Hybrid Nanocomposite Films Research Articles

Pentablock Ionomer Based TEOS-TIP Hybrid Nanocomposites: Morphology, Physical Properties, and Ion Transport

Nowadays, pure materials cannot embody all the physical, chemical, and mechanical properties required for a given application. Therefore, hybrid inorganic-organic composite materials were created to fill this critical void. The hybrid composites depend not only the properties of individual components, but also on the interfacial interactions between inorganic and organic phases. The significance of this work is to control the interaction-structure-property relationships of hybrid inorganic-organic nanocomposites in many applications such as fuel cells, lithium-ion batteries, biomimetic actuator, and water purification. The PBC based hybrid organic-inorganic films were synthesized based on tetraethylorthosilicate (TEOS), titanium isopropoxide (TIP), and poly(t-butylstyrene-b-hydrogenated isoprene-b-sulfonated styrene-b-hydrogenated isoprene-b-t-butylstyrene) or pentablock copolymer (PBC) via sol-gel chemistry. A ternary phase diagram was estibalished to understand the homogeneity of TEOS-TIP sol-gel system dependent on initial sol composition and reaction conditions leading to controllable materials. All hybrid PBC-TEOS-TIP membranes exhibited higher water uptake than unmodified PBC membranes. Proton conductivity increased 80% from 58 mS/cm for unmodified PBC film to 85 mS/cm for hybrid nanocomposite film due to the role TEOS-TIP within it. This can be attributed to the partial charge transfer from the titanate’s inorganic domains to sulfonate groups that promote acid dissociation and proton attraction. The PBC’s microphase-separated morphology changed from well-ordered lamella-like structure to a random and homogenous distribution of ionic domains with increasing TIP concentration, which was observed from AFM and SAXS results. TGA analyses revealed a decrease in degradation temperature due to titanate's catalytic character, and DMA results demonstrated reduced polymer chain mobility caused by inorganic-organic interactions. Finally, these PBC-TEOS-TIP hybrid composites were used as proton-exchange membranes (PEM) for hygroden fuel cells.

Enhanced Low-Temperature Response of PPy-WO3 Hybrid Nanocomposite Based Gas Sensor Deposited by Electrospinning Method For Selective and Sensitive Acetone Detection

In this paper, PPy-WO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> hybrid nanocomposites with different weight percentages of WO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> nanoparticles (5-40%wt) dispersed in polypyrrole (PPy) matrix were prepared and utilized as a new sensing material for acetone detection. PPy-WO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> hybrid nanocomposite were deposited on interdigitated electrode by the electrospinning technique. WO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> nanoparticles and PPy-WO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> nanocomposites sensor were characterized by X-ray diffraction and field emission scanning electron microscopy, respectively. The presence of WO3 in PPy matrix was confirmed by EDAX. The resistance changes of different nanocomposites in exposure to acetone and methanol in three temperature (70 °C, 90 °C, and 110 °C) was tested and the results were compared with polypyrrole-based sensor. It was found that enhanced acetone sensing properties of PPy-WO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> nanocomposite films strongly influenced by the WO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> weight percentage and temperature. Comparing with PPy-based sensor, prepared PPy-WO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> hybrid nanocomposite films exhibit excellent acetone vapor sensing properties at low temperature. The detection limit of PPy-WO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> (20%) hybrid nanocomposite sensor is about 16 times better than PPy sensor and it shows fast response (<; 5 s) toward acetone vapor at operating temperature of 90 °C. As a result, PPy-WO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> hybrid nanocomposite sensor can be a good candidate for high performance acetone detection.

