Showing papers on "Polymer blend published in 2020"

Optical and dielectric characteristics of polyethylene oxide/sodium alginate-modified gold nanocomposites

Abstract: Films of polyethylene oxide and sodium alginate polymer blend (50/50 wt%) embedded with different quantities of Au nanoparticles with size 3–32 nm were made using the casting process. The nanocomposite films were examined by XRD analysis, FT-IR spectroscopy, TEM, UV/vis spectroscopy, and AC conductivity and dielectric parameter measurements. The XRD spectra revealed the amorphous nature of the prepared films (PEO/SA–Au NPs). From the Fourier transform infrared spectra it can be seem that the intensity of the FT-IR bands decreased which depicted the existence of the interaction between (PEO/SA) virgin polymer and gold nanoparticles. The TEM micrographs showed a cubic-structure for Au NPs with an average size of 15–20 nm. The optical properties of the polymer composite were examined by ultraviolet-visible techniques. In a direct transition the optical energy gap (Eg) of the prepared films is decreased from 4.73 to 2.92 eV and in an indirect transition decreased from 2.95 to 1.50 eV. The dielectric and electrical spectra of the obtained films were examined via dielectric broad-band spectroscopy. The electrical and dielectric measurements are appropriate for the use of the polymer nanocomposite films in the fabrication of electroactive materials.

Preparation and characterization of polyaniline/sodium alginate-doped TiO2 nanoparticles with promising mechanical and electrical properties and antimicrobial activity for food packaging applications

Abstract: Polymer nanocomposite (PNC) films based on sodium alginate and polyaniline (SA/PANi) and TiO2 as nanoceramic were synthesized by solution casting method. XRD displayed that the average size crystalline of the TiO2 NPs is 19 nm, and the amorphuos degree of the SA/PANi blend decreased due to the addition of TiO2 NPs. The interaction between the TiO2 NPs and the SA/PANi blend was confirmed by FT-IR spectroscopy, due to vibrational changes that occurred after the addition of TiO2 dopant in the polymer blend. The UV–Visible spectrum was used to calculate optical energy band gaps (direct and indirect). Both of the Egdi and Egind were reduced with the rise in TiO2 content. Thermogravimetric showed that the thermal stability of the nanocomposite was higher than the pure SA/PANi. With the increase in TiO2 NPs concentrations and frequency, the electrical properties such as dielectric and ac conductivity of pure blend improved and displayed maximum electrical properties (dielectric and conductivity) at 1 wt% loading. Additionally, the doping of TiO2 NPs in the polymer matrix proved that the nanocomposites exhibited excellent antimicrobial activity against all the bacteria taken for the test. It is obvious from the results that the nanocomposites have the potential for use in active packaging applications.

Fabrication of high performance energy storage EDLC device from proton conducting methylcellulose: dextran polymer blend electrolytes

Abstract: This paper reports Methylcellulose:Dextran (MC:Dex) polymer blend based electrolyte system with NH4I salt for electrical double layer capacitor (EDLC) application. The structural and electrochemical properties of the electrolyte systems were investigated using X-ray diffraction (XRD), Fourier transformed infra-red (FTIR) spectroscopy, Field emission scanning electron microscope (FESEM), impedance spectroscopy, transference number measurement (TNM) and linear sweep voltammetry (LSV). The FTIR studies revealed the complexation between MC:Dex polymer blend and NH4I salt. The reduction in the crystallinity of MC:Dex polymer blend with the increasing salt concentration was observed in XRD analysis. The electrolyte system was observed to be predominantly ionic in nature. The electrolyte composition with 40 wt.% of NH4I showed the maximum ionic conductivity as 1.12 × 10−3 S/cm with electrochemical stability window of 1.27 V. The highest conducting composition of the electrolyte system was used to prepare EDLC with activated carbon electrodes. The EDLC exhibited initial specific capacitance as 79 F/g, energy density as 8.81 Wh/kg and power density as 1111.1 W/kg at a current density of 0.2 mA/cm2.

