Göppert A and Cölfen H (2018), Infiltration of biomineral templates for nanost...

ECB-ART-50726

RSC Adv 2018 Oct 02;859:33748-33752. doi: 10.1039/c8ra07805j.

Show Gene links Show Anatomy links

Infiltration of biomineral templates for nanostructured polypyrrole.

Göppert A , Cölfen H .

???displayArticle.abstract???
Biomineral templates like sea urchin spine, nacre or eggshell were applied in the polymerisation of pyrrole. The insufficient infiltration of pyrrole into the CaCO3 structure of the biomineral templates was improved using three different and universally applicable approaches and the electrochemical properties of the received polypyrrole were examined.

???displayArticle.pubmedLink??? 35548798
???displayArticle.pmcLink??? PMC9086734
???displayArticle.link??? RSC Adv

???attribute.lit??? ???displayArticles.show???

	Fig. 1. The schematic structure of a sea urchin spine according to Seto et al.1. (left) The structure on the micrometre scale in dark blue. The light blue domains clarify the pores on the micrometre scale. (right) The CaCO3 nanocrystals with amorphous CaCO3 and organic inclusions. After the removal of the organic inclusions the yellow parts between the nanocrystals are partly available as pores on the nanometre scale.
	Fig. 2. SEM images of (a) the sea urchin spine template and (b) the synthesised PPy. The PPy structure is equal to a coating of the original CaCO3 structure. This can be easily realised at the outer part marked with the red arrows. (c) and (d) show SEM images of the composite material consisting of CaCO3 from the sea urchin spine and PPy. The CaCO3 has been dissolved partly in this sample. (c) The light structures of CaCO3 can be seen. They are surrounded by a layer of PPy. The dark part of the structure is the remaining PPy where the CaCO3 has been dissolved already. (d) The image shows the inner part of the braces which are partly dissolved and a layer of PPy around the surface of the braces.
	Fig. 3. SEM images of the PPy structure (cross section) after the dissolution of the CaCO3 template (sea urchin spine). (a) The Py was infiltrated with an additional pressure of 1 bar as described in ESI 1.2.† (b) The Py was infiltrated from the gaseous phase after the oxidant has been infiltrated as described in ESI 1.3.†
	Fig. 4. SEM images of the cross section of the CaCO3 templates of (a) sea urchin spine (b) nacre (c) eggshell. The pictures show the structures on the micrometre scale and the nanopores of the templates are not resolved. The second row shows the cross section of the obtained PPy structures polymerised in (d) sea urchin spine after the dissolution of the CaCO3 template, (e) nacre and (f) eggshell before the dissolution of the CaCO3 template.
	Fig. 5. (a) SEM image of PPy structure (cross section) after the dissolution of the CaCO3 template (sea urchin spine). The PPy was infiltrated and polymerised as described elsewhere.14,16 The sketch under the picture shows the schematic structure of a sea urchin spine template. (left) The structure on the micrometre scale in dark blue. The light blue domains clarify the pores on the micrometre scale. The location of the PPy is drawn in red, its polymerisation resulted in the coating of the template structure. (right) The CaCO3 nanocrystals with amorphous CaCO3 and organic inclusions. After the removing of the organic inclusions the light blue parts between the nanocrystals are partly available as pores on the nanometre scale. With the original synthesis the Py could not be infiltrated into these nanopores. (b) As comparison on the right side the PPy structure (cross section) after the dissolution of the CaCO3 template (sea urchin spine). The PPy was infiltrated as a mixture with the polar solvent methanol as described in the ESI 1.2.† The sketch under the picture shows, the Py could be infiltrated into the nanopores and thus into the complete CaCO3 structure. After the dissolution of the CaCO3 template we obtain the same macrostructure made of PPy.
	Fig. 6. Electrochemical measurements of PPy, which was synthesised under the same conditions as the template synthesis, in solution. Results of cyclic voltammetry measurements: (a) graphs for the different scan rates (b) specific capacity calculated from the graphs versus the scan rates. (c) Results of galvanostatic charge/discharge curves for the different current densities. (d) Nyquist diagram. The EIS measurement was carried out over the frequency range of 0.1 Hz to 100 kHz.
	Fig. 7. Electrochemical measurements of PPy, which was synthesised under the same conditions as the template synthesis, in solution. Results of cyclic voltammetry measurements: (a) graphs for the different scan rates (b) specific capacity calculated from the graphs versus the scan rates. (c) Results of galvanostatic charge/discharge curves for the different current densities. (d) Nyquist diagram. The EIS measurement was carried out over the frequency range of 0.1 Hz to 100 kHz.

References [+] :

Bartlett, Electrodeposition from supercritical fluids. 2014, Pubmed