Aptamer based voltammetric biosensor for the detection of Mycobacterium tuberculosis antigen MPT64

The authors report an aptaelectrode based on graphene modified iron-oxide chitosan hybrid (CHIT-IO-GR) nanocomposite film deposited on fluorine tin oxide (FTO) for the detection of the Mycobacterium tuberculosis specific antigen MPT64. The biotinylated DNA aptamer sequence specific to the MPT64 was immobilized onto the CHIT-IO-GR/FTO electrode by using streptavidin-biotin interactions. XRD, FT-IR, FE-SEM and electrochemical studies were applied to monitor the steps of the fabrication. The aptaelectrode, operated best at typical voltage of 0.44 V, exhibited a limit of detection (LOD) of 0.9 fg⋅mL−1 within 20 min. The biosensor retained about 80% of its initial activity after 10 uses. The potential application of the aptasensor was established by spike-in studies to obtain recoveries between 83 and 95%.

Enhanced ammonia sensing characteristics of tungsten oxide decorated polyaniline hybrid nanocomposites

Polyaniline (PAni)-tungsten oxide (WO3) hybrid nanocomposites sensor have been lucratively synthesized by in-situ chemical oxidative polymerization method by entrapping tungsten oxide nanoparticles (10–50%) in the polyaniline matrix on precleaned glass substrate. The structural, morphological and surface composition elucidation of PAni-WO3 hybrid nanocomposites were explored by X-ray diffraction (XRD) technique, field emission scanning electron microscopy (FESEM) and X-ray photoelectron spectroscopy (XPS). The existence of WO3 in PAni matrix and interaction between them was confirmed using XRD and Raman spectroscopy. The incorporation of WO3 nanoparticles into the PAni matrix introduces porosity which enhanced gas sensing properties. The TEM image of PAni-WO3 hybrid nanocomposite film exploded the average diameter of WO3 nanoparticles ranging from 40 to 50 nm. Chemical composition of PAni-WO3 hybrid nanocomposites was characterized by using X-ray photoelectron spectroscopy (XPS). In order to investigate the gas sensing parameter of PAni-WO3 hybrid nanocomposite, hybrid nanocomposite film was exposed to different oxidizing gases (Cl2, NO2) and reducing gases (NH3, H2S, CH3OH, C2H5OH) in range 5–100 ppm concentration of gas. It was observed that the sensors of PAni-WO3 hybrid nanocomposites showed better sensitivity, selectivity, stability and reproducibility compared to pure PAni and pure WO3. PAni-WO3 (50%) hybrid nanocomposite sensor operating at room temperature reveals maximum response of 158% towards 100 ppm of NH3 gas and also capable to respond very little concentration of 5 ppm NH3 gas with reasonable response of 24%. The gas sensing mechanism of the nanocomposites in presence of air and with target NH3 gas atmosphere was discussed in detail with the help of energy band diagram. The interaction of NH3 and NO2 gas with PAni-WO3 hybrid nanocomposite sensor was investigated by employing an impedance spectroscopy also.

One-pot preparation of PEDOT:PSS-reduced graphene decorated with Au nanoparticles for enzymatic electrochemical sensing of H2O2

The development of novel graphene-based nanocomposites is a hotspot in materials science due to their unique optical, electronic, thermal, mechanical and catalytic properties for varied applications. The present work reports on the development of a graphene-based ternary nanocomposite of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate), reduced graphene oxide and gold nanoparticles (PEDOT:PSS-rGO-AuNPs) for the detection of hydrogen peroxide (H2O2). The hybrid nanocomposite showed superior electrochemical properties and higher stability compared to each individual component as electrode materials, showing a synergistic effect between PEDOT, rGO and AuNPs. The nanocomposite was obtained via a facile one-step approach and was assembly with horseradish peroxidase (HRP). The PEDOT:PSS-rGO-AuNPs-HRP modified electrode has been used for the amperometric detection of H2O2 and exhibited a high sensitivity of up to 677μAmM−1cm−2, with a wide linear range from 5 to 400μM and a low detection limit of 0.08μM (S/N=3). This developed enzymatic biosensor showed to be highly stable and unresponsive to potentially interfering substances, and it could be used for sensing H2O2 in real samples, including tap water and bovine milk samples. These enhanced sensing performance could be ascribed to the intimate contact of AuNPs onto the rough surface of the PEDOT:PSS-rGO nanocomposite, which has a high electrical conductivity and large surface area, providing it as an excellent substrate for the growth and support of nanoparticles. The method developed in this work opens up a general route to prepare a wide range of graphene-based hybrid nanocomposite films with multiple functions including sensing and biosensing.

