Biominerals, such as sea urchin spines and mollusk shells, are biogenically formed composite ceramics which show superb adaptation for given tasks. The 542 million years of evolution since the Cambrian explosion has rendered biominerals an immense source of inspiration for both material design and for the creation of ceramic materials at ambient temperature. The key step during genesis of these biogenic ceramics is the controlled solid-amorphous to crystalline transformation from a transient precursor to a highly co-oriented mosaic crystal. This solid-to-solid phase transformation is pseudomorphic, i.e. it proceeds with conservation of the macroscopic morphology of the mineral body which eventually leads to non-equilibrium shaped crystalline forms. Therefore, biominerals and biomineralization itself represents a huge source of inspiration for the synthesis of functional materials under morphological control. As of yet, the formation of ceramics at ambient conditions for anthropogenic ceramic materials is still in its infancy and Nature may guide us on this venture.
Fundamentals of Nucleation and Crystal Growth in Real Systems
Our research in biomimetic crystallization taught us that crystallization processes are not well understood for real systems; the classical models as given in 1920's work explicitly well for simple model systems (i.e. melts, NaCl, etc.). But already simple additives, such as polyacrylic acid, can strongly intervene in the crystallization process and trigger so-called Noncassical Crystallization processes. These processes i.e. oriented attachment, prenucleation cluster, and liquid-condensed mineral precursors (PILP) question our current understanding of crystal birth and growth. The third member of the nonclassical triumvirate is the so-called Polymer-Induced Liquid-Precursor Process (PILP), a process which has pronounced morphosynthetical potential. It proceeds in a colloid-mediated fashion via a liquid-phase amorphous intermediate. By addition of tiny amounts of poly-ionic polymers like poly-aspartate, poly-amines or selected biomineralization proteins, classical nucleation of a solid crystalline phase is suppressed which, in turn, promotes the formation of a liquid-condensed phase of mineral precursor. This unusual ion-enriched liquid-amorphous phase becomes the crucial agent of the precipitation reaction; the process of mineralization is converted from a solution crystallization process to a pseudomorphic solidification process. This change of pathway provides an efficient means to synthesize an impressive multitude of mineral morphologies, many of which mimic the features long considered enigmatic in biominerals.
Designing solid materials from their solute state: a Perspective in JACS.
“Non-classical” notions consider formation pathways of crystalline materials where larger species than monomeric chemical constituents, i.e., ions or single molecules, play crucial roles, which are not covered by the classical theories dating back to the 1870s and 1920s. Providing an outline of “non-classical” nucleation, we demonstrate that pre-nucleation clusters (PNCs) can lie on alternative pathways to phase separation, where the very event of demixing is not primarily based on the sizes of the species forming, as in the classical view, but their dynamics. Rationalizing, on the other hand, that precursors that can be analytically detected in pre-nucleation stages and that play a role in phase separation must be considered PNCs and cannot be explained by classical notions, we outline a variety of systems where PNCs are important. Indeed, in recent years, with the advent of “non-classical” theories, a primary focus of research concentrated on the fundamental understanding of oligomeric/polymeric and particulate species involved in nucleation and crystallization processes, respectively. At the same time, the near-to unfathomable potential of “non-classical” routes for the synthesis of inorganic functional materials slowly unfolds. An overview over recent developments in the fundamental and mechanistical understanding of “non-classical” nucleation and crystallization in this perspective then allows us mapping out the potential of cluster/particle-driven mineralization pathways to intrinsically tailor the properties of inorganic functional (hybrid) materials via structuration from the nano- to the mesoscale. This is of utter importance for the functionality and performance of materials as it may even confer emergent properties such as self-healing. Biominerals — often formed via particle accretion mechanisms— demonstrate this impressively and thus can serve as further source of inspiration how to exploit nonclassical crystallization routes for syntheses of structured and functional materials. These new avenues to synthetic approaches may finally provide a holistic material concept in whichfundamental chemistry and materials science synergistically alloy.
