双壳纲韧带文石纤维的纳米形貌及光学反射特征

采用场发射扫描电镜及微型光纤光谱仪对21种双壳纲韧带中文石纤维的纳米形貌及光学反射特征进行研究,经过对比分析及统计结果表明:形貌上,文石纤维是由约30 nm～80 nm的亚颗粒沿纤维轴向排列而成,呈串珠状结构;纤维横截面常呈近六边形或浑圆形,但棕带仙女蛤、砗蚝及粒帽蚶呈长六边形.纤维直径及相邻纤维间距与生物种类有关,变化范围分别为65 nm～222 nm及88 nm～214 nm.除了砗蚝及粒帽蚶韧带无光学反射外,其他韧带均存在位于可见光范围内单反射峰,并随湿润程度增大而增加,反射强度也增大主波长还发生红移,从而导致韧带的水致变色现象,变色范围为28 nm～145 nm.韧带文石纤维独特的纳米形貌及其复杂的水致变色现象的发现对生物的矿物学及光子学研究具有重要的意义.

NANOMORPHOLOGIES OF ARAGONITIC FIBERS AND OPTICAL REFLECTIONS OF BIVALVE LIGAMENTS

Field-emission scanning electron microscope and miniature fiber-optic spectrometer were used to investigate comparatively and statistically the aragonitic fibers in ligaments from 21 bivalve species,aiming to understand their nanomorphologies and optical reflections.It was fund that,morphologically,the aragonitic fibers were of bead-on-string structures with aligned subgrains of 30 nm~80 nm along the fiber axis,and nearly round or hexagonal across the fiber axis except those of Callista erycina,Hippopus hippopus,and Cucullaea granulose,which occurred as elongated hexagonal.In addition,the fiber diameters and interfiber spacing were species-specific and varied from 65 nm to 222 nm and 88 nm to 214 nm,respectively.Moreover,the ligament generally displayed a single optical reflection whose intensity and dominant wavelength increased with increasing humidity,resulting in a hydrochromsim of the ligament in the range of 28 nm~145 nm.However,the ligaments of Hippopus hippopus and Cucullaea granulose had no optical reflection.The findings of unusual nanomorphology and complex hydrochromism in ligaments may have significant implications to biomineralization and photonics.