Nanocomposites Of Poly Research Articles

Smartphone-enabled flow injection amperometric glucose monitoring based on a screen-printed carbon electrode modified with PEDOT@PB and a GOx@PPtNPs@MWCNTs nanocomposite

This study presents a modified screen-printed carbon electrode (SPCE) to determine glucose in a custom-built flow injection system. The biosensor was constructed by immobilizing glucose oxidase on porous platinum nanoparticles decorated on multi-walled carbon nanotubes (GOx@PPtNPs@MWCTNs). The fabrication of the biosensor was completed by coating the GOx@PPtNPs@MWCTNs nanocomposite on an SPCE modified with a nanocomposite of poly(3,4-ethylenedioxythiophene) and Prussian blue (GOx@PPtNPs@MWCTNs/PEDOT@PB/SPCE). The fabricated electrode accurately measured hydrogen peroxide (H2O2), the byproduct of the GOx-catalyzed oxidation of glucose, and was then applied as a glucose biosensor. The glucose response was amperometrically determined from the PB-mediated reduction of H2O2 at an applied potential of −0.10 V in a flow injection system. Under optimal conditions, the developed biosensor produced a linear range from 2.50 μM to 1.250 mM, a limit of detection of 2.50 μM, operational stability over 500 sample injections, and good selectivity. The proposed biosensor determined glucose in human plasma samples, achieving recoveries and results that agreed with the hexokinase-spectrophotometric method (P > 0.05). Combining the proposed biosensor with the custom-built sample feed, a portable potentiostat and a smartphone, enabled on-site glucose monitoring.

Morphology and electrical conductivity of carbon-coated Nickel reinforced high-performance polymer nanocomposites

Novel nanocomposites of poly (ether-ketone) (PEK) reinforced with carbon-coated Nickel nanoparticles (CCNi) were synthesized through a sequential process involving cost-effective ball milling and hot compaction. Scanning electron microscopy revealed an excellent dispersion and a three-dimensional network of CCNi nanoparticles in the matrix, causing a significant improvement in the electrical conductivity and electromagnetic interference shielding effectiveness (SE). Carbon coating of about 5 nm thick over Ni nanoparticle probably helps in uniform dispersion, avoids its oxidation and reduces its agglomeration in the matrix. An exceptionally low percolation threshold of 2.1 vol.% CCNi was found, and eight-orders of magnitude enhancement in the dc-electrical conductivity was achieved. The highest dc- and ac-electrical conductivities achieved were more than 0.01 S cm−1 at 5.89 vol.% CCNi nanoparticles content which were the highest values amongst reported Ni-filled polymer composites and comparable with those of carbon nanotubes filled PEK nanocomposites. Electromagnetic interference SE of the CCNi/PEK nanocomposites was measured in the X-band, and a total SE (SET) of 17.52 dB was obtained for 5.89 vol.% CCNi reinforced PEK nanocomposite.

Effect of acid treatment of eucalyptus fibers for improved poly(3-hydroxybutyrate) nanocomposites

Nanocomposites of poly (3-hydroxybutyrate) (PHB) containing fibrillated cellulose extracted from eucalyptus fibers were prepared and characterized. This study focuses initially on the method to follow the acid treatment of eucalyptus cellulose fibers (ECF) through an experimental design, where the studied parameters were the H2SO4 concentration, hydrolysis time, and reaction temperatures as independent variables for statistical analysis. The thermogravimetric analysis (TGA) of the ECF revealed that mild hydrolysis conditions shifted the degradation temperature of the fibers to higher values. The crystallinity index (CI) obtained by the X-ray diffraction was greater when intermediate hydrolysis conditions (30% H2SO4, 60 °C, 150 min) were employed. Afterward, the most promising ECFs hydrolyzed according to the experimental design were used to produce nanocomposites of PHB(ECF/PHB) containing 5 wt% of the fiber reinforcement via twin-screw mini extruder Haake MiniLab II operating at 180 °C, and varying the rotation speeds (60, 120, and 180 rpm). The ECF/PHB nanocomposites were characterized by TGA and dynamic mechanical analysis (DMA), through which the selected composites with higher thermal and mechanical properties were analyzed by differential scanning calorimetry (DSC), tensile test, and scanning electron microscopy (SEM). ECF/PHB nanocomposites processed at 120 rpm resulted in a material with improved properties. The DMA storage and loss moduli as well as the tensile elastic modulus increased 65%, 196% and 15%, respectively, as compared to the neat PHB. The SEM of the composites revealed nanowhiskers, microcrystalline and microfibrillated cellulose incorporated into PHB, which were attributed to improvements in the thermal and mechanical properties of the PHB matrix.