Read the full Perspective in J. Am. Chem. Soc. 2019
Chicken Eggs are Functionally Graded Materials
Avian (and formerly dinosaur) eggshells form a hard, protective biomineralized chamber for embryonic growth—an evolutionary strategy that has existed for hundreds of millions of years. We show in the calcitic chicken eggshell how the mineral and organic phases organize hierarchically across different length scales and how variation in nanostructure across the shell thickness modifies its hardness, elastic modulus, and dissolution properties. We also show that the nanostructure changes during egg incubation, weakening the shell for chick hatching. Nanostructure and increased hardness were reproduced in synthetic calcite crystals grown in the presence of the prominent eggshell protein osteopontin. These results demonstrate the contribution of nanostructure to avian eggshell formation, mechanical properties, and dissolution.
Check out online: Science Advances 2018
Nacre forms via a nonclassical route
Intricate biomineralization processes in molluscs engineer hierarchical structures with meso-, nano- and atomic architectures that give the final composite material exceptional mechanical strength and optical iridescence on the macroscale. This multiscale biological assembly inspires new synthetic routes to complex materials. Our investigation of the prism–nacre interface reveals nanoscale details governing the onset of nacre formation using high-resolution scanning transmission electron microscopy. A wedge-polishing technique provides unprecedented, large-area specimens required to span the entire interface. Within this region, we find a transition from nanofibrillar aggregation to irregular early-nacre layers, to well-ordered mature nacre suggesting the assembly process is driven by aggregation of nanoparticles (~50–80 nm) within an organic matrix that arrange in fibre-like polycrystalline configurations. The particle number increases successively and, when critical packing is reached, they merge into early-nacre platelets. These results give new insights into nacre formation and particle-accretion mechanisms that may be common to many calcareous biominerals.
Get Open-Acess Article from Nature Communications
Read Press Releases on Phys.org or IDW
Tilting Biomimetic Crystals
Classical crystal exhibit smooth and flat facets, they do not tilt. Only few examples are known in which the facets or the crystallographic organization of crystals show twisting or tilting. Employing amorphous calcium carbonate films synthesized by the polymer-induced liquid-precursor (PILP) process, we are able to convert these films into flat cylindrulites with crystallographically complex features. By tuning the experimental parameters, we can generate crystal lattice tilting similar to that found in calcareous biominerals. This contribution, recently published in CrystEngCom evidences the role of spherulitic growth mechanisms in pseudomorphic transformations of calcium carbonate and hints to a hidden role of spherultic processes in vivo.
This contribution is part of a special issue on Nanocrystal Formation and is featured by the outer cover page. Find the OpenAccess article online on CrystEngCom
31/05/2019 - Congratulations to Corinna!
Corinna published a couple of articles in our special issue, check them out!
01/01/0001 - Congratulations to Joe and his new article in Nanoscale Horizons!
Congratulations to Joe and his new article in Nanoscale Horizons!
27/12/2018 - Congratulations to Barbara
Barbara defended her thesis, congratulations to this great job!
03/02/2016 - Joe's paper is out!
Joe's Paper on crystal lattice tilting was accepted in CrystEngCom, see here!
Stephan E. Wolf studied Chemistry (Diplom) at the Johannes-Gutenberg University of Mainz and obtained his PhD (Dr. rer. nat.) under the supervision of Prof. Dr. Wolfgang Tremel. His thesis with the title "Nonclassical Crystallization of Bivalent Metal Carbonates" was supported by a scholarship of the Konrad-Adenauer Foundation. After a short postdoc visit in the group of Prof. Dr. Rademann at the Humboldt University of Berlin, he received a DFG PostDoc scholarship and joined the CNRS Laboratoire Biogéoscience (UMR CNRS/uB 6282) and worked with Dir. Dr. Frédéric Marin at the University of Dijon on proteomic characterization of intracrystalline biomineralization proteins in bivalves. Then he joined as a reasearch associate the group of Lara A. Estroff in Cornell, in the Department of Materials Science and Engineering. With the aid of a repatriation grant, he came back to Germany as a visiting scientist at the Max-Planck Institute for Polymer Chemistry in the group of Prof. Dr. H.-J. Butt. Since February 2014, he is Assistant Professor for Biomimetic Materials and Processing at the Chair of Glass and Ceramics in the Department of Materials Science and Engineering of the Friedrich-Alexander-University Erlangen-Nürnberg. Shorty after, he received an Emmy-Noether Scholarship (1.24 Mio€, WO1712/3-1) by the German Research Foundation.
