地質聚合物

地質聚合物（Geopolymer）屬於高分子科學、化學、地質學和工程技術領域。一般來說，聚合物可以指有機材料，即碳基聚合物，也可以指無機聚合物，例如硅基聚合物。有機聚合物包括天然聚合物（橡膠、纖維素）、合成有機聚合物（紡織纖維、塑料、薄膜、彈性體等）和天然生物聚合物（生物、醫藥、製藥）。合成硅基聚合物所用的原料主要是造岩礦物，因此得名地質聚合物。20世紀50年代，蘇聯基輔的Viktor Glukovsky最先開發了以「土硅酸鹽混凝土（soil silicate concretes）」和「土水泥（soil cements）」命名的混凝土材料^[1]。但是，自從Joseph Davidovits在1978年創造了Geopolymer^[2]，這個概念以來，「地質聚合物」的術語和定義變得更加多樣化，並且常常相互衝突。

地質聚合物可以被定義為兩大類^[3] :

純無機及含有機物的地質聚合物；
天然存在的大分子合成地質聚合物的類似物。

地質聚合物本質上是由礦物化合物或由重複單元組成的化合物的混合物，例如氧化硅（-Si-O-Si-O-）、鋁硅酸鹽（-Si-O-Al-O-）、鋁鐵硅酸鹽（-Fe-O-Si-O-Al-O-）或鋁磷酸鹽（-Al-O-P-O-）等^[4] 。

兩種主要的地質聚合物合成路線:

鹼性合成路線: Na⁺, K⁺, Li⁺, Ca²⁺, Cs⁺ 等；
酸性合成路線: 磷酸以及來源於植物抽提物的有機羧酸（乙酸、檸檬酸、草酸和腐殖質酸）。

其中，鹼性合成路線在研發和商業應用方面最為重要^[5]^[6]。

地質聚合物的機理

最為廣泛接受的的是法國J.Davidovits提出的解聚和縮聚的理論。他認為地聚物材料的凝結硬化過程就是原材料中硅氧鍵和鋁氧鍵在鹼性催化劑作用下斷裂後再重組的反應過程。 J.Davidovits在研究中假設鋁硅酸鹽地聚合過程是通過一些假設基團逐步發生縮聚過程，這些假設的組成單元進一步縮聚形成三維大分子結構。他將這些低相對分子質量單元（單體、二聚體、三聚體等）稱為低聚物。低聚硅鋁酸鹽指的是單體正硅鋁酸鹽、二聚體二硅鋁酸鹽等；類似的，也有低聚硅鋁酸鹽—硅氧體和低聚硅鋁酸鹽—二硅氧體。

地質聚合物的微觀結構基本上取決於溫度：地質聚合物在室溫下為無定形物質，但在高於500°C的溫度下，地質聚合物演變成晶體基質^[7]。

J.Davidovits提出地聚合物的反應可以如下表述：

（1）鋁硅酸鹽原料在鹼性溶液( NaOH, KOH) 中的溶解；（2）溶解的鋁硅配合物由固體顆粒表面向顆粒間隙的擴散；（3）凝膠相M {一(SiO₂)z—AlO₂}n·wH₂O的形成, 導致在鹼硅酸鹽溶液和鋁硅配合物之間發生聚合作用；（4）凝膠相逐漸排除剩餘的水分, 固結硬化成礦物聚合材料塊體。對於不同原料成分、不同用途的地聚合物材料，其具體反應機理不完全相同，但骨幹反應為上述過程。

地質聚合物的應用

地質聚合物存在着多種潛在和現有的應用，其中一部分應用已經實現工業化和商業化。其應用主要可以分為3大類，詳細內容請參閱地質聚合物研究所（Geopolymer Institute）提供的不完整列表^[8] :

