Freeze-fracture

Freeze-fracture is a natural occurrence leading to processes like erosion of the earths crust or simply deterioration of food via freeze-thaw cycles.[1][2] To investigate the process further freeze-fracture is artificially induced to view in detail the properties of materials. Fracture during freezing is often the result of crystallizing water which results in expansion. Crystallization is also a factor leading to chemical changes of a substance due to changes in the crystal surroundings called eutectic formation.[3]

Natural freeze-fracture. An iceberg fractured off a glacier. Erosion reveals the layering hidden within the original glacier

Imaging the fractured surface of a frozen substance allows the interior of the structure to be investigated as illustrated by the picture of a fractured piece of glacier called an iceberg. By photographing at high magnifications more can be learnt about the fractured object's substructure and the changes in the object that occur during freezing. When imaging fractured surfaces in detail, changes occurring during and immediately after fracture as well as sample preparation, must be taken into account if trying to infer the unbroken material's structure.[4][5] The often relatively cold temperatures needed to make an object solid enough to fracture, and the fracture process itself, stress and deform the material. Imaging of fine detail under sub-zero conditions is difficult. The material will start to warm again when removed to a position for photography. Ambient gases, often water vapor, will condense on the cold surfaces, reacting with them, obscuring detail and further warming the object allowing it to reshape.[6][7]

  1. ^ 孙, 宝洋; 李, 占斌; 肖, 俊波; 张, 乐涛; 马, 波; 李, 建明; 程, 冬兵 (2019). "Research progress on the effects of freeze-thaw on soil physical and chemical properties and wind and water erosion". 应用生态学报. 30 (1): 337–347. doi:10.13287/j.1001-9332.201901.019. PMID 30907557.
  2. ^ Liu, Hui; Guo, Xiao-Na; Zhu, Ke-Xue (September 2022). "Effects of freeze-thaw cycles on the quality of frozen raw noodles". Food Chemistry. 387: 132940. doi:10.1016/j.foodchem.2022.132940. PMID 35429938. S2CID 248072871.
  3. ^ Chang, Fu-Ling; Lin, Yu-Hsin; Hung, Han-Tang; Kao, Chen-Wei; Kao, C. R. (22 April 2023). "Artifact-Free Microstructures in the Interfacial Reaction between Eutectic In-48Sn and Cu Using Ion Milling". Materials. 16 (9): 3290. Bibcode:2023Mate...16.3290C. doi:10.3390/ma16093290. PMC 10179094. PMID 37176172.
  4. ^ Bullivant, S. (September 1977). "Evaluation of membrane structure facts and artefacts produced during freeze‐fracturing". Journal of Microscopy. 111 (1): 101–116. doi:10.1111/j.1365-2818.1977.tb00050.x. PMID 606830. S2CID 21981596.
  5. ^ Steere, R L; Erbe, E F; Moseley, J M (1 July 1980). "Prefracture and cold-fracture images of yeast plasma membranes". The Journal of Cell Biology. 86 (1): 113–122. doi:10.1083/jcb.86.1.113. PMC 2110657. PMID 6998983.
  6. ^ Lepault, J.; Dubochet, J. (1 August 1980). "Freezing, fracturing, and etching artifacts in particulate suspensions". Journal of Ultrastructure Research. 72 (2): 223–233. doi:10.1016/S0022-5320(80)90060-X. PMID 7420536.
  7. ^ Sleytr, U. B.; Robards, A. W. (April 1982). "Understanding the artefact problem in freeze-fracture replication: a review". Journal of Microscopy. 126 (1): 101–122. doi:10.1111/j.1365-2818.1982.tb00361.x. PMID 7040668. S2CID 22196963.