Corinna F. Böhm has undertaken an apprenticeship as metallographer at the Max-Planck-Institute for Metal Research in Stuttgart, before she started her Forensic Science studies (Bachelor) at the Hochschule Bonn-Rhein-Sieg, the Victoria University Melbourne and the Hogeschool van Amsterdam. She continued her studies with the Elite Master's Programme in Advanced Materials and Processes at the Friedrich-Alexander-Universität Erlangen-Nürnberg, which she completed in our group with her Master´s Thesis "Influence of the Nano- and Microscale Structure on the Macroscopic Properties of Bivalve Shells". She is currently working on her PhD focussing on nanoscale properties of biominerals and biomimetic materials.
If you need a authors copy of one of the publications, do not hesitate to drop me a line: firstname.lastname@example.org
- Nanoscale assembly processes revealed in the nacroprismatic transition zone of Pinna nobilis mollusc shells
Robert Hovden*, Stephan E. Wolf*, Megan E. Holtz, Frédéric Marin, David A. Muller and Lara A. Estroff (* equal contribution) in Nature Communications (2015) , Vol. 6, No. 10097. DOI:10.1038/ncomms10097.
Abstract: Intricate biomineralization processes in molluscs engineer hierarchical structures with meso-, nano- and atomic architectures that give the final composite material exceptional mechanical strength and optical iridescence on the macroscale. This multiscale biological assembly inspires new synthetic routes to complex materials. Our investigation of the prism–nacre interface reveals nanoscale details governing the onset of nacre formation using high-resolution scanning transmission electron microscopy. A wedge-polishing technique provides unprecedented, large-area specimens required to span the entire interface. Within this region, we find a transition from nanofibrillar aggregation to irregular early-nacre layers, to well-ordered mature nacre suggesting the assembly process is driven by aggregation of nanoparticles (~50–80 nm) within an organic matrix that arrange in fibre-like polycrystalline configurations. The particle number increases successively and, when critical packing is reached, they merge into early-nacre platelets. These results give new insights into nacre formation and particle-accretion mechanisms that may be common to many calcareous biominerals.
- Strong Stabilization of Amorphous Calcium Carbonate Emulsion by Ovalbumin: Gaining Insight into the Mechanism of 'Polymer-Induced Liquid Precursor' Processes.
Stephan E. Wolf, Jork Leiterer, Vitaliy Pipich, Raul Barrea, Franziska Emmerling and Wolfgang Tremel in J. Am. Chem. Soc. (2011) , Vol. 132, No. 32, pp. 1520-6. DOI:10.1021/ja202622g.
Abstract: The impact of the ovo proteins ovalbumin and lysozyme—present in the first stage of egg shell formation—on the homogeneous formation of the liquid amorphous calcium carbonate (LACC) precursor, was studied by a combination of complementing methods: in situ WAXS, SANS, XANES, TEM, and immunogold labeling. Lysozyme (pI = 9.3) destabilizes the LACC emulsion whereas the glycoprotein ovalbumin (pI = 4.7) extends the lifespan of the emulsified state remarkably. In the light of the presented data: (a) Ovalbumin is shown to behave commensurable to the 'polymer-induced liquid precursor' (PILP) process proposed by Gower et al. Ovalbumin can be assumed to take a key role during eggshell formation where it serves as an effective stabilization agent for transient precursors and prevents undirected mineralization of the eggshell. (b) It is further shown that the emulsified LACC carries a negative surface charge and is electrostatically stabilized. (c) We propose that the liquid amorphous calcium carbonate is affected by polymers by depletion stabilization and de-emulsification rather than 'induced' by acidic proteins and polymers during a so-called polymer-induced liquid-precursor process. The original PILP coating effect, first reported by Gower et al., appears to be a result of a de-emulsification process of a stabilized LACC phase. The behavior of the liquid amorphous carbonate phase and the polymer-induced liquid-precursor phase itself can be well described by colloid chemical terms: electrostatic and depletion stabilization and de-emulsification by depletion destabilization.
