, and 50 wt.% of the initial polyamic acid mass) were synthesized and studied using nitroxyl paramagnetic probe, measuring dielectric permittivity, X-ray structural analysis and optical microscopy. It was shown that in some cases the introduction of inorganic component is accompanied by a decrease in the segmental mobility of polyimide matrix as a result of the partial immobilization of organic macrochains during the formation of inorganic microregions. In the presence of inorganic component, a weak dependence of the polymer permeability on the content of the organic component in the system is observed, also the specific density changes little with an increase in TEOS content. Extreme changes in the segmental mobility and dielectric permittivity of the branched matrix formed in the presence of 5 wt% TEOS were found compared to systems of other compositions. This can be caused to a large extent by structural changes in the system. At a low content of TEOS occurs significant «loosening» of organic matrix, a sharp decrease in the dielectric constant and a significant increase in the segmental mobility of the polyimide matrix. Small angle X-ray scattering diffractograms demonstrate drastic changes in polyimide composite heterogeneity in the presence of 5 wt.% TEOS content. According to the optical microscopy data, the introduction of TEOS into polyimide is accompanied by the formation of microaggregates of inorganic nanoparticles in the system, the number and average size of which depend on the SiO2 content and looks most homogeneous at a low TEOS content.

Catalytic effect of N-phenylaminopropyl polyheadral oligomeric silsesquioxane in the synthesis of hybrid nanocomposites based on polycyanurate

Organic-inorganic nanocomposites based on heat-resistant crosslinked polycyanurate (PCN) and N-phenylaminopropyl polyhedral oligomeric silsesquioxane (NPAP-POSS), containing eight reactive secondary amino groups, were synthesized using the in situ reactive formation method. Fourier transmission infrared (FTIR) spectroscopy and dynamic differential scanning calorimetry (DSC) methods were used to study the effect of NPAP-POSS on the kinetics of bisphenol E dicyanate ester (DCBE) polycyclotrimerization during the formation of PCN in PCN/NPAP-POSS nanocomposites. The content of the nanofiller was varied from 0.05 to 1.00 wt.%. Based on the results of FTIR spectral studies, the main kinetic peculiarities of PCN formation were found and their changes under the action of NPAP-POSS nanofiller were determined. A significant catalytic effect of NPAP-POSS on the polycyclotrimerization of DCBE was found, which is confirmed by a decrease in the time of the onset of auto-acceleration, an acceleration of the conversion of cyanate groups of DCBE and the formation of triazine cycles of PCN, an increase in the values of the maximum reaction rate, a decrease in the duration of the reaction, etc. The dynamic DSC method also confirmed the catalytic effect of NPAP-POSS on the formation of PCN in the nanocomposites and established the main kinetic characteristics depending on the content of the nanofiller: a significant decrease in the temperature of the exothermic maximum, an increase in the reaction enthalpy, non-monotonic changes in the induction period and reaction rate, etc. From the analysis of the experimental data, it was concluded that the detected changes in the kinetics of the in situ reaction formation of PCN/NPAP-POSS nanocomposites and the recorded catalytic effect of the nanofiller are due to the fact that two chemical processes occur during the synthesis of the nanocomposites: chemical interaction of –O–C≡N groups of DCBE with secondary –NH groups of NPAP-POSS, which led to further embedding of nanoparticles into the resulting polymer matrix and the direct polycyclotrimerization of DCBE with formation of hybrid polycyanurate network. Schemes of the sequential reactions explaining the catalytic effect of the nanofiller in the synthesis of hybrid PCN/NPAP-POSS nanocomposites are proposed. It was concluded that under the selected conditions of the synthesis, the greatest catalytic effect of the nanofiller is manifested at its content of 0.10 wt.%, since for this sample the maximum shift of the reaction exothermic peak towards lower temperatures, the maximum reaction rate, and the minimum induction period and reaction start temperature were recorded. The results of the research make it possible to optimize the synthesis of heat-resistant materials promising for use in special-purpose structures.

