Synthesis and Physical and Thermodynamic Properties of Lactic Acid and Malic Acid-Based Natural Deep Eutectic Solvents

Abstract

In this paper, four natural deep eutectic solvents (NADES) systems were prepared at specific molar ratios, La:Bet (2:1) (lactic acid/betaine), La:Hist (9:1) (lactic acid/histidine), Ma:Bet:H 2 O (1:2:3) (malic acid/betaine/water) and Ma:Bet:Pro:H 2 O (1:1:1:2) (malic acid/betaine/proline/water). Their physical and thermodynamic properties were studied, namely viscosity, electrical conductivity, and heat capacity. The viscosity and electrical conductivity were determined as a function of temperature and the correlation for the temperature dependence was obtained and discussed based on Arrhenius theory. The heat capacity for all eutectic systems was measured by differential scanning calorimetry (DSC) over a temperature range of 293.15−363.15 K. The ability of these NADES to reduce cellulose crystallinity was evaluated. Cellulose crystallinity after suspension in these NADES was studied by X-ray diffraction. Cellulose suspended in Ma/Bet/H 2 O (1:2:3) suffer the highest crystallinity reduction among the systems studied and was about of 20%.

Therapeutic Role of Deep Eutectic Solvents Based on Menthol and Saturated Fatty Acids on Wound Healing

“…The thermograms of THEDES indicate that the molar ratio strongly affects the intensity and shift of the peaks, which was previously reported for other THEDES. 20 , 26 , 42 , 43 The DSC data together with POM were both used as easily accessible tools to assess the potential of particular molar ratios to originate THEDES. After this initial assessment, menthol was combined with LA, MA, and SA at 4:1, 8:1, and 8:1, respectively.…”

Polymer Science and Engineering Using Deep Eutectic Solvents

“…The exponential concern with environmental issues highly motivated the development of green technologies. DES have emerged as green solvents due to their low toxicity and volatility, biodegradability, biocompatibility, easy production, high yields and purity, and the fact that they are widely available precursors [9,10]. This type of solvent can fulfill the principles of green chemistry [11,12] while being highly tunable for several distinct areas.…”

Natural deep eutectic solvents (NADES) based on citric acid and sucrose as a potential green technology: a comprehensive study of water inclusion and its effect on thermal, physical and rheological properties

“…All NADES samples evaluated by DSC analysis showed only glass transition events (Tg), with values below 233.47 K (Table ), with no fusion events, characterising the NADESs as eutectic solvents, which present only glass transition events in their thermograms (Dai et al ., ,b; Craveiro et al ., ; Castro et al ., ). In the present study, it was possible to observe the presence of a supramolecular complex and a wide temperature range in liquid form (Dai et al ., ,b; Craveiro et al ., ).…”