Polymer Nanocomposite Thin Films Research Articles

Investigations on Impact of YSZ Nanoparticles on Morphology & Electrical conductivity of PEDOT: PSS

Conductive polymer nanocomposites, which combine the flexibility and conductivity of polymers with the unique properties of nanofillers, have generated interest in various fields such as energy storage, sensors, coatings, and corrosion protection. This study discusses the effect of Yttria-stabilized zirconium nanoparticles (YSZ NPs) on the morphology and electrical conductivity of poly(3,4-ethylenedioxythiophene): poly(4-styrenesulfonate) (PEDOT: PSS). Thin films of PEDOT: PSS and PEDOT: PSS: YSZ were fabricated using spin coating technique. FTIR and XRD characterizations confirmed the interaction between YSZ nanoparticles and the PEDOT: PSS matrix, leading to changes in chemical morphology and film crystallinity. The investigation of the current-voltage (I-V) relationship showed improved electrical conductivity in PEDOT: PSS films with the addition of YSZ nanoparticles, with respective conductivities of 0.028×10−6 S cm−1 and 0.0885×10−4 S cm−1 for pristine and YSZ-containing films. Additionally, the sensing properties of the PEDOT: PSS: YSZ film in detecting organic vapours were studied. These findings suggest that these conducting polymer nanocomposite thin films could potentially be used as electrolyte components in battery cells, supercapacitors, and fuel cells, as well as serve as sensors for certain organic vapours.

Enhancement of the mechanical properties in ultra-low weight SWCNT sandwiched PDMS composites using a novel stacked architecture

This study focuses on enhancing the mechanical properties of thin, soft, free-standing films via a layer-by-layer (LBL) fabrication process called LBL-FP. Soft polymer nanocomposite (PNC) thin films, combining polydimethylsiloxane (PDMS) and single-walled carbon nanotubes (SWCNT) at ultra-low loadings using a unique bottom-up LBL-FP, are examined. Two different structures of layered composites, (i) LBL PNCs- Layered composites with alternating layers of PDMS and SWCNT, (ii) Bulk PNCs- Layered composites with SWCNT dispersed in the bulk of PDMS, are comparatively investigated for their structural and mechanical properties. Silane-functionalized SWCNT strengthens the chemical bonding with PDMS, improving adhesion and dispersion. Mechanical analysis using nanoindentation, delamination, and dynamic analysis highlights the advantages of LBL PNCs with alternating layers of PDMS and SWCNT. Notably, LBL PNC (0.5 wt%) exhibits significant improvements, such as 2.6X increased nanoindentation resistance, 3X improved viscoelasticity, and (2–5)X enhanced tensile properties in comparison with neat PDMS. Due to this, LBL PNCs offer potential for soft, lightweight applications like wearables, electromagnetic interference shielding materials, and strain sensors while advancing composite thin film mechanics. The study emphasizes using a stacked architecture to produce PDMS-SWCNT multilayered PNCs with improved mechanics utilizing ultra-low concentrations of SWCNT. This first-of-its-kind stack design facilitates possibilities for lightweight composites utilizing less fillers. The LBL assembly involves the stacking of alternating layers of different materials, each contributing specific properties to enhance the overall strength and toughness of the structure.

Mechanistic insight into the role of the aspect ratio of nanofillers in the gas barrier properties of polymer nanocomposite thin films

The introduction and processing parameters of 2D graphene flakes into a polymer matrix were altered in order to understand the impact of dispersed flake geometry on the physical properties of nanocomposites.

Effective interactions and dielectric study of polymer nanocomposite thin films of polyvinylidene fluoride and graphene oxide

ABSTRACT Polyvinylidene fluoride (PVDF) is a well-known fluoropolymer for its electronic applications. The present work investigates the influence of Graphene oxide (GO) in various weight percentages over the dielectric profile of the PVDF matrix. Field emission scanning electron microscopy (FESEM) is used to explain the morphological features of the samples. The thermal stability of the PVDF polymer with the addition of GO was studied using thermogravimetric analysis (TGA). X-ray diffraction spectroscopy (XRD), confocal Raman microscopy (CRM), and Fourier Transform infrared spectroscopy (FTIR) were used to interpret the appreciable interfacial interactions between the matrix and the nanofiller and possible phase transformations. The presence of polar and non-polar polymorphic phases in PVDF was verified with the help of XRD, FTIR, and CRM analyses. The band gap energy of the samples was determined using the Tauc-plot method from UV–visible observations. The variation in the polarity of the matrix with the inclusion of GO is also noted. The dielectric and AC conductivity measurements were done at 100 Hz and 2 MHz. All these ascertain the candidacy of PVDF/GO nanocomposite thin films to be incorporated into electronic devices of this era.