Effect of ohmic-drop on electrochemical performance of EDLC fabricated from PVA:dextran:NH4I based polymer blend electrolytes

Abstract: Proton conducting solid polymer blend electrolytes based on poly(vinyl alcohol)(PVA):dextran that were doped with different quantities of ammonium iodide (NH4I) were prepared. The X-ray diffraction (XRD) and Fourier-transform infrared (FTIR) study were carried out to examine the compatibility of NH4I withPVA:dextran polymers. FTIR spectroscopy assessment was used to establish the presence of a complex formation between the PVA:dextran and added salt through the modification and reduction in the intensity of FTIR bands relevant to the functional groups. The field emission scanning electron microscopy (FESEM) examination was used to assess the channels for proton transport. Electrical impedance spectroscopy (EIS) was used to analyse the samples conductivity behaviour. The sample with 20 wt.% of added salt has shown a high DC conductivity which can be employed in electrochemical devices such as EDLC. It is also demonstrated by the transference number (TNM) and linear sweep voltammetry (LSV) that it is appropriate to use the largest conducting sample for electrochemical device. There was electrochemical stability of the electrolyte sample with voltage sweeping linearly to 1.3 V. It is shown by the outcome of cyclic voltammetry (CV) plot that charge storage at the site of electrode-electrolyte is non-Faradiac. A high drop voltage ( V d = I R ) is implied by the usual galvanostatic charge-discharge. The equivalent series resistance ( R e s ) increases as a result of the increase in V d all the way through the charge-discharge cycle. Specific capacitance ( C s p ) is nearly constant from the foremost cycle to the 100th cycle, with average of 4.2 F/g.

Enhanced Structural, Optical, and Electronic Properties of In 2 O 3 and Cr 2 O 3 Nanoparticles Doped Polymer Blend for Flexible Electronics and Potential Applications

Abstract: This paper aims to investigate the structural, optical, electronic and electrical properties of PVA/PVP blend and PVA/PVP blend doped with In2O3 and Cr2O3 nanoparticles to use it for various flexible electronics devices like solar cell, sensors diodes, electronics gates, transistors have low cost, high corrosion resistance, low energy gap, flexible, low weight, high optical and electrical conductivities. The results indicated that absorbance of PVA/PVP blend improved about 30% and 34 with the increase of In2O3 and Cr2O3 nanoparticles concentrations. The energy gap value of PVA/PVP blend was reduces from 2.8 eV of PVA/PVP to 1.2 eV and 1.77 eV as In2O3 and Cr2O3 nanoparticles concentrations increase. Doping PVA/PVP with In2O3 and Cr2O3 nanoparticles enhance the optical constants, electronics parameters and electrical conductivity. The obtained results showed that the doping PVA/PVP blend with In2O3 and Cr2O3 improved the structural, optical, electronic and electrical characteristics which make the (PVA/PVP/In2O3) and (PVA/PVP/Cr2O3) nanocomposites are promising materials for flexible optoelectronics fields in the development of electronics applications.

Recent Applications of Advanced Atomic Force Microscopy in Polymer Science: A Review.

Abstract: Atomic force microscopy (AFM) has been extensively used for the nanoscale characterization of polymeric materials. The coupling of AFM with infrared spectroscope (AFM-IR) provides another advantage to the chemical analyses and thus helps to shed light upon the study of polymers. This paper reviews some recent progress in the application of AFM and AFM-IR in polymer science. We describe the principle of AFM-IR and the recent improvements to enhance its resolution. We also discuss the latest progress in the use of AFM-IR as a super-resolution correlated scanned-probe infrared spectroscopy for the chemical characterization of polymer materials dealing with polymer composites, polymer blends, multilayers, and biopolymers. To highlight the advantages of AFM-IR, we report several results in studying the crystallization of both miscible and immiscible blends as well as polymer aging. Finally, we demonstrate how this novel technique can be used to determine phase separation, spherulitic structure, and crystallization mechanisms at nanoscales, which has never been achieved before. The review also discusses future trends in the use of AFM-IR in polymer materials, especially in polymer thin film investigation.

