Properties Of Polymer Films Research Articles

Fabrication of natural cellulose films with pattern by viscosity regulation of its solution

The structure and properties of polymer film are greatly affected by the patterns on its surface arising from solution convection. Therefore, it is necessary to explore more detail mechanism of pattern formation. Herein, we have successfully designed variable patterns on the surface of cellulose films via roller coating method. The cellulose with three degrees of polymerization was used as raw material, and a solution of N,N-dimethyl-acetamide/lithium chloride (DMAc-LiCl) was selected as the solvent system. The pattern variations were controlled by the solution viscosity, which was affected by the degree of polymerization of cellulose, concentration and temperature of solution. The formation process of the pattern on cellulose film was in situ tracked by video recording with the help of carbon black tracker. It was found that the solution moved from the edge of the cell pattern to the center at a relatively lower viscosity (η < 8.06 Pa s), and finally formed a polygon pattern with the convex center. With the increasing of the solution viscosity (η ≥ 8.06 Pa s), the direction of its convection was completely opposite and a circular or circular-like combination pattern with concave center appeared on the surface of the cellulose film. The higher the viscosity, the larger the concave area. Moreover, the film with polygon pattern demonstrated excellent mechanical properties, and also exhibited a potential anti-counterfeiting value. These results could provide guidance in perfecting the theory of polymer fluid, and regulating the structure and properties of polymer products.

Thermochromic and acidochromic properties of polymer films doped with pyridyl-β-diketonate boron(III) complexes

A novel family of organoborane complexes based on pyridyl-β-diketonate ligands has been synthesised, and their colorimetric and luminescence behaviour studied both in solution and in the solid state. The compounds behave as fluorescent materials, emitting a bluish light with high quantum yields of the order of 0.5–0.7. Although organoboranes usually show an aggregation-caused quenching effect in the solid state, the compounds described here maintain their emissive properties in the condensed state. Taking into account the ability of these emitters to act as dyes, several polymer thin films doped with these dyes have been fabricated. Interestingly, the new materials not only present fluorescence properties but also thermochromism and acidochromism. On the one hand, the increase of temperature causes the establishment of new intermolecular interactions between the boron(III) complexes and the polymer matrixes, which generate disturbances in the fluorescence emission. On the other hand, the protonation of the pyridyl nitrogen atom occurs in highly-acidic environments and causes a red-shift in the emission band that can be observed even with the naked eye. The application of these polymer materials as temperature and acid sensors is presented in this work.

TransPoly: A theoretical model to quantify the dynamics of water transfer through nanostructured polymer films

Mass transfer of penetrants is among the most important physical properties of polymer films to properly ensure function during service. In the case of interaction between penetrants and polymer, non-Fickian diffusion can be observed. This phenomenon is described by numerous reports and a few models have been proposed. Nevertheless, few of them quantify Fickian and non-Fickian behaviour using parameters with clear physical meaning. The present work develops a new non-Fickian mass transport model: TransPoly (Transfer through Polymers). Based on coupled heat and mass transfer, it accounts for simultaneous Fickian transport and molecular relaxation. This model is applied to data of water vapour mass transfer in nanocomposites of polylactide and cellulose nanocrystals. The contribution of the non-Fickian mass transfer on water vapour sorption is highlighted. TransPoly can be applied to several kinds of polymers and used for prediction purposes once the parameters are determined on a learning database.

Effect of Gellan Gum and Xanthan Gum Synergistic Interactions and Plasticizers on Physical Properties of Plant-Based Enteric Polymer Films.

