Chiral polymer helices with shape identical to previously reported helical calcium carbonate morphologies

Helices with highly ordered substructures were found sporadically during precipitation of self-assembled silica-barium carbonate "biomorphs". Identical morphologies are already known and cited in the literature as helical calcite structures, formed by the influence of chiral phosphoserine copolypeptides. Yamamoto et al. claim that the handedness of the helices can be tuned by the chirality of the amino acids in the phosphoserine copolypeptides. Optical and scanning electron microscopy, energy-dispersive X-ray analysis, thremogravimetry, as well as proton and carbon nuclear magnetic resonance were performed on selected twisted ribbons, proving that these helical superstructures - in shape identical to the helical calcite morphologies reported by Yamamoto et al. - do not consist of inorganic material but of an organic polymer, representing plastic abrasion caused by scratching glass pipettes along plastic surfaces.