Enhanced performance of PFO-ZnO nanorods nanocomposite photodiodes grown on ZnO NRs/ZnO/ITO-coated glass

An improved photodiode was fabricated using a nanocomposite of poly (9,9-di-n-octylfluorenyl-2,7-diyl) (PFO) and zinc oxide nanorods (ZnO NRs). The nanocomposite was prepared by scratching hydrothermally grown ZnO NRs on a glass substrate into the prepared PFO solution. The nanocomposite layer was deposited using the spin-coating method and silver (Ag) paste was applied as the electrode. The resulting photodiode configuration is Ag/PEDOT:PSS/PFO-ZnO NR/ZnO NRs/ZnO/ITO. Ultraviolet–visible (UV–Vis) spectroscopy showed a slight blue shift and a slight increase in the optical bandgap. The nanocomposite-based photodiode showed improved performance, due to increased active surface area for the separation of photogenerated electron-hole pairs between PFO and ZnO and also because of the higher current density of ZnO. Finite-Difference Time-Domain (FDTD) simulations showed ZnO NRs increased electric field strength and exciton generation rate throughout the PFO polymer in the nanocomposite. The photodiode with the nanocomposite showed the best performance at −5 V bias voltage under 385 nm illumination, obtaining responsivity of 1.45 A W−1, Detectivity of 2.19 x 1010 Jones, and External quantum efficiency (EQE %) of 468 %.

Synthesis of Poly(methylmethacrylate-cobutylacrylate) Nanocompounds and Silver Nanoparticles Using Sustainable Method

Nanocomposites of poly(methylmethacrylate-cobutylacrylate) P(MMA-co-BuA) and silver nanoparticles (NPsAg) synthesized with extracts of O. ficus-indica (OFI) and A. vera (AV) were obtained by using microwaves. The nanocomposites were synthesized by “in situ” emulsion polymerization, where different concentrations of NPsAg (0.05, 0.1, 0.5 and 1%) with respect to the polymer were studied. Films were formed from the latex, which were characterized by different techniques. Using UV-Vis, the characteristic absorbance of the surface plasmon resonance of the NPsAg in the nanocomposite was observed in the range of 415-436 nm. The thermal stability of the nanocomposites was carried out using TGA, where it was observed that the higher the concentration of NPsAg, the lower thethermal stability. The DSC results showed that the glass transition temperatures (Tg) for the nanocomposites with nanoparticles are between 8 and 12ºC. The percentage elongation of the nanocomposites was 400%, in addition, the Young’s modulus and the tensile strength of the same were determined, observing that the higher the content of NPsAg, the lower the elastic behavior and the mechanical resistance of the nanocomposites. Using SEM, it was confirmed that the NPsAg maintain a spherical morphology. Finally, using FTIR, the possible interaction between the PMMA-Co-BuA copolymer and the NPsAg was determined.

An ANN based biosensor for the detection of Pyrocatechol and hydroquinone in aqueous solutions

This study presents a novel method using an artificial neural network (ANN) to detect Pyrocatechol and hydroquinone in an aqueous solution. The technique utilizes a nanocomposite Poly 3,4-ethylenedioxythiophene-Graphene Oxide Nanosheets (PEDOT-GONs) Laccase biosensor, which demonstrates excellent electrocatalytic activity and electrochemical performance for the redox reactions of the target compounds. The study successfully develops a radical cation electropolymerization process involving poly EDOT with GONs and Lac as dopants to ensure the effective entrapment of the enzymes. Experimental techniques such as electrochemical characterization and SEM confirm the successful entrapment of the enzymes. Further, the ANN was trained using the backpropagation algorithm by applying the experimental results, with current and Pyrocatechol as inputs and hydroquinone concentrations as output. The application of ANN modeling to biosensor technology is validated, demonstrating its utility. The biosensor's linear response detection limit is 0.041 μM within the 0.040–0.41 μM and 0.41–3.0 μM ranges. Finally, the model's performances were evaluated by testing it within the test samples. The performances were measured using precision, recall, accuracy, F1-score, sensitivity, etc., and validated with existing mechanisms.

