Publicação
Synthesis and Physical and Thermodynamic Properties of Lactic Acid and Malic Acid-Based Natural Deep Eutectic Solvents
| Resumo: | 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 293.15â 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%. |
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| Autores principais: | Castro, Vânia Isabel Baptista |
| Outros Autores: | Mano, F.; Reis, R. L.; Paiva, A.; Duarte, Ana Rita C. |
| Assunto: | Natural deep eutectic solvents Physical properties Thermodynamic properties |
| Ano: | 2018 |
| País: | Portugal |
| Tipo de documento: | artigo |
| Tipo de acesso: | acesso restrito |
| Instituição associada: | Universidade do Minho |
| Idioma: | inglês |
| Origem: | RepositóriUM - Universidade do Minho |
| Resumo: | 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 293.15â 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%. |
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