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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Agriculture, Food & Beverage NMR Analysis

Quality control for consistency of food products from field to fork is of prime concern to manufacturers and consumers alike. Making products that look, smell and taste good ensures consumers come back for more. So, with an ever-growing population demanding more food products than ever before, simple instrumental test methods are required to provide quick and reproducible data from the field to the factory via the shopping cart to the consumer. For example, the measurement of oil and fats are invaluable in the control of many foods, particularly in snack food products such as potato chips. In a similar way, the quality of the simple bar of chocolate may be judged its solid fat content using a rapid measurement which will determine a perfect product while on the farm, oil in seeds is vital to productivity and yield, ultimately dictating the price the farmer is paid for his products.

Quality control for consistency of products at maximum yield produced in the most environmentally friendly yet cost-effective manner is a major driver in today’s agriculture markets.

With an ever-growing population demanding more food products than ever before, simple instrumental test methods are required to provide quick and reproducible data from the farm to the table of the consumer.

Parameters such as the measurement of oil and moisture are invaluable in the control of animal and fish feeds. Similarly, seed quality may also be judged on oil and moisture content with a rapid measurement determining acceptance or rejection and ultimately the price paid by the factory.

Using Benchtop NMR Analyzer  for Food Authenticity Screening

Recent advances in benchtop NMR (Nuclear Magnetic Resonance) mean that it is suitable as a fast and easy technique for assessing suspected edible oil contamination/adulteration and meat speciation. The system can be used to discriminate between different oil types and provide quantitative information for mixtures. The NMR spectra of triglycerides contain valuable information indicating what the meat species is.

Spin Finish NMR Analyzer

Nuclear magnetic resonance (NMR), as an effective non-destructive inspection analysis technology, has been widely used in many fields, such as biomedical, chemical industry, petroleum energy and materials science.

Since the first time the NMR signal was discovered in 1945, more than ten scientists have won the Nobel Prize because of their great contributions to NMR development. NMR is now one of the most advanced technologies in the world which have extensive development prospects.

About 25 years ago, NMR was first used to study molecular structure and dynamics of cross-linked polymers. Based on De Genne and Kimmich’s fundamental theoretical and experimental research, Gronski and others did further research on crosslink density and the network structure of rubber. All of their research proved the consistency of the results given by the NMR method and the traditional methods such as swelling and mechanical test method.

With the addition of commercial applications with NMR microscopy and the development of parameter-selection imaging and image analytical technique, both detailed spatial information of morphological structures and image analysis reflecting material properties as molecular dynamics, crosslink density, aging, swelling, etc., all these can be given by NMR. MicroMR-CL was developed for polymer studies. It has been widely used in a local domestic research institutes, and it has made excellent contributions to the polymer industry.

PQ001 Spin Finish NMR Analyzer for Oil Content Examination of Textile Fiber

Product Description
PQ001 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 characteristics. Based on these advantages, PQ001 has been widely used in the determination of oil content of textile fiber.

Basic Parameters:
  • Magnet type: permanent magnet
  • Magnetic field intensity: 0.5±0.08T
  • Probe: Ø25mm
  • Size (LxWxH): 1685mm×520mm×386mm
  • Weight: 134Kg

Functions:
  • Rapid determination of Spin Finish content of textile fiber

pq001-ca

 

VTMR TD-NMR Cross-linking Density MRI System Analyzer for Polymer

Nuclear magnetic resonance (NMR) is widely used as a non-invasive means of obtaining clinical images and studying tissue metabolism in vivo. In this revised and updated edition, the principles of NMR are introduced, with descriptions of the ways in which NMR can be used to study living systems, and the scope and limitations of each technique. Chapters in the book illustrate applications of magnetic resonance spectroscopy (MRS) and imaging (MRI), and provide more theoretical and technical descriptions of benchtop NMR. While the focus is on applications in human physiological and biochemical studies, the book also discusses the ways in which basic NMR analyzer research studies can complement and aid interpretation of clinical findings. Written at an accessible level for newcomers to NMR, this book is a good introduction for students, biomedical researchers, and radiologists.

A useful introduction for biological and biomedical researchers, many of whom have reported finding the first edition both informative and stimulating. The presentation is helped by many colorful illustrations and diagrams.”–Journal of the American Chemical Society
This would make a good introductory text for medical and biochemically related professions. — NMR Newsletter

A tremendous amount of material has been included in this volume by careful organization. . .The author definitely has a knack for clear and simple, but rigorous, explanations, and he has paid great attention to detail. The volume is to be highly recommended.–Journal of Magnetic Resonance

VTMR TD-NMR Cross-linking Density MRI System Analyzer for Polymer

Product Description
Combined with the sample temperature control system, VTMR20-010V-T can control the environmental temperature to research change in physical properties of samples over a wide range of temperatures and rates of change. It can be used for food, energy, organic materials and other areas of research.


