Corrosion Research Centre, CSIR - Central Electrochemical Research Institute, Mandapam Camp 623519, Tamil Nadu, India.
Biofouling. 2013;29(2):185-93. doi: 10.1080/08927014.2012.755673.
In replicate series of experiments in natural seawater, one in full darkness and the other in a 1:1 diurnal cycle with as little as ~5% of natural solar illumination, sunlight promoted calcareous deposition on cathodic stainless steel surfaces. As exemplified by scanning electron microscopy, the deposit that formed under the natural diurnal cycle, in the presence of photosynthetic biofilms, was composed of finer calcareous crystals that provided more compact and more uniform surface coverage than the one formed in the dark. The light-enhanced deposit also possessed better scale properties, as suggested by X-ray analysis and electrochemical measurements. Sunlight enhancement of calcareous deposition looked all the more conspicuous when day and night regimes were examined independently. These results not only bear important implications for cathodic protection in marine waters, but also provide an intriguing analogy to coral reef calcification.
在自然海水中的重复实验系列中，一个实验是完全黑暗的，另一个实验是在自然光下进行的 1:1 昼夜循环，光照强度低至约 5%的自然太阳光。结果表明，太阳光促进了阴极不锈钢表面的碳酸钙沉积。如扫描电子显微镜所示，在有光合作用生物膜的情况下，在自然昼夜循环下形成的沉积物由更细的碳酸钙晶体组成，与在黑暗中形成的沉积物相比，提供了更紧凑和更均匀的表面覆盖。X 射线分析和电化学测量表明，增强光照的沉积物具有更好的结垢性能。当分别检查白天和黑夜的情况时，光照对碳酸钙沉积的增强作用显得更加明显。这些结果不仅对海洋中的阴极保护具有重要意义，而且为珊瑚礁钙化提供了一个有趣的类比。
