Deep eutectic solvent and poly (vinyl alcohol) based eutectogels: Characterization and properties

Abstract

In this work, deep eutectic polymer blend Choline chloride with polyvinyl alcohol (PVA) and eutectogel based on PVA and deep eutectic solvent (DES) (Choline Chloride-Xylitol) were synthesized. Quantum chemistry calculations (QCC) and Fourier transforms middle infrared (FTIR), C^l3 and H¹ NMR spectroscopy were used to study the interactions between Choline Chloride and Xylitol at the formation of DES. The H–H interaction in the DES was detected in the 4.0 to 6.5 ppm range in H¹ NMR, corresponding to hydrogen bonding between hydroxyl groups and chloride ions. QCC show that DES is a stable solvent with an energy gap between the donor and the acceptor of 0.39 eV. The thermal stability, viscosity and electrical resistance of the DES have been studied. The perspective of using a DES to obtain a hydrophilic polymer was shown. The FTIR results reveal that intermolecular hydrogen bonds are formed between PVA and Choline Chloride and DES Choline Chloride-Xylitol in the composites. The physical properties (thermal stability) of hydrophilic polymers were investigated. The T_onset, of the DES is 160 ºC, T_decomp, ºC amounts to 280 ºC. For the polymers the T_decom up to 300 and 410 ºC were increases by the Choline Chloride or DES addition, respectively. The DES has fairly high electrical (0.129 Sm/m). The eutectogel also exhibited good functional properties such as stability in various pH and absorptivity capacity. Every sample showed maximal swelling at acidic pH and reduced swelling at neutral pH; hydrogels began to swell once again at pH = 9.18. The addition of Choline Chloride and DES did not affect the microstructure of PVA. While the microstructures of PVA and the blend of PVA and Choline Chloride exhibited comparable morphologies, there was little variation when compared to pure PVA at a Choline Chloride level of 10:3. Additionally, a series of experiments was carried out to assess the eutectic polymer blend and DES-Based eutectogel antibacterial efficacy against C. albicans.