Biodegradable nanocomposite poly(lactic acid) foams containing carvacrol-based cocrystal prepared by supercritical CO2 processing for controlled release in active food packaging

Compounds derived from essential oils have been used in active packaging, but their volatility and degradability negatively affect stability and leads to high release rates. The present study aimed to develop PLA bionanocomposite foams loaded with carvacrol cocrystal by supercritical CO2 and its release into a food simulant for control release in food packaging. For this purpose, 4,4′-bipyridine was used as coformer and carvacrol as active agent. Cocrystallized closed cell foams were obtained using supercritical CO2 and were characterized in terms of their physicochemical and mechanical properties, and release kinetics to a D1 simulant were evaluated as well as the antioxidant ability. A better overall mechanical behavior due to the nanoclay promoting a higher interfacial adhesion with the polymeric matrix was revealed. A higher incorporation of carvacrol was observed in samples with higher C30B content. The incorporated cocrystals showed a decrease of one order of magnitude in the estimated effective diffusion coefficient of carvacrol and showed antioxidant activity. These results suggest that the nanocomposite foam containing carvacrol-based cocrystals could be used in active packaging systems with controlled release characteristics, especially with highly volatile compounds, and can be proposed for other fields such as biomedical applications.

Nanocomposites of poly(butylene adipate‐co‐terephthalate) containing sepiolite modified with 3‐aminopropyltriethoxysilane and octadecyl isocyanate

AbstractThe properties of nanocomposites are directly affected by the filler–matrix interaction and therefore surface filler modification is often necessary to improve the mechanical properties of nanocomposites. Our study evaluated surface modification of sepiolite (SEP) on properties of poly(butylene adipate‐co‐terephthalate) (PBAT)‐based nanocomposites. The nanofillers were modified using two organic modifiers, octadecyl isocyanate (OI), and 3‐aminopropyltriethoxysilane (APTES). OI showed higher treatment efficiency than APTES and better results in alkyl groups on the surface of the nanofiller, with crystalline profile, which remained in the nanocomposites. The effect of organo‐sepiolites on the properties of PBAT nanocomposites was investigated by DSC, XRD, TGA, FTIR, scanning electron microscopy (SEM), and mechanical tensile tests. TGA analysis showed that the addition of O‐SEP on PBAT decreases its thermal stability. SEM analysis showed cavities and fiber tips in the matrix associated with clay agglomerates and some untreated clay faces, which impair filler‐matrix interfacial adhesion. Both treatments increased the elastic modulus and preserved the elongation and tensile strength of PBAT and the treatment with OI results in a higher modulus. Although some studies to improve the clay dispersion are necessary, the promising results reveal the potential of using OI and APTES as SEP modifiers to reinforce PBAT or other polyesters.

Synthesis and Evaluation of Antifungal and Antibacterial Abilities of Carbon Nanotubes Grafted to Poly(2-hydroxyethyl methacrylate) Nanocomposites.

Developing nanomaterials with the capacity to restrict the growth of bacteria and fungus is of current interest. In this study, nanocomposites of poly(2-hydroxyethyl methacrylate) (PHEMA) and carbon nanotubes (CNTs) functionalized with primary amine, hydroxyl, and carboxyl groups were prepared and characterized. An analysis by Fourier-transform infrared (FT-IR) spectroscopy showed that PHEMA chains were grafted to the functionalized CNTs. X-ray photoelectron spectroscopy suggested that the grafting reaction was viable. The morphology of the prepared nanocomposites studied by field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) showed significant changes with respect to the observed for pure PHEMA. The thermal behavior of the nanocomposites studied by differential scanning calorimetry (DSC) revealed that the functionalized CNTs strongly affect the mobility of the PHEMA chains. Tests carried out by thermogravimetric analysis (TGA) were used to calculate the degree of grafting of the PHEMA chains. The ability of the prepared nanocomposites to inhibit the growth of the fungus Candida albicans and the bacteria Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli was evaluated. A reduced antifungal and antibacterial capacity of the prepared nanocomposites was determined.