The mechanical and barrier properties of plant-based enteric polymer films were enhanced by synergistic interactions between binary gum mixtures and adding plasticizers. The results indicated that the best ratio of gellan gum (GG) and xanthan gum (XG) was 7:3 by comparing tensile strength, tensile elongation, transmittance, and water vapor permeability of plant-based enteric polymer films and rheological properties of solutions. Polyethylene glycol 400 (PEG-400) was an effective plasticizer in improving plasticity and water vapor barrier property of the plant-based enteric polymer film. Rheology measurement and different characterization methods, including Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, X-ray diffraction, and scanning electron microscopy, were used to explain interactions between GG and XG as well as PEG-400 and components of the film. The new mixed system, composed of GG/XG mixture with ratio of 7:3 as a novel gelling agent and PEG-400 as a plasticizer, was applied to prepare plant-based enteric hard capsules, which have potential applications in medicines and functional food preparations.

Preparation and evaluation of fouling-release properties of amphiphilic perfluoropolyether-zwitterion cross-linked polymer films

The biofouling of marine structures presents a problem for maritime industries, including increasing fuel and operational costs. There has been much work developing and evaluating chemically ‘ambiguous’ amphiphilic coatings based upon hydrophobic fluoropolymer and hydrophilic poly(ethylene glycol) (PEG). Many of these coatings have shown good fouling-release performance against diatoms, which present a fouling challenge to commercially-available state-of-the-art silicone-based fouling-release coatings. However, PEG is prone to oxidation, which limits its practical use in the marine environment, and thus an alternative hydrophilic material would be desirable in the future development of amphiphilic coatings. In this regard, zwitterionic materials are emerging as a promising class of hydrophilic antifouling material, which we hypothesized would be a suitable alternative to PEG within amphiphilic coatings. To test this hypothesis, cross-linked amphiphilic films consisting of commercially available perfluoropolyethers and the zwitterionic monomer sulfobetaine methacrylate were developed and studied. The difficulty in formulating these chemically incompatible species was overcome by careful choice of solvents and a series of prototype cross-linked films were prepared in which increasing quantities of zwitterion were systematically incorporated. The fouling-release performance of these films was tested against the diatom Navicula incerta, a common microfouling organism responsible for the formation of so-called ‘slime’ layers, and antifouling performance with cypris larvae of two barnacle species, Balanus amphitrite, and Balanus improvisus. To expand the scope of the study, the clinically-relevant biofilm-forming pathogen Staphylococcus aureus, which is a major culprit in the infection and failure of millions of indwelling medical devices, was also evaluated. Results indicate that the incorporation of zwitterion into perfluoropolyethers leads to significant improvements in fouling-release performance and these amphiphilic coatings display potential in fouling-release applications.

Дослідження полімерних плівок на основі суміші дисперсій стирол-акрилових сополімерів

The article presents the results of a study of the physical, mechanical, structural and chemical properties of polymer films based on a mixture of styrene acrylic aqueous dispersions Akratam AS 02.1 and Akratam AS 03.1. The physical and mechanical properties of individual and combined polymer films were evaluated in terms of transparency, stickiness, thickness, surface density and elongation at break. Individual styrene acrylic film Akratam AS 02.1 is characterized by high elasticity and stickiness, and Akratam AS 03.1. dispersion forms a strong, hard and brittle film. It was found that an increase in the concentration of Akratam AS 03.1 in the polymer mixture Akratam AS 02.1 / Akratam AS 03.1 leads to a decrease in stickiness, thickness, surface density and the degree of deformation of the combined film. Changes in the structural parameters of the network of combined polymer films depending on the concentration of the components in the mixture were studied using the sol-gel method. It was determined that the individual film Akratam AS 02.1 has a high content of the soluble fraction (28.5%), which is due to the low degree of intermolecular crosslinking (1.221). For films of the composition Akratam AS 02.1 / Akratam AS 03.1 90:10 and 50:50, an increase in the degree of crosslinking and a decrease in the sol fraction to 27.6 and 27.3% are observed, respectively. The obtained data on the structural characteristics of the polymer network of the studied films correlate with the results of determining the effect of the composition of the polymer mixture on the hydrolytic stability of the combined film. The greatest indicators of resistance to the action of cold, hot water and soap-soda solution are characteristic for the film of the composition Akratam AS 02.1 / Akratam AS 03.1 50:50 and are 98.3, 97.8 and 98.7%, respectively. Thus, the mixed styrene acrylic films of the composition Akratam AS 02.1 / Akratam AS 03.1 90:10 and 50:50 can be used to form a polymer coating on a textile material with improved performance properties. Key words: polymer film, styrene acrylic dispersion, polymer mixture, physical and mechanical properties, structural parameters of the network, hydrolytic stability.

