Relaxing water
Water as the most prevalent liquid in and around us never ceases to fascinate us. Nevertheless many of its unusual properties are not well understood and therefore the scientific interest is unbroken. Studying its molecular dynamics by means of dielectric and optical spectroscopy might help to solve some of these issues. But the interpretation of liquid waters’ broadband spectrum is still discussed controversially.
We present dielectric data for pure bulk water in the frequency range between 500 MHz and 13 THz and temperatures between 275K an 350K to follow the evolution of its fast relaxations and IR resonances. Some experimental details will be given especially in the challenging THz and far infrared region.
By introducing some concepts of glass physics and comparing the obtained data of water with broadband spectra of canonical glass formers, monohydroxy alcohols and concentrated electrolyte solutions we come to a conclusive, consistent and partly new assignment of all observed spectral features, which should give new insights into the complex dynamics of water.