Freezing and Melting Temperature Hysteresis of Water in Porous Materials: Application to the Study of Pore Form

Homshaw, L. G.

doi:10.1111/j.1365-2389.1980.tb02090.x

Cited by 19 publications

(12 citation statements)

References 11 publications

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“…A reduction in freezing point was observed in pores having a diameter of 100 nm or less. The experimental values were comparable to predicted ones (5,9). Pores with diameters of less than 6 nm were not available for this study.…”

Section: Discussionsupporting

confidence: 72%

“…This principle has been applied to studying the freezing ofwater in soils and building materials. Both the freezing temperature and the spread of ice were influenced by the size and distribution of small diameter pores (2,(5)(6)(7). Calorimetry has been used to determine the melting point of water in porous materials so that the porosity and pore size distribution can be estimated (5-7).…”

Section: Introductionmentioning

confidence: 99%

“…

ABSTRACTTwo model systems were used to study the (2,5,9). This principle has been applied to studying the freezing ofwater in soils and building materials.

…”

mentioning

confidence: 99%

“…Both the freezing temperature and the spread of ice were influenced by the size and distribution of small diameter pores (2,(5)(6)(7). Calorimetry has been used to determine the melting point of water in porous materials so that the porosity and pore size distribution can be estimated (5)(6)(7). Possible effects of small diameter pores on the freezing of water in plant tissues have received little attention.…”

mentioning

confidence: 99%

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Freezing Behavior of Water in Small Pores and the Possible Role in the Freezing of Plant Tissues

Ashworth

Abeles²

1984

Plant Physiol.

120

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Two model systems were used to study the (2,5,9). This principle has been applied to studying the freezing ofwater in soils and building materials. Both the freezing temperature and the spread of ice were influenced by the size and distribution of small diameter pores (2,(5)(6)(7). Calorimetry has been used to determine the melting point of water in porous materials so that the porosity and pore size distribution can be estimated (5-7). Possible effects of small diameter pores on the freezing of water in plant tissues have received little attention. Mazur (9) discussed this principle and related it to the prevention of ice propagation through cell membrane pores and into the protoplasm. George (4) recently observed that melting began near -30C in water saturated sycamore heartwood. He speculated that this fraction of water may be located in cell wall microcapillaries and discussed the possible role of the microcapillaries in limiting the spread of ice in these tissues. In reduced to 16 mm to facilitate temperature equilibration between the chamber and cooling bath. The chamber was fitted with 13-mm diameter polycarbonate filters (Nuclepore Corporation, Pleasanton, CA 94566) or aluminum discs. The chamber was cooled in a 30% ethanol bath held at -12C. Chamber temperatures were monitored using copper-constantan thermocouples and a recording potentiometer. The experimental apparatus is illustrated in Figure 1. Chamber 1 was designated as the ice donor chamber and was filled with a suspension of an ice nucleating strain of Erwinia herbicola (Lohnis) Dye, isolate 26 (106 cells/ml). Nuclepore filters or aluminum discs separated the donor from the second chamber. Thermocouples were inserted into both sides of the modified Boyden chamber which was then lowered into the -12C bath. Freezing was initiated in the donor chamber between 0 and -1C. The temperature at which freezing was initiated in the second chamber was recorded. Individual experiments required 15 min and were repeated three times. Values reported are the mean plus or minus the standard deviation.Experiments with Controlled Pore Glass. Controlled pore glass particles (Sigma Chemical Co.) were obtained with a range of nanometer pore diameters (7.5 ± 6%, 16 ± 12%, 33 ± 8%, 73 ± 9%, 149 ± 6%, and 300 ± 9%). Glass particles were uniformly sized (80-120 mesh) by the manufacturer. Both the particles and the pores were irregularly shaped as observed using scanning electron microscopy (data not presented). Dry glass particles were placed into modified Beem capsules (Ladd Research Industries, Inc., Burlington, VT 05402) (100 psl) and saturated with either deionized water or dilute aqueous solutions.The freezing of water within saturated controlled pore glass particles was characterized using DTA.2 The technique was a modification of that described by Quamme et al. (11). The junction of a 40-gauge copper-constantan thermocouple was submerged into the slurry of glass particles. Excess solution was removed using a micropipette. Dry controlled pore glass was ...

