Physics and Chemistry of Hybrid Organic-Inorganic Materials Lecture 5: Naturally occurring hybrids

1. Physics and Chemistry of Hybrid Organic-Inorganic MaterialsLecture 5: Naturally occurring hybrids

2. Biological hybrids: key points • Hybrids made by plants or animals • Strong composites from very weak components • Wet protein and carbohydrates are very soft • calcium carbonate is also weak and soft • Multiple phases, hierarchical structures

3. Hybrid Organic-Inorganic materials are common in nature: composites Animals Organic phase is biopolymers Nacre Plants phytolith Argonite (CaCO3) plates as inorganic with protein (polyamide) as organic Teeth, spines in echinderms Mussel shells, sponges, diatoms and corals are utilize hybrid organic-inorganic materials Carbohydrates are the template and organic phase

4. What is a hierarchical structure? In materials, a structure with different structures at different length scales: like in tendons (above)

5. The Building Plan Fabrication Conditions in Living Organisms only few elements: C, H, O, N, P, S, Ca, Si, Mg mild pH ambient pressure and temperature Calcite Crystals Extracted from the Prismatic Layer of Pinna Nobilis Shells Marin et al., J. Biol. Chem., 2005, 40, 33895 www.cutgana.it/acquario/specie

6. The Building Plan Fabrication Conditions in Living Organisms only few elements: C, H, O, N, P, S, Ca, Si, Mg mild pH ambient pressure and temperature Interaction of an Organic and an Inorganic Component Hierarchical Design – Morhpology Control on Several Levels & Incorporation of biopolymers  increased fracture resistence chitin network Nudelman et al., Faraday Discuss. 2007, 136, 9 aspartate residue in peptide bond

7. Colloidal silica in diatoms: Hierarchical structure pH ≈ 5 Silica walls are build up from ca. 5nm particles to give ca. 40nm diameter particles that are organized within the frustule.

8. Silica (SiO2)& protein radiolaria diatoms Proteins act as templates for building silica architectures

9. Bio-Hybrids based on CaCO3: Nacre Argonite (CaCO3) plates as inorganic phase with protein (polyamide) as organic phase Fracture strength is 3000 times higher than its mineral constituent CaCO3. Mother-of-pearl Opalescence from light diffraction in nacre (argonite blocks height ≈ λ light)

10. The hierarchical structure of nacre Macromolecular Growth rings (mesolayers) Phase morphology The shell itself Inner surface of shell (mother or pearl) Long range order: stacked crystals argonite crystal structure Barthelat F Phil. Trans. R. Soc. A 2007;365:2907-2919

11. Lobster exoskelton CaCO3 & Carbohydrate & protein

12. Teeth: Enamel, dentin, & cementum Apatite – hydrated CaPO4 Protein– collagen & others

13. The layered, rod structure of hydroxyapatite (a calcium phopshate) in dental enamel. Very tough for a ceramic.

14. Hierarchical structure of alligator gar, a primitive fish, scales. Ganoine is mostly mineral, like enamel, with tougher bone beneath.

15. Regular Fish Scales Enamel and collagen

16. Fish scale puncture resistance fish scales are better than polycarbonate. note how they give, and then reload. This is just one scale.

17. Bones Apatite – hydrated CaPO4 Protein– collagen 200 MPa yield strength 30 MPaM0.5 toughness

18. The Building Plan Fabrication Conditions in Living Organisms only few elements: C, H, O, N, P, S, Ca, Si, Mg mild pH ambient pressure and temperature Interaction of an Organic and an Inorganic Component Hierarchical Design – Morhpology Control on Several Levels & structural optimization from the atomic to the macroscopic scale Bone Peterlik et al., Nat. Mat., 2006 Gupta et al., PNAS, 2006 Fratzl et al., Progr. Mat. Science, 2007

19. Echinoderm spine CaCO3 Protein templating

20. Phytoliths SiO2 silica 2-3% silicon by weight Horsetail, banana leaves

21. Silica in Sponges hierarchical structures Templated by proteins

22. Euplectella sp.  7 hierarchical levels Stress-deflection responses of synthetic silica rod and sponge spicule in flexuretesting. (Courtesy of M. Sarikaya and G. Mayer.)

23. Almost no protein 3 hierarchical levels of layers made from layers of calcite. conch shell

24. Chiton Teeth the tips of the teeth are hard magnetite (Fe3O4) with a tough fibrous calcite interior

25. Metal in Spider Fangs carbohydrate fibers in a protein matrix with zinc and magnesium ions Politi, Y., Priewasser, M., Pippel, E., Zaslansky, P., Hartmann, J., Siegel, S., Li, C., Barth, F. G. and Fratzl, P. (2012), A Spider's Fang: How to Design an Injection Needle Using Chitin-Based Composite Material. Adv. Funct. Mater., 22: 2519–2528

26. Biomaterial: Toucan Beak Cellular materials: (a) synthetic aluminium foam; (b) foam found in the inside of toucan beak.(Courtesy of M. S. Schneider andK. S. Vecchio.) (a) Toucan beak; (b) external shell made of keratin scales.

27. Bio Hybrid Organic-Inorganic Materials Sophisticated, highly evolved hybrids -nominally weak, but bio-accessible minerals (eg. CaCO3) -hydrophilic, water plasticized biopolymers (eg. protein) -Integrated at nano-length scales -Phase separation templating of hierarchical structures -All water based chemistry!! The ultimate green chemistry Optimized to give non-additive property (synergistic effects) Models for many research programs in hybrid materials