Type Of Polymeric Matrix Research Articles

Fabrication Approaches of Soft Electronics

The use of conductive materials to be printed/embedded onto/within a polymeric matrix has gained increasing attention in the fabrication of next-generation soft electronics. In this review, we provide a comprehensive overview of the materials and approaches for the fabrication of 2D and 3D conductive structures while focusing on the importance of the compatibility between the particles’ shape, the polymeric matrix type, and the deposition method, along with the target application. The review presents a summary of the main conductive materials and the type of polymeric materials which were utilized for fabricating soft electronic devices that are bendable/twistable and stretchable. It is divided into two sections: Introduction section, which presents briefly conductive materials, polymeric matrix, and fabrication methods, and Fabrication section, presenting the main 6 approaches of fabrication. Each of the fabrication subsections presents the main recent reports in a detailed table. The review is concluded with an Outlook section, describing the current challenges in this field. Despite the progress in the fabrication of 2D bendable/twistable electronic devices toward industrial integration, there is still a need for tailoring and improving the durability and robustness of 3D stretchable electronic devices.

3D printed composites with uniform distribution of Fe3O4 nanoparticles and magnetic shape anisotropy

A novel approach to fabricate magnetic elements made from nanocomposite materials by material extrusion is proposed. Flexibility in the shape and dimensions of this technology leads to the possibility to overcome the restrictions in the design and manufacturing of complex-shaped bulk magnets. The nanocomposites discussed here were fabricated by the addition of magnetite (Fe3O4) nanoparticles into a polymeric matrix: PEG-PVB and silicone gel. Composites with nanoparticles to polymer blend weight concentrations varying from 20% to 60% were prepared. The rheological behaviour of the suspensions was studied using rotational rheometry. The 3D prints were performed with and without an externally applied magnetic field. Microstructure, morphology and magnetic properties of the synthesised nanocomposites were confirmed by Fourier-transform infra-red spectroscopy (FT-IR), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM), respectively. The composites showed a uniform morphology with nanoparticles embedded homogeneously in the matrix. Magnetic response, namely remanence, saturation, coercive field and squareness, depend substantially on the type of polymeric matrix and nanoparticles concentration. Composites based on silicone have around 20–25% lower squareness ratio than the PEG-PVB-Fe3O4 ones. The elements printed from selected composites exhibit weak but well pronounced magnetic shape anisotropy – a feature characteristic for bulk magnets.

Synergic Effect of TiO2 Filler on the Mechanical Properties of Polymer Nanocomposites.

Nanocomposites with polymer matrix offer excellent opportunities to explore new functionalities beyond those of conventional materials. TiO2, as a reinforcement agent in polymeric nanocomposites, is a viable strategy that significantly enhanced their mechanical properties. The size of the filler plays an essential role in determining the mechanical properties of the nanocomposite. A defining feature of polymer nanocomposites is that the small size of the fillers leads to an increase in the interfacial area compared to traditional composites. The interfacial area generates a significant volume fraction of interfacial polymer, with properties different from the bulk polymer even at low loadings of the nanofiller. This review aims to provide specific guidelines on the correlations between the structures of TiO2 nanocomposites with polymeric matrix and their mechanical properties. The correlations will be established and explained based on interfaces realized between the polymer matrix and inorganic filler. The paper focuses on the influence of the composition parameters (type of polymeric matrix, TiO2 filler with surface modified/unmodified, additives) and technological parameters (processing methods, temperature, time, pressure) on the mechanical strength of TiO2 nanocomposites with the polymeric matrix.

