Imaging droplet freezing using MRI

Hindmarsh, Jason P.; Buckley, Craig; Russell, Alison; Chen, Xiao; Gladden, Lynn F.; Wilson, D.I.; Johns, Michael L.

doi:10.1016/j.ces.2003.12.031

Cited by 37 publications

(18 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Visualization of the freezing process following the spatial distribution of non-frozen water Images of the freezing process and final microstructure after the solution becomes opaque due to ice formation 70,71 Indirect methods: freeze substitution, freeze fixation, and freeze drying…”

Section: Freeze Dryingmentioning

confidence: 99%

“…68,69 Nondestructive MRI techniques allow the visualization of the freezing process and generation of 3D images by following the spatial distribution of non-frozen water. 70,71 In MachZender optical interferometry, small relative changes in refractive index are accurately measured and subsequently related to changes in the solution concentration and in the morphology of the ice-solution interface. 72 This optical method has been employed to obtain the 3D morphology and the solute concentration field around the dendritic tip for various solutes at different concentration 73 as well as to study the ice crystal growth in supercooled pure water.…”

Section: Observing and Measuring Ice Morphologymentioning

confidence: 99%

See 1 more Smart Citation

Ice Morphology: Fundamentals and Technological Applications in Foods

2009

View full text Add to dashboard Cite

Freezing is the process of ice crystallization from supercooled water. Ice crystal morphology plays an important role in the textural and physical properties of frozen and frozen-thawed foods and in processes such as freeze drying, freeze concentration, and freeze texturization. Size and location of ice crystals are key in the quality of thawed tissue products. In ice cream, smaller ice crystals are preferred because large crystals results in an icy texture. In freeze drying, ice morphology influences the rate of sublimation and several morphological characteristics of the freeze-dried matrix as well as the biological activity of components (e.g., in pharmaceuticals). In freeze concentration, ice morphology influences the efficiency of separation of ice crystals from the concentrated solution. The cooling rate has been the most common variable controlling ice morphology in frozen and partly frozen systems. However, several new approaches show promise in controlling nucleation (consequently, ice morphology), among them are the use of ice nucleation agents, antifreeze proteins, ultrasound, and high pressure. This paper summarizes the fundamentals of freezing, methods of observation and measurement of ice morphology, and the role of ice morphology in technological applications.

show abstract

Section: Freeze Dryingmentioning

confidence: 99%

Section: Observing and Measuring Ice Morphologymentioning

confidence: 99%

Ice Morphology: Fundamentals and Technological Applications in Foods

2009

View full text Add to dashboard Cite

show abstract

“…Smaller pixel matrix sizes and larger slice thicknesses as well as suitable imaging techniques can reduce the acquisition time of MRI considerably. Hindmarsh et al 13 imaged sucrose solution droplets during nucleation and recalescence in still air at )25°C. The 32 Â 32 pixel images were sampled every 0.5 s. The in-plane pixel size was 125 Â 125 lm 2 at a slice thickness of 4 mm, i.e.…”

Section: Introductionmentioning

confidence: 99%

Use of X-ray Tomography to Map Crystalline and Amorphous Phases in Frozen Biomaterials