Basic Parameters:
  • Magnet type: permanent magnet
  • Magnetic field intensity: 0.5±0.08T
  • Probe coil: Ø10mm
  • Sample temperature range: 35-150℃
  • .Size (L x W x H): 1400mm×670mm×1070mm
  • Weight: 330Kg

Applications:
 Polymers
-Determination of crosslink density of rubber and other polymers (Physical crosslinking , chemical crosslinking)
-Quality control of Polymer products
-Quality inspection of Polymer aging process
-Rubber vulcanization process and
Formulation research
-Determination of moisture content and moisture distribution in the solid matrix
-Curing and aging process characterization for Thermosetting resin
-Determination of the activation energy for Thermosetting resin
-Environmental response material transformation process of hydrophilic and hydrophobic
-Composites multiphase system compatibility
-Crystallization kinetics -Block copolymer hard / soft segment Content molecular motion study
-Determination for fluorine content
-Determination for rubber content and plasticizer in the polymer
-Rubber micro fractures, 2D crosslinking density uniformity
vtmr-366x3661

Flow and Diffusion Measurement with MR

Nuclear magnetic resonance (NMR) non-invasively accesses many parameters in contrast with other commonly used measurement methods, whether they are non-invasive or not.
These parameters can be divided roughly into three classes of information: chemical, physical, and spatial.Chemical includes benchtop NMR spectroscopy, the workhorse in analytical chemistry and in structural biochemistry but, to date, there has been relatively little overlap between this class and this conference.
Physical information accessible with NMR analyzer includes molecular structure, phase transition, diffusion, and flow.Both chemical and physical information can be combined with spatial information to produce maps of such information.In addition, flow and diffusion, by their nature, involve spatial information.
Such spatially resolved information is the main emphasis of this meeting.In this lecture, I shall review NMR flow and diffusion measurements.What is needed for such measurements is the presence of a known gradient of the static magnetic field strength in which the experiments are conducted.
When a nuclear spin moves in the field gradient, its precession rate changes and this can be detected to yield the displacement of the spin in the time required to do the experiment–times measured in milliseconds.The dependence of such displacements as a function of measurement time results in identification of the nature of sample motion, i. e., whether it is flow or diffusion.
We will start with basic principles and go on to examples with emphasis on gaining physical background knowledge that may aid in understanding flow and diffusion presentations during this meeting.Some references to this subject are listed below.The last three are based on previous ICMRM conferences, specifically in 1991, 1997, and 2009.

Excellent introduction to nmr theory

Used in concert with complementary analytical techniques such as light spectroscopy and mass spectrometry, Nuclear Magnetic Resonance (NMR) spectroscopy is the most powerful tool for the determination of organic structure. This book fosters a real-world understanding of NMR spectroscopy and how it works without burying the reader in technical details and physical and mathematical formalism. With an accessible, clear style and approach, benchtop NMR Spectroscopy Explained:

Introduces readers to modern NMR spectroscopy as it is applied to the analysis of organic compounds and biomolecules

Minimizes complicated theory and focuses on the practical aspects of NMR spectroscopy

Provides comprehensive coverage of how NMR spectroscopy experiments actually work and how to optimize them on the spectrometer

Provides examples of every experiment, with detailed interpretation of data

Presents essential descriptive theory in mainly nonmathematical terms

The guide starts with a basic model and expands it one step at a time, complete with experiments and examples, helping readers who are not experts in physics or physical chemistry to develop an empowering understanding of even the most complex biological NMR spectroscopy techniques. It is an ideal reference for professionals in industry and academia who use NMR analyzer technology, NMR facility managers, and upper-level undergraduates and graduate students in organic chemistry, biochemistry, pharmacology, biophysics, and engineering.

Moreover, cutting-edge examples and applications throughout the texts show the relevance of the chemistry being described to current research and industry. The learning features provided, including questions at the end of every chapter and online multiple-choice questions, encourage active learning and promote understanding. Furthermore, frequent diagrams, margin notes, and glossary definitions all help to enhance a student’s understanding of these essential areas of chemistry. Nuclear Magnetic Resonance offers a concise and accessible introduction to the physical principles of liquid-state NMR, a powerful technique for probing molecular structures. Examples, applications, and exercises are provided throughout to enable beginning undergraduates to get to grips with this important analytical technique. Online Resource Centre The Online Resource Centre to accompany Nuclear Magnetic Resonance features: For registered adopters of the text: * Figures from the book available to download For students: * Multiple-choice questions for self-directed learning * Full worked solutions to the end-of-chapter exercises