Polymer nanocomposite thin films prepared using single- and multi-walled carbon nanotubes for flexible electronics

Polymer nanocomposite thin films prepared using single- and multi-walled carbon nanotubes for flexible electronics

A new approach for synthesizing plasmonic polymer nanocomposite thin films by combining a gold salt aerosol and an atmospheric pressure low-temperature plasma

The proof of the concept of a new, onestep and safe by design process to synthesize metal-polymer nanocomposites thin films on a large surface is presented. It is based on the injection of an aerosol of a solution of metal (gold) salts dissolved in a polymerizable solvent (isopropanol) into an argon atmospheric pressure dielectric barrier discharge. The main novelty of this method resides in the fact that the nanoparticles are formed in situ, inside the plasma reactor, in the gas phase. Consequently, the nanoparticle synthesis and deposition are concomitant with the solvent polymerization used to produce the matrix, which makes it possible to obtain homogeneous layers of non-agglomerated nanoparticles (NPs) with high NPs density. By toggling between low and high-frequency discharges, gold/polymer nanocomposites with different morphologies and optical properties are synthesized. The effect of the concentration of gold in the aerosol and the gas residence time in the plasma as well as the ratio of high and low-frequency discharge and their repetition rate are presented. The thin films are systematically characterized by AFM and UV–visible spectroscopy to analyze their morphologies along with their plasmonic resonances.

Projectile Impact Shock-Induced Deformation of One-Component Polymer Nanocomposite Thin Films.

Matrix-free assemblies of polymer-grafted nanoparticles (PGNs) enable mechanically robust materials for a variety of structural, electronic, and optical applications. Recent quasi-static mechanical studies have identified the key parameters that enhance canopy entanglement and promote plasticity of the PGNs below Tg. Here we experimentally explore the high-strain-rate shock impact behavior of polystyrene grafted NPs and compare their energy absorption capabilities to that of homopolystyrene for film thicknesses ranging from 75 to 550 nm and for impact velocities from 350 to 800 m/s. Modeling reveals that the initial shock compression results in a rapid temperature increase at the impact site. The uniformity of this heating is consistent with observations of greater kinetic energy absorption per mass (Ep*) of thinner films due to extensive visco-plastic deformation of molten film around the penetration site. Adiabatic heating is insufficient to raise the temperature at the exit surface of the thickest films resulting in increased strain localization at the impact periphery with less melt elongation. The extent and distribution of entanglements also influence Ep*. Structurally, each NP acts as a giant cross-link node, coupling surrounding nodes via the number of canopy chains per NP and the nature and number of entanglements between canopies anchored to different NPs. Load sharing via this dual network, along with geometrical factors such as film thickness, lead to extreme Ep* arising from the sequence of instantaneous adiabatic shock heating followed by visco-plastic drawing of the film by the projectile. These observations elucidate the critical factors necessary to create robust polymer-nanocomposite multifunctional films.

Electrical and Structural properties of (ZnTiO3)/Epoxy System Nanocomposite Thin films

Spin coating technique using to prepare two layers of epoxy reinforced by weight (0Wt%,1Wt%,2Wt%,3Wt%,4Wt%) nano ZnTiO3additives uniform thin films with a fixed thickness of (0.7 ☐m) on glass floors at room temperature, dispersion and magnetic stirring techniques are used to prepare the nanocomposites thin films. The purpose of this study was to produce a new modified polymer (ZnTiO3/Epoxy) nanocomposite thin films then evaluate electrical and structural properties of these thin films. The electrical properties of thin films have a degree effect temperature on the resistance (R) of thin films within the range (303- 433) k or (30-160) C0. Electrical conductivity and activation energy of the thin film was calculated where the results indicate that there is a two activation energy and this means there is two mechanisms connection. It is also shown by measurements of the effect of the whole (ZnTiO3/Epoxy) nanocomposite thin films have a connection from the negative type (n-type). Stractural properties include XR-D and SEM. XRD, show crystal structure of zinc titanite (ZnTiO3) nano powder. Scanning electron microscopy SEM, show clearly analysis for different weight ratio affected thin films surfaces.