et al. 2006

View full text Add to dashboard Cite

The outcome of both cryopreservation and cryosurgical freezing applications is influenced by the concentration and type of the cryoprotective agent (CPA) or the cryodestructive agent (i.e., the chemical adjuvants referred to here as CDA) added prior to freezing. It also depends on the amount and type of crystalline, amorphous and/or eutectic phases formed during freezing which can differentially affect viability. This work describes the use of X-ray computer tomography (CT) for non-invasive, indirect determination of the phase, solute concentration and temperature within biomaterials (CPA, CDA loaded solutions and tissues) by X-ray attenuation before and after freezing. Specifically, this work focuses on establishing the feasibility of CT (100-420 kV acceleration voltage) to accurately measure the concentration of glycerol or salt as model CPA and CDAs in unfrozen solutions and tissues at 20 degrees C, or the phase in frozen solutions and tissue systems at -78.5 and -196 degrees C. The solutions are composed of water with physiological concentrations of NaCl (0.88% wt/wt) and DMEM (Dulbecco's Modified Eagle's Medium) with added glycerol (0-8 M). The tissue system is chosen as 3 mm thick porcine liver slices as well as 2 cm diameter cores which were either imaged fresh (3-4 h cold ischemia) or after loading with DMEM based glycerol solutions (0-8 M) for times ranging from hours to 7 days at 4 degrees C. The X-ray attenuation is reported in Hounsfield units (HU), a clinical measurement which normalizes X-ray attenuation values by the difference between those of water and air. NaCl solutions from 0 to 23.3% wt/wt (i.e. water to eutectic concentration) were found to linearly correspond to HU in a range from 0 to 155. At -196 degrees C the variation was from -80 to 95 HU while at -78.5 degrees C all readings were roughly 10 HU lower. At 20 degrees C NaCl and DMEM solutions with 0-8 M glycerol loading show a linear variation from 0 to 145 HU. After freezing to -78.5 degrees C the variation of the NaCl and DMEM solutions is more than twice as large between -90 and +190 HU and was distinctly non-linear above 6 M. After freezing to -196 degrees C the variation of the NaCl and DMEM solutions increased even further to -80 to +225 HU and was distinctly non-linear above 4 M, which after modeling the phase change and crystallization process is shown to correlate with an amorphous phase. In all tissue systems the HU readings were similar to solutions but higher by roughly 30 HU, as well as showing some deviations at 0 M after storage, probably due to tissue swelling. The standard deviations in all measurements were roughly 5 HU or below in all samples. In addition, two practical examples for CT use were demonstrated including: (1) glycerol loading and freezing of tissue cores and, (2) a mock cryosurgical procedure. In the loading experiment CT was able to measure the permeation of the glycerol into the sample at 20 degrees C, as well as the evolution of distinct amorphous vs. crystalline phases after freezing to -196 degrees C....

show abstract

“…Tabakova and Feuillebois [6] modeled the solidification and subsequent cooling of a supercooled liquid droplet that was lying on a cold solid test plate after impact, with the assumption that solidification occurred for a given fixed droplet shape. Hindmarsh et al [7] used magnetic resonance imaging (MRI) to provide spatially resolved structural and chemical composition characterization of freezing droplets.…”

Section: Introductionmentioning

confidence: 99%

An experimental investigation into the icing and melting process of a water droplet impinging onto a superhydrophobic surface

Jin

Yang

2013

Sci. China Phys. Mech. Astron.

View full text Add to dashboard Cite

The freezing and melting process of a small water droplet on a superhydrophobic cold surface was investigated using the Laser Induced Fluorescence (LIF) technique. The superhydrophobic surface was prepared using a sol-gel method on a red copper test plate. From the obtained fluorescence images, the phase transition characteristics during the freezing and melting process of a water droplet were clearly observed. It was found that, at the beginning of the droplet freezing process, liquid water turned into ice at a very fast rate. Such phase transition process decreased gradually with time and the volume of frozen ice approached a constant value at the end of the icing process. In addition, the freezing time was found to reduce with the decrease of the test plate temperature. Besides, when the test plate temperature is relatively high, the effect of droplet volume on the freezing time is very significant. Over all, we provide some tentative insights into the microphysical process related to the icing and melting process of water droplets. sol-gel, icing, melting, superhydrophobic surface, water droplet PACS number(s): 44.10.+i, 68.08.-p, 68.18.Jk Citation: experimental investigation into the icing and melting process of a water droplet impinging onto a superhydrophobic surface.

show abstract

Imaging droplet freezing using MRI

Cited by 37 publications

References 27 publications

Ice Morphology: Fundamentals and Technological Applications in Foods

Ice Morphology: Fundamentals and Technological Applications in Foods

Use of X-ray Tomography to Map Crystalline and Amorphous Phases in Frozen Biomaterials

An experimental investigation into the icing and melting process of a water droplet impinging onto a superhydrophobic surface

Contact Info

Product

Resources

About