Novel eco-friendly antimicrobial UV-blocking PBAT/PBS/TiO2 nanocomposite films for improved shelf-life of bananas

Novel nanocomposite poly (butylene adipate-co-terephthalate) (PBAT)/polybutylene succinate (PBS) blend films functionalized with titanium dioxide (TiO2) nanoparticles (0, 0.9, 1.8, 2.7, 3.6 and 4.5% w/w) were produced using cast-sheet extrusion. Atomic force microscopy, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and dynamic mechanical thermal analysis were used to investigate film morphology and structure. The crystallinity of the films was modified due to interactions between the nanoparticles and the PBAT/PBS blends, as confirmed by FTIR and XRD. Tensile strength and elongation of films slightly reduced with TiO2 addition up to 4.5% in both machine direction (MD) and cross direction (CD). The tensile strength of the T5 films was nearly 25% less than the control films. Adding TiO2 gave excellent UV-blocking properties with slightly reduced water vapor by 16.5% and oxygen permeability by 4% for films with maximum loading. The film surface became more hydrophilic, as evidenced by the reduced contact angle. The results, as acquired from turbidity measurements, show that films with 3.6% TiO2 loading and above have high antimicrobial activity against both Bacillus cereus (Gram-positive) and Escherichia coli (Gram-negative). The relative area of microbial growth on agar media exhibited better antibacterial capacity against Escherichia coli than Bacillus cereus, with a sharp reduction of microbial growth at TiO2 contents above 2.7%. Films containing TiO2 (≥0.9%) effectively delayed ripening and increased peel yellowness of packaged bananas during storage for 6 days at room temperature. The developed PBAT/PBS/TiO2 nanocomposites films hence showed enhanced UV-resistance and antimicrobial properties, while maintaining adequate mechanical strength necessary for food packaging. The film is an eco-friendly alternative antimicrobial food packaging to extend the shelf-life of fresh produce.

ZnO-containing nanocomposites produced from Mentha pulegium L. of a new HEMA-based methacrylate copolymer: improvement the thermal and antimicrobial effect

In this study, firstly, (2-oxo-2-(3,4,5-trifluoroanilino)-ethyl-2-methylprop-2-enoate) FAOEME, a methacrylate monomer with arylamide side group containing three fluorine atoms in the side branch, was synthesized. Poly(HEMA-co-FAOEME) was obtained due to radical copolymerization of FAOEME with 2-hydroxyethyl methacrylate (HEMA). Structural characterization of its copolymer with FAOEME and HEMA was performed by spectroscopy methods such as FTIR, 1H, and 13C-NMR. Biosynthesis of ZnO nanoparticles was carried out using Mentha Plegium L. extract. Three nanocomposites of poly(HEMA-co-FAOEME) containing biosynthesized ZnO nanoparticles were produced by hydrothermal technique, which is an environmentally friendly method. The formation of Poly(HEMA-co-FAOEME)/ZnO nanocomposites and the structural changes of the components was elucidated by SEM, XRD, and FTIR techniques. The effect of ZnO nanoparticles on the thermal properties of Poly(HEMA-co-FAOEME) was investigated by TGA and DSC techniques. The results showed that ZnO nanoparticles significantly increased the thermal stability and glass transition temperature (Tg) of the matrix (poly(HEMA-co-FAOEME). The antimicrobial properties of the materials were determined by the disk diffusion method using five different bacteria and one yeast cell. It was observed that the nanocomposites showed activity against all pathogens except one bacterial species, and the source of the activity was ZnO nanoparticles.

Spider-Silk-Inspired Nanocomposite Polymers for Durable Daytime Radiative Cooling.

