Tatjana Haramina

Study of thermal stability of (3-aminopropyl) trimethoxy silane-grafted titanate nanotubes for application as nanofillers in polymers

Protonated titanate nanotubes (TiNT-H) were surface-modified with (3-aminopropyl)trimethoxy silane (APTMS) by a novel method suitable for the syntheses of large amounts of materials at a low cost. The usage of prepared nanotubes for polymer reinforcement was studied. Since the thermal stability of the nanofiller was important to preserve its functional properties, its stability was studied by in situ high-temperature measurements. The most thermally stable nanotubes were silanized for 20 min and used for the preparation of epoxy-based nanocomposites. The nanofiller formed smaller (a few hundred nm) and larger (a few μm) aggregates in the polymer matrix, and the amount of aggregates increased as the nanofiller content increased. The APTMS-modified titanate nanotubes bonded well with the epoxy matrix since amine groups on the TiNTs surface can react with an epoxy group to form covalent bonds between the matrix and the nanofiller. A very small addition (0.19-1.52 wt%) of the nanotubes significantly increased the glass transition temperature and the modulus in the rubbery state of the epoxy-based polymer. Smaller nanofiller content leads to a larger increase in these parameters and therefore better dynamic mechanical properties due to the smaller amount of large aggregates. APTMS-modified titanate nanotubes have proven to be a promising nanofiller in epoxy-based nanocomposites.

Metal nanoparticles and carbon nanotubes—perfect antimicrobial nano-fillers in polymer-based food packaging materials

Abstract Advances in food packages are oriented to obtain improved quality and safety. Incorporation of antimicrobial compounds in the form of nano-fillers into polymer-based food packaging materials has received considerable attention. These active packages are applied to extend shelf life while maintaining nutrition quality and ensuring microbiological safety. Antimicrobial nanocomposite films are desirable for application in the food industry due to their advantages: structural integrity and barrier properties imparted by the matrix, as well as the antimicrobial properties resulting from impregnated antimicrobial agents. Metal nanoparticles, metal oxide nanomaterials, and carbon nanotubes are mostly used in developing antimicrobially active polymer materials. This chapter deals with some of the most important questions related to metallic nanoparticles in food packaging (health and environmental considerations, performance, and costs), with the special emphasize on their applicable and toxicological properties.