Charge transport in lead sulfide quantum dots/phthalocyanines hybrid nanocomposites

A hybrid composite of non-aggregated lead sulfide (PbS) nanoparticles of average size 5.8 ± 1 nm embedded within a film of an octaalkyl substituted metal-free phthalocyanine (Compound 2) was prepared on interdigitated gold electrodes by mild acidic treatment of newly synthesised octasubstituted lead phthalocyanine analogue (Compound 1) in solid state phase. This nanocomposite film shows an enhancement of in-plane electrical conductivity over that of a film of octaalkyl substituted metal-free phthalocyanine alone by nearly 65%. This observation is consistent with the formation of charge complex compound as indicated by Raman and XPS data. The presence of PbS in the composite was examined on the basis of XRD peak positions which are comparable with those of bulk PbS. A band gap of 2.22 eV was calculated from optical absorption data using Tauc's law, implying quantum confinement. The mono dispersal behaviour of PbS nanoparticles was established from TEM and XRD studies. The hopping conduction mechanism is found to be primarily responsible for charge transport in the hybrid nanocomposite film with the hopping distance larger than PbS diameter.

Structural and electrical characteristics of solution processed P3HT-carbon nanotube composite

Organic semiconductors have been identified as a fascinating class of low cost and flexible novel semiconductor materials that have the electrical and optical properties which can be easily processed. Due to their interesting physical properties, organic semiconductors have attracted tremendous research attention for next generation electronics and optoelectronics. Multiwalled carbon nanotubes (MWCNT) incorporated Poly[3-hexylthiophene-2,5-diyl] (P3HT) hybrid nano-composite film have been fabricated by solution processing technique followed by spin coating method using 1,2-dichlorobenzene as an intermediate solvent. Structural and morphological characteristics of the composite film have been studied by x-ray diffraction (XRD) and scanning electron microscope (SEM). The MWCNTs were observed to be well dispersed in the polymer matrix. Crystallites were found to be more ordered barely affecting the lamellar structure of P3HT in the nano-composite film. Structural and functional characteristics of P3HT and its hybrid nano-composite have been studied by UV-Visible (UV-Vis), Fourier transform infrared (FTIR) and Raman spectroscopic characterization. Excellent electrical properties have been observed from I-V and cyclic-voltammetric characterization of the well dispersed MWCNT in the P3HT composite. Improvement in electrical properties can be attributed to the higher carrier mobility of MWCNTs in the composites.

Metal-Carbon Interactions on Reduced Graphene Oxide under Facile Thermal Treatment: Microbiological and Cell Assay

Silver-functionalized reduced graphene oxide (Ag-rGO) nanosheets were prepared by single chemical and thermal processes, with very low concentration of silver. The resulting carbon framework consists of reduced graphene oxide (rGO) sheets or 3D networks, decorated with anchored silver nanoparticles. The Ag-rGO nanosheets were dispersed into a polymer matrix and the composites evaluated for use as biological scaffolds. The rGO material in poly(dimethylsiloxane) (PDMS) has been tested for antimicrobial activity against Gram-positiveStaphylococcus aureus(S. Aureus) bacteria, after exposure times of 24 and 120 hours, as well as in the determination of cell viability on cultures of fibroblast cells (NIH/3T3). Using 1 mL of Ag-rGO in PDMS the antibacterial effectiveness againstStaphylococcus aureuswas limited, showing an increased amount of Colony Forming Units (CFU), after 24 hours of contact. In the cell viability assay, after 48 hours of contact, the group of 1 mL of Ag-rGO with PDMS was the only group that increased cell viability when compared to the control group. In this context, it is believed these behaviors are due to the increase in cell adhesion capacity promoted by the rGO. Thus, the Ag-rGO/PDMS hybrid nanocomposite films can be used as scaffolds for tissue engineering, as they limit antimicrobial activity.