Colorimetric detection of Staphylococcus aureus based on self-linkable and hollow organic-inorganic nanocomposites as light-driven oxidase-like nanozyme for cascade signal amplification

Facing increasingly serious bacterial infections and their threat to food safety and human health, exploring specific and sensitive bacterial strategies is indispensable. Nanozyme-based colorimetric biosensors with the superiorities of easy-to-read and catalytic signal amplification have attracted increasing interest. However, few investigations relate to the nanozymes with excellent light-driven oxidase-like activity. In this study, a sensitive colorimetric biosensor for Staphylococcus aureus (S. aureus) detection was constructed based on a light-driven oxidase-like nanozyme (PHCS@CuNcPOPTP) as well as the self-chain linking process. The hollow organic-inorganic nanocomposite (PHCS@CuNcPOPTP) was prepared by a one-step Friedel-Crafts alkylation reaction. The PHCS@CuNcPOPTP exhibited excellent and synergistically enhanced light-driven oxidase-like activity originating from its unique photosensitive properties. Subsequently, PHCS@CuNcPOPTP was served as a scaffold, loading with the rabbit anti-Staphylococcus aureus Rosenbach tropina antibody (bs-4582R, Ab2), DNA1, and DNA2, respectively, to construct signal probes (PHCS@CuNcPOPTP@Au-Ab2/DNA1, PHCS@CuNcPOPTP@Au-DNA1, and PHCS@CuNcPOPTP@Au-DNA2). By the repetitive DNA hybridization among signal probes, a large amount of PHCS@CuNcPOPTP-DNA dendrimers were formed and utilized to trigger the chromogenic reaction without the participation of high-concentration H2O2, resulting in the cascaded catalytic amplification and the lower background signal. As expected, the suggested sensing platform presented ultrasensitive bacterial detection with a remarkably broad linear range (101 to 108 CFU/mL) and a limit of detection (LOD, 3.40 CFU/mL).

Sol-Gel Derived Gelatin-Bioactive Glass Nanocomposite Biomaterials Incorporating Calcium Chloride and Calcium Ethoxide.

Calcium-containing organic-inorganic nanocomposites play an essential role in developing bioactive bone biomaterials. Ideally, bone substitute materials should mimic the organic-inorganic composition of bone. In this study, the roles of calcium chloride (CaCl2) and calcium ethoxide (Ca(OEt)2) were evaluated for the development of sol-gel-derived organic-inorganic biomaterials composed of gelatin, bioactive glass (BG) and multiwall carbon nanotubes (MWCNTs) to create nanocomposites that mimic the elemental composition of bone. Nanocomposites composed of either CaCl2 or Ca(OEt)2 were chemically different but presented uniform elemental distribution. The role of calcium sources in the matrix of the nanocomposites played a major role in the swelling and degradation properties of biomaterials as a function of time, as well as the resulting porous properties of the nanocomposites. Regardless of the calcium source type, biomineralization in simulated body fluid and favorable cell attachment were promoted on the nanocomposites. 10T1/2 cell viability studies using standard media (DMEM with 5% FBS) and conditioned media showed that Ca(OEt)2-based nanocomposites seemed more favorable biomaterials. Collectively, our study demonstrated that CaCl2 and Ca(OEt)2 could be used to prepare sol-gel-derived gelatin-BG-MWCNT nanocomposites, which have the potential to function as bone biomaterials.

Biodistribution and human absorbed dose evaluation of an organic-inorganic nanocomposite containing 198Au (198Au/PG4D)

Biodistribution and human absorbed dose evaluation of an organic-inorganic nanocomposite containing 198Au (198Au/PG4D)

Optimizing magnetic, dielectric, and antimicrobial performance in chitosan-PEG-Fe2O3@NiO nanomagnetic composites

