Hyphenated low-field NMR techniques: combining NMR with NIR, GPC/SEC and rheometry

Area of Science:

• Analytical Chemistry
• Materials Science
• Spectroscopy

Background:

• Low-field Nuclear Magnetic Resonance (NMR) is valuable for analyzing soft materials.
• Combining NMR with other techniques (hyphenation) can provide richer insights.
• Online process analytics and offline studies benefit from advanced characterization methods.

Purpose of the Study:

• To review hyphenated low-field NMR techniques for soft material characterization.
• To highlight the integration of NMR with spectroscopy, chromatography, and rheometry.
• To discuss the possibilities and challenges of these combined methods.

Main Methods:

• Near-infrared spectroscopy coupled with time-domain NMR (TD-NMR) relaxometry.
• Online proton NMR ((1)H-NMR) spectroscopy following size exclusion chromatography (SEC).
• Rheometry combined with TD-NMR relaxometry for viscous materials.

Main Results:

• Demonstrated correlation of chemical/physical properties with molecular dynamics.
• Showcased the utility of hyphenated techniques for comprehensive analysis.
• Presented case studies illustrating practical applications and limitations.

Conclusions:

• Hyphenated low-field NMR techniques are effective for detailed soft material analysis.
• These integrated methods offer complementary chemical and dynamic information.
• Further development can enhance online process monitoring and offline material studies.