A5058527610- Calcium Carbonate Crystallization and Inhibition
- Bone Tissue Engineering Materials
- Marine Biology and Environmental Chemistry
- Cephalopods and Marine Biology
- Collagen: Extraction and Characterization
- Catalytic Processes in Materials Science
- Polymer Surface Interaction Studies
- Silk-based biomaterials and applications
- Magnetic and Electromagnetic Effects
- Mesoporous Materials and Catalysis
- Advanced Cellulose Research Studies
- Adhesion, Friction, and Surface Interactions
- Catalysis and Oxidation Reactions
- Quantum Dots Synthesis And Properties
- Nanomaterials for catalytic reactions
- Echinoderm biology and ecology
- Paleontology and Stratigraphy of Fossils
- Cellular Mechanics and Interactions
- Geomagnetism and Paleomagnetism Studies
- Tendon Structure and Treatment
- Bone health and osteoporosis research
- Crystallization and Solubility Studies
- Surface Modification and Superhydrophobicity
- Zeolite Catalysis and Synthesis
- Material Dynamics and Properties
Technische Universität Dresden
2019-2024
University of Hong Kong
2024
Delft University of Technology
2024
University of Haifa
2024
Carnegie Mellon University
2024
Max Planck Institute of Colloids and Interfaces
2014-2023
Technical University of Darmstadt
2022
Bioengineering Center
2022
Institut du Cerveau
2021
Pitié-Salpêtrière Hospital
2021
Hydrous CaCO 3 gets a new structure Calcium carbonate (CaCO ) forms important minerals on Earth and is model system for understanding crystal nucleation. Three different structures of are known, along with two that hydrated. Zou et al. found third hydrated formed from amorphous in the presence magnesium ions. The discovery illustrates importance precursors producing materials. Science , this issue p. 396
Mussel mooring made mighty by metals Mussels produce an exceptional proteinaceous adhesive so they can withstand waves and currents. Metal ions bound to modified tyrosine residues play important role in reinforcing the adhesive. Priemel et al . brought together a variety of spectroscopy microscopy techniques study cellular mechanisms involved fabrication mussels (see Perspective Wilker). They found that metal ion–rich vesicles are secreted alongside containing protein mix microfluidic-like...
Abstract Coccoliths are calcitic particles produced inside the cells of unicellular marine algae known as coccolithophores. They abundant components sea-floor carbonates, and stoichiometry calcium to other elements in fossil coccoliths is widely used infer past environmental conditions. Here we study cryo-preserved dominant coccolithophore Emiliania huxleyi using state-of-the-art nanoscale imaging spectroscopy. We identify a compartment, distinct from coccolith-producing filled with high...
Many organisms use amorphous calcium carbonate (ACC) and control its stability by various additives water; however, the underlying mechanisms are yet unclear. Here, effect of water inorganic commonly found in biology on dynamics structure ACC during crystallization energetics this process is studied. Total X-ray scattering pair distribution function analysis show that short- medium-range order all studied samples similar; situ methodologies allow observation small structural modifications...
The incorporation of foreign ions, such as Mg2+, exhibiting a biological activity for bone regeneration is presently considered promising route increasing the bioactivity bone-engineering scaffolds. In this work, morphology, structure, and surface hydration biomimetic nanocrystalline apatites were investigated before after exchange with Mg2+ by combining chemical alterations (ion exchange, H2O−D2O exchanges) physical examinations (Fourier transform infrared spectroscopy (FTIR)...
The room temperature co-precipitation of ferrous and ferric iron under alkaline conditions typically yields superparamagnetic magnetite nanoparticles below a size 20 nm. We show that at pH = 9 this method can be tuned to grow larger particles with single stable domain magnetic (> 20–30 nm) or even multi-domain behavior 80 nm). crystal growth kinetics resembles surprisingly observations formation in magnetotactic bacteria. physicochemical parameters required for mineralization these organisms...