There is a growing interest in eco-friendly and cost-effective organic-inorganic nanocomposites due to their alignment with the principles of “green” chemistry, as well as their biocompatibility and non-toxicity. This study focused on producing Chitosan-PEG-Fe2O3@NiO nanomagnetic composites to improve the stability, dielectric properties, and antimicrobial effectiveness of these nanocomposite materials. The process involved synthesizing Fe2O3@NiO via sol-gel and polymerizing chitosan-PEG. The nanocomposites were characterized by XRD, TEM, FTIR, optical, dielectric, and VSM. Incorporating Fe2O3@NiO significantly improved stability, and the interaction with Fe2O3 during the sol-gel process facilitated the formation of NiFe2O4 with an increase in the crystallinity within the chitosan-PEG matrix. The study examined optical and dielectric properties, highlighting that the 3 NiO-doped chitosan-PEG-Fe2O3 composites had high electrical conductivity (1.8 ∗ 10−3 S/cm) and a significant dielectric constant (106 at low frequencies). As the ratio of NiO NPs within the chitosan-PEG-Fe2O3 increases, the energy band gap of chitosan-PEG-Fe2O3 films decreases up to 3.7 eV. This decrease is owing to the quantum confinement effect. These composites also demonstrated improved antimicrobial activity against E. coli and S. aureus and higher activity in the presence of nanomagnetic particles. The minimum inhibitory concentrations of CS-PEG-Fe2O3/NiO NPs against (Bacillus cereus, M. luteus, S. aureus and (S. enterica, H. pylori, E. coli) were (22–35 mm) and (21–34 mm), respectively.

Efficient pre-concentration of trace levels of the synthetic food dye in foodstuff samples through an adsorption extraction technique using a novel inorganic–organic nanocomposite

In the present study, a maleic acid-functionalized exfoliated graphite/calcium hydroxide (MA-EG/Ca(OH)2) was constructed and employed as a novel inorganic–organic nanocomposite for an efficient dispersive solid-phase microextraction (DSPME) of trace levels of sunset yellow (SY), a synthetic food dye in foodstuff samples before UV–Vis determination. To identify and characterize of the sorbent, various analytical techniques were utilized, including, Fourier transform-infrared spectroscopy (FT-IR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), and Brunauer-Emmett-Teller (BET) analyses. The MA-EG/Ca(OH)2 exhibited a specific surface area of 40.35 m2 g−1 and adsorption capacity of 46.72 mg g−1 towards SY. Central composite design (CCD) in conjunction with a response surface methodology (RSM)-based ANOVA analysis was applied for evaluation and optimization of effective factors including pH (X1), sorbent mass (X2), contact time (X3), and elution volume (X4). According to the results, the optimum values were pH: 6.0, sorbent mass: 12 mg, contact time: 12 min, and elution volume: 0.18 µL. Under theses optimized conditions, DSPME/UV–Vis determination demonstrated a linear range of 50–4800 ng mL−1, a limit of detection (LOD) of 12.45 ng mL−1, and a limit of quantification (LOQ) of 41.49 ng mL−1 (n = 3). The relative standard deviation (RSD) at low concentration level (50–500 ng mL−1) of SY was 4.58 %. Recovery values in different concentration levels were in the range of 96.4–102.9 %. Overall, the proposed method showed the superior features, including ease of synthesizing the sorbent, acceptable LOD and LOQ values, remarkable sensitivity, a wide operational range, good reusability (up to five cycles), environmentally friendly as well as cost-effectiveness, that make it a promising candidate for the analysis of SY in foodstuff samples.

Protein-guided biomimetic nanomaterials: a versatile theranostic nanoplatform for biomedical applications.

Over the years, bioinspired mineralization-based approaches have been applied to synthesize multifunctional organic-inorganic nanocomposites. These nanocomposites can address the growing demands of modern biomedical applications. Proteins, serving as vital biological templates, play a pivotal role in the nucleation and growth processes of various organic-inorganic nanocomposites. Protein-mineralized nanomaterials (PMNMs) have attracted significant interest from researchers due to their facile and convenient preparation, strong physiological activity, stability, impressive biocompatibility, and biodegradability. Nevertheless, few comprehensive reviews have expounded on the progress of these nanomaterials in biomedicine. This article systematically reviews the principles and strategies for constructing nanomaterials using protein-directed biomineralization and biomimetic mineralization techniques. Subsequently, we focus on their recent applications in the biomedical field, encompassing areas such as bioimaging, as well as anti-tumor, anti-bacterial, and anti-inflammatory therapies. Furthermore, we discuss the challenges encountered in practical applications of these materials and explore their potential in future applications. This review aspired to catalyze the continued development of these bioinspired nanomaterials in drug development and clinical diagnosis, ultimately contributing to the fields of precision medicine and translational medicine.