Passive daytime radiative cooling (PDRC) materials, that strongly reflect sunlight and emit thermal radiation to outer space, demonstrate great potential in energy-saving for sustainable development. Particularly, polymer-based PDRC materials, with advantages of easy-processing, low cost, and outstanding cooling performance, have attracted intense attention. However, just like other polymer devices (for example polymer solar cells) working under sunlight, the issue of durability related to mechanical and UV properties needs to be addressed for large-scale practical applications. Here, a spider-silk-inspired design of nanocomposite polymers with potassium titanate (K2 Ti6 O13 ) nanofiber dopants is proposed for enhancing the durability without compromising their cooling performance. The formed tough interface of nanofiber/polymer effectively disperses stress, enhancing the mechanical properties of the polymer matrix; while the K2 Ti6 O13 can absorb high-energy UV photons and transform them into less harmful heat, thereby improving the UV stabilities. Taking poly(ethylene oxide) radiative cooler as an example for demonstration, its Young's modulus and UV resistance increase by 7 and 12 times, respectively. Consequently, the solar reflectance of nanocomposite poly(ethylene oxide) is maintained as constant in acontinuous aging test for 720h under outdoor sunlight. The work provides a general strategy to simultaneously enhance both the mechanical stability and the UV durability of polymer-based PDRC materialstoward large-scale applications.

Improvement of compatibility, mechanical, thermal and dielectric properties of poly(lactic acid) and poly(butylene adipate‐co‐terephthalate) blends and their composites with porous clay heterostructures from mixed surfactant systems

AbstractIn this study, nanocomposite poly(lactic acid) and poly(butylene adipate‐co‐terephthalate) (PLA/PBAT) blends were prepared through polymer blending in the presence of multi‐functional epoxy as a compatibilizer that could react with epoxy group and terminated end group of two phases to increase interfacial adhesion between PLA and PBAT and improve the toughness of PLA. The effects of porous clay heterostructure from mixed CTAB:CTAC surfactant in the mole ratio of 1:2 (B1C2‐PCH) were also investigated. The elongation at break of the blends reached 38%, which was eight times that of neat PLA. The cryo‐fractured surface demonstrated the interfacial adhesion caused by the interaction of the epoxy group of the reactive compatibilizer with the terminal carboxyl and hydroxyl groups of PLA and PBAT. Moreover, PBAT reduced the crystallization rate and percent crystallinity of the PLA matrix and further decreased when compatibilizer was used. Alternatively, B1C2‐PCH accelerated the heterogeneous nucleation and crystallization of the nanocomposite films. After adding small amount of B1C2‐PCH, the nanocomposite films demonstrated excellent dielectric properties. Therefore, the improvement of PLA/PBAT nanocomposite blends are capable to be further developed as polymeric capacitor films.

The effects of SiO2@Y2O2S:Eu3+ phosphor on the optic characteristics of white light-emitting diodes

The study <span>investigated the effectiveness of coating silica nanoparticles (SiO<sub>2</sub>) and resin-silica nanocomposites poly methyl methacrylate (PMMA)-silicaover the surface of Y<sub>2</sub>O<sub>2</sub>S:Eu<sup>3+</sup> red phosphors. The purpose of this surface coating is to enhance the optical properties, including the photoluminescence (PL) and long-term stability, of Y<sub>2</sub>O<sub>2</sub>S:Eu<sup>3+</sup>. Two methods used to coat the phosphor with 5-mm silica nanoparticles are dip-coating and sol-gel (Stöber) methods. SiO<sub>2</sub> nanoparticles were formed via hydrolysis and condensation reactions, while radical polymerization was performed to fabricate the poly (1-vinyl-2-pyrrolidone). The Y<sub>2</sub>O<sub>2</sub>S:Eu<sup>3+ </sup>surface coating of PMMA-silica composite was performed via two reactions. One is the reaction of SiO<sub>2</sub> nanoparticles with methyl methacrylate (MMA) monomer, and the other is MMA-tetraethyl orthosilicate (TEOS) reaction. The results showed that by using the latter method, Y<sub>2</sub>O<sub>2</sub>S:Eu<sup>3+</sup> yielded better PL and long-term stability. Additionally, surface coating with the PMMA-SiO<sub>2</sub> nanocomposite using the second technique resulted in 5% enhancement in PL and stabilized the cathode luminescence (CL) intensity of Y<sub>2</sub>O<sub>2</sub>S:Eu<sup>3+</sup>, compared to those properties of uncoated Y<sub>2</sub>O<sub>3</sub>S:Eu<sup>3+</sup> phosphor particles.</span>

