Related Experiment Video
Updated: Aug 19, 2026

In Situ Monitoring of Diffusion of Guest Molecules in Porous Media Using Electron Paramagnetic Resonance Imaging
Published on: September 2, 2016
The characterization of porous solids by NMR
S M Alnaimi1, J H Strange, E G Smith
1Physics Laboratory, University of Kent, Canterbury, UK.
Abstract:
We are using a novel NMR method, that has been developed in our laboratory and employs the depression of the freezing point (delta Tm) of confined liquid within porous media, to investigate the effect of pre-drying silica with average pore diameter ranging from 60 A to 1000 A. Cyclohexane was the confined liquid. Pre-drying was found to affect only the smallest pores. A study to compare partially filled and over-filled samples showed that the average delta Tm for partially filled samples is greater than for over-filled. We have also investigated the use of water as the absorbed liquid and compared results with those obtained from cyclohexane studies. Reasonable agreement was found but cyclohexane was more sensitive. The method is fast and is suitable for monitoring pore size distributions in the range of 50-1000 A.
Related Concept Videos
Nuclear Magnetic Resonance (NMR): Overview
NMR spectroscopy generates a spectrum where the characteristic absorption frequencies of the sample are...
NMR Spectrometers: Overview
Two-Dimensional (2D) NMR: Overview
The first step is the preparation period, during which nucleus A is excited with a radiofrequency pulse.
NMR Spectroscopy of Aromatic Compounds
NMR Spectrometers: Resolution and Error Correction
2D NMR: Overview of Homonuclear Correlation Techniques
COSY90 is the standard two-dimensional (2D) COSY experiment that...