Concentration dependent dielectric, AC conductivity and sensing study of ZnO-polyvinyl alcohol nanocomposite films

The dielectric properties of polyvinyl alcohol (PVA) - zinc oxide (ZnO) hybrid nanocomposite films for different concentrations of nano ZnO (5 mol%-20 mol%) have been studied at ambient temperature in the frequency range 10 Hz-10 MHz. These studies indicate that the dielectric constant is maximum for 10 mol% ZnO-PVA hybrid film. An unusual low intensity loss peak is observed around 2.5-5 MHz in all the samples and this peak is more pronounced in the 10 mol% ZnO film. Impedance and modulus spectroscopy have been used to understand the dielectric and conductivity behaviour of these samples. These samples exhibit high bulk resistance and the Cole-Cole plot shows only the onset of the semicircles at room temperature. AC conductivity is found to obey Jonscher's power law and the enhancement in the conductivity is found to be highest for 10 mol% ZnO doped PVA nanocomposite film suggesting its suitability for use in sensing applications. The gas sensing performance of the hybrid films for detection of various gases such as NO2, H2S, NH3, LPG, and C2H5OH was studied and compared with that of pure PVA film. It was found that the hybrid sensor can complement the drawbacks of pure PVA as porous surface morphology and surface area of interface of nano-ZnO plays a vital role in sensing applications. At ambient temperature, 100 ppm concentration of both NO2 gas and H2S gas exhibit maximum response of 7.1% and 4.1% respectively for the 10 mol% hybrid sensor, whereas at 50 ppm concentration of H2S gas the 20 mol% ZnO-PVA sensor was found to be more sensitive with a reasonable response of 7%.

Flexible hybrid eu3+ doped P(VDF-HFP) nanocomposite film possess hypersensitive electronic transitions and piezoelectric throughput

A novel red light-emitter made of Eu3+ doped self-poled electroactive poly(vinylidene fluoride–hexafluoropropylene) [P(VDF-HFP)] hybrid nanocomposite film possesses piezoelectric throughput that is suitable for flexible piezoelectric nanogenerator (PNG) fabrication. We observed that PNG is enabled to generate an open-circuit voltage of 5 V and 0.35 μA of short-circuit current under an applied pressure amplitude of ∼10.4 kPa. By simple mechanical energy scavenging, PNG demonstrates an ability to light more than ten blue commercial light emitting diodes instantly, without using an energy-storage device. Additionally, it successfully charges up capacitors by simple repeating finger touch motion, which indicates its potency as an efficient energy harvesting power source. The high performance of PNG is due to well-coated Eu3+ with P(VDF-HFP) in a hybrid nanocomposite so it displays improved dielectric permittivity and energy storage capacity. This flexible composite film also possesses a hypersensitive electronic transition as it responds by an intense red light-emission confirmed by the CIE 1931 chart. This enables applications in piezo-photonics as a high-performance, energy-saving, flexible solid-state red light emitter. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016, 54, 2335–2345.

Biodegradable hybrid nanocomposites of starch/lysine and ZnO nanoparticles with shape memory properties