Enhancement of optical and electrical properties of PVC/PMMA blend films doped with Li4Ti5O12 nanoparticles

Abstract: Nanocomposite films of polyvinyl chloride/polymethyl methacrylate (PVC/PMMA)/ lithium titanium oxide (Li4Ti5O12) were prepared through a casting method. The structural features of the prepared films were investigated using XRD, TEM, FTIR, SEM, and UV/Vis. spectroscopy techniques. XRD pattern reveals the formation of the crystalline phase of lithium titanium oxide of average crystallite size 40 nm embedded in the amorphous polymeric matrix. The average crystallite size observed from TEM images is in good agreement with the XRD results. The physical interaction between the PVC/PMMA blend and Li4Ti5O12 NPs was confirmed by FTIR through the formation of a hydrogen bond. SEM micrographs showed partial compatibility between the polymer blend and the Li4Ti5O12 NPs. UV/Vis. analysis displayed that the values of the optical energy gap are decreased with increasing the concentration of Li4Ti5O12 NPs, this means that charge transfer complexes are arising between the polymer blend and Li-ions. The DC conductivity results are explained in the light of an intrachain one-dimensional interpolaron hopping model. The obtained results recommend the choice of Li4Ti5O12 NPs as dopants to enhance the electrical properties of virgin PVC/PMMA blend. Also, nanocomposite films can be employed in different electrochemical and industrial fields such as Li-ion batteries.

Application of compatibilized polymer blends in biomedical fields

Abstract: Advanced biomaterials designed for tissue engineering are mostly precise polymers with well-controlled surface and bulk properties. The need for extremely specific biomaterials having multifunctional tasks necessitates the use of complex systems composed of synthetic or natural polymers in the form of blend or alloy, but unexpected phase separation appears sometimes as a drawback with deteriorating function when used in biological environments. In this sense, blends of polymers should experience compatibilization toward targeted biomedical uses. There have been wide varieties of blending technologies aided by compatibilization that not only enhance the mechanical properties but also improve the cellular response of polymer blends. This chapter is targeted at classification and understanding the properties of such systems.

Protonic EDLC cell based on chitosan (CS): methylcellulose (MC) solid polymer blend electrolytes

Abstract: In this work, preparation and application of solid polymer blend electrolytes (SPBEs) based on chitosan: methylcellulose (CS:MC) incorporated with various amounts of ammonium iodide (NH4I) salt are described. Solution cast technique was adapted for the preparation of the SPBE films. Structural investigation and extent of interaction of the NH4I salt with the CS:MC film surface were conducted through X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy measurements. Electrical DC conductivity of the prepared samples was studied by electrochemical impedance spectroscopy. It is confirmed through transference number (TNM) analysis that ions are the dominant charge carrier in the polymer electrolyte system, in which the ionic (tion) and electron (tel) transference numbers were found to be 0.934 and 0.036, respectively. Through the use of linear sweep voltammetry (LSV), the CS:MC:NH4I system is found to experience electrolyte degradation at 2.1 V. The polymer blend electrolyte sample with highest DC conductivity property was also used as separator in electrical double-layer capacitor (EDLC) cell. Two identical activated carbon electrodes were used to sandwich the electrolyte film. Cyclic voltammetry (CV) was used to show the capacitive behavior of the fabricated EDLC cell, in which no redox peaks were observed. The EDLC was examined for 100 cycles at current density of 0.2 mA/cm2. The values of specific capacitance and equivalent series resistance were determined to be 1.76 F/g, and 650 to 1050 Ω, respectively.