Urethane-Acrylate/Aramid Nanocomposites Based on Graphenic Materials. A Comparative Study of Their Mechanical Properties

Urethane-acrylate thermoset resins (UATR) are a new type of polymeric matrix that have recently made a strong breakthrough in the composites sector. This is because of their properties, which make them an advantageous alternative to epoxy resins, especially if they are reinforced with high-performance fibers such as aramids. Graphene-based nanocomposites are one of the most dynamic research fields in nanotechnology, because graphenic materials greatly improve the properties of traditional composites. This work represents a comparative study of the effect of adding three types of graphenic materials on the mechanical properties of UATR/aramid composites. Several UATR polymeric matrices were doped at 2% w/w with graphene nanoplatelets (GNPs), reduced graphene oxide (rGO) and pristine few-layer graphene (FLG), and reinforced with Twaron CT709 para-aramid fibers. The obtained laminates showed low density (1.38 g·cm−3), a high volumetric fiber–resin ratio (80:20), homogeneous dispersion of the nanoreinforcement, high reproducibility, and easy scalability. The tensile, flexural and impact strength properties of the undoped composite and the graphene-doped nanocomposites were determined. FLG-doped nanocomposites showed the highest increase in all the mentioned mechanical properties and attained a very significant relative improvement over the undoped laminate (up to 134.4% in aCU).

Effect of oxygen and polymer matrix on photo-induced changes in CdSe quantum dots

When quantum dots (QDs) are irradiated with light, they are subject to photoinduced phenomena, such as photooxidation, photoluminescence (PL) blue-shift, photodarkening (PD) and photobrightening (PB). Some applications of QDs require their dispersion in a polymer matrix. In the present work, the type of polymeric matrix and surrounding gas were investigated as interdependent factors that induce blue shift, PD, and PB of CdSe QDs. CdSe QDs were dispersed in films of polystyrene (PS) and poly (methylmethacrylate) (PMMA). The films were purged with Ar and O2 gases for 8 h and then continuously irradiated with a 0.115 W visible laser while collecting PL spectra at time intervals. PD was obvious in PS, while in PMMA, significant PB was observed with no sign of PD. Irradiation under O2 led to a pronounced blue shift, but this was not observed under Ar. In summary, these polymers either protected against or contributed to photochemical alteration of the QDs in very different ways. PS/O2 is a suitable combination for illumination-based applications/studies that require conservation of PL intensity, but not wavelength. On the other hand, PMMA/Ar is suitable for those that require high PL intensity and conservation of PL wavelength. The changes are explained on the basis of the tendencies of molecular oxygen and the PMMA ester group to oxidize or passivate the QDs, while PS and Ar act as spectators.

Novel PEG-Modified Hybrid PLGA-Vegetable Oils Nanostructured Carriers for Improving Performances of Indomethacin Delivery.

The purpose of this work was to more exhaustively study the influence of nanocarrier matrix composition and also the polyethylene glycol (PEG)-modified surface on the performances of formulations as lipophilic drug delivery systems. Poly (d,l-lactide-co-glycolide), two vegetable oils (Nigella sativa oil and Echium oil) and indomethacin were employed to prepare novel PEG-coated nanocarriers through emulsion solvent evaporation method. The surface modification was achieved by physical PEG adsorption (in the post-production step). Transmission electron microscopy (TEM) nanographs highlighted the core-shell structure of hybrid formulations while scanning electron microscopy (SEM) images showed no obvious morphological changes after PEG adsorption. Drug loading (DL) and entrapment efficiency (EE) varied from 4.6% to 16.4% and 28.7% to 61.4%, solely depending on the type of polymeric matrix. The oil dispersion within hybrid matrix determined a more amorphous structure, as was emphasized by differential scanning calorimetry (DSC) investigations. The release studies highlighted the oil effect upon the ability of nanocarrier to discharge in a more sustained manner the encapsulated drug. Among the kinetic models employed, the Weibull and Korsmeyer-Peppas models showed the better fit (R2 = 0.999 and 0.981) with n < 0.43 indicating a Fickian type release pattern. According to cytotoxic assessment the PEG presence on the surface increased the cellular viability with ~1.5 times as compared to uncoated formulations.

Development and Characterization of Medicated Polymeric Matrix Type Bone Cement for Effective and Rapid Healing in Bone Fracture

Development and Characterization of Medicated Polymeric Matrix Type Bone Cement for Effective and Rapid Healing in Bone Fracture

Effect of the Structure of Polymethine Dyes on Their Photovoltaic Properties in Polymer Films

The photovoltaic properties of a wide selection of structures based on cationic and anionic polycarbocyanines in polymeric matrices were investigated. It was shown that the sign of the electric potential (photo-emf) is reversed during the transition from a photoconductive polymer to a nonphotoconductive polymer. It was established that the magnitude of the photovoltaic response depends on the electron-donating ability of the terminal groups, the length of the polymethine chain, the charge of the chromophoric ion, and the type of polymeric matrix. The experimental data were analyzed by quantum-chemical calculations on the ions of the dyes and the elementary unit of the polymer using the nonempirical DFT/B3LYP method in the 6-31G(d,p) basis set.