Polypyrrole fabricated Laponite RD conductive nanocomposites: influence of grafting efficiency on structural and conductive properties.

In the present work novel conductive organic-inorganic nanocomposites were produced by grafting of pyrrole monomer onto silanized Laponite RD utilizing emulsion graft polymerization. Influence of some important factors like concentration of monomer, initiator and surfactant were investigated on grafting efficiency. Grafting of polypyrrole chains onto modified Laponite RD was verified by Fourier transform infrared spectroscopy (FT-IR). Scanning electron microscope (SEM) revealed the spherical particles of nanocomposite with average diameter of 271.5 nm. XRD pattern showed that molecular framework of pure polypyrrole almost remains same in nanocomposite. Surface area and pore volume of Laponite RD, measured by Brunauer-Emmett-Teller (BET) analysis, was also altered indicating effective grafting of polypyrrole chains onto modified substrate. Maximum grafting efficiency (%), determined gravimetrically, was 87.3% at monomer, initiator, and surfactant concentrations of 1.50, 1.00, and 0.50% respectively. Prepared nanocomposites with grafting efficiency of 87.3% have displayed maximum electrical conductivity of 0.23 × 10-2 Scm-1. These nanocomposites can be used for manifold applications like biomedical and energy storage devices.

Advances in organic–inorganic nanocomposites for cancer imaging and therapy

Abstract “All in one” organic–inorganic nanocomposites with high biocompatibility and excellent physicochemical properties have recently attracted special attention in cancer imaging and therapy. Combination of organic and inorganic materials confers the nanocomposites with superior biocompatibility and biodegradability of organic materials, as well as magnetic, mechanical, and optical properties of inorganic materials. Increased endeavors have been made to produce diverse organic–inorganic nanocomposites and investigate their potential applications in cancer treatment. Thus, a systematic review of research progresses of diverse organic–inorganic nanocomposites in cancer imaging and therapy is indispensable. Following a brief overview of nanocomposites synthesis, classification, and functionalization, the current review is focused on comprehensively summarizing representatives of both organic–inorganic nanoscale nanocomposites (including organic-silica, organic-carbon, organic-quantum dots, organic-platinum family metals, organic-gold, organic metal oxides, and other nanocomposites) and organic–inorganic molecular nanocomposites (including metal-organic frameworks, organosilica nanoparticles, and amorphous metal coordination polymer particles), and further analyzing their working mechanism in cancer imaging and therapy. Finally, the challenges and future perspectives of organic–inorganic nanocomposites are addressed for promoting their developments and clinical application in cancer treatment.

Interfacial Tension-Impelled Self-Assembly and Morphology Tuning of Poly(3,4-ethylene dioxythiophene)/Tellurium Nanocomposites at Various Liquid/Liquid Interfaces.