Structural, Optical and Electrical Properties of PVA/PEO/SnO2 New Nanocomposites for Flexible Devices

Abstract: Fabrication of polyvinyl alcohol (PVA)–polyethylene oxide (PEO) blend doped with tin dioxide (SnO2) nanocomposites has been investigated for flexible electrical and optical applications. The prepared nanocomposites have low cost, lightweight, flexible, high corrosion resistance, good optical and electrical properties. These properties of fabricated nanocomposites make it useful for different optoelectronics applications such as: sensors, solar cells, transistors, diodes, capacitors, energy storage etc. The structural, optical and electrical properties of (PVA–PEO–SnO2) nanocomposites have been studied. The experimental results of optical properties for (PVA–PEO–SnO2) nanocomposites showed that the nanocomposites have higher absorbance in UV region at wavelength range (200–280) nm. This behavior makes the nanocomposites may be used for optoelectronics applications. The absorbance, absorption coefficient, extinction coefficient, refractive index, real and imaginary dielectric constants and optical conductivity of polymer blend are increased with the increase in SnO2 nanoparticles concentrations while the transmittance and energy band gap are decreased with the increase in SnO2 nanoparticles concentrations. The decrease in energy band gap is useful for different optoelectronics devices industries. Also, the results showed that the dielectric constant and dielectric loss decrease while the conductivity increases with the increase in frequency. The dielectric constant, dielectric loss and conductivity are increased with the increase in SnO2 nanoparticles concentrations. The electrical properties showed that the (PVA–PEO–SnO2) nanocomposites have good dielectric parameters which it may be used for different electronics applications.

Recent advancements in self-healing polymers, polymer blends, and nanocomposites:

Abstract: Polymer composites for structural applications are prone to damage emanating from cracks which are formed deep within the material where detection is not easy and repairing almost not feasible. Mat...

Uniformizing the electric field distribution and ion migration during zinc plating/stripping via a binary polymer blend artificial interphase

Abstract: Aqueous zinc hybrid capacitors are receiving intensive scientific interest due to them having the merits of both capacitors and batteries in achieving safety, high power and energy density, as well as long cycle life. Nonetheless, the dendrite growth and side reactions at the Zn/electrolyte interface are the biggest obstacles preventing them from large-scale applications. Here, we show that a non-conductive polyacrylamide (PAM)/polyvinylpyrrolidone (PVP) binary blend layer coated on a Zn anode can effectively suppress Zn dendrites and side reactions. The precise combination of ultra-high molecular weight PAM and low molecular weight PVP provides an excellent artificial anode/electrolyte interfacial layer with balanced adhesion, mechanical strength and hydrophilicity. The binary polymer interphase fundamentally uniformizes the localized electric field to regulate the ion migration in Zn plating/stripping, giving rise to superior electrochemical performance for the aqueous zinc hybrid capacitors. This study represents a promising approach for mitigating the long-lasting Zn dendrite growth issue.

Structural, Morphological, Electrical and Electrochemical Properties of PVA: CS-Based Proton-Conducting Polymer Blend Electrolytes.

Abstract: Polymer blend electrolytes based on poly(vinyl alcohol):chitosan (PVA:CS) incorporated with various quantities of ammonium iodide were prepared and characterized using a range of electrochemical, structural and microscopic techniques. In the structural analysis, X-ray diffraction (XRD) was used to confirm the buildup of the amorphous phase. To reveal the effect of dopant addition on structural changes, field-emission scanning electron microscope (FESEM) was used. The protrusions of salt aggregates with large quantity were seen at the surface of the formed films at 50 wt.% of the added salt. The nature of the relationship between conductivity and dielectric properties was shown using electrochemical impedance spectroscopy (EIS). The EIS spectra were fitted with electrical equivalent circuits (EECs). It was observed that both dielectric constant and dielectric loss were high in the low-frequency region. For all samples, loss tangent and electric modulus plots were analyzed to become familiar with the relaxation behavior. Linear sweep voltammetry (LSV) and transference number measurement (TNM) were recorded. A relatively high cut-off potential for the polymer electrolyte was obtained at 1.33 V and both values of the transference number for ion (tion) and electronic (telec) showed the ion dominant as charge carrier species. The TNM and LSV measurements indicate the suitability of the samples for energy storage application if their conductivity can be more enhanced.

Pyrolysis of Mixed Plastic Waste: I. Kinetic Study.

