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Aging society demands advanced bone implants that can achieve long‐term success through osseointegration at the bone‐implant interface. Polyetheretherketone (PEEK), a bioinert implant material, often struggles with connecting to existing bone tissue, leading to inflammation and implant replacement. Following nature's lessons, a new strategy is introduced that masks the surface of bio‐ and chemically inert Polyetheretherketone implants with a covalently anchored bone‐mimetic surface. This method transforms PEEK into a bone‐integrative material by grafting a ≈300 nm thick gelatin layer onto its surface, subsequently mineralized with calcium phosphate. Herein, it is showed that this surface modification for implant materials combines excellent bulk implant properties with the characteristic structure and functional properties of natural bone. In vitro biocompatibility assays, employing NIH‐3T3 fibroblast and MC3T3‐E1 osteoblast cell lines, confirm the enhanced biocompatibility of the modified material. This strategy offers promising prospects for improving bone implants and exemplifies the adaptation of a non‐osseointegrative material to a bone‐like interface. [ABSTRACT FROM AUTHOR]

Mineral plastics are a promising class of bio‐inspired materials that offer exceptional properties, like self‐heal ability, stretchability in the hydrogel state, and high hardness, toughness, transparency, and non‐flammability in the dry state along with reversible transformation into the hydrogel by addition of water. This enables easy reshape‐ability and recycling like the solubility in mild acids to subsequently form mineral plastics again by base addition. However, current mineral plastics rely on petrochemistry, are hardly biodegradable, and thus persistent in nature. This work presents the next generation of mineral plastics, which are bio‐based and biodegradable, making them a promising, new class of polymers for the development of environmentally friendly materials. Physically cross‐linked (poly)glutamic‐acid (PGlu)‐based mineral plastics are synthesized using various alcohol‐water mixtures, metal ion ratios and molecular weights. The rheological properties are easily adjusted using these parameters. The general procedure involves addition of equimolar solution of CaCl2 to PGlu in equal volumes followed by addition of iPrOH (iPrOH:H2O = 1:1) under vigorous stirring conditions. The ready biodegradability of PGlu/CaFe mineral plastic is confirmed in this study where the elements N, Ca, and Fe present in it tend to act as additional nutrients, supporting the growth of microorganisms and consequently, promoting the biodegradation process. [ABSTRACT FROM AUTHOR]

The low toughness under the tension of cement and concrete materials has been a long‐standing issue for decades and it has become increasingly urgent to address in modern society due to the growing demand for the development of high‐performance and sustainable constructions. Manipulating calcium silicate hydrate (C‐S‐H), the main hydration product of Portland cement, which determines the mechanical properties of cementitious materials, is an attractive method for improving their toughness following a bottom‐up approach. Inspired by the microstructure of nacre, a high energy absorption C‐S‐H‐based composite with a highly ordered structure is fabricated by a designed ternary building block, in which exfoliated montmorillonite provides a template for the nucleation and growth of C‐S‐H generating the "brick", and polyvinyl alcohol acts as a "mortar" binding all the building blocks together. With the hierarchical toughening strategy explored here, the obtained C‐S‐H composite achieves a remarkable energy absorption of 16.2 ± 2.6 MJ m−3, which surprisingly outperforms the ultra‐high toughness cementitious materials by a factor of 20–60 and is even higher than that of natural nacre and other nacre‐like composites. These findings not only provide valuable insights into enhancing the toughness of cementitious materials but also open possibilities for broadening potential applications of C‐S‐H. [ABSTRACT FROM AUTHOR]

Developing efficient and affordable electrocatalysts for the sluggish oxygen evolution reaction (OER) remains a significant barrier that needs to be overcome for the practical applications of hydrogen production via water electrolysis, transforming CO2 to value‐added chemicals, and metal‐air batteries. Recently, hydroxides have shown promise as electrocatalysts for OER. In situ or operando techniques are particularly indispensable for monitoring the key intermediates together with understanding the reaction process, which is extremely important for revealing the formation/OER catalytic mechanism of hydroxides and preparing cost‐effective electrocatalysts for OER. However, there is a lack of comprehensive discussion on the current status and challenges of studying these mechanisms using in situ or operando techniques, which hinders our ability to identify and address the obstacles present in this field. This review offers an overview of in situ or operando techniques, outlining their capabilities, advantages, and disadvantages. Recent findings related to the formation mechanism and OER catalytic mechanism of hydroxides revealed by in situ or operando techniques are also discussed in detail. Additionally, some current challenges in this field are concluded and appropriate solution strategies are provided. [ABSTRACT FROM AUTHOR]