Piezoelectric β-polymorph enhancement in graphene oxide -PLA nanocomposite films

The flexible piezoelectric nanocomposite films have attracted considerable interest for use in autonomous nanosystems, sensors and portable electronics. The effect of graphene oxide (GO) nanoparticles on the crystal structure, unique crystallization, mechanical behavior and significant improvement in piezoelectricity of polylactic acid (PLA) has been reported. Polylactic acid / graphene oxide (PLA/GO) nanocomposite films were prepared by the solvent casting technique using different percentages of GO. The different samples were characterized by Polarized optical microscope (POM), Fourier transformed infrared (FTIR) and X-ray diffraction analysis. The presence of β phase in nanocomposites and the enhancement of their piezoelectric properties were confirmed by FTIR and XRD analysis. These electroactive and biodegradable polymer nanocomposite thin films may be a potential candidate for the piezoelectric nanogenerators, energy storage devices and energy harvesting applications.

Spatial structures formation of surface-modified nanoparticles in polymer nanocomposite thin films

The spatial structures of polystyrene (PS) nanocomposite thin films containing oleic acid-modified nanoparticles were investigated. A layer of the nanoparticles was formed at the surface of the thin film under all conditions in this work. Aggregates of the nanoparticles were formed simultaneously in the film when the concentration of the nanoparticles was relatively high. The effects of the evaporation rate and the molecular weight of PS on the spatial structures of the nanoparticles in the thin films were discussed using the ratio of the time constants for phase separation (diffusion) of the nanoparticles, gravitational sedimentation of the aggregates and drying. As the ratio of the diffusion time to the drying time increased, the thickness of the nanoparticle layer and the diameter of the nanoparticle aggregates decreased, and then reached a constant value. When the ratio of the sedimentation time to the drying time was high, the relatively small aggregates were dispersed throughout the thin film since the effect of gravitational sedimentation was small.

Mechanical behavior of ABS plastic-matrix nanocomposites with three different carbon-based nanofillers

Acrylonitrile butadiene styrene (ABS) polymer nanocomposite thin films with carbon-based nanofillers (CBNs: fullerene, carbon nanotubes, and graphene) were fabricated in a wet reversal process followed by hot pressing. To understand the effect of CBNs on the fabricated nanocomposites, tensile tests and nanoindentation tests were performed. The tensile strength of the fullerene composite was about 30 MPa based on the specimen containing 1 wt% of CBNs, which was measured to be up to 35% higher than the other two composites. In the nanoindentation test, the elastic modulus and hardness value decreased as the amount of CBNs increased. This is considered to be because the nanoindentation test reflects more mechanical behavior of the local part of the composite than the tensile test. In the tensile and nanoindentation tests, all of the nanofillers exhibited the mechanical properties of ABS polymers, among which the ABS composites with fullerene exhibited the best properties. It is concluded that nanofillers should be added appropriately, and in the case of polymers, nanofillers, which may be located between polymer chains such as fullerene, may be more efficient.

Erbium-Doped Nanoparticle-Polymer Composite Thin Films for Photonic Applications: Structural and Optical Properties.

Erbium-doped nanocrystal (NC)-dispersed polymer thin films are attractive core materials for use in optical waveguides as they can provide high optical gain and enable the formation of compact waveguide amplifiers. Nonetheless, there are significant challenges associated with obtaining good dispersibility of NCs into a polymer matrix and favorable optical properties. Therefore, in this paper, we report the fabrication of Er3+-doped ceria (EGC) NCs employing the Leeds alginate process (LAP) and their incorporation into a siloxane polymer matrix. The surface morphology and compositional, structural, and optical properties of the fabricated films are evaluated to assess the NC dispersion and their suitability for the waveguide amplifier. The photoluminescence (PL) and lifetime measurements of the NCs–polymer nanocomposite thin film samples show intense, broadband PL emission of the Er3+ ions at 1534 nm (4I13/2 → 4I15/3 transition) with a full width at half-maximum (fwhm) of ∼64 nm and lifetime in the range of 2.6–3.0 ms. The inhomogeneously broadened PL spectra and improvement in lifetime of NCs in the polymer are important results that we report. The EGC NCs–polymer nanocomposite thin films also exhibit excellent transparency in the NIR wavelength range and a refractive index in the range of 1.53–1.58 in the visible wavelength. The work presented here clearly demonstrates the potential of using high-quality Er-doped nanocomposite polymer thin films for interesting applications such as compact low-cost waveguide amplifiers and lasers.

