Applications of fast field cycling NMR relaxometry

Conte, Pellegrino

doi:10.1016/bs.arnmr.2021.05.001

Cited by 11 publications

(21 citation statements)

References 127 publications

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“…Conversely, an increase in water mobility (i.e., presence of large pores) weakens the dipolar interaction producing the shift in T 1 values towards longer values. According to this, longitudinal relaxation times (T 1 ) distributions at a fixed proton Larmor frequency (i.e., 10 kHz in our case) can be used to extrapolate the pore distribution of porous media [47]. Values of relaxation times are related to water mobility within the biochar's porous surface.…”

Section: Properties Of the Wc And CC Biocharsmentioning

confidence: 99%

Biochar from Wood Chips and Corn Cobs for Adsorption of Thioflavin T and Erythrosine B

et al. 2022

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Biochars from wood chips (WC) and corn cobs (CC) were prepared by slow pyrolysis and used for sorption separation of erythrosine B (EB) and thioflavin T (TT) in batch experiments. Biochar-based adsorbents were extensively characterized using FTIR, XRD, SEM-EDX, and XPS techniques. The kinetics studies revealed that adsorption on external surfaces was the rate-limiting step for the removal of TT on both WC and CC biochar, while intraparticle diffusion was the rate-limiting step for the adsorption of EB. Maximal experimental adsorption capacities Qmaxexp of TT reached 182 ± 5 (WC) and 45 ± 2 mg g−1 (CC), and EB 12.7 ± 0.9 (WC) and 1.5 ± 0.4 mg g−1 (CC), respectively, thereby indicating a higher affinity of biochars for TT. The adsorption mechanism was found to be associated with π-π interaction, hydrogen bonding, and pore filling. Application of the innovative dynamic approach based on fast-field-cycling NMR relaxometry indicates that variations in the retention of water-soluble dyes could be explained by distinct water dynamics in the porous structures of WC and CC. The obtained results suggest that studied biochars will be more effective in adsorbing of cationic than anionic dyes from contaminated effluents.

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Section: Properties Of the Wc And CC Biocharsmentioning

confidence: 99%

Biochar from Wood Chips and Corn Cobs for Adsorption of Thioflavin T and Erythrosine B

et al. 2022

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“…By means of the FFC NMR technique, valuable information can be achieved on the molecular dynamics of material systems in general, provided that suitable data analysis is performed [20]. In the particular case of porous systems, such as biochars, soils, nano sponges (NS), etc., which have been equilibrated with an aqueous medium, most of the 1 H magnetization (induced in the sample after its introduction into a magnetic field) is due to the water molecules.…”

Section: General Considerations On Ffc Nmr Experimentsmentioning

confidence: 99%

“…Conversely, as water moves in larger-sized pores, the T 1 lengthens and R 1 slows down. A complete description of the relationship between pore systems and parameters from FFC NMR relaxometry is given in references [20,28,29,35].…”

Section: General Considerations On Ffc Nmr Experimentsmentioning

confidence: 99%

“…Conversely, Gonzaga et al [19] reported proximate (ash content, volatile matter, and fixed carbon) and ultimate (elemental C, N, H, and S content) analyses, but no indication on biochar surface areas, porosity, etc. As indicated in a recent paper by Conte [20], in order to understand how biochar may affect nutrient dynamics in soils and, therefore, crop yield, ultimate and proximate investigations are not sufficient. Detailed information about biochar spatial conformation and surface physical-chemistry must be achieved [1,5,20,21].…”

Section: Introductionmentioning

confidence: 99%

“…As indicated in a recent paper by Conte [20], in order to understand how biochar may affect nutrient dynamics in soils and, therefore, crop yield, ultimate and proximate investigations are not sufficient. Detailed information about biochar spatial conformation and surface physical-chemistry must be achieved [1,5,20,21].…”

Section: Introductionmentioning

confidence: 99%

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Changes in Physicochemical Properties of Biochar after Addition to Soil

et al. 2022

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It is recognized that biochar undergoes changes when it is applied to soils. However, the mechanisms of biochar alterations are not fully understood yet. To this purpose, the present study is designed to investigate the transformations in the soil of two different biochars obtained from pyrolysis of fir-wood pellets. The production of the biochars differed for the dry and wet quenching procedures used to terminate the pyrolysis. Both biochars were applied to clay soil (26% sand, 6% silt, and 68% clay) placed into lysimeters. After water saturation and 15 days of equilibration, seeds of watercress (Lepidium sativum) were cultivated. After a further 7 weeks, the biochars were manually separated from the systems. A total of four samples were collected. They were analyzed for chemical–physical characteristics by using an innovative technique referred to as fast field cycling nuclear magnetic resonance relaxometry. The results showed that the dry−quenching produced a material that was mainly chemically altered after application to soil compared to the biochar obtained by the wet−quenching. Indeed, the latter was both chemically and physically modified. In particular, results showed that water was better retained in the soil treated with the dry−quenched material. Consequently, we may suggest that crop productivity and environmental remediation may be modulated by applying either the dry−quenched or the wet−quenched biochar.

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Broadband NMR Relaxometry as a Powerful Technique to Study Molecular Dynamics of Ionic Liquids

Fraenza

Greenbaum

2023

ChemPhysChem

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Fast field cycling nuclear magnetic resonance (FFC NMR) relaxometry technique has been demonstrated to be a useful analytical tool to investigate molecular dynamics in very diverse systems during the last decades. Of particular importance has been its application in studying ionic liquids, upon which this review article is based. Some of the research carried out on ionic liquids during the last ten years using this technique is highlighted in this article with the aim of promoting the favorable features of FFC NMR applied toward understanding dynamics of complex systems.

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Applications of fast field cycling NMR relaxometry

Cited by 11 publications

References 127 publications

Biochar from Wood Chips and Corn Cobs for Adsorption of Thioflavin T and Erythrosine B

Biochar from Wood Chips and Corn Cobs for Adsorption of Thioflavin T and Erythrosine B

Changes in Physicochemical Properties of Biochar after Addition to Soil

Broadband NMR Relaxometry as a Powerful Technique to Study Molecular Dynamics of Ionic Liquids

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