Compared to the enormous number of nanostructures that have been documented, the variety of nanostructures produced by organic polymerization is rather limited. We devised an unconventional route and a sustainable approach to distribute tellurium nanoparticles (Te NPs) in a poly(3,4-ethylene dioxythiophene) (PEDOT) matrix to form semiconducting organic-inorganic nanocomposites for potential applications in electrochemical sensing. The adopted strategy of in situ liquid/liquid interface-assisted polymerization aids in the formation of intimately tethered Te NPs on the PEDOT polymer chains, thereby preventing the aggregation of Te NPs. The untapped versatility inherent to using biphasic systems for interfacial polymerization is explored at three interface systems of immiscible solvents: chloroform/water, dichloromethane/water, and hexane/water, giving rise to PEDOT/Te nanocomposite (PTeNC) of distinct morphology. Chemical nature, crystallinity, and morphology investigations proved the successful formation of PTeNC in different interface systems. Consequently, the temporal evolution of interfacial tension in the preferential adsorption of nanoparticles and final product morphology was monitored by pendant drop tensiometry. Owing to the role of morphology, PTeNC synthesized at the hexane/water interface showcased the best electrocatalytic behavior toward nonenzymatic detection of l-ascorbic acid, an essential nutritional factor, and a neuromodulator with a limit of detection of 0.66 μM and excellent sensitivity, selectivity, and reproducibility. Hence, we envision that interface-assisted polymerization offers a nascent and robust strategy for encapsulating unusual electrode materials in polymeric matrices.

Tailoring flower-like Zn(OH)2 nanoarchitectures and stearic acid on cellulosic fibers for structurally robust superhydrophobic surface

Structurally robust nanostructures on the surface of matrix highly determine the durability of superhydrophobic surface of cellulosic materials. Traditionally, the hydrophobic inorganic-organic nanocomposites were physically coated on the surface of cellulose fibers, whereas the nanocomposite was easy to fall off under external force due to the weak interfacial interaction between inorganic materials and cellulose, restricting their practical application. In this work, a sort of structurally stable superhydrophobic cellulosic materials was elaborately designed by successive in situ synthesis of Zn(OH)2 nanoarchitectures and coating stearic acid (STA). The unique flower-like micro/nano structures as well as the presence of hydrophobic STA imparted the cellulosic materials with superhydrophobic behavior and the optimized water contact angle of synthesized STA@Zn(OH)2/paper nanocomposite was enhanced to 171°. Moreover, the resultant cellulosic nanocomposite also possesses excellent structural stability without STA and Zn(OH)2 fall off as well as hydrophobicity reduction after bending 100 times. Compared to bare filter paper, both tensile stress and elongation at break of optimized flower-like nanocomposite reached 14.04 MPa and 25.24% with 109.6% and 323.5% improvement, respectively. Furthermore, such superhydrophobic cellulose-based material also presented excellent anti-fouling and antibacterial performances. This work proposed a facial and efficient strategy to construct structurally stable superhydrophobic cellulose-based materials, displaying great potential application in food packaging and outdoor anti-fouling fields.

High-performance H2 sensor based on Polyaniline-WO3 nanocomposite for portable batteries and breathomics-diagnosis of irritable bowel syndrome

Low-trace airborne hydrogen (H2) detection at room temperature is a prerequisite in designing sensors for portable batteries and breathomics-based diagnosis of human diseases/disorders. The state-of-the-art H2 sensor engineering is concerned with developing organic-inorganic nanocomposites with controlled morphology and enhanced physicochemical attributes. This unprecedented study reports a chemo-resistive-module H2 sensor based on polyaniline-tungsten oxide (PAni-WO3) nanocomposite fabricated through a facile and economic one-pot polymerization route. The morphological and structural analysis revealed the formation of nanocomposite consisting of WO3 nanorods (∼100 nm diameter) dispersed in the PAni matrix consists of particles with size around 200 nm. The PAni-WO3 chemiresistor exhibited a 5-fold enhanced performance towards one ppm of H2 at room temperature compared to pristine WO3 nanorods/PAni. It demonstrated high performance for room temperature H2 detection in terms of low detection limit (1 ppm), high sensitivity, prompt response, fast recovery, and high repeatability. Besides, the fabricated sensor is highly selective and stable for H2 monitoring in capricious environmental conditions (in varying humidity, temperature and interfering analytes). The well-engineered nanocomposite system possessing rational morphology has latent for real-time monitoring of low-trace human breath-borne H2 for non-invasive irritable bowel syndrome (IBS) diagnosis and for sensing leaks in portable batteries, hydrogen production and storage industries, and environmental monitoring.