Abstract: Plastic wastes have become one of the biggest global environmental issues and thus recycling such massive quantities is targeted. Low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene (PP), and polystyrene (PS) are considered among the main types of plastic wastes. Since pyrolysis is one of the most promising recycling techniques, this work aims to build knowledge on the co-pyrolysis of mixed polymers using two model-fitting (Criado and Coats–Redfern) methods. Seventeen co-pyrolysis tests using a thermogravimetric analyzer (TGA) at 60 K/min for different mixed compositions of LDPE, HDPE, PP, and PS were conducted. It was observed that the pyrolysis of the pure polymer samples occurs at different temperature ranges in the following order: PS < PP < LDPE < HDPE. However, compared to pure polymer samples, the co-pyrolysis of all-polymer mixtures was delayed. In addition, the synergistic effect on the co-pyrolysis of polymer blends was reported. The Master plot of the Criado model was used to determine the most suitable reaction mechanism. Then, the Coats–Redfern model was used to efficiently obtain the kinetic parameters (R2 ≥ 97.83%) and the obtained values of the activation energy of different polymer blends were ranging from 104 to 260 kJ/mol. Furthermore, the most controlling reaction mechanisms were in the following orders: First order reaction (F1), Contracting sphere (R3), and then Contracting cylinder (R2).

Significantly Improved Morphology and Efficiency of Nonhalogenated Solvent-Processed Solar Cells Derived from a Conjugated Donor-Acceptor Block Copolymer.

Abstract: A highly crystalline conjugated donor (D)-acceptor (A) block copolymer (PBDT2T-b-N2200) that has good solubility in nonhalogenated solvents is successfully synthesized. PBDT2T-b-N2200 shows a broad complementary absorption behavior owing to a wide-band gap donor (PBDT2T) present as a D-block and a narrow-band gap acceptor (N2200) present as an A-block. Polymer solar cells (PSCs) with conjugated block copolymer (CBCP) are fabricated using a toluene solution and PSC created with an annealed film showing the highest power conversion efficiency of 6.43%, which is 2.4 times higher than that made with an annealed blend film of PBDT2T and N2200. Compared to the blend film, the PBDT2T-b-N2200 film exhibits a highly improved surface and internal morphology, as well as a faster photoluminescence decay lifetime, indicating a more efficient photoinduced electron transfer. In addition, the PBDT2T-b-N2200 film shows high crystallinity through an effective self-assembly of each block during thermal annealing and a predominant face-on chain orientation favorable to a vertical-type PSC. Moreover, the CBCP-based PSCs exhibit an excellent shelf-life time of over 1020 h owing to their morphological stability. From these results, a D-A block copolymer system is one of the efficient strategies to improve miscibility and morphological stability in all polymer blend systems.

Investigations of lithium ion conducting polymer blend electrolytes using biodegradable cornstarch and PVP

Abstract: Solid polymer electrolytes used in energy storage devices based on Cornstarch and Poly (vinyl Pyrrolidone) blend incorporated with lithium acetate was prepared using the solution casting method. XRD results confirmed that the amorphous nature of the as-prepared polymer electrolyte was increased by addition of salt. 80 wt % Cornstarch/20 wt % PVP/60 wt % lithium acetate added polymer blend system attains better amorphous nature than others. At ambient temperature, 60 wt % of lithium acetate added system has better bulk conductivity of 3.52 × 10−5Scm−1 over the frequency range of 42 Hz to 1 MHz using AC impedance spectroscopy studies. The dielectric analysis is confirmed that the higher conducting sample was having high dielectric constant and low relaxation time for enhancing ions dynamic behaviour. The conduction mechanism of the higher conducting polymer electrolyte is explained by small polaron hopping and overlapping large polaron tunnelling conduction mechanism. From the argand plot, it is confirmed that higher conducting sample has low relaxation time.

Flexible, Reconfigurable, and Self-Healing TPU/Vitrimer Polymer Blend with Copolymerization Triggered by Bond Exchange Reaction.

