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In this study, two different non-ionic surfactants have been evaluated as a plasticizer in lithium polymer electrolytes and compared with an organic carbonate-based plasticizer. To that end, non-ionic surfactants with different molecular weight and structure have been selected (Triton® X-100 and Brij®L23) and compared with organic carbonates (EC:DEC1:1) as plasticizers in lithium polymer electrolytes. The effect of the plasticizer content, salt content and surfactant characteristics on properties such as ionic conductivity, thermal stability and electrochemical stability of lithium polymer electrolytes has been studied. The results obtained show that the non-ionic surfactants studied as plasticizers (Triton® X-100 and Brij®L23) give lithium polymer electrolytes with higher thermal and electrochemical stability than organic carbonates, thus making them promising plasticizers for lithium polymer electrolytes, especially for high voltage lithium-ion batteries. Surfactant structure could influence the ionic conductivity of the polymer electrolytes, with the linear surfactants being more suitable for this application.

The aim of this study is to characterize (wettability, surface roughness and gloss) and test (microhardness and diametral compression) four types of light-cured composite resins, one of which is commercial. The first lab-made composite is the reference, obtained by mechanical mixing of three monomers, in equal concentrations. The following two lab-made materials can be considered nanocomposites because they were mechanically mixed in the base solution (Bis-GMA/TEGDMA/Bis-EMA) with α-Al2O3 nanopowders, with a concentration of 5 wt.% for one solution and 10 wt.% for the other. The benchmark material comparison for these lab-made composite and nanocomposite resins is the bioresin system, Filtek™ Supreme Ultra Universal Restorative. Results were promising, especially for the 10 wt.% Al2O3/Bis-GMA/TEGDMA/Bis-EMA system, characterized by mechanical improvment in comparison with the reference composite.

The study of the mechanical behavior of materials intended for dental restorations is of crucial importance in the production of a finished product. In the present work, two resins were used for the material matrix, Bisphenol A diglycidyl methacrylate (Bis-GMA), hydroxyethylmethacrylate (HEMA) and a nanofiller (SiO2). This study focuses on the influence of nanoparticle size (30, 50, 100 and 150 nm) on the mechanical properties (flexural strenght and modulus, compression strenght and modulus and work of fracture) of the manufactured composite materials. The results showed improvements in the mechanical integrity of the samples, but differed depending on the size of the nanoparticles added. These differences are closely related to the active surface of the nanoparticles, leading to differences in filler-resin matrix compatibility.

The paper aims to evaluate the gel time and exotherm temperature properties of the curing of unsaturated polyester resin at various amounts of Methyl ethyl ketone peroxide, cobalt octoate and porcelain powder. The gel time of samples are determined using the simple method, while the exotherm temperature are evaluated using the thermocouple. The variation of these properties is discussed theoretically and experimentally.

The most significant disadvantage of cold cured poly (methyl methacrylate) – PMMA is its poor mechanical properties, mainly in flexure. The aim of this work is to explore the modulus and flexural strength of modified cold cured PMMA modified with low TiO2 addition, which can also have antibacterial properties. Commercial cold cured PMMA resin, consisting of powder and liquid components, were modified by adding 0.05 %, 0.2 %, and 1.5 wt. % 20 nm hydrophobic TiO2. The specimen`s flexural modulus and strength were tested, while heat properties were determined with DSC analysis. SEM and EDX were used to study fracture surfaces of tested specimens. In all modified specimens, an increased flexural modulus and flexural strength were recorded. In all specimens, the appearance of agglomerates was noted. Glass transition temperatures also increased, as the result of the appearance of polymer chains with reduced mobility around nanoparticles. 0.2 % of 20 nm TiO2 nanoparticle content proved to be the most efficient in increasing flexural modulus and strength.

With the development of unmanned aerial vehicle (UAV) systems for a multitude of real-time applications, 3D printing technologies have been developed to make thermoplastic structures by fusing filament Fused Deposition Modeling (FDM) or Fused Filament Fabrication (FFF). However, we consider that the realization of new technologies of experimental models / technological demonstrators / prototypes becomes profitable by using 3D printing technologies. The main aim of the paper is to highlight how the use of three types of materials, which are processed differently, influences the Von Mises stresses of the payload used for a UAV, with the mission of photographing and filming from high altitude.

The aim of this paper is to obtain two types of bio-based membranes by electrospinning process: one based on polylactic acid (PLA), and PLA/polyhydroxybutyrate (PHB), and the second by coating the PLA/PHB membrane with chitosan (CS) and CS/activated coal (AC), respectively for removal of micropollutants from aqueous water. The designed bio-based electrospun membranes were analyzed through scanning electron microscopy (SEM), attenuated total reflectance (ATR) – Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), the removal of solid suspension and Pb (II) from aqueous water. The quality of filtrates was evaluated by physical-chemical methods, while the retaining of Pb (II) from wastewaters was reported.

In the present work, the effect of the addition of different types of carbon nano structures on the mechanical, thermomechanical and thermal properties of a radial structure of styrene-butadiene-styrene (SBSR) copolymer matrix is reported. Different carbon nanostructures were used as nano-rein-forcements: expanded graphite (XG), graphene oxide (GO), reduced graphene oxide (RGO) and exfo-liated graphene (EG). These carbon structures present various functional groups, such as carbonyl, epoxy, and others, which are the responsible for the interaction between the polymer matrix and the nano particles. The compatibility induced between the nanomaterials and the elastomeric matrix fa-vors the stable dispersion of the nanocomposites during their obtention process. For instance, the ad-dition of GO increased in 10 and 16% the tensile strength and storage modulus of the nanocomposites. The fracture surface patterns in the nanocomposites after the tensile test was observed by scanning electron microscopy. Also, the dynamic mechanical analysis (DMA) and thermal characterization showed differences in the viscoelastic behavior of the reinforced nanocomposites with different carbon nanomaterials.

Membrane research has managed to reach ever greater heights. The optimization of membrane processes is of common interest to industry, research and the domestic environment. Nanomaterials have been progressively researched in the membrane sector within the last decade, contributing in particular to their beneficial properties for the prevention of membrane fouling. This research investigates the effect of two shapes of ZnO nanomaterials, respectively nanoparticles and nanowires, on the properties of ultrafiltration membranes composed of 25 wt.% polysulfone. The method of membrane manufacturing is phase inversion, the immersion precipitation technique, and the procedure of nanomaterial incorporation into the polymeric matrix is known as blending. The results demonstrated the positive influence of nanomaterials on the performance of membranes, regardless of their shape, compared to the control membrane. In terms of permeability, the membrane with addition of ZnO nanoparticles showed an increase of 207.19 %, while the membrane with addition of zinc oxide nanowires recorded an increase of 89.16%.

The aim of this paper was to present the synthesis, characterization and application of the Fe3O4 - chitosan composite as potential adsorbent for removing lead ions from industrial wastewater. The nanocomposite nanomaterial was characterized by XRD and SEM analyzes. The influence of some parameters (pH of wastewater, lead ions concentration and dose of Fe3O4 - chitosan absorbent) upon the efficiency of wastewater treatment were investigated. The Pb (II) ions concentrations in wastewater were 0.5, 1, 1.5 and 2 mg/L. The amounts of Fe3O4 - chitosan nanocomposite adsorbent tested were 0.05, 0.1 and 0.2 g. In some experimental conditions, Fe3O4 - chitosan nanocomposite adsorbent leaded to obtaining of 100% wastewater treatment efficiency.