Porous Media NMR Analysis

Recent years have seen a significant progress in the study of porous media of natural and industrial sources. This paper provides a brief outline of the recent technical development of NMR in this area. These progresses are relevant for NMR application in material characterization.

The wettability conditions in a porous media containing two or more immiscible fluid phases determine the microscopic fluid distribution in the pore network. Nuclear magnetic resonance measurements are sensitive to wettability because of the strong effect that the solid surface has on promoting magnetic relaxation of the saturating fluid. The idea of using NMR as a tool to measure wettability was presented by Brown and Fatt in 1956. The magnitude of this effect depends upon the wettability characteristics of the solid with respect to the liquid in contact with the surface.Their theory is based on the hypothesis that molecular movements are slower in the bulk liquid than at the solid-liquid interface. In this solid-liquid interface the diffusion coefficient is reduced, which correspond to a zone of higher viscosity. In this higher viscosity zone, the magnetically aligned protons can more easily transfer their energy to their surroundings. The magnitude of this effect depends upon the wettability characteristics of the solid with respect to the liquid in contact with the surface.

NMR Cryoporometry (NMRC) is a recent technique for measuring total porosity and pore size distributions. It makes use of the Gibbs-Thomson effect : small crystals of a liquid in the pores melt at a lower temperature than the bulk liquid : The melting point depression is inversely proportional to the pore size. The technique is closely related to that of the use of gas adsorption to measure pore sizes (Kelvin equation). Both techniques are particular cases of the Gibbs Equations (Josiah Willard Gibbs): the Kelvin Equation is the constant temperature case, and the Gibbs-Thomson Equation is the constant pressure case.

To make a Cryoporometry measurement, a liquid is imbibed into the porous sample, the sample cooled until all the liquid is frozen, and then warmed slowly while measuring the quantity of the liquid that has melted. Thus it is similar to DSC thermoporosimetry, but has higher resolution, as the signal detection does not rely on transient heat flows, and the measurement can be made arbitrarily slowly. It is suitable for measuring pore diameters in the range 2 nm–2 μm.

Nuclear Magnetic Resonance (NMR) may be used as a convenient method of measuring the quantity of liquid that has melted, as a function of temperature, making use of the fact that the {\displaystyle T_{2}} T_{2} relaxation time in a frozen material is usually much shorter than that in a mobile liquid. The technique was developed at the University of Kent in the UK.It is also possible to adapt the basic NMRC experiment to provide structural resolution in spatially dependent pore size distributions, or to provide behavioural information about the confined liquid.porous media NMR

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NMR Solid Fat Content Analyzer

The determination of solid fat content (SFC) by NMR analysis is recognized by the international standards. Niumag has been dedicated to research and develop NMR PQ001 SFC Analyzer which offers the determination of SFC values and presentation of the melting curve with non-destructive, fast and accurate measurements.

Solid Fat Content (SFC) is generally accepted analysis of fats and oils in the food industry. The traditional extraction methods for SFC determination are slow, irreproducible and require additional chemicals. Direct measurements of SFC by NMR (nuclear magnetic resonance) provides quick and accurate determination of SFC value. NMR as method of fats and oils analysis is included in the following international standards:

  • AOCS Cd 16b-93 revised in 2000 (in USA)
  • ISO 8292 (in Europe)

Solid Fat Content determination by benchtop NMR is based on direct ratio measuring between the solid and liquid parts of the sample.

 

The PQ001 SFC NMR Analyzer was launched in 2008. After years of upgrading, PQ001 has many advantages such as small size, high precision, good repeatability, good stability and excellent cost/benefit performance. Based on these advantages, PQ001 has been widely used in the determination of Solid Fat Content.

Basic Parameters:
  • Magnet: permanent magnet
  • Magnetic field intensity: 0.5±0.08T
  • Probe: Ø10mm
  • Size (L x W x H): 1685mm×520mm×386mm;
  • Weight: 134Kg;

Functions:
  • Determination of solid fat content(Cocoa butter, Margarine and butter etc.)

nmr-solid-fat-content-analyzer

 

NMR Spectroscopy Explained

This is the best all around benchtop NMR text I have come across. Jacobsen does a great job of explaining the vast array of topics in NMR ranging from the nuclear magnetism and pulse sequences to biological NMR. It is very well written, easy to read and follow, while still going into great amounts of detail.

For those who do not enjoy heavy amounts of differential equations and linear algebra, then you will appreciate this book as there is just enough math to aid the written explanations, but not so much as to make your head spin. This book also has one of the best explanations/discussions on multi-dimensional techniques commonly used in organic and biological chemistry.

There is one specific area where I find this book is somewhat lacking, the discussion on T1, T2 and NOE which is fairly rudimentary. It is more than sufficient for those new to the topic or working on small molecules, but does not offer much past that in my opinion. Also, if you are looking for a better understanding in solid state NMR, this is not the book for you. I would highly recommend this book for anyone wanting to learn more about NMR analyzer.

NMR Spectroscopy Explained : Simplified Theory, Applications and Examples for Organic Chemistry and Structural Biology provides a fresh, practical guide to NMR for both students and practitioners, in a clearly written and non-mathematical format. It gives the reader an intermediate level theoretical basis for understanding laboratory applications, developing concepts gradually within the context of examples and useful experiments.
Introduces students to modern NMR as applied to analysis of organic compounds.
Presents material in a clear, conversational style that is appealing to students.
Contains comprehensive coverage of how NMR experiments actually work.
Combines basic ideas with practical implementation of the spectrometer.
Provides an intermediate level theoretical basis for understanding laboratory experiments.
Develops concepts gradually within the context of examples and useful experiments.
Introduces the product operator formalism after introducing the simpler (but limited) vector model.