Film Fiber Radio-Absorbing Material

The dielectric properties of nonwoven webs and polymer films filled with dispersed carbon web, as well as multilayer materials obtained by addition of webs and films, were investigated. Webs and films have a pronounced interference mechanism of absorption of electromagnetic waves. Dielectric properties with an asymmetric structure relative to the middle of the thickness of the multilayer materials depend on the side on which electromagnetic radiation enters the material. Multilayer materials based on nonwoven web and polymer films have an interference absorption mechanism, but their use expands the frequency range of absorption of electromagnetic radiation.

Hydrophobic Properties of Polymer Films on Cast Iron Substrates

Author(s): Villa, Syndee; Broome, Dewayne | Abstract: The properties of hydrophobic surfaces have been of recent interest due to their applications in cookware and automotive components. The wetting properties of surfaces usually have an effect on the frictional forces due to the surface roughness of a material and the degree of wetting it creates. Non-stick in cookware has been used because it is easier to clean, cook, heats the food evenly, and requires less oil each time it's used which makes it a healthy alternative. For the cookware the necessity arises from users not wanting food or debris to stick to their surfaces and the automotive necessity arises from the need of car parts to maintain their tolerances in order for them to function properly. This study aims to explore the surface chemistry properties of cast iron in these applications where we measure contact angles between water molecules, observe the microstructure, and measure frictional and adhesion forces to a grey cast iron sample with deposited oil layer. Our main goal is to design and quantify the hydrophobic properties of a cast iron surface.

Adaptable Eu-containing polymeric films with dynamic control of mechanical properties in response to moisture.

Self-healing polymers often have a trade-off between healing efficiency and mechanical stiffness. Stiff polymers that sacrifice their chain mobility are slow to repair upon mechanical failure. We herein report adaptable polymer films with dynamically moisture-controlled mechanical and optical properties, therefore having tunable self-healing efficiency. The design of the polymer film is based on the coordination of europium (Eu) with dipicolylamine (DPA)-containing random copolymers of poly(n-butyl acrylate-co-2-hydroxy-3-dipicolylamino methacrylate) (P(nBA-co-GMADPA)). The Eu-DPA complexation results in the formation of mechanically robust polymer films. The coordination of Eu-DPA has proven to be moisture-switchable given the preferential coordination of lanthanide metals to O over N, using nuclear magnetic resonance and fluorescence spectroscopy. Water competing with DPA to bind Eu3+ ions can weaken the cross-linking networks formed by Eu-DPA coordination, leading to the increase of chain mobility. The in situ dynamic mechanical analysis and ex situ rheological studies confirm that the viscofluid and the elastic solid states of Eu-polymers are switchable by moisture. Water speeds up the self-healing of the polymer film by roughly 100 times; while it can be removed after healing to recover the original mechanical stiffness of polymers.

Structural and Electrical Properties of Ammonium Thiocyanate Doped Poly Ethylene Oxide / Poly Vinyl Pyrrolidone Blend Polymer Electrolytes

Blend polymer electrolytes based on PEO:PVP with various wt% of NH4SCN are prepared by simple solution casting method. The prepared polymer electrolytes are characterized using several techniques. The XRD studies confirm the amorphous and crystalline behavior of prepared BPEs. Functional groups present in the systems are confirmed by Fourier Transform Infrared spectroscopy (FTIR) studies. The electrical properties are analyzed by ac impedance technique. The maximum ionic conductivity is obtained for 20wt% of ammonium thiocyanate doped system and it is 1.81×10-5 S/cm-1 . The dielectric properties of polymer films are also studied and discussed.

