Pore size dependent dynamics of confined water probed by FIR spectroscopy.
We measured the FIR (Far Infrared) absorbance of a series of organic hydrated sub-nanopores (i.e. pores of the size of several A) containing confined water. Our results show that the FIR frequency region between 400 and 570 cm(-1) is sensitive to the differences in water mobility. The absorbance of these compounds was significantly higher than that of chemically similar anhydrous or non-porous hydrated compounds in the same region. Moreover, changes in the water dynamics inside the hydrated pores were found and characterized by their temperature dependent studies in the range from -5 to 20 degrees C. Upon increasing the temperature, water confined in narrow pores shows a small increase in FIR absorbance, while less confined water molecules inside larger pores exhibit a higher increase in absorbance, resembling more what has been observed for bulk water.
Pérez-Hernández
Natalia
N
Instituto de Investigaciones Químicas, Avda. Américo Vespucio, 49, 41092 Seville, Spain. natalia.perez@iiq.csic.es
Luong
Trung Quan
TQ
Pérez
Cirilo
C
Martín
Julio D
JD
Havenith
Martina
M
D006860:Hydrogen Bonding; D016062:Porosity; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D014867:Water / Q000737:chemistry*
D014867:Water