Polymer Blend Films Research Articles

Biodegradable and highly conductive polymeric blend based on the latex of Calotropis gigantea as solid electrolyte in energy storage applications

A blend polymer based on the latex of the South-Asian giant milkweed Calotropis gigantea (CGL) combined with poly (vinylidene fluoride)-co-hexafluoropropylene (PVDF-HFP) at a mass ratio of 1:1 without the addition of doping salts was synthesized via solution casting to prepare an ionic conductive film. The morphology, crystalline state, vibrational and thermal properties of the film were investigated by Scanning electron microscopy, X-ray diffraction, Fourier Transform infrared spectroscopy (FTIR), Thermal gravimetric analysis (TGA) and Differential scanning calorimetry (DSC). The ionic conductivity and transport properties were investigated by using electrochemical impedance spectroscopy (EIS) Technique. Due the highest ionic conductivity at room temperature (2.7 x 10−2 S/cm), all-solid-state electrolyte was assembled using the prepared polymer film and a comparative study was conducted with respect to 1M H2SO4 liquid electrolyte, regarding the specific capacitance and the electrical properties. The results demonstrate that the fabricated all-solid-state supercapacitor using PVDF-HFP/CGL blend polymer film as electrolyte matches the performance of the liquid electrolyte.

Study the effect of loading non-stoichiometric zinc sulfide on optical characteristics of PVA/CMC/PVP blended polymer films

Study the effect of loading non-stoichiometric zinc sulfide on optical characteristics of PVA/CMC/PVP blended polymer films

Visualizing Surface Phase Separation in PS-PMMA Polymer Blends at the Nanoscale.

Phase-separated polymer blend films are an important class of functional materials with numerous technological applications in solar cells, catalysis, and biotechnology. These technologies are underpinned by the precise control of phase separation at the nanometer length-scales, which is highly challenging to visualize using conventional analytical tools. Herein, we introduce tip-enhanced Raman spectroscopy (TERS), in combination with atomic force microscopy (AFM), confocal Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS), as a sensitive nanoanalytical method to determine lateral and vertical phase-separation in polystyrene (PS)-poly(methyl methacrylate) (PMMA) polymer blend films. Correlative topographical, molecular, and elemental information reveals a vertical phase separation of the polymers within the top ca. 20 nm of the blend surface in addition to the lateral phase separation in the bulk. Furthermore, complementary TERS and XPS measurements reveal the presence of PMMA within 9.2 nm of the surface and PS at the subsurface of the polymer blend. This fundamental work establishes TERS as a powerful analytical tool for surface characterization of this important class of polymers at nanometer length scales.

Structural and photoluminescence properties of a trivalent rare earth Sm ion-doped PVA/PVP blend polymer films

Transparent polyvinyl alcohol (PVA)/polyvinylpyrrolidone (PVP) and various concentrations of Sm3+ ion-doped PVA/PVP blend-polymer films were prepared using the solution cast method. The structural properties were studied by using XRD and FTIR. Optical UV-Vis, photoluminescence, and decay studies were carried out for prepared PVA/PVP blend polymer films. The XRD confirms the structural change in PVA/PVP blend-polymer with the doping of Sm3+ ion. From FTIR, Sm3+ ion forms the complex formation within the PVA/PVP polymer structure. The allowed band gap decreased from 5 to 4.6 eV, and the refractive index increased from 2.4 to 2.45, increasing Sm3+ ion concentration. From the energy band gap, the bonding parameters ( and δ) were calculated to find the covalent/ionic bond nature of the prepared polymer films. The emission spectra were measured for Sm3+: PVA/PVP with the excitation of 402 nm wavelength (6H5/2→4F7/2). 4G5/2→ 6H7/2 shows maximum intensity at 0.4 wt % of Sm3+, and beyond concentration, quenching was noticed. It is observed from the decay curve that the lifetime of PVA/PVP samples doped with Sm3+ at all concentrations decreases with the increase of Sm3+ ion concentration. It was noticed from CIE chromaticity that Sm3+: PVA/PVP blend polymer films are more appropriate for enhancing reddish-orange photonic emission. Based on the above results, Sm3+: PVA/PVP blend polymer films are suitable for reddish-orange luminescent applications.