Customized Microenvironments Spontaneously Facilitate Coupled Engineering of Real-Life Large-Scale Clean Water Capture and Pollution Remediation.

Harnessing abundant renewable resources and pollutants on a large scale to address environmental challenges, while providing sustainable freshwater, is a significant endeavour. This study presents the design of fully functional solar vaporization devices (SVD) based on organic-inorganic hybrid nanocomposites (CCMs-x). These devices exhibit efficient photothermal properties that facilitate multitargeted interfacial reactions, enabling simultaneous catalysis of sewage and desalination. The localized interfacial heating generated by the photothermal effect of CCMs-x triggers surface-dominated catalysis and steam generation. The CCMs-x SVD achieves a solar water-vapor generation rate of 1.41kg m-2 h-1 (90.8%), and it achieves over 95% removal of pollutants within 60min under one-sun for practical application. The exceptional photothermal conversion rate of wastewater for environmental remediation and water capture is attributed to customized microenvironments within the system. The integrated parallel reaction system in SVD ensures it is a real-life application in multiple scenarios such as municipal/medical wastewater and brine containing high concentrations. Additionally, the SVD exhibits long-term durability, antifouling functionality toward complex ionic contaminants. This study not only demonstrates a one-stone-two-birds strategy for large-scale direct production of potable water from polluted seawater, but also opens up exciting possibilities for parallel production of energy and water resources.

Proton Exchange Membrane Fuel Cells: Focused on Organic-Inorganic Nanocomposite Membranes

The application of organic-inorganic nanocomposite membranes allows for a synergy between the desirable thermal and mechanical properties of inorganic materials with the reactivity, dielectric properties, durability, flexibility, and processability of the polymeric materials. Proton exchange membrane fuel cells (PEMFCs) suffer from some problems including water content management, carbon monoxide poisoning, hydrogen reformate, and fuel crossover through the membrane. Herein, specific solutions have been proposed to the above-mentioned problems using organ-inorganic nanocomposites. These solutions include doping proton conductive inorganic nano-particles in the proton exchange membrane, preparing nanocomposites via the sol-gel method, covalence bond of inorganic compounds with the polymer structure, and acid-based proton exchange nanocomposite membranes. Furthermore, hydrogen production with low carbon monoxide content using the ethanol steam reforming method, as well as the effect of CO in the hydrogen feed of PEMFC are explained and discussed. Finally, desirable conditions for achieving the maximum power density in exchange membrane cells (EMFCs) are discussed.

Construction of ZnONRs-PDA/PMPC nanocomposites on the surface of magnesium alloy with enhanced corrosion resistance and antibacterial performances

Magnesium alloy (MgA) with satisfactory biodegradability and excellent mechanical properties has been widely applied in new degradable medical implant materials, especially cardiovascular scaffold materials. However, fast degradation and limited biological activities always restrict the application of MgA. Herein, we have constructed multi-functional inorganic-organic nanocomposites (ZnONRs-PDA/PMPC) onto the surface of micro-arc oxidation pretreated magnesium alloys (MgA-MgO), where ZnO nanorods (ZnONRs) were grown by a microwave-assisted hydrothermal method, and polydopamine/poly(2-methacryloyloxyethyl phosphorylcholine) (PDA/PMPC) films were prepared by a co-deposition strategy. The morphology and composition of MgA-MgO-ZnONRs-PDA/PMPC were characterized by field emission-scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD), and so on. The MgA-MgO-ZnONRs-PDA/PMPC exhibited good hydrophilic property with a water contact angle of 37.4° and improved the corrosion resistance performance with decreasing the corrosion current density (icorr) by 3 orders of magnitude compared with pristine MgA. Moreover, the MgA-MgO-ZnONRs-PDA/PMPC showed good anti-platelet adhesion performance and excellent antibacterial activities with bactericidal rates of 98.1% against S. aureus and 96.2% against E. coli. This work provides an easy and effective method to fabricate a multi-functional nanocomposite with excellent corrosion resistance and biological activities that would facilitate the potential applications of MgA in biomedical fields.

