期刊
JOURNAL OF NEUTRON RESEARCH
卷 21, 期 3-4, 页码 155-166出版社
IOS PRESS
DOI: 10.3233/JNR-190114
关键词
Critical phenomena; gelation; kinetics; LCST; PMAA; SANS; low-field one-sided NMR
资金
- program Investissements d'Avenir LabEx PALM [ANR-.10-LABX-0039-PALM]
- Laboratoire Leon Brillouin (CEA-CNRS)
- Agence Nationale de la Recherche (ANR) under Grant NMR2GO [ANR-06-JCJC0061]
- European Research Council under the European Community's Seventh Framework Program (FP7/2007-2013), an ERC Grant [205119]
- Research Foundation Flanders (FWO) under Grant PorMedNMR [G0D5419N]
- LNCMI-CNRS, member of the European Magnetic Field Laboratory (EMFL)
In soft condensed matter, Small Angle Neutron Scattering (SANS) is a central tool to probe structures with characteristic sizes ranging from 1 to 100 nm. However, when used as a standalone technique, the dynamic properties of the sample are not accessible. Nuclear Magnetic Resonance (NMR) is a versatile technique which can easily probe dynamical information. Here, we report on the coupling of a low-field NMR system to a SANS instrument. We show that this original set-up makes it possible to obtain structural information and to simultaneously extract in situ on a same sample, long-range translational diffusion coefficient, T-1 and T-2 nuclear spin relaxation times. Such a feature is of major interest when a sample experiences a transient physical state or evolves rapidly. We illustrate the capabilities of alliancing these experimental methods by following the critical temperature-induced phase separation of a concentrated Poly(Methacrylic Acid) solution at its Lower Critical Solution Temperature. The characteristic size related to the domain growth of the polymer-rich phase of the gel is monitored by the evolution of the SANS spectra, while the dynamics of the sol phase (H2O and polymer) is simultaneously characterized by NMR by measuring T-1, T-2 and the diffusion coefficient. Great care has been taken to design a cell able to optimize the thermalization of the sample and in particular its equilibration time. Details are given on the sample cell specifically designed and manufactured for these experiments. The acquisition time needed to reach good signal-to-noise ratios, for both NMR and SANS, match: it is of the order of one hour. Altogether, we show that in situ low-field NMR/SANS coupling the NMR is meaningful and is a promising experimental approach.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据