Abstract: In recent decades, flexible, reconfigurable, and fast-response self-healing polymers have attracted considerable attention for both industrial field and scientific research. Mechanical blending remains the most mature, economical, effective, and the simplest approach to produce polymer blends, which can combine several distinctive advantages from different thermoplastic materials. However, such a process cannot be simply applied to thermosetting materials due to their permanent molecular structures. The synthesis of high-performance polymer blends connected by covalent cross-links remains a big challenge for the present industrial system. In this paper, we proposed a novel approach to synthesize polymer blends via blending thermosetting vitrimer containing dynamic covalent networks with thermoplastic polymers. It is demonstrated that the intrinsic relationship could be established by controlling the bond exchange reactions between the thermoset and the thermoplastic, thus triggering copolymerization. Due to the highly controlled processing conditions, the synthesized polymer is highly flexible, recyclable, and reprocessable, and possesses self-healing behavior at the same time. In addition, it shows potential applications in adhesive film and wearable electronics. This new technology opens a new way to reprocess thermoset in a fashion similar to thermoplastic in the current polymer industry.

Applications of compatibilized polymer blends in automobile industry

Abstract: Polymers in automotive applications have replaced the conventional metals; blending polymers has enhanced the use of polymers in automotive applications. Blending polymers in fabrication of automotive parts enhances structural strength, impact resistance, low and high temperature properties, and surface properties (for good printability). Polymer bends are corrosion resistance and light in weight than metals, which saves fuel and hence economic in automobile parts.

Synthesis of Porous Proton Ion Conducting Solid Polymer Blend Electrolytes Based on PVA: CS Polymers: Structural, Morphological and Electrochemical Properties.

Abstract: In this study, porous cationic hydrogen (H+) conducting polymer blend electrolytes with an amorphous structure were prepared using a casting technique. Poly(vinyl alcohol) (PVA), chitosan (CS), and NH4SCN were used as raw materials. The peak broadening and drop in intensity of the X-ray diffraction (XRD) pattern of the electrolyte systems established the growth of the amorphous phase. The porous structure is associated with the amorphous nature, which was visualized through the field-emission scanning electron microscope (FESEM) images. The enhancement of DC ionic conductivity with increasing salt content was observed up to 40 wt.% of the added salt. The dielectric and electric modulus results were helpful in understanding the ionic conductivity behavior. The transfer number measurement (TNM) technique was used to determine the ion (tion) and electron (telec) transference numbers. The high electrochemical stability up to 2.25 V was recorded using the linear sweep voltammetry (LSV) technique.

Effect of ammonium thiocyanate on ionic conductivity and thermal properties of polyvinyl alcohol–methylcellulose–based polymer electrolytes

Abstract: In this work, a polymer blend–based electrolyte system using polyvinyl alcohol (PVA) and methylcellulose (MC) in the weight ratio of 50:50 as hosts and ammonium thiocyanate (NH4SCN) as dopant salt has been prepared and characterized. Fourier transform infrared spectroscopy (FTIR) studies indicate that functional groups containing oxygen atom in both polymers have interacted with each other. Complexation between the polymer hosts and dopant salt is confirmed from the shifting of hydroxyl band and SCN- band. Phenomena of ion association and ion dissociation have been analysed by deconvoluting the FTIR band between 2030 and 2090 cm−1. Sample with 40 wt% NH4SCN achieves the highest ambient conductivity of (1.45 ± 0.51) × 10-4 S cm-1. It is inferred that the conductivity is mainly governed by the diffusion coefficient and mobility of charge carriers. It is found that the increase in conductivity is accompanied by a decrease in the glass transition temperature (Tg). The variation of conductivity can be verified by the results from field emission scanning electron microscopy (FESEM).

The Study of Plasticized Solid Polymer Blend Electrolytes Based on Natural Polymers and Their Application for Energy Storage EDLC Devices.

