Detail publikace

DSC study on hyaluronan drying and hydration

KUČERÍK, J. PRŮŠOVÁ, A. ROTARU, A FLIMEL, K. JANEČEK, J. CONTE, P.

Originální název

Typ

článek v časopise - ostatní, Jost

Jazyk

angličtina

Originální abstrakt

The processes of hyaluronan (HYA) drying and hydration were studied using differential scanning calorimetry. In the first approach the isoconversional Kissinger Akahita Sunose (KAS) method was applied in order to determine actual activation energies of evaporation of pure water and water from concentrated HYA solutions. Since the evaporation is a single-step process, the activation energies for pure water provided results consistent with tabulated values of evaporation enthalpies. In the course of water evaporation from hyaluronan solution a break in increasing enthalpy followed by a decrease below 0.34 g of water per 1 g of HYA was observed. This result confirmed earlier observation that at this particular water content evaporation from hyaluronan is compensated by heat evolution associated with the formation of new bonds in hyaluronan supramolecular structure. Subtraction of water evaporation enthalpy from enthalpies obtained for HYA concentrated solution provided a possibility to extrapolate the evaporation enthalpies to the concentration (approximately 2 g of water per 1 g of HYA) at which free water is not present any longer and only bound water starts being evaporated from the HYA solution. Similar results were obtained in the second approach in which using slightly modified traditional freezing/thawing experiment, melting enthalpy of ice was plotted against water fraction in HYA. It was found out that the melting enthalpy of ice exponentially increases from 0.8 up to 2 g of water per g of hyaluronan where it reaches and keeps the melting enthalpy of hexagonal ice. It was shown that both approaches can serve as alternatives providing an additional insight into the state of water and biopolymers in highly concentrated solutions.

Klíčová slova

Evaporation kinetics; Hyaluronan; Hydration; Drying; Isoconversional methods; KAS

Autoři

KUČERÍK, J.; PRŮŠOVÁ, A.; ROTARU, A; FLIMEL, K.; JANEČEK, J.; CONTE, P.

Rok RIV

2011

Vydáno

1. 8. 2011

Nakladatel

Elsevier

Místo

Amsterdam

ISSN

0040-6031

Periodikum

Thermochimica Acta

Ročník

523

Číslo

1-2

Stát

Nizozemsko

Strany od

245

Strany do

249

Strany počet

BibTex

@article{BUT73638,
  author="KUČERÍK, J. and PRŮŠOVÁ, A. and ROTARU, A and FLIMEL, K. and JANEČEK, J. and CONTE, P.",
  title="DSC study on hyaluronan drying and hydration",
  journal="Thermochimica Acta",
  year="2011",
  volume="523",
  number="1-2",
  pages="245--249",
  issn="0040-6031"
}