In food packing applications; the research works have been focused on the development of biodegradable packing materials by using biopolymers such as starch, carrageenan, agar, and gelatine to replace with petroleum-based non-biodegradable polymers. In this present work we studied novel synthesis of biodegradable hybrid nanocomposites using starch, amino acid (lysine), polypropylene glycol (PPG) and ZnO nanoparticles (NPs) and their shape memory properties. A series of hybrid nanocomposites were prepared by solution casting method, with various ZnO nanoparticles content such as 0wt%, 1wt%, 3wt% and 5wt% by keeping peptide content constant and varying the ratio between starch and ZnO nanoparticles content. The thermogravimetric analysis (TGA) of the hybrid nanocomposites suggested increased thermal stability with increasing ZnO nanoparticles content. The solubility of the hybrid nanocomposites in H2O is decreased with increasing ZnO nanoparticles content. The moisture content in the hybrid nanocomposites is decreased with increasing ZnO nanoparticles content. The mechanical properties of the materials were increased with increasing ZnO nanoparticle content. Furthermore, the hybrid nanocomposites showed a shape memory properties by placing the sample at room temperature and then at 55°C. The morphology of the hybrid nanocomposites was revealed using scanning electron microscopy (SEM). We believe that these biodegradable hybrid nanocomposite films can be useful in food packing applications.

Facile Fabrication of MoS2-Modified SnO2 Hybrid Nanocomposite for Ultrasensitive Humidity Sensing.

An ultrasensitive humidity sensor based on molybdenum-disulfide- (MoS2)-modified tin oxide (SnO2) nanocomposite has been demonstrated in this work. The nanostructural, morphological, and compositional properties of an as-prepared MoS2/SnO2 nanocomposite were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), energy dispersive spectrometry (EDS), nitrogen sorption analysis, and Raman spectroscopy, which confirmed its successful preparation and rationality. The sensing characteristics of the MoS2/SnO2 hybrid film device against relative humidity (RH) were investigated at room temperature. The RH sensing results revealed an unprecedented response, ultrafast response/recovery behaviors, and outstanding repeatability. To our knowledge, the sensor response yielded in this work was tens of times higher than that of the existing humidity sensors. Moreover, the MoS2/SnO2 hybrid nanocomposite film sensor exhibited great enhancement in humidity sensing performances as compared to the pure MoS2, SnO2, and graphene counterparts. Furthermore, complex impedance spectroscopy and bode plots were employed to understand the underlying sensing mechanisms of the MoS2/SnO2 nanocomposite toward humidity. The synthesized MoS2/SnO2 hybrid composite was proved to be an excellent candidate for constructing ultrahigh-performance humidity sensor toward various applications.

Facile fabrication of white-emitting hybrid colloids and nanocomposite films using CdSe/CdS quantum dots and zinc phthalocyanines as building blocks

In this work, we have designed a facile protocol to prepare white emitting colloid solutions and polymer nanocomposite films via the self-assembly of zinc phthalocyanine (ZnPc) in the presence of semiconductor CdSe/CdS quantum dots (QD). Specifically, a dendritic zinc phthalocyanine showing two independent emission bands at blue (∼450nm) and red region (∼690nm) in N, N-dimethylformamide (DMF) solution was synthesized by using a biphenyl phthalonitrile based precursor. In order to fulfill the missing green emission band and overcome the strong intermolecular aggregation tendency of ZnPc that normally results to obviously quenched fluorescence in solution, an ultrasmall sized CdSe/CdS QD with green emitting capabilities, was synthesized, surface modified with a hydrophobic capping agent (oleic acid) and dispersed uniformly in nonpolar hexane. When the hexane solution of QD was introduced to the immiscible ZnPc solution in DMF, nanoconjugates exhibiting three independent emission bands can be formulated by using ZnPc and QD as building blocks via the non-covalent hydrophobic interaction established in the incompatible DMF/hexane interface. Furthermore, the white emitting ZnPc/QD colloid solutions and nanocomposite films can be readily obtained by controlling the relative concentration of ZnPc and QD.

Experimental investigations on NO2 sensing of pure ZnO and PANI–ZnO composite thin films

In the present work, comparative investigations on NO2 gas sensing properties of the hybrid nanocomposite thin films of polyaniline (PANI), ZnO and PANI–ZnO towards NO2 gas at room temperature have been reported.