The Development Study of a Prototype of Sodium Carboxymethylcellulose and Poly(Vinyl Alcohol) Wound Dressings Using a Mixer Torque Rheometer

The search for new materials that serve as dressings and promote the proper means for wound healing, without yielding toxic waste to the wound bed and at low cost, is currently the subject of research. In this sense, the present study aimed to develop a prototype of a poly(vinyl alcohol) (PVA) polymeric film, sodium carboxymethylcellulose (NaCMC). PVA and NaCMC as miscible polymer blend films for wound dressings was developed using internal mixing chamber processing in a mix torque rheometer (MTR) without the use of binders or crosslinks in different mixing conditions that were investigated by thermal characteristics (differential scanning calorimetry (DSC)) and thermogravimetric analysis (TGA) and crystallinity (X-ray Diffraction Technique (XRD)). The films obtained by pouring from this starting material were characterized by DSC, TGA, Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), optical microscopy and swelling assay. All stages of development of this prototype are discussed, from the quality control of the raw materials, through the development of the preparation technique of the blends in 14 different processing conditions. The processed PVA/NaCMC film showed physical crosslinking which may have promoted its ability to resist dissolution in water (unprocessed PVA/NaCMC films’ characteristic). The results demonstrated that the processing of the PVA and NaCMC polymers in the MTR constitutes a viable technique to obtain membranes for use as dressings.

Hierarchical Self-Assembly and Chemical Imaging of Nanoscale Domains in Polymer Blend Thin Films

Self-assembly of polymers driven by intermolecular and intramolecular interactions leads to rich structural variations in thin films of polymer blends. In this work, ordering of poly(3-hexylthiophene-2,5-diyl) (P3HT) to form nanoparticles (NPs) and the self-assembly pattern of the NPs in poly(4-vinylpyridine) (P4VP) matrix are revealed by using scattering-type scanning near-field optical microscopy (s-SNOM). The P3HT NPs are formed spontaneously when the P3HT/P4VP/chloroform solution is spin-cast on unpatterned silicon wafer at room temperature. We find that the P3HT NPs organize within the P4VP matrix forming continuous stripes along the parallel striations, depending on the solution composition and spin-coating angular speed. The spacing between the parallel P3HT stripes that runs along the center of the ridges varies from sample to sample within 4–12 μm, whereas the width of the P3HT stripes confined within the ridges ranges from 0.2 to 1.1 μm as determined from the s-SNOM infrared phase contrast. The sizes of the P3HT NPs range from 5 to over 100 nm depending on the composition of the blend as determined by using an atomic force microscope after selectively dissolving the P4VP matrix. The smallest size observed in our experiment is significantly smaller than the smallest diameter (larger than 20 nm) reported in the literature. The results presented here show that interaction between immiscible polymers during solvent evaporation can be manipulated to control hierarchical self-assembly from molecular ordering to mesoscale dimensions, and high-resolution chemical imaging is necessary to resolve nanoscale domains so that solution processes can be optimized.

Preparation, characterization, and electrochemical properties of PEO/PVDF blend films

This paper reports the electrochemical properties of PEO, PEO/PVDF10, and PEO/PVDF30 blend films, The XRD spectra reveal the structural properties of the blend and, FTIR spectra provide the chemical interaction between the blends, and observed FESEM images of PEO/PVDF blend film shows the porous with spherulite grain structure and AFM images gives the surface topology. The thermal stability, melting point, and decomposes of the polymer blend film were examined through TGA, DTA, and DSC. CV curve shows the proper oxidation and redox reaction involved in the blend film, these results provide the prepared polymer blend film is a good candidate for used to the separator in energy storage applications.

Investigation on the effect of in-situ growth of PPy on structural, thermal and dielectric properties of PVA-CMC blend films

ABSTRACT The intrinsic conducting polymer (ICP) Polypyrrole (PPy) was grown in situ in the matrix of polyvinyl alcohol (PVA)-Sodium carboxymethyl cellulose (CMC) using chemical oxidative polymerization method. The effect of in-situ growth of PPy on structural, morphological, thermal and dielectric properties of PVA-CMC blend films were investigated. Growth of PPy in the matrix of PVA-CMC was seen in SEM micrographs along with structural modifications which were confirmed by XRD and FT-IR analysis suggesting the amorphous nature of PVA-CMC-PPy blend films. Thermal analysis suggests good miscibility and compatibility of the polymers in the blend. The changes in the dielectric properties of in-situ-grown conducting polymer blend films of PVA-CMC-PPy were studied in detail at low frequency (100 Hz to 2 MHz) . Enhancement in the dielectric constant and ac conductivity values of PVA-CMC- PPy films were observed in this frequency range that is related to increased amorphousness and formation of conductive channels due to the presence of PPy. Further, the microwave absorption and dielectric behavior of PVA-CMC-PPy films in high-frequency region (200 MHz – 20 GHz) were specially studied to see the suitability of these films for EMI shielding application.