Structure and properties of polymer–wood composites based on an aliphatic copolyamide and secondary polyethylenes

AbstractComposite materials based on an aliphatic copolyamide and a secondary polyethylene, as thermoplastic matrices, and wood chips as filler were obtained and characterized. The influence of different factors (polymeric matrix type, fractional composition and geometrical characteristics of wood filler, processing parameters and ratio polymer/wood) on the properties of polymer–wood composites (PWCs) was studied. It was demonstrated that the packing factor F has an essential influence on the properties of PWCs: increasing F values determines an improvement in mechanical properties of these materials. Mechanical properties, thermal behaviour, morphological and diffusion characteristics of the analyzed composites were evaluated through specific methods and reported herein. Morphological and DSC data confirmed the presence of strong interface interactions between polymer and wood. The diffusion characteristics of PWCs showed that the diffusion coefficient D essentially depends on filler content in composites. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1700–1710, 2006

Preparation and characterization of polymer‐stabilized metal nanoparticles for sensor applications

AbstractNanomaterial‐based sensing devices attract great attention of scientist and technologists due to the special properties of nano‐objects, such as for example, Metal Nanoclusters (MNC), which differ from those of the bulk materials. The further development of these devices requires novel approaches to stabilize MNC and therefore, to save their unique properties. The Solid‐Phase‐Incorporated‐Reagents (SPHINER) technique was used for in situ synthesis of Polymer‐Stabilized Metal Nanoclusters (PSMNC), which were used in the construction of new composite electrodes. The size of Pt‐PSMNC synthesized in polyvinyl chloride (PVC) and polysulfone stabilizing matrices was determined by Transmission Electron Microscopy (TEM) technique and appeared to be in majority of cases of 6–20 nm. The electrochemical characterization of PSMNC‐based amperometric sensors has demonstrated that inclusion of Pt‐MNC increases the electrical conductivity of the membrane and that the electrode performance strongly depends on both the type of polymeric matrix and the membrane preparation technique. (© 2006 WILEY‐VCH Verlag GmbH &amp; Co. KGaA, Weinheim)

Preparation and release studies of alkannin-containing microcapsules

Microcapsules containing the pharmaceutical substance alkannin were prepared by the solvent evaporation method to enhance alkannin stability (reduce photo-oxidation, polymerization), to decrease its hydrophobicity and to control its release rate. The effect of various parameters, such as the type of polymeric matrix, the type of surfactant used for microcapsules preparation and the addition of Pistacia lentiscus resin in the core, on the characteristics of the produced microcapsules and the release rate of alkannin were investigated experimentally. Among the polymers tested for matrix, ethylcellulose of viscosity 46cp was the most successful, while ethylcellulose 10cp gave microcapsules with good morphological characteristics but high release rate. Beeswax resulted in flocculation and P. lentiscus resin with or without colophony as the matrix resulted in compact particles with no pores and much slower release, but did not allow alkannin to release easily from the matrix. Sodium dodecyl sulfate resulted in microcapsules with desirable morphological and physicochemical characteristics, while acacia and tragacanth gums were not indicated as surfactants in alkannin microencapsulation since they gave a high release rate and a great extent of particle size, respectively. The incorporation of Pistacia lentiscus resin in the capsule core increased loading and microencapsulation efficiency. Ethylcellulose of 46cp viscosity with sodium dodecyl sulfate as surfactant had the best characteristics studied for alkannin microencapsulation. Finally, the dissolution rate of alkannin from microcapsules was studied in a simulated intestinal and gastric environment and an external environment. Alkannin-containing microcapsules with improved properties can be used internally and externally as a new drug-delivery system.