Fabrication, Characterization, and Properties of Poly (Ethylene-Co-Vinyl Acetate) Composite Thin Films Doped with Piezoelectric Nanofillers

Abstract

Ethylene vinyl acetate (EVA) is a copolymer comprehending the semi-crystalline polyethylene and amorphous vinyl acetate phases, which potentially allow the fabrication of tunable materials. This paper aims at describing the fabrication and characterization of nanocomposite thin films made of polyethylene vinyl acetate, at different polymer concentration and vinyl acetate content, doped with piezoelectric nanomaterials, namely zinc oxide and barium titanate. These membranes are prepared by solvent casting, achieving a thickness in the order of 100–200 µm. The nanocomposites are characterized in terms of morphological, mechanical, and chemical properties. Analysis of the nanocomposites shows the nanofillers to be homogeneously dispersed in EVA matrix at different vinyl acetate content. Their influence is also noted in the mechanical behavior of thin films, which elastic modulus ranged from about 2 to 25 MPa, while keeping an elongation break from 600% to 1500% and tensile strength from 2 up to 13 MPa. At the same time, doped nanocomposite materials increase their crystallinity degree than the bare ones. The radiopacity provided by the addition of the dopant agents is proven. Finally, the direct piezoelectricity of nanocomposites membranes is demonstrated, showing higher voltage outputs (up to 2.5 V) for stiffer doped matrices. These results show the potentialities provided by the addition of piezoelectric nanomaterials towards mechanical reinforcement of EVA-based matrices while introducing radiopaque properties and responsiveness to mechanical stimuli.

Biochar as an Effective Filler of Carbon Fiber Reinforced Bio-Epoxy Composites

“…The value of the flexural modulus slightly decreased, which may have been a result of a lower amount of epoxy in the composites, in comparison with the reference sample. The increase in inorganic filler content caused an increase in the flexural modulus of the composites [43,44].…”

Influence of Polymer Composition on the Controlled Release of Docetaxel: A Comparison of Non-Degradable Polymer Films for Oesophageal Drug-Eluting Stents

“…The absence of a DTX T m may be due to the dissolution of the drug in the polymer matrix when it melts, or the presence of amorphous drug aggregates that lack a distinct, sharp melting point. For the blank and DTX-loaded PEVA films an endothermic peak was observed in the thermogram at ~46 • C corresponding to the T m for PEVA (40% VA) [32,64], and indicate that the inclusion of DTX does not influence the morphology of the polymer nor does the drug interact strongly with the polymer. The thermogram of blank PU displayed glass transition temperatures (T g ) at 70 and 92 • C that correspond to different segments of the PU [65].…”

Enhanced chitin gel with magnetic nanofiller for lysozyme purification

“…The polymer chains at the proximity of the nanofillers can be stretched, thus leading to a decrease of their conformational entropy. The presence of a rigid interface could drive the segregation of lower molecular weight chains during the hydrogel formation upon the wet-spinning process [35]. These phenomena are due to modification of the polymer segmental mobility and that of purely geometric factors [36] A comparison of the crystalline index (CI %) was performed according to the following equation [37]: parameters are summarized in Table 1.…”