Abstract: In this work, plasticized magnesium ion-conducting polymer blend electrolytes based on chitosan:methylcellulose (CS:MC) were prepared using a solution cast technique. Magnesium acetate [Mg(CH3COO)2] was used as a source of the ions. Nickel metal-complex [Ni(II)-complex)] was employed to expand the amorphous phase. For the ions dissociation enhancement, glycerol plasticizer was also engaged. Incorporating 42 wt% of the glycerol into the electrolyte system has been shown to improve the conductivity to 1.02 × 10−4 S cm−1. X-ray diffraction (XRD) analysis showed that the electrolyte with the highest conductivity has a minimum crystallinity degree. The ionic transference number was estimated to be more than the electronic transference number. It is concluded that in CS:MC:Mg(CH3COO)2:Ni(II)-complex:glycerol, ions are the primary charge carriers. Results from linear sweep voltammetry (LSV) showed electrochemical stability to be 2.48 V. An electric double-layer capacitor (EDLC) based on activated carbon electrode and a prepared solid polymer electrolyte was constructed. The EDLC cell was then analyzed by cyclic voltammetry (CV) and galvanostatic charge–discharge methods. The CV test disclosed rectangular shapes with slight distortion, and there was no appearance of any redox currents on both anodic and cathodic parts, signifying a typical behavior of EDLC. The EDLC cell indicated a good cyclability of about (95%) for throughout of 200 cycles with a specific capacitance of 47.4 F/g.

Morphology and properties of PEDOT:PSS/soft polymer blends through hydrogen bonding interaction and their pressure sensor application

Abstract: We report the effects of the composition on the stretchability and conductivity of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) polymer blends with soft polymers including poly(vinyl alcohol) (PVA), poly(acrylic acid) (PAA), and poly(methacrylic acid) (PMAA) and their application in pressure sensors. The composition–stretchability relationship was investigated with the stress–strain curves of the bulk films. Among these polymer blends, PAA-based blends outperformed in stretchability, attributed to the low glass transition temperature and ductile nature of PAA. And the composition–conductivity relationship was studied with conductive atomic force microscopy, Gaussian simulation and infrared spectroscopy. The PAA-based blends presented well-dispersed morphology for PEDOT and the strongest hydrogen bonding network between PAA and PEDOT:PSS was created through the blending, which gave rise to stable and high conductivity. Furthermore, the conductivity of the PEDOT:PSS/PAA blend at 20/80 wt ratio was largely increased (13 to 125 S cm−1) and stretchability (elongation at break) increased from 20 to 40% through methanol treatment. Finally, PAA-based blends treated with methanol were applied to the pressure sensor device, achieving a very high sensitivity of 39.90 kPa−1 at 20% tensile strain, a quick response time of around 49 ms, and a low detection limit of about 27.4 Pa. This study suggested a novel and facile approach to manipulate the structure and stretchability of the PEDOT:PSS polymer blending system for stretchable electronics.

Structural, thermal, optical and conductive properties of PAM/PVA polymer composite doped with Ag nanoparticles for electrochemical application

Abstract: In the present study, the chemical preparation of silver nanoparticles (Ag NPs) solution was achieved by decreasing silver salt via the use of sodium borohydride (NaBH4). The particles appeared to have a crystalline nature through the XRD study, with a face-centered cubic (FCC) structure. The formation of silver nanoparticles (Ag NPs) was asserted by the UV, XRD and TEM. An absorption peak at around 430 nm was demonstrated through UV–visible spectrum of the aqueous medium which related to of Ag NPs. The solution casting method was used to prepare new nanocomposites films on the bases of polymer blend which related to of PAM- and PVA-doped with different wt% of Ag NPs. Various analytical techniques were used to characterize the prepared films. It was confirmed through the XRD analysis that there existed a complex formation between polymer blend and Ag NPs. A reduction in the value of the optical bandgap was displayed by UV–Vis with an increase in the concentration of Ag NPs. It was shown through the FTIR spectrum that there existed changes in the FTIR spectrum with dopant concentration indicating the interaction of dopant with the polymer blend. A great improvement in the thermal stability of the composites was proved through the TGA study with the loading of Ag NPs. The ionic conductivity at room temperature was improved by the doping of Ag NPs ions into the polymer blend system. This is attributed to the increase in mobile charge carriers and their mobility. The dielectric values in the studied frequency range indicate a strong dielectric dispersion which increases as the content of the Ag NPs increases. Consequently, these films can be suggested as a suitable application in optical devices and dielectric applications due to the observed improvement in optical properties and ac conductivity.