石油產品如鋼鐵，促戰略儲存石油

運用納米技術，密執根大學科研人員最近研製出新型塑製板塊，其性能如鋼鐵般堅硬，同時具有玻璃一樣的透明度。

從石油中提煉出來的多聚體 (polymer) 是一種高分子化合物，在納米體積時，它們的堅硬度可以很高。但是在多聚體組合成塑膠時，形成的板塊堅硬度下降。為了解決這一難題，密大的 Kotov 教授和他的助理研究人員研製了一台可以使用納米技術組裝多聚體的機器人(點擊此處看機器人和塗料的有關資料的 PDF 文件)。

利用這台機器人，他們采用了類似砌磚牆時的疊加方法，所用的材料是納米級的多聚體 (類似磚塊) 和納米級的粘土 (製成玻璃用的原料，也類似磚塊)。步驟是先將一塊玻璃浸入具有水溶性和粘性的多聚體中，這等於塗上一層納米級的粘料，再將塗有粘料的玻璃浸入裝有粘土的容器裏，塗上一層薄薄的粘土。等粘土層幹了，再重複以上過程。這樣的納米層，一共塗了三百層。

這一層層製造出來的新型合成材料，在完成後的測試中，具有不鏽鋼一般的堅硬度，同時質量更輕盈，而且是透光的。

(金筆是外行，以上描述可能有錯和漏的地方，請包涵)

部分原文的摘要如下

網址：

http://www.sciencemag.org/cgi/content/abstract/318/5847/80

Science 5 October 2007:
Vol. 318. no. 5847, pp. 80 - 83

Reports:
Ultrastrong and Stiff Layered Polymer Nanocomposites

Authors:
Paul Podsiadlo, Amit K. Kaushik, Ellen M. Arruda, Anthony M. Waas, Bong Sup Shim,1 Jiadi Xu, Himabindu Nandivada, Benjamin G. Pumplin, Joerg Lahann, Ayyalusamy Ramamoorthy, Nicholas A. Kotov*(corespondant author)

Abstract:
Nanoscale building blocks are individually exceptionally strong because they are close to ideal, defect-free materials. It is, however, difficult to retain the ideal properties in macroscale composites. Bottom-up assembly of a clay/polymer nanocomposite allowed for the preparation of a homogeneous, optically transparent material with planar orientation of the alumosilicate nanosheets. The stiffness and tensile strength of these multilayer composites are one order of magnitude greater than those of analogous nanocomposites at a processing temperature that is much lower than those of ceramic or polymer materials with similar characteristics. A high level of ordering of the nanoscale building blocks, combined with dense covalent and hydrogen bonding and stiffening of the polymer chains, leads to highly effective load transfer between nanosheets and the polymer.


Fig. 1. Preparation of PVA/MTM nanocomposites. (A) Schematic representation of the internal architecture of the PVA/MTM nanocomposite (picture shows 8 bilayers). (B) ATM phase image of a single PVA/MTM bilayer adsorbed on top of a silicon wafer. (Inset) Close up of the main image showing individual MTM platelets more clearly. Scale bar in inset, 400 nm. (C) Compilation of UV/VIS absorbance spectra collected after multiples of 25 bilayers of PVA/MTM composite deposited on both sides of a microscope glass slide up to 200 bilayers. a.u., arbitrary units. (D) Free-standing, 300-bilayer PVA/MTM composite film showing high flexibility and transparency. The lower image was taken at an angle to show diffraction colors. [View Larger Version of this Image (26K GIF file)]


Fig. 2. Scanning electron microscopy characterization of a 300-bilayer, free-standing PVA/MTM nanocomposite. (A) Cross section of the film. Arrows indicate the span of the cross section. (B) Close-up of the cross section showing the separation of layers. (C) Top-down view of a fracture edge of the composite after tensile testing. Dashed line indicates edge of the sample. (D) Top-down view of the composite's surface. The slight separation of the layers seen in (A) and (B) is due to a shearing force resulting from cutting the sample with a razor blade during scanning electron microscopy sample preparation. [View Larger Version of this Image (141K GIF file)]

討論和建議：

石油除了燃燒以外，其他更有價值的用途很多，包括各種塑製材料。比如上麵所提的材料，因為鋼硬度，輕型和透明，他們的用途很多。而且 Kotov 教授在采訪中 (另外報道) 還談到，這個工藝還不成熟，有待完善，因此這類的材料還很有發展潛力。

問題是，石油有這麽多更寶貴的用途，今天我們隻是將它燃燒了，既造成汙染，又浪費了資源，金筆覺得實在太可惜了。正確的做法是應該將部分石油作為戰略儲備，為將來的更好的用途而儲存起來。

謝謝閱讀。