Exciton Dynamics of MEH‐PPV polymer based Nanocomposites: Effect of Molecular Orbital Energy Levels of Nanoparticles**

AbstractExploring and investigating the strategies to improve quantum efficiency and photostability of light‐emitting polymers in polymer light‐emitting diodes is significantly an important topic of research. Thus this study endeavours towards the determination of the role of molecular orbital energy levels of metal oxide nanoparticles on the performance characteristics of hybrid nanocomposites. This work attempts to vary the proportions of zirconium dioxide (ZrO2) nanoparticles in nanocomposites of poly[2‐methoxy‐5‐(2’‐ethylhexyloxy)‐1,4‐phenylenevinylene] (MEH‐PPV), which leads to a six‐fold enhancement of luminescence quantum efficiency and increased radiative recombination rate due to an appropriate energy level alignment. An improvement in photostability was also reported due to a reduction in polymer chain defects, inhibition of moisture intervention and most importantly, impediment of the photo‐oxidation by controlling the triplet exciton dynamics. Thus, efforts are made to validate the role of energy levels of ZrO2 nanoparticles in improving the luminescence quantum efficiency and photostability of MEH‐PPV compared to ZnO incorporated MEH‐PPV.

Effect of the Surface Functionalization of Graphene and MWCNT on the Thermodynamic, Mechanical and Electrical Properties of the Graphene/MWCNT-PVDF Nanocomposites.

The nanocomposites of poly(vinylidene fluoride) (PVDF) with pristine graphene nanoflakes (GNF) and a multi-wall carbon nanotube (MWCNT) were prepared by the solution casting method. Additionally, the GNF and MWCNT were functionalized by acid treatment, and nanocomposites of the acid-treated MWCNT/GNF and PVDF were prepared in the same method. The effect of the acid treatment of MWCNT and GNF on the mechanical, thermal and thermo-oxidative stability and the thermal conductivity of the MWCNT/GNF-PVDF nanocomposites was evaluated, and the results were compared with the untreated MWCNT/GNF-PVDF nanocomposites. In both cases, the amount of GNF and MWCNT was varied to observe and compare their thermal and mechanical properties. The functionalization of the GNF or MWCNT resulted in the change in the crystallization and melting behavior of the nanocomposites, as confirmed by the differential scanning calorimetry analysis. The addition of the functionalized GNF/MWCNT led to the improved thermal stability of the PVDF nanocomposites compared to that of the non-functionalized GNF/MWCNT-PVDF nanocomposites. The thermal and electrical conductivity of the functionalized and non-functionalized GNF/MWCNT-PVDF composites were also measured and compared. The functional groups, crystal structure, microstructure and morphology of the nanocomposites were characterized by Fourier transformed infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively.

Effect of Fabrication Method on the Thermo Mechanical and Electrical Properties of Graphene Doped PVDF Nanocomposites.

Nanocomposites of poly (vinylidene fluoride) PVDF with graphene nanoflakes (GNF) were prepared using two different routes. Initially, a mix-melting method was used to prepare composites, and their thermal and mechanical properties were evaluated to choose the better method for future experiment and properties investigation. Then, nanocomposite films were prepared by a simple solution-casting technique using a PVDF/graphene solution. In both cases, the amount of graphene was varied to observe and to compare their thermal and mechanical properties. The addition of graphene to the PVDF matrix resulted in changes in the crystallization and melting behaviors as confirmed by DSC analyses. Increasing the graphene content led to improved thermal stability of the PVDF nanocomposites prepared using both methods. Improvements in mechanical properties by the addition of graphene were also observed. Better performance was observed by the nanocomposites prepared by a mix-melting technique suggesting better dispersion and strong interface bonding between PVDF and graphene particles. Thermal and electrical conductivity were measured and compared. Microstructure and morphology were characterized using FTIR, XRD, and SEM analyses.