Self‐poled Efficient Flexible “Ferroelectretic” Nanogenerator: A New Class of Piezoelectric Energy Harvester

AbstractSuperior ferro‐ and piezo‐electret properties in a self‐poled, porous hybrid ferroelectretic polymer nanocomposite film for next‐generation device paradigms is introduced by in situ generation of platinum (Pt) nanoparticles (NPs) embedded in poly(vinylidenefluoride‐co‐hexafluoropropylene) P(VDF–HFP). The cooperative functionality between the self‐polarized β‐phase and the micropores as charge trapping sites is realized by using a simple solvent evaporation method. As a consequence, the resulting film exhibits extraordinary ferroelectretic behavior, as demonstrated by the superior electrical square‐shaped hysteresis loop with large remnant polarization (Pr≈61.7 μC cm−2), piezoelectric charge coefficient (d33∼−686 pC N−1), and ultrahigh dielectric properties (εr=2678, tan δ=0.79 at 1 kHz). A new type of ferroelectretic nanogenerator (FTNG) is fabricated using a flexible hybrid nanocomposite film that effectively converts the applied mechanical energy into electrical energy upon compressive normal stress (e.g., by actuating with a human finger). The 18 V of the open‐circuit output voltage with expected 17.7 μA short‐circuit current are generated from the FTNG under 4 MPa of normal stress amplitude. The high piezoelectric energy conversion efficiency (ηpiezo≈0.2 %) of the FTNG shows that the hybrid polymer nanocomposite film is well suited for the next generation of piezoelectric‐based energy harvesters. The operation of more than 50 blue LEDs, 25 green LEDs, and several capacitors without any subsidiary batteries is demonstrated using the FTNG.

Enhancement of photocurrent generation from a series of hybrid nanocomposite self-assembled films of transition element-substituted tungstoborates/hemicyanine

A series of electrostatically self-assembled films have successfully been prepared by alternating adsorption of transition element-monosubstituted tungstoborate anions [BW11M(H2O)O39]7− (BW11M, M = Ni, Cu, Cd) and a bichromophore hemicyanine cation of (E)-1,1′-(hexane-1,6-diyl)bis(4-(4-(dimethylamino)styryl)pyridinium) (H6), respectively. The UV–Visible spectra showed that the films were uniformly deposited and H6 molecules formed J-aggregations in the films. The (BW11M/H6) n films could generate stable cathodic photocurrents of 0.56–1.32 μA/cm2 as irradiated with white light (100 mW/cm2, 730 nm > λ > 325 nm) at zero bias voltage versus SCE, and the photocurrent action spectra indicated that the cathodic photocurrents were generated based on charge transfer excitation of the H6 in the (BW11M/ H6) n films. The composition and structure of polyoxometalate anion in the films have important influences on photocurrents. Moreover, the effects of layer number of (BW11M/H6) n film, applied potentials, and electron acceptor in the electrolyte on photocurrent generation of the (BW11M/H6) n films have been examined, and photoelectric mechanism is also discussed

Hybrid nanocomposite thin films deposited by emulsion-based resonant infrared matrix-assisted pulsed laser evaporation for photovoltaic applications

Emulsion-based, resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) was used to deposit CdSe nanoparticle films and hybrid nanocomposite films comprising colloidal CdSe nanoparticles embedded in a low band gap polymer, poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b′]dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (PCPDTBT). We show that, in contrast to traditional MAPLE deposition, the CdSe nanoparticle film deposited by emulsion based RIR-MAPLE is contiguous and uniform, and it maintains the optical properties of the nanoparticle solution. Moreover, we show that the RIR-MAPLE deposited PCPDTBT/CdSe hybrid nanocomposite film exhibits a relatively random and uniform distribution of CdSe nanoparticles without the significant phase segregation that is observed in hybrid nanocomposite films deposited by spin-casting. Finally, hybrid organic solar cells based on nanocomposite films deposited by the RIR-MAPLE technique were fabricated and characterized, showing 0.4% power conversion efficiency. This is the first demonstration of a polymer–nanoparticle hybrid organic solar cell fabricated by a MAPLE-related technique.