- Formation of silicones mediated by the sponge enzyme silicatein-α
Stephan E. Wolf, Ute Schlossmacher, Anna Pietuch, Bernd Mathiasch, Heinz-Christoph Schröder, Werner E G Müller and Wolfgang Tremel in Dalton Transact. (2010) , Vol. 39, pp. 9245-9. DOI:10.1039/B921640E. This article is part of a themed issue: New Horizon of Organosilicon Chemistry.
Abstract: The sponge-restricted enzyme silicatein-α catalyzes in vivo silica formation from monomeric silicon compounds from sea water (i.e. silicic acid) and plays the pivotal role during synthesis of the siliceous sponge spicules. Recombinant silicatein-α, which was cloned from the demosponge Suberites domuncula (phylum Porifera), is shown to catalyze in vitro condensation of alkoxy silanes during a phase transfer reaction at neutral pH and ambient temperature to yield silicones like the straight-chained polydimethylsiloxane (PDMS). The reported condensation reaction is considered to be the first description of an enzymatically enhanced organometallic condensation reaction.
- Early homogenous amorphous precursor stages of calcium carbonate and subsequent crystal growth in levitated droplets.
Stephan E. Wolf, Jork Leiterer and Michael Kappl, Franziska Emmerling and Wolfgang Tremel in J. Am. Chem. Soc. (2008) , Vol. 130, No. 37, pp. 12342-7. DOI:10.1021/ja800984y. Highlighted in Nachr. Chemie (2009).
Abstract: An in situ study of the contact-free crystallization of calcium carbonate in acoustic levitated droplets is reported. The levitated droplet technique allows an in situ monitoring of the crystallization while avoiding any foreign phase boundaries that may influence the precipitation process by heterogeneous nucleation. The diffusion-controlled precipitation of CaCO3 at neutral pH starts in the initial step with the homogeneous formation of a stable, nanosized liquid-like amorphous calcium carbonate phase that undergoes in a subsequent step a solution-assisted transformation to calcite. Cryogenic scanning electron microscopy studies indicate that precipitation is not induced at the solution/air interface. Our findings demonstrate that a liquid-liquid phase separation occurs at the outset of the precipitation under diffusion-controlled conditions (typical for biomineral formation) with a slow increase of the supersaturation at neutral pH.
- Phase selection of calcium carbonate through the chirality of adsorbed amino acids.
Stephan E. Wolf, Niklas Loges, Bernd Mathiasch, Martin Panthöfer, Ingo Mey, Andreas Janshoff and Wolfgang Tremel in Angew. Chem. Int. Ed. (2007) , Vol. 46, No. 29, pp. 5618-23. DOI:10.1002/anie.200700010. This is featured as a VIP paper.
Abstract: On the phase of it: The phase selection of calcium carbonate (spheres: C gray, Ca green, O red) is determined by chiral amino acids (stick models) present during the crystallization. The interplay of composition and chirality of the crystal surfaces and additives leads to enantiospecific adsorption of the D and L amino acids on chiral surface steps. The resulting surface passivation creates a kinetic barrier, which controls the phase selection.
- Ultra-smooth and space-filling mineral films generated via particle accretion processes. J Harris, IP Mey, CF Böhm, TTH Trinh, S Leupold, C Prinz, P Tripal, R Palmisano & SE Wolf* in Nanoscale Horizons (2019), angenommen und online publiziert am 2019-06-17. ▶doi: 10.1039/c9nh00175a
- Bioinspired materials: from living systems to new concepts in materials chemistry. CF Böhm, J Harris, P Schodder & SE Wolf* in Materials (2019), 12, 2117; peer-reviewed Editorial Review der Spezialausgabe Bioinspired Materials: From Living System to New Concepts in Materials Chemistry. ▶doi: 10.3390/ma12132117.
