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Original publish date:Feb 09, 2011

編輯 JYWu 報導

披鐵甲的深海螺─Crysomallon squamiferum外殼為硫化鐵的“三明治”層狀結構,具備耐高壓、耐溫及耐腐蝕的特性,對改善承重和防護工程材料的發展,擁有極大的潛力。

一般的螺貝類外殼結構,外層為角質層由殼蛋白構成,往內為棱柱層及珍珠層由碳酸鈣結晶組成,2001年印度洋2420公尺深的熱泉噴口(Kairei Indian hydrothermal vent field)中所發現的C. squamiferum ,卻擁有不同於眾所皆知的構造,殼最外層為硫化鐵成份,內層為碳酸鈣組成。因此,美國麻省理工學院材料科學與工程學系Christine Ortiz的研究團隊利用奈米尺度的壓痕實驗(nanoindentation experiments),還有電腦模擬捕食者如螃蟹攻擊時對C. squamiferum各殼層的破壞程度、力的消散等,對殼進行了一系列的材料力學的分析研究。

研究團隊發現C. squamiferum外殼具有獨特性的三層(剛─軟─剛)結構:最外層由奈米至微米粒狀的硫化鐵組成提供第一線防禦,含有硫複鐵礦(greigite, Fe3S4),約有30μm 的厚度,在受到攻擊時,就會使這層防禦的粒狀結構分裂,此犧牲性的裂痕導致攻擊力量被分散,可防止整個外殼產生破壞性的裂痕;中間是具彈性的有機層,由殼蛋白組成,厚度約為150μm,能在外殼受到攻擊時吸收能量,以緩解來自外部的衝擊和壓力,並可減緩環境溫度變化所造成的影響;內層由碳酸鈣片狀的霰石晶體組成(aragonite),厚度約為250μm,其堅硬度可提供外殼結構上的支撐,並且抵抗彎曲變形,以達保護脆弱的軟組織之功能。藉由這種生物防護材料原理的發現,可望開發出高負載的保護材料、防爆裝備等實用於生物材料、航空及航太等科學。

參考來源:

  • H. Yao et al., PNAS 107, 987-992, 2010

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  • JYWu

    Jingying Wu 吳靖穎
    現於中山大學海洋生物研究所中作研究助理的工作,研究軟體動物相關之生理生態,人生是寂寞的旅程,一個人的時間也是最好沉澱思維的時間,雖愛好自然,喜好旅遊登山潛水及攝影,但是將體會分享給別人時是最大的喜悅,也是靈感來源及成長的機會。
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