Experimental evaluation on surface plasmon resonance sensor performance based on sensitive hyperbranched polymer nanocomposite thin films

The plethora of optical techniques have been developed to detect the dengue virus, regrettably, the existing techniques are cumbersome and have limitations to provide early identification of the low-level of dengue virus. For this purpose, surface plasmon resonance (SPR) optical sensor was designed with a highly sensitive thin film based on hyperbranched polymer nanocomposites for conjugation of antibodies that specifically detect the dengue virus type II (DENV). In particular, we investigate the SPR sensing performance for gold/cadmium sulfide quantum dots-polyamidoamine/antibody (Au/CdS QDs-PAMAM/IgM) sensor film in terms of linear sensitivity, binding affinity, detection accuracy, full-width-half-maximum, selectivity, and spike and recovery test. The results show a strong affinity value, good sensitivity and selectivity, high accuracy, and excellent recovery value, obeying the ideal value based on conventional assay analysis. Additionally, this Au/CdS QDs-PAMAM/IgM based SPR sensor was successfully applied for the lowest detection of 1 pM of DENV E-proteins. To this end, a highly sensitive Au/CdS QDs-PAMAM/IgM sensor film was characterized using Raman spectroscopy, ultraviolet-visible (UV–Vis-NIR) spectroscopy, and atomic force microscopy (AFM) to confirm the binding of DENV.

Johnson Noise and Optical Characteristics of Polymer Nanocomposites based on Colloidal Quantum Dots and in-situ Nanoparticles Formation

Electrical and optical properties of polymer nanocomposite thin films have been analyzed to study their reliability and competency as a component for optoelectronic devices such as LED and solar cells. Polymer nanocomposite encounters various challenges, such as the dispersion of nanoparticles in the matrix that hinders their efficiency for potential devices. In this paper, two types of polymer nanocomposites have been fabricated, and their Johnson noise, current density-voltage, and optical have been measured. The first type of nanocomposite produced through an in-situ method, that is by impregnating CdS or CdSe nanoparticles in conjugated polymer, P3HT (NP-CdX:P3HT). The nucleation of the nanoparticles was done using gas exposure. The second type is by directly adding CdS or CdSe quantum dots into P3HT (QD-CdX:P3HT). Both kinds of polymer nanocomposite thin films were fabricated using modified Langmuir-Blodgett technique. Results showed that for frequency above 10 Hz, the Johnson noise was less than 1× 10-27 A2/Hz, regardless of the quantity of quantum dots or nanoparticles. The J-V results show (NP-CdX:P3HT) electrical performance compared with QD-CdX:P3HT. High polymer crystallization of NP-CdX:P3HT thin films is revealed by UV-Vis absorbance spectra. The quantum confinement effect is evidence through peak shifting and depreciation of absorption. The photoluminescence intensity of thin films decreased when they were exposed to the gas. It can be concluded that the NP-CdX:P3HT nanocomposites can be further studied as they have greater potential to be exploited in optoelectronic devices.

Hydrogen sulfide sensors based on PANI/f-SWCNT polymer nanocomposite thin films prepared by electrochemical polymerization

Abstract Hydrogen sulfide (H2S) gas sensors in the form of thin films based on polyaniline (PAN) incorporated with various concentrations of functionalized single wall carbon nanotubes (f-SWCNT) were prepared by electrochemical polymerization of Aniline monomer with sulfuric acid in an aqueous solution. Surface morphology of the thin film nanocomposites was investigated by Field Emission Scanning Electron Microscopy (FE-SEM) and revealed that the f-SWCNTs were almost uniformly distributed on the surface of the host PANI matrix. The X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) spectroscopy, and Hall effect measurements were used to characterize the synthesized PANI/f-SWCNT nanocomposites. The Hall measurements reveal the p-type conductivity. The grown FTIR band at 1145 cm−1 with the increase of the f-SWCNT content evidence a formation of charge transfers due to a remarkable interaction between PANI and f-SWCNTs. The response of this nanocomposite film towards the H2S gas was investigated by monitoring the change in the electrical resistance with the time in the presence of 30% H2S at different operating temperatures. The sensing analysis showed that the sensitivity increased with f-SWCNT content in the PANI matrix. The rapid response/recovery times toward the H2S gas, at 50 °C, was achieved for a PANI/0.01% f-SWCNT nanocomposite sample.