Amperometric Glucose Biosensor Based on Homopolymer-Chitosan Double Layered Glucose Oxidase Electrode Modified with Zinc Oxide Nanoparticles

GOD was immobilized onto polypyrrole (PPy) or poly(o-anisidine) (POA) coated Pt electrode to construct glucose sensitive biosensor. Because polymer film properties and enzyme activity affect the current response, PPy and POA synthesis conditions and also enzyme immobilization parameters were optimized in detail. The optimal monomer concentrations were determined as 25 and 50 mM for PPy and POA, respectively, whereas scan rate was 50 mV/s for both polymer films. In case of immobilization procedure, the optimal Chitosan (Chi), glucose oxidase (GOD) and glutaraldehyde (GAL) concentrations were determined as 0.5%, 2 mg/ml and 0.05% for PPy and 0.5%, 4 mg/ml and 0.075% for POA, respectively. Zinc oxide nanoparticles (ZnONP) were co-immobilized with GOD enzyme and it was revealed that ZnONP modification enhanced the efficiencies of both electrodes in terms of current responses and stabilities. Nyquist diagrams showed that enzyme electrodes were sensitive to glucose molecule and ZnONP modification improved the sensor efficiency.

The effect of the geikeilite (MgTiO3) nanofiller concentration in PVdF-HFP/PVAc–based polymer blend electrolytes for magnesium ion battery

Magnesium ion–conducting polymer electrolyte is one of the necessary components of current rechargeable magnesium batteries because of its good interfacial contact with electrodes and efficient mechanical properties. In the recent analysis, we described synthesis and characterization of a composite polymer electrolyte (CPE) based on poly (vinylidene fluoride-co-hexafluoro propylene)/poly vinyl acetate, salt as magnesium perchlorate, and various weight percentages (wt %) of geikeilite filler (MgTiO3) by the solution casting method with tetrahydrofuran as a solvent. Structural analysis, Thermogravimetric analysis (TGA), complex impedance spectroscopy, ionic transference number analysis, linear sweep voltammetry (LSV) and cyclic voltammetry (CV) studies exhibit promising characteristics of prepared CPEs for appropriate utilization in magnesium battery application. The CPEs display high thermal constancy, high ionic conductivity (~ 5.80 × 10−3 Scm−1 at 30 °C), high magnesium transference number (= 0.34) and high electrochemical stability window. Dielectric properties of polymer films are analyzed and discussed. The electrochemical stability of 1.4 V and 2.4 V was get for 6 wt% incorporated MgTiO3 nanofiller system R3 polymer electrolytes, respectively, utilizing linear sweep voltammetry, cyclic voltammetry, and charge-discharge characteristics. The prepared CPE is expected to be a promising electrolyte candidate for magnesium battery utilization.

Investigation of spectral and kinetic properties of polymer films based on some analogs of bacteriorhodopsin.

We investigated the characteristics of modified forms of bacteriorhodopsin in which the native retinal chromophore is replaced by a chemical analog ("bacteriorhodopsin analogs"), embedded in a polymer film. We found they displayed differential absorption spectra and kinetic curves for the most long-lived intermediates of the BR photocycle. We also studied the influence of chemical reagents on the functioning of bacteriorhodopsin analogs in polymeric films. We found that the immobilization of BR analogs in polymer leads, as in the case of native BR, to a slowing down of their photocycles. Kinetic analysis showed that M-like state intermediates of all the BR analogs have a longer dark relaxation time than native BR. The retention and retardation of the photocycle in these films suggest that films based on BR analogs can be used as photochromic materials. Moreover, 4-keto BR seems to be more promising for this application as compared not only with native BR, but also with other analogs of BR studied in this work.

Hyperspectral infrared laser polarimetry for single-shot phase-amplitude imaging of thin films.