Red-shifted optical absorption in films of azo-polyurea - polystyrene blends: Structural correlations and implications

We report the optical absorption characteristics in thin film coatings of a blend of two polymers: azo-polyurea (azo-PU) and polystyrene (PS). It is shown using UV–visible spectroscopy that the absorption spectrum of the resultant blend undergoes a distinct and decisive redshift towards the visible wavelength regime, accompanied by broadening and overlapping of the characteristic absorption peaks. Light exposure studies reveal that the red-shifted optical absorption induces trans to cis isomerization of the blended polymer films upon exposure to visible wavelengths, which would otherwise occur typically only by stimulus from ultraviolet wavelengths. The extent of redshift in the absorption maxima and broadening in the absorption spectrum of the polymer blend films are found to be sensitive to the amounts of the constituent polymers. The changes in spectral configuration are understood in terms of lattice structural changes that occur in azo-PU chains due to the incorporation of PS, in particular the disarrangement in hydrogen bonding. It is suggested that the modified optical absorption characteristics would endow significant advantages, such as the possibility of replacing UV with visible light in applications requiring cis → trans and trans → cis isomerization, as well as photoswitchability due to trans-cis-trans cycling.

Investigate the Optical, Structural and electrochemical properties of PVC/PMMA/NiO blend films

PVC/PMMA and PVC/PMMA/NiO blend films were prepared by solution casting technique. The FT-IR spectra confirms the change in the band structure and presence of hydrogen chlorine and Ni-O bond in the PVC/PMMA and NiO loaded blend film and XRD pattern reveals the formation of NiO phase in the PVC/PMMA polymer with exhibits the amorphous nature, it may increase the conductivity and stability of the material.The surface morphology shows the NiO homogeneously dispersed on the surface of PVC/PMMA matrix, and CV curve demonstrate that the rectangular shape at different scan rate from 10 mV/s to 50 mV/s. The PVC/PMMA/NiO 3% loaded polymer blend films shows the synergistic properties towards the electrochemical performance.

Optical Properties and Dispersion Parameters of PAAm-PEG Polymer Blend Doped with Antimony (III) Oxide Nanoparticles

Oxide of antimony (III) (Sb2O3) is a type of amphoteric oxide, is used in a variety of applications is a pacifying agent for glasses, ceramics, enamels, catalyst, production of plastic, and the vulcanization of rubber. Polymer blend films were prepared by mixing polyacrylamide (PAAm) and polyethylene glycol (PEG4000), with different contents of Sb2O3 nanoparticles by casting method. The diffusions of Sb2O3 nanoparticles within the mixture were examined using optical microscopy. The optical microscopic images showed that good diffusions of nanoparticles with some agglomerations. The optical characteristics were studied by the Spectrophotometer for ultraviolet and visible light in the range of (200-1100) nm. Most optical properties increased with the increasing of wavelength except for transmittance and energy gaps. The analysis of optical properties is the focus of this paper of (PAAm-PEG-Sb2O3) nanocomposite polymer films and study the (Dispersion energy)Ed, (single oscillator energy)Eo, (static refraction index)n(0), and (Moments) M-1 and M-3 are examples of dispersion parameters.

Meniscus-Assisted Coating with Optimized Active-Layer Morphology toward Highly Efficient All-Polymer Solar Cells.

Morphology control is the key to engineering highly efficient solution-processed solar cells. Focusing on the most promising application-oriented photovoltaic all-polymer solar cells (all-PSCs), herein a facile and effective meniscus-assisted-coating (MAC) strategy is reported for preparing high-quality blend films with enhanced crystallinity and an interpenetrating nanofiber network morphology. The all-PSCs based on MAC exhibit excellent optoelectronic properties with efficiencies exceeding 15%, which is the best performance of solution-printing-based all-PSCs, as well as better stability. The crystallization kinetics of the polymer blend film is investigated by in situ UV-vis absorption spectroscopy, and the result explains the linear relationship between the meniscus advance speed and the crystallinity (crystallization rate) of the polymer. To verify the compatibility and universality of this strategy, the MAC strategy is applied to the other three binary systems. By precisely controlling the meniscus advancing speed, 1 cm2 all-PSC devices whose efficiencies exceed 12% are fabricated. Such progress demonstrates that the application of the MAC strategy is a promising approach for the fabrication of high-efficiency all-PSCs.