- Phase-specific bioactivity and altered Ostwald ripening pathways of calcium carbonate polymorphs in simulated body fluid. B Myszka, M Schüßler, K Hurle, B Demmert, R Detsch, AR Boccaccini & SE Wolf* in RSC Advances (2019), 9, 18232. ▶doi: 10.1039/C9TB00237E
- Polymer-Functionalised Nanograins of Mg-Doped Amorphous Calcium Carbonate via a Flow-Chemistry Approach. B Demmert, F Schinzel, M Schüßler, M Mondeshki, J Kaschta, DW Schubert, DE Jacob & SE Wolf* in Materials (2019), 10 (12), 1818. Beitrag in der Spezialausgabe Bioinspired Materials: From Living System to New Concepts in Materials Chemistry. ▶doi: 10.3390/ma12111818
- Conical Nanoindentation Allows Azimuthally Independent Hardness Determination in Geological and Biogenic Minerals. CF Böhm, P Feldner, B Merle, SE Wolf in Materials (2019), 10 (12), 1630. Beitrag in der Spezialausgabe Bioinspired Materials: From Living System to New Concepts in Materials Chemistry. ▶doi: 10.3390/ma12101630
- Mechanical improvement of an all-calcium carbonate cement by in situ HEMA polymerization during hardening. B Myszka, K Hurle, K Zheng, SE Wolf* & AR Boccaccini in Journal of Materials Chemistry B (2019), 7 (21), 3403-3411. ▶doi: 10.1039/C9TB00237E
- Designing Solid Materials from Their Solute State: A Shift in Paradigms toward a Holistic Approach in Functional Materials. D. Gebauer & SE Wolf* in Journal of the American Chemical Society (2019), ASAP online 12/02/2019. Perspective auf Einladung des Editors. ▶Doi: 10.1021/jacs.8b13231
- Bioinspired Supertough Graphene Fibers through Sequential Interfacial Interactions. Y Zhang, J Peng, M Li, E Saiz, SE Wolf & Q Cheng* in ACS Nano (2018) 12 (9), 8901–8908. ▶Doi: 10.1021/acsnano.8b04322
- Nanostructure, osteopontin and mechanical properties of avian calcitic eggshell. D Athanasiadou, W Jiang, D Goldbaum, A Saleem, K Basu, MS Pacella, CF Böhm, RR Chromik, MT Hincke, AB Rodríguez-Navarro, H Vali, SE Wolf, JJ Gray, KH Bui & MD McKee in Science Advances (2018), 4 (3), eaar3219. ▶Doi: 10.3390/min7070122
- Desiccator volume: a vital yet ignored parameter in CaCO3 crystallization by the ammonium carbonate diffusion method. J Harris & SE Wolf* in Minerals (2017) 7 (7), 122. Eingeladener Beitrag in der Spezialausgabe Nucleation of Minerals: Precursors, Intermediates and their use in Materials Chemistry. ▶Doi: 10.3390/min7070122
- Enhancement of the carbothermal reduction of hafnium oxide by silicon. B Weisenseel, J Harris, M Stumpf, SE Wolf, T Fey & P Greil in Advanced Engineering Materials (2016) 19 (1), 1600377. ▶Doi: 10.1002/adem.201600377
- Universal structure motifs in biominerals: a lesson from nature for the efficient design of bioinspired functional materials. J Harris, CF Böhm & SE Wolf* in Interface Focus (2017) 7 (4), 20160120. Eingeladener Beitrag in der Spezialausgabe Growth and Function of Complex Forms in Biological Tissue and Synthetic Self-Assembly. ▶Doi: 10.1098/rsfs.2016.0120
- Nonclassical crystallization in vivo et in vitro (I): process-structure-property relationships of nanogranular biominerals. SE Wolf*, CF Böhm, J Harris, BDemmert, DE Jacob, M Mondeshki, E Ruiz-Agudo & C Rodríguez-Navarro in Journal of Structural Biology (2016) 196 (2), 244-259. Eingeladener Beitrag in der Spezialausgabe Biomineralization. ▶Doi: 10.1016/j.jsb.2016.07.016
- Nonclassical crystallization in vivo et in vitro (II): nanogranular features in biomimetic minerals disclose a general colloid-mediated crystal growth mechanism. C Rodríguez-Navarro, E Ruiz-Agudo, J Harris & SE Wolf in Journal of Structural Biology (2016) 196 (2), 260-287. Eingeladener Beitrag in der Spezialausgabe Biomineralization.