Synthesis, characterization, magnetoelectric properties and gas sensing application of Poly(anthranilic acid-co-indole)/ magnetite nanocomposites

The increased demand for the discovery of new conducting materials encourages the researchers for the development of advanced electronic technologies. In the present study, nanocomposites of poly (anthranilic acid- co-indole)/(PANA- C o-PIN) and magnetite nanoparticles (Fe3O4) were prepared via a one-step polymerization method and evaluated by various analytical techniques. The Fourier transform infrared spectroscopy (FT-IR) spectra proved the presence of Fe3O4 nanofillers in the copolymer at 507 cm−1. Optical characterization (UV-Vis) shows a clear blueshift indicating strong interactions between Fe3O4 and PANA- C o-PIN. The X-Ray diffraction (XRD) patterns revealed an increase in crystallinity due to the well dispersed nanoparticles. FESEM images evidenced the morphological changes caused by the uniform dispersion of nanoparticles in the copolymer matrix. The nano-dispersion of magnetite nanoparticles in the copolymer was confirmed by High-resolution transmission electron microscopy analysis. Magnetic properties of nanocomposites obtained from a vibrating sample magnetometer (VSM) showed an increase in the saturation of magnetism with the addition of nanoparticles and the composite exhibited superparamagnetic behaviour. The thermal stability and glass transition temperature of the nanocomposites were greatly enhanced with the addition of nanoparticles and were determined with the help of Thermogravimetric Analysis (TGA) and Differential scanning calorimetry (DSC) respectively. Filler-dependent electrical properties showed a linearly increased DC conductivity with the addition of nanoparticles. The impedance analysis showed that the AC conductivity and dielectric properties of the nanocomposites were higher than the copolymer and the maximum electrical properties were observed for 15 wt.% of composites. The ammonia gas sensing performance of copolymer composite indicates the easy access of gas molecules to the sensor surface through the metal oxide nanoparticles. The synthesized copolymer nanocomposites showed high sensitivity and fast response to ammonia gas. The prepared composite with good thermal properties, dielectric constant, ammonia gas sensing and magnetoelectric properties is a promising candidate for use in nanoelectronics devices.

Nanocomposite parylene-C memristors with embedded Ag nanoparticles for biomedical data processing

Neuromorphic networks adopt human brain mechanisms and create a promising way to solve various artificial cognitive problems. Memristors, novel circuit design elements, could play the role of hardware synapses in such systems. Memristors based on parylene, safe material for usage within the human body, have already shown their eligibility for neuromorphic applications. The embedding of metal nanoparticles into the parylene layer leads to even better memristive characteristics, but the usage of such memristors in neuromorphic systems is still questionable. In this paper, the characteristics of nanocomposite poly(chloro- p -xylylene) memristors are studied, and the possibility of their training following spike-timing-dependent plasticity rules is demonstrated. Furthermore, a simple spiking neuromorphic network based on such memristors is successfully simulated to solve the task of breast cancer data classification. The results pave the way towards bio-compatible and energy-efficient wearable neuromorphic systems based on parylene memristors. • Parylene-C memristors with embedded Ag nanoparticles are studied for the first time. • These devices demonstrate suitable for neuromorphic applications characteristics. • Studied memristors support bio-inspired STDP learning rules. • Simulated memristive spiking network demonstrates decent classification accuracy.

Nanocomposite Poly(lactic acid)/sepiolite with Improved Mechanical and Biofilms Formation Properties

Nanocomposites of poly(lactic acid) with sepiolite needles (5 wt.%) were evaluated in terms of the mechanical and biofilm formation properties. The nanocomposite exhibited higher values of the Young�s modulus and tensile strength at break compared to the PLA, without detriment in the percent elongation at break. These improvements were related to the high aspect ratio of the nanoclay, the polymer-clay interactions, and the degree of dispersion. The growth of Pseudomonas aeruginosa on the surface of the PLA and nPLA materials was promoted in different conditions. Medium with different concentration of nutrients were used and also were compared the effect of the medium physical state (solid or liquid medium). Biofilms were formed in all the conditions. However, the nanocomposite presented a higher area coverage of microorganisms on its surface, possibly due to the positive effects of the nanoclay on the bacterial adhesion.