Influence of Flexible and Textile Substrates on Frequency-Selective Surfaces (FSS).

Frequency-selective surfaces (FSS) are two-dimensional geometric structures made of conductive materials that selectively transmit or reflect electromagnetic waves. In this paper, flexible FSS made on textile and film substrates is presented and compared to show the effect of the texture associated with the type of substrate on the shielding properties. Three geometries of patterns of squares in the border, inversion of squares in the border, and circles with a border were used, and the patterns were made by the silver paste screen printing technique.

Analysis of Fractional-Order Models Of Polyaniline Doped Polyacrylonitrile Fibres Impedances' (PAN/PANI).

The paper describes the use of electrical impedance spectroscopy (EIS) for characterizing the impedance of polyaniline doped polyacrylonitrile fibres. The electrical impedance of fibres samples was measured by means of high impedance analyser and modeled by four types of models: Debye, Cole-Cole, Davidson-Cole and Havriliak-Negami. The fitting errors are presented for all model types.

Multifunctional Nanocomposite Cellulose Fibers Doped in Situ with Silver Nanoparticles.

This paper presents a method for the preparation of nanocomposite cellulose fibers doped with silver nanoparticles (AgNPs), as well as the effect of silver nanoparticles on the structure and properties of fibers. The fibers were obtained by an environmentally friendly method using N-Methylmorpholine N-oxide (NMMO) as a solvent, in a non-polluting closed system. Doping with silver nanoparticles was carried out as a direct (in situ) reduction of Ag⁺ ions in the presence of a stabilizing agent during the preparation of the spinning solution.

The Preparation and Characterization of Polyacrylonitrile-Polyaniline (PAN/PANI) Fibers.

The paper presents a method of modifying polyacrylonitrile (PAN) fibers using polyaniline (PANI). The PAN fibers were doped with polyaniline that was obtained in two different ways. The first consisted of doping a spinning solution with polyaniline that was synthesized in an aqueous solution (PAN/PANI blended), and the second involved the synthesis of polyaniline directly in the spinning solution (PAN/PANI in situ).