- Structural commonalities and deviations in the hierarchical organization of crossed-lamellar shells: a case study on the shell of the bivalve Glycymeris glycymeris. CF Böhm, B Demmert, J Harris, T Fey, F Marin & SE Wolf* in Journal of Materials Research (2016) 31 (5), 536-546. ▶Doi: 10.1557/jmr.2016.46
- Nanoscale assembly processes revealed in the nacroprismatic transition zone of Pinna nobilis mollusc shells. RM Hovden× & SE Wolf×, ME Holtz, F Marin, DA Muller & LA Estroff in Nature Communications (2015) 6, 10097. ×Gemeinsame Erstautorschaft von RMH & SEW. ▶Doi: 10.1038/NCOMMS10097
- Pseudomorphic transformation of amorphous calcium carbonate films follows spherulitic growth mechanisms and can give rise to crystal lattice tilting. J Harris, I Mey, M Hajir, M Mondeshki & SE Wolf* in CrystEngComm (2015) 17 (36), 6831-6837. Artikel in der Spezialausgabe Fundamentals of Nanocrystal Formation. Artikel mit Titelseite. ▶Doi: 10.1039/C5CE00441A
- Single nanogranules preserve intracrystalline amorphicity in biominerals. SE Wolf*, C Böhm, J Harris, M Hajir, M Mondeshki & F Marin in Key Engineering Materials (2016) 672, 47. ▶Doi: 10.4028/www.scientific.net/KEM.672.47
- Synthesis of calcium carbonate biological materials: how many proteins are needed?
F Marin, N Le Roy, B Marie, P Ramos-Silva, SE Wolf, S Benhamada, N Guichard & F Immel in Key Engineering Materials (2014) 614, 52-61.
- ‘Shellome’: Proteins involved in mollusk shell biomineralization: diversity, functions.
F Marin, B Marie, SB Hamada, P Ramos-Silva, N Le Roy, SE Wolf, C Montagnani, C Joubert & D Piquemal in Recent Advances in Pearl Research (2013), 149, 168.
- Merging models of biomineralisation with concepts of nonclassical crystallisation: is a liquid amorphous precursor involved in the formation of the prismatic layer of the Mediterranean fan mussel Pinna nobilis? SE Wolf*, I Lieberwirth, F Natalio, JF Bardeau, N Delorme, F Emmerling, R Barrea, M Kappl & F Marin in Faraday Discussions N°159 Crystallization – a biological perspective (2014) 159 (1), 433-448.
- Carbonate-coordinated metal complexes precede the formation of liquid amorphous mineral emulsions of divalent metal carbonates. SE Wolf, L Müller, R Barrea, CJ Kampf, J Leiterer, U Panne, T Hoffmann, F Emmerling & W Tremel in Nanoscale (2011) 3 (3), 1158-1165. ▶doi: 10.1039/C0NR00761G
- Strong stabilization of liquid amorphous calcium carbonate by ovalbumin: gaining insight into the mechanism of ‘polymer-induced liquid precursor’ processes. SE Wolf*, J Leiterer, V Pipich, R Barrea, F Emmerling & W Tremel in Journal of the American Chemical Society (2011) 133 (32), 12642. ▶Doi: 10.1021/ja202622g
- Formation of silicones mediated by the sponge enzyme silicatein-α. SE Wolf, U Schlossmacher, A Pietuch, B Mathiasch, HC Schröder, WEG Müller & W Tremel in Dalton Transactions (2010) 39 (39), 9245-9249. Teil der Sonderausgabe New Horizon of Organosilicon Chemistry. ▶Doi: 10.1039/B921640E
- Evidence for biogenic processes during formation of ferromanganese crusts from the Pacific Ocean: implications of biologically induced mineralization. X Wang, U Schloßmacher, F Natalio, HC Schröder, SE Wolf, W Tremel & WEG Müller in Micron (2009) 40 (5-6), 526-535. Doi: 10.1016/J.MICRON.2009.04.005
- Bioencapsulation of living bacteria (Escherichia coli) with poly(silicate) after transformation with silicatein-alpha gene. WEG Müller, S Engel, X Wang, SE Wolf, W Tremel, NL Thakur, A Krasko, M Divekar & HC Schröder in Biomaterials (2008) 29 (7), 771-779. ▶Doi: 10.1016/j.biomaterials.2007.10.038