Initially I wanted to write a review for this book after I finish the whole book. However, since the publication of this book, I have noticed that nobody has ever written a review. I have only finished approximately 400 pages but I want to let people to know that this is clearest exposition on modern nmr spectroscopy I have ever come across. I have read a number of nmr books. These include the following

J.D. Roberts “ABC of FT NMR”
T. Claridge “High Resolution NMR spectroscopy in organic chemistry”
J. Sanders ” Modern NMR spectroscopy”
H. Friebolin “Basic One- and Two-Dimenionsal NMR”

None of the above is as good as this book. The one that comes close to this is Friebolin’s book. However, it is not as detail and does not cover topics such as operator formalism and density matrix. This book also covers the basic theoretical principles and presented in a very lucid way. I enjoy reading this book tremendously.

Dec 14, 2009. It has been almost 2 years since I wrote the initial review. Since then, I have the opportunity to read the whole book a second time. My opinion of this book remains the same. If you really want to understand NMR, you cannot go wrong with this book.

NMR Spectroscopy Explained: Simplified Theory, Applications and Examples for Organic Chemistry and Structural Biology

This book along with “Structure Determination of Organic Compounds” by Pretsch, Buhlmann, and Affolter and maybe “200 and More NMR experiments” by Berger and Braun are currently the only NMR books worth owning. Skip the rest.

I’ve been working with NMR analyzer for over 11 years and over the years have acquired numerous books on the subject. This book is hands down the best on the subject. The author clearly explains everything, where other books throw up a graph/spectrum/equation and expect you to figure it out magically at times. Areas I’ve been confused on for years suddenly all make sense.

Initially I wanted to write a review for this book after I finish the whole book. However, since the publication of this book, I have noticed that nobody has ever written a review. I have only finished approximately 400 pages but I want to let people to know that this is clearest exposition on modern nmr spectroscopy I have ever come across. I have read a number of nmr books. These include the following

J.D. Roberts “ABC of FT NMR”
T. Claridge “High Resolution NMR spectroscopy in organic chemistry”
J. Sanders ” Modern NMR spectroscopy”
H. Friebolin “Basic One- and Two-Dimenionsal NMR”

None of the above is as good as this book. The one that comes close to this is Friebolin’s book. However, it is not as detail and does not cover topics such as operator formalism and density matrix. This book also covers the basic theoretical principles and presented in a very lucid way. I enjoy reading this book tremendously.

Dec 14, 2009. It has been almost 2 years since I wrote the initial review. Since then, I have the opportunity to read the whole book a second ti

I’ve been working with NMR for over 11 years and over the years have acquired numerous books on the subject. This book is hands down the best on the subject. The author clearly explains everything, where other books throw up a graph/spectrum/equation and expect you to figure it out magically at times. Areas I’ve been confused on for years suddenly all make sense.

This book along with “Structure Determination of Organic Compounds” by Pretsch, Buhlmann, and Affolter and maybe “200 and More NMR experiments” by Berger and Braun are currently the only NMR books worth owning. Skip the rest.

Initially I wanted to write a review for this book after I finish the whole book. However, since the publication of this book, I have noticed that nobody has ever written a review. I have only finished approximately 400 pages but I want to let people to know that this is clearest exposition on modern nmr spectroscopy I have ever come across. I have read a number of nmr books. These include the following

J.D. Roberts “ABC of FT NMR”
T. Claridge “High Resolution NMR spectroscopy in organic chemistry”
J. Sanders ” Modern NMR spectroscopy”
H. Friebolin “Basic One- and Two-Dimenionsal NMR”

None of the above is as good as this book. The one that comes close to this is Friebolin’s book. However, it is not as detail and does not cover topics such as operator formalism and density matrix. This book also covers the basic theoretical principles and presented in a very lucid way. I enjoy reading this book tremendously.

Dec 14, 2009. It has been almost 2 years since I wrote the initial review. Since then, I have the opportunity to read the whole book a second time. My opinion of this book remains the same. If you really want to understand NMR, you cannot go wrong with this book.

I’ve always found NMR to be extremely difficult but when I got this book, it really helped me to understand how to read and analyze NMR spectra. I also had the great honor of having the author of this book as my professor recently and the guy really knows his stuff and is great at conveying his knowledge. So if you never understood NMR or don’t really understand it that much, or just want a great book about NMR, this is the book for you and you can trust in the fact that the author knows his stuff. I know this book is costly, but trust me you won’t regret it at all!

me. My opinion of this book remains the same. If you really want to understand NMR, you cannot go wrong with this book.

I’ve always found NMR to be extremely difficult but when I got this book, it really helped me to understand how to read and analyze NMR spectra. I also had the great honor of having the author of this book as my professor recently and the guy really knows his stuff and is great at conveying his knowledge. So if you never understood NMR or don’t really understand it that much, or just want a great book about spin finish NMR analyzer, this is the book for you and you can trust in the fact that the author knows his stuff. I know this book is costly, but trust me you won’t regret it at all!