Surface engineering of polystyrene–cerium oxide nanocomposite thin films for refractive index enhancement

Polymer nanocomposites have gained much importance in the field of optoelectronics due to their unique optical properties. Refractive index engineering using nanoparticles is an effective strategy that could be applied for the fabrication of optical devices. Herein, we report three different strategies which are employed to enhance the refractive index of polymer thin films. These include incorporating cerium oxide nanoparticles onto the polystyrene matrix, secondly adding cerium oxide nanoparticles onto the cross-linkable polystyrene and thirdly by embedding functionalized cerium oxide nanoparticles onto the cross-linkable polystyrene. Refractive index of the polystyrene thin films was enhanced by dispersing neat CeO2 nanoparticles and functionalized CeO2 nanoparticles into the polystyrene matrix. 1.38% enhancement in the refractive index of the polymer nanocomposite thin films could be achieved using our technique. The blending of polystyrene with cerium oxide nanoparticle presents a prospective way to engineer the refractive index of polymer thin films. We firmly believe that the study will be an effective guide towards future research in the area of surface engineering of polymer thin films for refractive index enhancement.

Fabrication of uniform vertically-aligned carbon nanotube–polymer composite thin films by capillary flow intrusion

Polymer and nanomaterial composites, known as nanocomposites, are advanced materials that have many potential applications. One type of thin-film nanocomposite is a polymer–carbon nanotube (CNT) nanocomposite, whose properties are strongly dependent on the uniformity and alignment of CNTs in the nanocomposite. However, the control of CNT alignment in these nanocomposites is still difficult to achieve. Here, we propose a facile single-step method, a capillary flow intrusion method, to fabricate uniform polymer nanocomposite thin films of vertically aligned (VA) single-/multi-walled CNTs that range from 15 to 300 µm in thickness. Raman scattering spectroscopy and polarized Raman spectroscopy measurements, and cross-sectional scanning electron microscopy (SEM) observations confirmed that the polymer was uniformly infiltrated into VACNTs, such that the alignment of CNTs in the nanocomposite was preserved and there were no excess portions of the polymer. Experimental and numerical calculation results indicated that capillary flow rate, wettability, and polymer shrinkage are important factors in the capillary flow intrusion method.

Removal of heavy metal ions using polystyrene nanocomposite thin films

Polymer nanocomposite thin films consisting of polystyrene and furnace carbon black were prepared in this study as adsorbent materials for the removal of heavy metals from industrial wastewater. The film properties were characterized, and the effect of carbon content in the nanocomposite, initial concentration, separation time, and pH on the removal efficiency were investigated. The optimal operating conditions were 120 min of separation time at pH 6 with a carbon content of 15 wt%. The adsorption equilibrium data and adsorption kinetics are also described herein. The Freundlich model best fit the equilibrium data, and the adsorption rate followed pseudo second-order kinetics.

Light-Activated Hybrid Nanocomposite Film for Water and Oxygen Sensing.

Oxygen and water vapor sensing properties are investigated in metal-oxide-hybrid polymer nanocomposite thin films generated by infiltration synthesis, which incorporates molecular ZnO into the matrix of SU-8 polymer, a common negative-tone photoresist. The hybrid thin films display 20-fold higher gravimetric responses to oxygen and water vapor than those of control ZnO thin films in the dark. An additional 50-500% enhanced responses are detected under UV irradiation. The overall enhanced gravimetric response in the hybrid film is attributed to the ZnO molecules distributed in the polymer matrix, whereas the UV enhancement is explained by the light-induced, reversible generation of hydrophilic fluoroantimonic acid from triarylsulfonium hexafluoroantimonate photoacids, which leads to the increased surface potential and adsorption energies for oxygen and water. A gravimetric sensor based on a series of ZnO-infiltrated SU-8 films under UV excitation enables 96% accurate classification of water and oxygen environment with sub 10 mTorr detection limits. The results demonstrate UV-induced fully reversible surface hydrophilicity of ZnO/SU-8 hybrid nanocomposites.

Crack Formation in Polymer Nanocomposite Thin Films Containing Surface-Modified Nanoparticles during Solution Casting

Crack Formation in Polymer Nanocomposite Thin Films Containing Surface-Modified Nanoparticles during Solution Casting