Use of niobium oxide nanoparticles as nanofillers in PVP/PVA blends to enhance UV–visible absorption, opto‐linear, and nonlinear optical properties

AbstractTransition metal oxide (TMO)—filled polymer films have numerous applications, including electromagnetic shielding and nonlinear optical devices. Nb2O5‐filled polyvinyl pyrrolidone (PVP)/polyvinyl alcohol (PVA) blend was prepared using a solution casting process. Pristine and nanocomposite films from these blends were studied. X‐ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier infrared spectroscopy confirmed the formation of nanocomposites via interfacial interactions between the polymer chains and Nb2O5 nanoparticles. These nanoparticles influence the amorphous nature and transparency of the PVA/PVP blends. The improvement of Dopt (optical density) becomes particularly obvious in blended polymer films with considerable Nb2O5‐nanofiller concentrations. By increasing the weight percentage of Nb2O5, the probability of producing additional levels in the bandgap increased. The optical absorption coefficient of each nanocomposite film was less than 106 m−1, indicating indirect electron transfer. Thus, the indirect optical band‐gap declined from 3.9 to 1.9 eV as calculated from Tauc's and the absorption spectral fitting (ASF) formula. Additionally, the effects of Nb2O5 on the extinction coefficient, refractive index, high‐frequency (ε∞), and static‐frequency (εo) dielectrics have been reported. The nonlinear refractive index and optical susceptibilities (x1 and x3) were enhanced by increasing the Nb2O5 content in the blend. The penetration depth (δ) and optical limiting (OL) properties were also investigated. The developed nanocomposite materials could be used for advanced technology‐based devices such as reflective coatings, opto‐linear, and nonlinear optoelectronic applications.

Balancing the trade-off between the mechanical and electrical properties of conjugated polymer blend films for organic field-effect transistors

A balance between the mechanical and electrical performance is achieved in conjugated polymer blend films with an optimal blend ratio.

Preparation of Sodium Alginate/Rice starch blend polymer film for soil moisture sensing

A sodium alginate/rice starch blended polymer film was prepared by solution casting method by dissolving the two polymers in water. The structure and the properties of the film were characterized by X-ray diffraction analysis (XRD), Fourier transform infrared (FTIR) spectroscopy and dielectric spectroscopy. The soil moisture sensing ability of the polymer film was demonstrated by measuring the dielectric constant of the polymer with soil samples of low and high moisture contents. The results revealed that the film exhibited high moisture sensing properties at frequencies up to a few kHz. This study indicates the potential of blended biopolymers for measuring the soil moisture content in agriculture applications.

Multi-modal vibrational analysis of blend polymers using mid-infrared photothermal and Raman microscopies

Chemical characterization of polymeric samples, such as blend polymers is a fundamental analytical approach for advancement of polymer science and polymer technologies. Vibrational imaging is a promising technique to analyze chemical compositions of materials in a wide range of fields. Raman scattering and infrared (IR) absorption reflect complementary molecular vibrations; therefore, Raman and IR imaging provide rich information of the spatial distributions of chemical compositions of samples, revealing their complicated chemical structures. However, the discrepancy of spatial resolution in Raman and conventional IR imaging makes it difficult to merge these techniques. In the present study, we performed chemical characterization of polymeric samples using Raman and IR imaging enabled by mid-infrared photothermal (MIP) microscopy. The chemical compositions of blend polymer films were visualized based on both Raman scattering and IR absorption with the spatial resolution of the sub-micrometer scale. We found that the varying contrasts in Raman and MIP imaging enabled the investigation of averaged and surface-sensitive compositions of polymer blends. Raman and MIP imaging holds a promise of unique applications in a wide range of current research fields, such as polymers, two-dimensional materials, and biology.