Synthesis of a novel multifunctional organic–inorganic nanocomposite for metal ions and organic dye removals

In this study, we used solvent assisted mechano-synthesis strategies to form multifunctional organic–inorganic nanocomposites capable of removing both organic and inorganic contaminants. A zeolite X (Ze) and activated carbon (AC) composite was synthesized via state-of-the-art mechanical mixing in the presence of few drops of water to form Ze/AC. The second composite (Ze/L/AC) was synthesized in a similar fashion, however this composite had the addition of disodium terephthalate as a linker. Both materials, Ze/AC and Ze/L/AC, were characterized using scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), Powdered X-ray diffraction (P-XRD), Fourier-transform infrared spectrometry (FTIR), Accelerated Surface Area and Porosimetry System (ASAP), and thermal gravimetric analysis (TGA). The SEM–EDS displayed the surface structure and composition of each material. The sodium, oxygen and carbon contents increased after linker connected Ze and AC. The P-XRD confirmed the crystallinity of each material as well as the composites, while FTIR indicated the function groups (C=C, O–H) in Ze/L/AC. The contaminant adsorption experiments investigated the effects of pH, temperature, and ionic strength on the adsorption of methylene blue (MB) and Co(II) for each material. In MB adsorption, the first-order reaction rate of Ze/L/AC (0.02 h−1) was double that of Ze/AC (0.01 h−1). The reaction rate of Ze/L/AC (4.8 h−1) was also extraordinarily higher than that of Ze/AC (0.6 h−1) in the adsorption of Co(II). Ze/L/AC composite achieved a maximum adsorption capacity of 44.8 mg/g for MB and 66.6 mg/g for Co(II) ions. The MB adsorption of Ze/AC and Ze/L/AC was best fit in Freundlich model with R2 of 0.96 and 0.97, respectively, which indicated the multilayer adsorption. In the Co(II) adsorption, the data was highly fit in Langmuir model with R2 of 0.94 and 0.92 which indicated the monolayer adsorption. These results indicated both materials exhibited chemisorption. The activation energy of Ze/L/AC in MB adsorption (34.9 kJ mol−1) was higher than that of Ze/L/AC in Co (II) adsorption (26 kJ mol−1).

Synthesis and DC Electrical Conductivity of Nanocomposites Based on Poly(1-vinyl-1,2,4-triazole) and Thermoelectric Tellurium Nanoparticles.

In this work, the structural characteristics and DC electrical conductivity of firstly synthesized organic-inorganic nanocomposites of thermoelectric Te0 nanoparticles (1.4, 2.8, 4.3 wt%) and poly(1-vinyl-1,2,4-triazole) (PVT) were analyzed. The composites were characterized by high-resolution transmission electron microscopy, X-ray diffractometry, UV-Vis spectroscopy, and dynamic light scattering analysis. The study results showed that the nanocomposite nanoparticles distributed in the polymer matrix had a shape close to spherical and an average size of 4-18 nm. The average size of the nanoparticles was determined using the Brus model relation. The optical band gap applied in the model was determined on the basis of UV-Vis data by the Tauc method and the 10% absorption method. The values obtained varied between 2.9 and 5.1 nm. These values are in good agreement with the values of the nanoparticle size, which are typical for their fractions presented in the nanocomposite. The characteristic sizes of the nanoparticles in the fractions obtained from the Pesika size distribution data were 4.6, 4.9, and 5.0 nm for the nanocomposites with percentages of 1.4, 2.8, and 4.3%, respectively. The DC electrical conductivity of the nanocomposites was measured by a two-probe method in the temperature range of 25-80 °C. It was found that the formation of an inorganic nanophase in the PVT polymer as well as an increase in the average size of nanoparticles led to an increase in the DC conductivity over the entire temperature range. The results revealed that the DC electrical conductivity of nanocomposites with a Tellurium content of 2.8, 4.3 wt% at 80 °C becomes higher than the conventional boundary of 10-10 S/cm separating dielectrics and semiconductors.