地質聚合物基膠黏劑

環保型耐火材料、保溫材料（無機泡沫）；
塗料、粘合劑和灌漿。

地質聚合物基水泥和混凝土

低成本建築材料（磚頭）
環保低能耗[瓷磚]]，[耐火材料]]等。
低CO₂ 排放的環保水泥和混凝土；
放射性和有毒有害廢物的封裝材料；

藝術和考古學領域

裝飾石飾品和藝術品；
文化遺產、考古學和科學史：埃及金字塔上的石頭，羅馬石。

參考文獻

^ Gluchovskij V.D.:"Gruntosilikaty" Gosstrojizdat Kiev 1959, Patent USSR 245 627 (1967), Patent USSR 449894 (Patent appl. 1958, granted 1974).
^ An article published by the Commission of the European Communities in 1982, outlines the reasons why the generic term geopolymer was chosen for this new chemistry. See: J. Davidovits, The Need to Create a New Technical Language For the Transfer of Basic Scientific Information, in Transfer and Exploitation of Scientific and Technical Information, Proceedings of the symposium, Luxemburg, 10–12 June 1981, pp. 316-320. It is available as a pdf-file and may be downloaded from the European Parliament Bookshop. Go to < https://publications.europa.eu/en/publication-detail/-/publication/02a1db8b-3873-46d7-9e72-a6e02660e154 （頁面存檔備份，存於網際網路檔案館） > and click on 'download'.
^ Kim, D.; Lai, H.T.; Chilingar, G.V.; Yen T.F. (2006), Geopolymer formation and its unique properties, Environ. Geol, 51[1], 103–111.
^ 存档副本. [2020-02-24]. （原始內容存檔於2020-02-24）.
^ Wagh, A.S. (2004), Chemically Bonded Phosphate Ceramics – A Novel Class of Geopolymers, Proceedings of the 106th Ann. Mtg. of the American Ceramic Society, Indianapolis. See also, Chapter 13, Phosphate-based Geopolymers, in J. Davidovits' book Geopolymer Chemistry and Applications.
^ Perera, D.S., Hanna, J.V., Davis, J., Blackford, M.G., Latella, B.A., Sasaki, Y. and Vance E.R. (2008), Relative strengths of phosphoric acid-reacted and alkali-reacted metakaolin materials, J. Mater. Sci., 43, 6562–6566. See also, Cao, D.; Su, D.; Lu, B. and Yang Y. (2005), Synthesis and structure characterization of geopolymeric material based on metakaolinite and phosphoric acid, Journal Chinese Ceramic Society, 33, 1385–89.
^ Zoulgami, M; Lucas-Girot, A.; Michaud, V.; Briard, P.; Gaudé, J. and Oudadesse, H. (2002); Synthesis and physico-chemical characterization of a polysialate-hydroxyapatite composite for potential biomedical application, Eur. Phys. J. AP, 19, 173-179. See also: Kriven, W.M.; Bell, J.; Gordon, M. (2003), Microstructure and Microchemistry of Fully-Reacted Geopolymers and Geopolymer Matrix Composites, Ceramic Transactions, 153, 227–250; Perera, D.S. and Trautman R.L. (2005), Geopolymers with the Potential for Use as Refractory Castables, Advances in Technology of Materials and Materials Processing, 7[2], 187–190.
^ 存档副本. [2020-02-24]. （原始內容存檔於2019-09-25）.

外部連結

地質聚合物研究所（Geopolymer Institute）: https://www.geopolymer.org/（頁面存檔備份，存於網際網路檔案館）
地質聚合物聯盟（Geopolymer Alliance）: https://web.archive.org/web/20130409024601/http://geopolymers.com.au/

[1] Gluchovskij V.D.:"Gruntosilikaty" Gosstrojizdat Kiev 1959, Patent USSR 245 627 (1967), Patent USSR 449894 (Patent appl. 1958, granted 1974).

[2] An article published by the Commission of the European Communities in 1982, outlines the reasons why the generic term geopolymer was chosen for this new chemistry. See: J. Davidovits, The Need to Create a New Technical Language For the Transfer of Basic Scientific Information, in Transfer and Exploitation of Scientific and Technical Information, Proceedings of the symposium, Luxemburg, 10–12 June 1981, pp. 316-320. It is available as a pdf-file and may be downloaded from the European Parliament Bookshop. Go to < https://publications.europa.eu/en/publication-detail/-/publication/02a1db8b-3873-46d7-9e72-a6e02660e154 （頁面存檔備份，存於網際網路檔案館） > and click on 'download'.

[3] Kim, D.; Lai, H.T.; Chilingar, G.V.; Yen T.F. (2006), Geopolymer formation and its unique properties, Environ. Geol, 51[1], 103–111.

[4] 存档副本. [2020-02-24]. （原始內容存檔於2020-02-24）.

[5] Wagh, A.S. (2004), Chemically Bonded Phosphate Ceramics – A Novel Class of Geopolymers, Proceedings of the 106th Ann. Mtg. of the American Ceramic Society, Indianapolis. See also, Chapter 13, Phosphate-based Geopolymers, in J. Davidovits' book Geopolymer Chemistry and Applications.

[6] Perera, D.S., Hanna, J.V., Davis, J., Blackford, M.G., Latella, B.A., Sasaki, Y. and Vance E.R. (2008), Relative strengths of phosphoric acid-reacted and alkali-reacted metakaolin materials, J. Mater. Sci., 43, 6562–6566. See also, Cao, D.; Su, D.; Lu, B. and Yang Y. (2005), Synthesis and structure characterization of geopolymeric material based on metakaolinite and phosphoric acid, Journal Chinese Ceramic Society, 33, 1385–89.

[7] Zoulgami, M; Lucas-Girot, A.; Michaud, V.; Briard, P.; Gaudé, J. and Oudadesse, H. (2002); Synthesis and physico-chemical characterization of a polysialate-hydroxyapatite composite for potential biomedical application, Eur. Phys. J. AP, 19, 173-179. See also: Kriven, W.M.; Bell, J.; Gordon, M. (2003), Microstructure and Microchemistry of Fully-Reacted Geopolymers and Geopolymer Matrix Composites, Ceramic Transactions, 153, 227–250; Perera, D.S. and Trautman R.L. (2005), Geopolymers with the Potential for Use as Refractory Castables, Advances in Technology of Materials and Materials Processing, 7[2], 187–190.

[8] 存档副本. [2020-02-24]. （原始內容存檔於2019-09-25）.

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