Structural, thermal, optical characterizations of polyaniline/polymethyl methacrylate composite doped by titanium dioxide nanoparticles as an application in optoelectronic devices

The casting method was employed for the preparation of polymer blend films doped with TiO2 (0.5, 1, 1.5, and 2.3 wt%). The TiO2 phase formation is anatase, with an average crystal size of 20.25 nm, according to the XRD results. The samples of PANI/PMMA-TiO2 nanocomposite are amorphous nature. Furthermore, as the concentration of TiO2 NPs increases, the amorphousity degree increases. The FTIR technique is used to reveal the nanocomposites' vibrational bands as well as the intermolecular bonding between the blend and the TiO2 NPs. Absorption spectra, reflectance, transmission spectra, extinction coefficient, refractive index, real and imaginary parts of the dielectric constant, third-order susceptibility (χ3), and optical band gaps are among the optical constants studied. As preselected TiO2 NPs are put into thin films (doping ≤1.5 wt%), the optical band gap values (Eg) of the fabricated nanocomposite films decreased. These results are extremely similar to those obtained using the Tauc method. DSC and TGA techniques show that TiO2 NPs help to improve the thermal stability of the polymer blend. The DSC measurement reveals a single Tg of the polymer blend (PANI/PMMA), indicating that the two polymers are miscible. The optical constants revealed noticeable changes with increasing doping concentrations; according to the experimental data. The doped thin films that were developed have a great promise for manufacturing high-efficiency optoelectronic devices.

Polyvinyl alcohol‐based membranes for filtration of aqueous solutions: A comprehensive review

AbstractThis review provides a comprehensive overview on applications, preparation methods, and most notably the performance efficiency of polyvinyl alcohol (PVA)‐based membranes for filtration of aqueous environments. Incorporation of PVA into the membrane matrix significantly enhances such characteristics as antifouling and antibacterial properties as well as hydrophilicity and permeability in the water and wastewater filtrations. Contribution of different PVA‐based modular membranes for water purification targets via a comparative review on previous researches is the main theme in this work. Alongside with the focused topic, some basic theories and principals of blend and composite polymer films as well as polymer fibers are debated before the main discussions. This review will ultimately facilitate further development of PVA membranes for the future investigations.

Structural and optical properties of PPO/PVP blended polymer film

In the present work, a polyphenylene oxide/Polyvinyl pyrrolidone (PPO/PVP) thin film has been synthesized by using a spin coating technique. The structural and optical properties of the thin film were studied by using X-ray diffraction and optical absorption spectroscopic techniques. The XRD results showed that precursor polymers PPO and PVP along with PPO/PVP-based polymer film exhibited amorphous behavior. Optical properties were obtained using UV–Vis spectroscopy. Two absorption peaks were identified in the UV area, at 311 nm and 367 nm, respectively, and the optical band gap of the PPO/PVP film was found at 2.9 eV. The synthesized PPO/PVP thin film had an Urbach energy of 0.294 eV, as per the findings.

Structural characterization of PVDF/PVA polymer blend film doped with different concentration of NiO NPs for photocatalytic degradation of malachite green dye under visible light

AbstractStructural, optical and photodegradation performance of PVDF/PVA polymer blend doped with different concentration of NiO NPs were studied using casting technique method. The effect of adding NiO NPs on PVDF/PVA are investigated using X‐ray Diffraction (XRD), High Resolution Transmission Electron Microscope (HRTEM), Fourier Transform Infrared–Attenuated Total Reflection (FTIR–ATR), Ultraviolet–Visible Spectroscopy (UV–Vis), and High Resolution Scanning Electron Microscope (HRSEM). XRD results showed that the addition of NiO NPs increase the crystallinity of PVDF/PVA. The appearance and shifting of bands in FTIR–ATR indicate the structural change in the PVDF/PVA with adding NiO NPs combined with decrease in the band gap of nanocomposite films compared to pure blend in UV–Vis confirmed the incorporation of NiO NPs in PVDF/PVA. HRTEM shows the size of NiO NPs ranges from 3 to 10 nm which is agreed with that calculated from Scherrer equation. HRSEM shows a change in surface morphology of nanocomposite sample. Malachite green dye as a textile wastewater pollutant model was chosen to assess the photocatalytic degradation efficiency of PVDF/PVA/NiO NPs. Gradual rising of the weight % of NiO in the prepared films results in higher photocatalytic efficiencies. Photocatalytic activity of PVDF/PVA/7% NiO NPs was 95.4% degradation of malachite green dye at pH 9, 3 g/L film weight and 300 min visible light irradiation. Photocatalytic degradation reaction for malachite green dyes is compatible with Pseudo first‐order kinetic model. Reusability results affirm a low decrease in photocatalytic performance after five runs makes the nanocomposite suitable for applications where reusability is a significant core factor.