Ammonia sensing properties of polyaniline/α-Fe2O3 hybrid nanocomposites

Polyaniline (PAni) films modified by different loading of α-Fe2O3 nanoparticles have been formed by solid state synthesis method and investigated for various oxidizing and reducing gases. We demonstrates that α-Fe2O3 nanoparticles (50%): PAni hybrid nanocomposites films are highly selective to NH3 with high sensitivity (50 at 100ppm), fast response time (29s) and highly reproducible response curves. X-ray diffraction analysis, field emission scanning electron microscopy observations, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy analysis revealed that the n-type α-Fe2O3 nanoparticle transfers the electrons to polyaniline forms into a incredibly reduced state. These observations in PAni/α-Fe2O3 hybrid nanocomposites is insensitive to interaction with other gases except ammonia. The sensing mechanism of PAni/α-Fe2O3 hybrid nanocomposites to NH3 was interpreted with the help of proposed energy band diagram. In-addition to this, the interaction mechanism between the NH3 and PAni/α-Fe2O3 hybrid nanocomposite was investigated by an impedance spectroscopy tool.

Nonvolatile organic field-effect transistors memory devices using supramolecular block copolymer/functional small molecule nanocomposite electret.

Organic field-effect transistors (OFETs) memory devices based on hybrid nanocomposite electret were fabricated by cooperative supramolecular polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) with two different block compositions (asymmetric L1 and symmetric L2) that contain hydroxyl-functionalized ferrocene small molecules (FMs). Because of the selective hydrogen interaction between the hydroxyl groups of FM and pyridine groups in P4VP block, the small FMs can preferentially disperse in the P4VP nanodomain, which can be used as nanostructured charge-trapping nanocomposite electret (L1-FMX and L2-FMX) under solvent-annealing process. The charge-storage functionalities can be easily tailored by morphologies of the hybrid nanocomposite thin film and spatial distribution of the FM molecules in which the relative molecular mass of block copolymers and the FM loading ratio can further control both of them. These block copolymer nanocomposite thin film electrets with charge-controlling guest FM for OFETs memory devices exhibit significant features including the ternary bits storage, high-density trapping sites, charge-carrier trapping of both polarities (ambipolar trapping), and solution processing that can make important progress for future advanced storage and memory technology.

A novel immunosensor for detection of beta-galactoside alpha-2, 6-sialyltransferase in serum based on gold nanoparticles loaded on Prussian blue-based hybrid nanocomposite film

In this paper, we presented a novel electrochemical immunosensor using gold nanoparticles (AuNPs) loaded on the Prussian blue (PB)-based hybrid nanocomposite film that sensitively detects β-galactoside α-2, 6-sialyltransferase (ST6Gal-I). The immunosensor was fabricated based on a Prussian blue-based (PB) hybrid nanocomposite, consisting of graphene oxide (GO), multi-walled carbon nanotubes (MWCNTs), PTA (a derivative of 3, 4, 9, 10-perylenetetracarboxylicdianhydride, PTC-NH2) and chitosan (CS). With the assistance of the abundance of amino groups from CS and PTA, AuNPs were densely adsorbed onto the surface of the nanocomposite, providing a large available surface area for the immobilization of abundant anti-ST6Gal-I. As measured by cyclic voltammogram (CV) and differential pulse voltammogram (DPV), PB served as an electroactive and biocompatible redox probe in achieving electrochemical signal. Under the optimal detection conditions, the immunosensor exhibited a good linear response to ST6Gal-I in the range from 0.01 to 250ngmL−1 and a lower detection limit of 3pgmL−1 (S/N=3). Furthermore, the method was successfully applied to analyze ST6Gal-I from human serum samples and yielded satisfactory results. In conclusion, our prepared immunosensor presented a high sensitivity and excellent selectivity to ST6Gal-I, indicating its potential in future clinical and experimental analysis.