Microscale and macroscale diffusion of water in colloidal gels. A pulse field gradient and NMR imaging investigation
Article Abstract:
Water diffusion in Laponite gels was shown to occur with basically the same rate at short and long time and length scales, despite the complex hierarchical structure of the gel, using two nuclear magnetic resonance techniques, namely, pulsed-gradient spin-echo and magnetic resonance imaging. The water diffusion coefficient was also found to be only marginally smaller than that of bulk water, possibly due to the very open structure at all length scales of the gel made from small platelets. Results demonstrate the feasibility of measuring a macroscopic interdiffusion coefficient using an MRI-based technique.
Publication Name: Journal of Physical Chemistry B
Subject: Chemicals, plastics and rubber industries
ISSN: 1520-6106
Year: 1999
User Contributions:
Comment about this article or add new information about this topic:
Phase distribution during isothermal crystallization of polyethylene probed by solid-state proton NMR free induction decay
Article Abstract:
The use of the NMR free induction decay method to characterize the crystallization process of polyethylene is investigated. It is shown that the method allows the observation of the three different phases of crystallization. An extended Avrami model can be used to model the time development of different phases. Kinetic data on the crystallization process can also be determined via in situ NMR measurements.
Publication Name: Journal of Physical Chemistry B
Subject: Chemicals, plastics and rubber industries
ISSN: 1520-6106
Year: 1999
User Contributions:
Comment about this article or add new information about this topic:
- Abstracts: Structural and macroscopic characterization of a gel phase of densely packed monodisperse, unilamellar vesicles
- Abstracts: On measurement of molecular and thermal diffusion coefficients in multicomponent mixtures. A new strategy for evaluating the self-diffusion coefficient in restricted diffusion: case of polydisperse emulsions with small mean radii
- Abstracts: Self-guided molecular dynamics simulation for efficient conformational search
- Abstracts: Dynamics of nematic MBBA film induced by transient grating under a strong absorption condition. In situ infrared reflection absorption spectroscopic studies of coadsorption of CO with underpotential-deposited lead on Pt(111) in an aqueous acidic solution
- Abstracts: Structural and magnetic properties of [Gd.sub.3]N@[C.sub.80]. Line shape analysis of NMR powder spectra of 2H2O in lipid bilayer systems