Next Article in Journal / Special Issue
Irreversible Swelling Behavior and Reversible Hysteresis in Chemically Crosslinked Poly(vinyl alcohol) Gels
Previous Article in Journal
Advanced Recycled Polyethylene Terephthalate Aerogels from Plastic Waste for Acoustic and Thermal Insulation Applications
Previous Article in Special Issue
Emergence of Wrinkles during the Curing of Coatings
Article Menu
Issue 2 (June) cover image

Export Article

Open AccessArticle

Frozen State of Sephadex® Gels of Different Crosslink Density Analyzed by X-ray Computed Tomography and X-ray Diffraction

1
Division of Life Science and Engineering, School of Science and Engineering, Tokyo Denki University, Hatoyama, Hiki-gun, Saitama 350-0394, Japan
2
Nisshin Seifun Group Inc., Research Center for Basic Science, Research and Development, Quality Assurance Division, 5-3-1 Tsurugaoka, Fujimino-city, Saitama 356-8511, Japan
3
Graduate School of Science and Technology, Gunma University, 4-2 Aramaki, Maebashi, Gunma 371-8510, Japan
Present Affiliation: Professor Emeritus of Tokyo Denki University.
*
Author to whom correspondence should be addressed.
Received: 12 March 2018 / Revised: 22 April 2018 / Accepted: 6 May 2018 / Published: 18 May 2018
Full-Text   |   PDF [4515 KB, uploaded 18 May 2018]   |  

Abstract

Water in Sephadex® (crosslinked dextran) gels is known to indicate different freezing behavior which is dependent on the density of the crosslinks, and water in a Sephadex® G25 gel remains partially unfrozen during cooling and crystallizes during rewarming. The mechanism of anomalous ice crystallization during rewarming is still unclear. The objective of this study is to observe the ice grains that form in Sephadex® beads and to comprehend their frozen state with a focus on the ice crystallization during rewarming. Sephadex® beads containing 50 wt % water were prepared and used for the measurements. The observation of the ice grains was carried out by using synchrotron radiation-sourced X-ray CT (computed tomography). XRD (X-ray diffraction) analysis was also conducted to investigate the frozen state. As a result, ice grains that were larger than ~1 μm were hardly observed after the slow cooling of Sephadex® beads, except in the G25 beads. However, at the occurrence of ice crystallization during rewarming, ice grains that were larger than 10 μm appeared in the G25 beads. Using XRD, it was found that small incomplete ice crystals were formed in G25 beads and the presence of glassy water was indicated in the gel. In conclusion, the size and distribution of ice grains that formed in Sephadex® beads were different depending on the density of the crosslinks. View Full-Text
Keywords: Sephadex® (crosslinked dextran); crosslink density (density of crosslinks); ice grain; ice crystallization during rewarming; glassy water; X-ray CT; XRD Sephadex® (crosslinked dextran); crosslink density (density of crosslinks); ice grain; ice crystallization during rewarming; glassy water; X-ray CT; XRD
Figures

Graphical abstract

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).
SciFeed

Share & Cite This Article

MDPI and ACS Style

Murase, N.; Uetake, Y.; Sato, Y.; Irie, K.; Ueno, Y.; Hirauchi, T.; Kawahara, T.; Hirai, M. Frozen State of Sephadex® Gels of Different Crosslink Density Analyzed by X-ray Computed Tomography and X-ray Diffraction. Gels 2018, 4, 44.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Gels EISSN 2310-2861 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top