Calcium carbonate is a common constituent of many natural materials, such as shells and skeletons marine animals. While it well-documented that additives (organic inorganic) modulate the crystallization amorphous calcium (ACC), effects intrinsic physicochemical characteristics ACC, particle size, shape, water content on transformation to crystalline polymorphs, are still poorly understood. Here, we investigate effect size by preparing ACC nanoparticles with an average ranging from ∼66 ∼196...
Abstract The mechanisms by which organisms control the stability of amorphous calcium carbonate (ACC) are yet not fully understood. Previous studies have shown that intrinsic properties ACC and its environment critical in determining stability. Here, question, what is effect bulk incorporation versus surface adsorption additives on synthetic ACC, addressed. Using a wide range situ characterization techniques, it poly(Aspartic acid) (pAsp) has much larger stabilization than pAsp only 1.5%...
Significance Biofilms are multicellular, soft microbial communities that able to colonize synthetic surfaces as well living organisms. To survive sudden environmental changes and efficiently share their common resources, cells in a biofilm divide into subgroups with distinct functions, leading phenotypic heterogeneity. Here, by studying intact biofilms synchrotron X-ray diffraction fluorescence, we revealed correlations between macroscopic, architectural heterogeneity the spatiotemporal...
In this work we used several complementary techniques (TEM, TPR, CO chemisorption, EXAFS and FTIR spectroscopy) to understand the effects of activation temperature atmosphere (air or H2) on particle size distribution, fraction, type exposed surface sites Pd nanoparticles supported a high area SiO2−Al2O3 (SA) support. distribution has been carefully determined by statistic TEM study, from which cuboctahedral-like shape metal particles is demonstrated. Assuming model perfect cuboctahedral...
A multi-technique study devoted to investigate the surface features of nanosized hydroxyapatite (HA) was carried out. UHR-TEM observation provided evidence that HA nanoparticles are constituted by a crystalline core, elongated in direction crystallographic c-axis, coated an amorphous layer 1−2 nm thick. By means IR spectroscopy and microgravimetry, amount water hydroxy groups on evaluated. For as-prepared material, it found first hydration is mainly H2O molecules interacting through...
Magnetotactic bacteria (MTB) use magnetosomes, membrane-bound crystals of magnetite or greigite, for navigation along geomagnetic fields. In Magnetospirillum magneticum sp. AMB-1, and other MTB, a magnetosome gene island (MAI) is essential every step formation. An 8-gene region the MAI encodes several factors implicated in control crystal size morphology previous genetic proteomic studies. We show that these play minor role biomineralization vivo. contrast, MmsF, previously uncharacterized...
Collagen is a versatile structural molecule in nature and used as building block many highly organized tissues, such bone, skin, cornea. The functionality performance of these tissues are controlled by their hierarchical organization ranging from the molecular up to macroscopic length scales. In present study, polarized Raman microspectroscopic imaging analyses were elucidate collagen fibril orientation at various levels structure native rat tail tendon under mechanical load. situ...
Poly(aspartic acid) (pAsp) is known to stabilize amorphous calcium carbonate (ACC) and affect its crystallization pathways. However, little about the mechanisms behind these phenomena. Here it shown that ACC stabilized by pAsp molecules in solution rather than amount of incorporated into bulk, effect on polymorph selection entirely different at low high concentration pAsp. At concentrations, more effective inhibiting nucleation growth vaterite calcite. when calcite formation prevented,...
We study water adsorption-induced deformation of a monolithic, mesoporous silicon membrane traversed by independent channels $\sim$8 nm diameter. focus on the elastic constant associated with Laplace pressure-induced upon capillary condensation, i.e. pore-load modulus. perform finite-element method (FEM) simulations hexagonal and square lattices cylindrical pores representing membrane. find that modulus weakly depends geometrical arrangement pores, can be expressed as function porosity....
Abstract Complex hierarchical structure governs emergent properties in biopolymeric materials; yet, the material processing involved remains poorly understood. Here, we investigated multi-scale and composition of mussel byssus cuticle before, during after formation to gain insight into this hard, yet extensible metal cross-linked protein composite. Our findings reveal that granular substructure crucial cuticle’s function as a wear-resistant coating an polymer fiber is pre-organized condensed...