We recently presented a novel laser-based infrared (IR) spectroscopic phase-amplitude polarimeter for sub-decisecond and sub-mm2 measurements of organic thin films [Opt. Lett.44, 4387 (2019)OPLEDP0146-959210.1364/OL.44.004387]. Here we report on the hyperspectral-imaging capabilities of this device. The single-shot polarimeter employs a broadly tunable mid-IR (1318-1765 cm-1) quantum cascade laser (QCL) and a four-channel beam-division design for simultaneous phase and amplitude measurements. Fast QCL tuning speeds of up to 1500 cm-1/s enable hyperspectral mapping of large sample areas (50×50 mm2) within several tens of minutes, achieving 120 μm spatial and <0.5 cm-1 spectral resolution. We apply the instrument for imaging both the heterogeneous chemical and structural properties of sub-100 nm thin polymer and fatty-acid films. Our polarimeter opens up new applications regarding laterally resolved IR analyses of complex thin films.

Strain-optical behavior of polyethylene terephthalate film during uniaxial stretching investigated by Mueller matrix ellipsometry

Polyethylene terephthalate (PET) has gained widespread applications in various flexible devices where its optical properties after drawing process in manufacturing play a great importance in the performance of devices. In this work, the strain-optical behavior of pre-oriented polyethylene terephthalate (PET) film during uniaxial stretching is studied utilizing a proposed anisotropic model and Mueller matrix ellipsometry (MME). In the biaxial anisotropic model, the molecular chain orientation is correlated to the change of refractive indices and strain-induced birefringence, while the rotation of molecular chains is directly characterized by the rotation of principal optical axis. According to this model, the refractive indices, extinction coefficients and Euler angles extracted from measured Mueller matrix spectra can be used to interpret the micro-structural response of PET. A set of tensile tests have been carried out, with loading direction being varied. The results show that the strain-induced birefringence is linearly correlated to strain, while loading direction significantly affects the slope of achieved birefringence-strain curve. Meanwhile, the birefringence exhibits a positive linear relation with the orientation estimated by extinction coefficients. Through the analysis of the Euler angle ϕE, the principal optical axis rotating towards the tensile direction is accurately observed. Our results show that MME can provide a deep and systematic understanding of strain-optical behavior which can give accurate control of the optical properties of polymer films during deformation.

Electrically Insulating Plasma Polymer/ZnO Composite Films.

In this report, the electrical properties of plasma polymer films functionalized with ZnO nanoparticles were investigated with respect to their potential applications in biomaterials and microelectronics fields. The nanocomposite films were produced using a single-step method that combines simultaneous plasma polymerization of renewable geranium essential oil with thermal decomposition of zinc acetylacetonate Zn(acac)2. The input power used for the deposition of composites were 10 W and 50 W, and the resulting composite structures were abbreviated as Zn/Ge 10 W and Zn/Ge 50 W, respectively. The electrical properties of pristine polymers and Zn/polymer composite films were studied in metal–insulator–metal structures. At a quantity of ZnO of around ~1%, it was found that ZnO had a small influence on the capacitance and dielectric constants of thus-fabricated films. The dielectric constant of films with smaller-sized nanoparticles exhibited the highest value, whereas, with the increase in ZnO particle size, the dielectric constant decreases. The conductivity of the composites was calculated to be in the in the range of 10−14–10−15 Ω−1 m−1, significantly greater than that for the pristine polymer, the latter estimated to be in the range of 10−16–10−17 Ω−1 m−1.

Superposition-based predictions of creep for polymer films at cryogenic temperatures

The purpose of this study was to examine a novel application of superposition techniques for estimation of mechanical properties of polymer films at extreme cryogenic temperatures (e.g. 4 K). Polymer core films of the electronic laminates, ULTRALAM® 3850HT liquid crystal polymer (LCP) and Pyralux TK185018R (polyimide), were tested on a TA Instruments Q800 dynamic mechanical analyzer in tensile mode to obtain time-dependent creep compliance. Activation energy of flows, Ea, were calculated using an Arrhenius model. All data were accumulated within the range from about 150–293 K. Both polymers were found to have relaxation transitions within this range and predictions therefore initiated from the colder side of the transition. Predictive equations are proposed for creep compliance of these polymers. These compliances will be useful for overall failure models associated with devices ranging from electronics to magnetic cavities.

