Supercritical carbon dioxide assisted impregnation of eugenol into polyamide fibers for application as a dental floss

Recent advances in supercritical fluid dyeing

“…99 Anti-bacterial textiles are attracting increasing attention in aseptic medical applications, such as wound healing, 10 or in the apparel industry due to consumers' demands for more comfortable odour-free clothing. 11 Different supercritical fluid technology-based strategies can be adopted, such as the impregnation with natural phenolic compounds 10,102 as well as coating with synthetic polymers (ie polysiloxane) equipped with biocidal functionalities 13,104 or coating with biopolymers (ie chitosan) that possess intrinsic antimicrobial activity. 15 In 2014, Abou Elmaaty et al 97 first reported the synthesis of new monoazo disperse dyestuffs with anti-bacterial properties to dye PET in supercritical carbon dioxide.…”

Mass transfer kinetics of CO2 and eugenol in the supercritical impregnation of polyamide fibers: Experimental data and modeling

“…Supercritical CO2-assisted impregnation assays were performed in the same high-pressure impregnation apparatus illustrated in Fig. 1, following the procedure described in a previous contribution [41] with slight modifications. For each experiment, a 1 m long PA6 floss sample is placed into the cell using a cylindrical support (12) with a metal mesh in the borders, threading the sample through this mesh (see Fig.…”

“…Samples were impregnated using a constant eugenol mole fraction of 0.0015 in the fluid phase at two temperature levels (40 and 60 °C), two pressure levels (10 and 12 MPa), and different time intervals (from 15 min J o u r n a l P r e -p r o o f to 3 h) before depressurization. All the experiments were performed at a constant depressurization rate of 0.5 MPa min −1 , condition at which the maximum eugenol loading is achieved, according to a previous study [41]. The depressurization rate was controlled by measuring at regular intervals the pressure drop with time, using a manometer and a chronometer, and adjusting the CO2 outflow with a micrometering valve accordingly.…”

“…4). The diffusion kinetics of eugenol into the polymer under high-pressure conditions was evaluated taking into account that the dental floss is composed of several long solid cylindrical filaments (24.7 ± 11 µm diameter), as previously confirmed by scanning electron microscopy [41]. Experimental uptake curves were fitted by an analytical solution of the second Fick's law of diffusion in a solid cylinder under non-steady state conditions (Eq.…”

“…In this work, the CO2 sorption kinetics in polyamide (PA) fibers and their scCO2-assisted impregnation with eugenol as an active compound are studied. In a previous contribution [41] scCO2-assisted impregnation was evaluated for obtaining an active floss suitable for dental care applications by loading PA fibers with eugenol at 60 °C and different pressure levels and depressurization rates, analyzing the effect of these variables on the impregnation yield. In addition to confirming the feasibility of the process, with loading results up to 15% wt., it was also observed that the high-pressure treatment did not significantly affect the mechanical behavior of the material.…”