- Early homogenous amorphous precursor stages of calcium carbonate and subsequent crystal growth in levitated droplets. SE Wolf, J Leiterer, M Kappl, F Emmerling & W Tremel in Journal of the American Chemical Society (2008) 130 (37), 12342-12347. Doi: 10.1021/ja800984y
- Nucleation and growth of CaCO3 mediated by the egg-white protein ovalbumin: a time-resolved in situ study using small-angle neutron scattering. V Pipich, M Balz, SE Wolf, W Tremel & D Schwahn in Journal of the American Chemical Society (2008) 130 (21), 6879-6892. ▶Doi: 10.1021/ja801798h
- Poly(silicate)‐metabolizing silicatein in siliceous spicules and silicasomes of demosponges comprises dual enzymatic activities. WEG Müller, U Schloßmacher, X Wang, A Boreiko, D Brandt, SE Wolf, W Tremel & HC Schröder in The FEBS Journal (2008) 275 (2), 362-370. ▶Doi: 10.1111/j.1742-4658.2007.06206.x
- Reply to “mirror symmetry breaking” of the centrosymmetric CaCO3 crystals with amino acids. N Loges, SE Wolf, M Panthöfer, L Müller, MC Reinnig, T Hoffmann & W Tremel in Angewandte Chemie (2008) 120 (20), 3741-3744 bzw. Angewandte Chemie International Edition (2008), 47, 3683–3686. ▶Doi: 10.1002/anie.200800120
- Analysis of the axial filament in spicules of the demosponge Geodia cydonium: different silicatein composition in microscleres and megascleres. WEG Müller, U Schloßmacher, C Eckert, A Krasko, A Boreiko, H Ushijima, SE Wolf, W Tremel & HC Schröder in European Journal of Cell Biology (2007) 86 (8), 473-487.
- Formation of giant spicules in the deep-sea hexactinellid Monorhaphis chuni (Schulze 1904): electron-microscopic and biochemical studies. WEG Müller, C Eckert, K Kropf, X Wang, U Schloßmacher, C Seckert, K Kropf, X Wang, U Schloßmacher, CS Eckert, SE Wolf, W Tremel & HC Schröder in Cell and Tissue Research (2007) 329 (2), 363-378. ▶Doi: 10.1007/S00441-007-0402-X
- Phase selection of calcium carbonate through the chirality of adsorbed amino acids. SE Wolf, N Loges, B Mathiasch, M Panthöfer, I Mey, A Janshoff & W Tremel in Angewandte Chemie International Edition (2007) 46 (29), 5618-5623 bzw. Angewandte Chemie (2007), 119, 5716 – 5721. VIP-Artikel mit Innentitelbild.
▶Doi: 10.1002/anie.200700010 bzw. ▶Doi: 10.1002/ange.200700010
- Potential relevance of nonclassical crystallization processes to nephrolithiasis. SE Wolf, J Harris, A Lovett & L. B. Gower in Kidney Stones: Medical and Surgical Management. Eds.: FL Coe, EM Worcester, JE Lingeman & A Evan, Jaypee Medical Publishers, in print.
- Challenges and perspectives of the polymer-induced liquid-precursor process: the pathway from liquid-condensed mineral precursors to mesocrystalline products.
SE Wolf & LB Gower in New Perspectives on Mineral Nucleation and Growth. Eds.: M Kellermeier, A van Driessche, L Benning, D Gebauer. Springer, 2018, 43-75.
- Nonclassical crystallization of bivalent metal carbonates. SE Wolf SVH Verlag (Saarbrücken) 2011.
- Template surfaces for the formation of calcium carbonate. W Tremel, J Küther, M Balz, N Loges & SE Wolf in Handbook of Biomineralization: Biomimetic and Bio-inspired Materials Chemistry (Vol. 2). Ed.: E Bäuerlein. Wiley-VCH, 2007, 209 – 232.
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Prof. Dr. rer. nat. Stephan E. Wolf
Juniorprofessor for Biomimetic Materials and Processing
Department of Materials Science and Engineering
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