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Section: Discussionsupporting

confidence: 72%

Section: Introductionmentioning

confidence: 99%

“…

ABSTRACTTwo model systems were used to study the (2,5,9). This principle has been applied to studying the freezing ofwater in soils and building materials.

…”

mentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Freezing Behavior of Water in Small Pores and the Possible Role in the Freezing of Plant Tissues

Ashworth

Abeles²

1984

Plant Physiol.

120

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“…The approach permits an element of the area underneath the exotherm to be compared to the appropriate equivalent portion of area underneath the endotherm. This is useful for investigation of freezing and melting temperature hysteresis in relation to pore form in water saturated porous materials [2,16].…”

Section: Container Design For the Study Of Phase Transitions In Poroumentioning

confidence: 99%

High resolution heat flow DSC: Application to study of phase transitions, and pore size distribution in saturated porous materials

Homshaw

1980

Journal of Thermal Analysis

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Suitable container design permits very high temperature and differential temperature resolution in DSC even when relatively large (_~ 0.14 cm 3) samples are used; and thus energy signals associated with phase change occurring over large temperature intervals may be analysed in differential elements.An original and powerful high resolution low temperature DSC technique (the authors plot") for studying and comparing pore size distributions (PSD) in water saturated samples (for pores having Kelvin radii between 1,2 and about 500 nm) is given, together with an application which shows that the PSD in a water saturated organic ion exchanger could be obtained from analysis of three Gaussian distributions which precisely generate a curve which is an excellent empirical fit to the recorded low temperature exotherm obtained by freezing pure water within the sample.The temperature at which liquids and solids change phase in porous materials depends upon pore size [1]. For water the lowering of freezing or melting temperatures is inversely proportional to the pore Kelvin radius [2]. For cylindrical pores the Kelvin radius is equivalent to the radius of the cylinder, whereas for parallel-sided fissures it corresponds to the wall to wall distance [3].Low temperature high resolution DSC is a powerful tool for investigating water and solution behaviour in porous materials [2] and knowledge of the relationship between phase transition temperature and pore size allows the distribution of pore sizes in wet porous materials to be determined. The shape of a pore determines the extent to which hysteresis occurs between the equilibrium freezing and melting temperatures of water (or salt eutectic) in the pore space [2]. For materials which swell in contact with water or for materials which contain "ink-bottle" shaped pores, monitoring of the freezing and melting behaviour of pure water in the substance gives quick and valuable information about the geometry of the pore spaces-these applications being suitable for studying pore sizes up to about 500 nm Kelvin radius, which size corresponds, for ice, to a lowering melting temperature of about 0.1 ~ [2]. In this report a description is given of how DSC investigations may be optimized for this type of study by appropriate choice of experimental conditions, some modifications to standard equipment and suitable sample container-design.Exotherms or endotherms corresponding to water changing phase (under equilibrium conditions) within porous materials, are curves which occur over a temper-

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Charakterisierung poröser Adsorberharze mit Hilfe der DSC

Arndt

Sandring

Häusler³

et al. 1990

Acta Polymerica

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Freezing and Melting Temperature Hysteresis of Water in Porous Materials: Application to the Study of Pore Form

Cited by 19 publications

References 11 publications

Freezing Behavior of Water in Small Pores and the Possible Role in the Freezing of Plant Tissues

Freezing Behavior of Water in Small Pores and the Possible Role in the Freezing of Plant Tissues

High resolution heat flow DSC: Application to study of phase transitions, and pore size distribution in saturated porous materials

Charakterisierung poröser Adsorberharze mit Hilfe der DSC

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