Abstract

Although techniques such as AFM and optical/electron microscopy give exquisitely detailed information about the matrix microstructure of aqueous (bio-)polymer systems they fail to provide any significant quantitative information about the microscopic distribution of water throughout the various microphases and (bio-)polymer components comprising the polymer matrix. Yet knowledge of this microscopic distribution is essential if we are to develop a quantitative understanding of structure-function relationships in aqueous soft solid systems. Unfortunately there are very few experimental methods capable of probing this microscopic water distribution. The talk will therefore focus on the potential of novel multi-dimensional NMR relaxation and diffusion methods for monitoring the microscopic water and solute (re-)distribution in complex multicomponent, multiphase (bio-)polymer systems. Results will be presented for nano-porous synthetic hydrogels; microscopically heterogeneous mixed biopolymer systems and cellular tissue. Methods to be discussed include 2- and 3-dimensional cross correlation NMR methods, NMR field-cycling techniques as well as the possible advantages of cross-correlating different spectroscopic methods using novel Halbach open-access NMR . The importance of working over a wide range of frequencies is emphasised and the strengths and limitations of NMR microimaging will be discussed.