Tag: Scientific Publications

Authors: Dimitris G. Mintis, Marco Dompé, Panagiotis D. Kolokathis, Jasper van der Gucht, Antreas Afantitis and Vlasis G. Mavrantzas

Abstract

We study the microstructural properties and state of hydration of aqueous low-molecular-weight poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) solutions and their dependence on polymer concentration and pH by means of detailed atomistic Molecular Dynamics (MD) simulations and experiments. For infinitely dilute solutions with a degree of polymerization of N = 30 at basic pH conditions, no temperature dependence is observed on the overall shape and state of hydration of the polyelectrolyte. This is supported by the experimental component of our work according to which the hydrodynamic radius, Rh, does not change dramatically with temperature. Small, but not drastic, changes are observed for solutions with longer PDMAEMA chains (N = 50, 70, and 110). Although the
MD simulations demonstrate that temperature and salt do affect the strength of hydrophobic interactions between PDMAEMA and water, apparently these effects are not strong enough to cause drastic changes to the overall shape of the polymer. MD simulations also reveal that Na+ salt ions strongly interact with the oxygen atoms located at the side chain of the polyelectrolyte. While no significant changes in the global shape or state of hydration of the PDMAEMA chain are found, a strong dependence is revealed for the aggregation behavior of the polymer on temperature and salt in slightly more concentrated solutions. A structural transition from a collapsed coil to a stretched conformation is also observed as we move from basic to acidic pH conditions, which is strongly correlated with the degree
of chain rigidity as a function of pH.

Follow the link to read the full article https://doi.org/10.3390/polym17162189

Authors: Luca Fiore, Arianna Antinucci, Giorgia Leotta, Laura Fabiani, Alessandro Iannini, Pierluca Galloni, Riccardo De Santis, Andrea Ciammaruconi, Giorgia Grilli, Elisa Recchia, Florigio Lista, Fabiana Arduini

A B S T R A C T
In the era of sustainability, the use of natural compounds as antimicrobial compounds is the rational selection to avoid the release of pollutants into the environment. Among natural compounds, essential oils are characterized by reliable antimicrobial activity and their use is estimated to grow in the future, thus their detection is an asked point. Herein, we report an electrochemical reagent-free paper-based device for the detection of essential oils, namely thymol, eugenol, and carvacrol by adding 5 µL of solution onto the electrode. We functionalized the working electrode with carbon black by drop casting, demonstrating for the first time the proved sensitivity in essential oil detection using this affordable nanomaterial. To deliver a reagent-free device, the paper-based electrode was loaded with the working buffer for asking the end-user only the addition of the sample. This sensor detected the selected essential oils in a dynamic linear range of up to 16 ppm, with a detection limit equal to 0.1, 0.1, and 0.2 ppm for thymol, eugenol, and carvacrol, respectively. Moreover, the sensor’s sustainability was evaluated using the RGBfast method, highlighting its whiteness compared to conventional chromatographic techniques. The reliable results obtained using the paper-based electrochemical sensor demonstrated the versatility, eco-friendliness, and practicality of this sensing tool, enlarging its use in essential oil detection.

Follow the link to read the full paper published in Green Analytical Chemistry https://doi.org/10.1016/j.greeac.2025.100217