Methylated Poly(ethylene)imine Modified Capacitive Micromachined Ultrasonic Transducer for Measurements of CO2 and SO2 in Their Mixtures.

A gravimetric gas detection device based on surface functionalized Capacitive Micromachined Ultrasound Transducers (CMUTs) was designed, fabricated and tested for detection of carbon dioxide (CO2) and sulfur dioxide (SO2) mixtures in nitrogen. The created measurement setup of continuous data collection, integrated with an in-situ Fourier Transform Infrared (FT-IR) spectroscopy, allows for better understanding of the mechanisms and molecular interactions with the sensing layer (methylated poly(ethylene)imine) and its need of surface functionalization for multiple gas detection. During experimentation with CO2 gases, weak molecular interactions were observed in spectroscopy data. Linear sensor response to frequency shift was observed with CO2 concentrations ranging from 0.16 vol % to 1 vol %. Moreover, the Raman and FT-IR spectroscopy data showed much stronger SO2 and the polymer interactions, molecules were bound by stronger forces and irreversibly changed the polymer film properties. However, the sensor change in resonance frequency in the tested region of 1 vol % to 5 vol % SO2 showed a linear response. This effect changed not only the device resonance frequency but also affected the magnitude of electroacoustic impedance which was used for differentiating the gas mixture of CO2, SO2, in dry N2.

Dissipative Properties of Polymer Films and Composite Materials Based on Polyvinyl Acetate

Commercial thermoplastic plasticized polymer films based on polyvinyl acetate of different chemical compositions and composite metal-viscoelastic polymer film-metal three-layer materials were studied by dynamic mechanical analysis. The dependences of the mechanical loss coefficient and elastic modulus of polymer films on temperature and strain frequency at dynamic extension were determined experimentally. The temperature intervals of efficient damping were determined. In these intervals, the mechanical loss coefficient of each polymer film exceeds 0.5 for the frequency range 1–10 000 Hz. The dissipative properties of polymer films and composite materials based on them were compared. The mechanical loss coefficients of the films materials are higher than those of the composite materials, but the composite materials have higher mechanical loss moduli. Their absolute values at the maximum-damping temperature reach ∼1011 Pa and more, which allows using them as effective vibration-damping coatings.

Time and space dependence of large-scale synthesis of colloidal particle with special morphology and tuneable polymer film architecture

This paper describes a facile method to control the morphology of polymer colloids and the architecture of polymer film via miniemulsion polymerization. By taking advantage of cyclization between the symmetrical diacrylate cross-linker hexamethylene diacrylate (HDDA) and the pendent vinyl in colloidal particles, the morphology of polymer colloids and the architecture of the after-formed polymer film were able to be well controlled by tuning the loading of cross-linker HDDA and crosslinking time. Four kinds of polymer colloid morphologies and four kinds of film architecture (honeycomb, close-packed, loose-packed, and enhanced-honeycomb) were characterized by TEM. The film formation mechanisms behind them were proposed based on the special and interesting results including Z-average size of the colloidal particles, Mc (molecular weight between crosslinking points) and mechanical properties of polymer film. Our results highly suggested that the morphology of polymer colloids and the polymer film architecture together determine the adhesive properties of the colloidal polymer film. The best of 180°-peel resistance, T-peel resistance and shear resistance of the polymer films were 138.12 N/25 mm, 40.98 N/25 mm and 25.72 N/cm2 at 2.0 phm, 2.0 phm and 0.4 phm with the same crosslinking time of 90 min, respectively. The proposed method is promising to be scaled up for industrial production due to its well adaptability.