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Medical treatment options for bones and teeth can be significantly enhanced by taking control over the crystallization of biomaterials like hydroxyapatite in the healing process. Light‐induced techniques are particularly interesting for this approach as they offer tremendous accuracy in spatial resolution. However, in the field of calcium phosphates, light‐induced crystallization has not been investigated so far. Here, proof of principle is established to successfully induce carbonate‐hydroxyapatite precipitation by light irradiation. Phosphoric acid is released by a photolabile molecule exclusively after irradiation, combining with calcium ions to form a calcium phosphate in the crystallization medium. 4‐Nitrophenylphosphate (4NPP) is established as the photolabile molecule and the system is optimized and fully characterized. A calcium phosphate is crystallized exclusively by irradiation in aqueous solution and identified as carbonate apatite. Control over the localization and stabilization of the carbonate apatite is achieved by a pulsed laser, triggering precipitation in calcium and 4NPP‐containing gel matrices. The results of this communication open up a wide range of new opportunities, both in the field of chemistry for more sophisticated reaction control in localized crystallization processes and in the field of medicine for enhanced treatment of calcium phosphate containing biomaterials. [ABSTRACT FROM AUTHOR]

Die Verwendung von kalziniertem Ton als Zementersatzstoff ist ein vielversprechender Weg, um die künftige Zementproduktion umweltfreundlicher zu gestalten und den CO2‐Fußabdruck von Beton zu verringern. Jedoch wird durch den Ersatz von kalziniertem Ton wird die Zementhydratation häufig verzögert. Obwohl die kombinierte Verwendung von Kalkstein und kalziniertem Ton mit Portlandzement die Verzögerung kompensieren kann, werden die Ursachen für diesen Effekt noch immer diskutiert. Insbesondere die Rolle der gebildeten C‐A‐S‐H‐Phasen in Kombination mit C‐S‐H‐Phasen ist umstritten. Die vorliegende Studie untersucht die geschilderte Verzögerung in Modellsystem C3S und Metakaolin. Die Hydratationsreaktionen von Metakaolin und C3S wurden mittels optischer Emissionsspektroskopie, Rasterelektronenmikroskopie, Röntgenbeugung und Reaktionskalorimetrie analysiert. Die Ergebnisse zeigen, dass Calcium‐ und Sulfationen eine dominierende Rolle für die Reaktionsgeschwindigkeit von Metakaolin spielen, was sich wiederum auf die Hydratationsgeschwindigkeit von C3S auswirkt. Die Rolle der C‐A‐S‐H‐ gegenüber der C‐S‐H‐Bildung wird in diesem Zusammenhang hervorgehoben. [ABSTRACT FROM AUTHOR]

We have developed a straightforward, one-pot, low-temperature hydrothermal method to transform oyster shell waste particles (bCCP) from the species Crassostrea gigas (Mg-calcite, 5 wt% Mg) into hydroxyapatite (HA) micro/nanoparticles. The influence of the P reagents (H3PO4, KH2PO4, and K2HPO4), P/bCCP molar ratios (0.24, 0.6, and 0.96), digestion temperatures (25–200 °C), and digestion times (1 week–2 months) on the transformation process was thoroughly investigated. At 1 week, the minimum temperature to yield the full transformation significantly reduced from 160 °C to 120 °C when using K2HPO4 instead of KH2PO4 at a P/bCCP ratio of 0.6, and even to 80 °C at a P/bCCP ratio of 0.96. The transformation took place via a dissolution–reprecipitation mechanism driven by the favorable balance between HA precipitation and bCCP dissolution, due to the lower solubility product of HA than that of calcite at any of the tested temperatures. Both the bCCP and the derived HA particles were cytocompatible for MG-63 human osteosarcoma cells and m17.ASC murine mesenchymal stem cells, and additionally, they promoted the osteogenic differentiation of m17.ASC, especially the HA particles. Because of their physicochemical features and biological compatibility, both particles could be useful osteoinductive platforms for translational applications in bone tissue engineering. [ABSTRACT FROM AUTHOR]

Analytical ultracentrifugation (AUC) is a classical polymer and colloid analysis technique invented by Theodor Svedberg 100 years ago. Modern hard- and software and powerful computers make it now possible to develop the methodology beyond what was possible with this technique before. This perspective aims to describe new possibilities, which extend the possibilities of AUC beyond the classical repertoire of the determination of distributions of sedimentation coefficient, particle size, and molar mass as well as stoichiometries and interaction constants of interacting systems. High-resolution simultaneous characterization of particle size and optical property distributions, investigation of nucleation by reaction in the AUC cell, characterization of particle interactions at a very high concentration, and characterization of complex fluids or osmotic pressures over large concentration ranges even crossing phase boundaries are among the discussed topics. They show that even after 100 years of successful application, AUC still has much yet unexplored potential in colloid and polymer science. This perspective paper spans from the days of invention of analytical ultracentrifugation to now including nonmainstream methodology and instrumentation, which has a huge potential for the future. This includes multiwavelength detectors, high-resolution particle size distributions, chemical reactions in the ultracentrifuge, high-concentration work, osmotic pressure distributions, and characterization of complex fluids. [ABSTRACT FROM AUTHOR]

Cellulose is the most abundant naturally-occurring polymer, and possesses a one-dimensional (1D) anisotropic crystalline nanostructure with outstanding mechanical robustness, biocompatibility, renewability and rich surface chemistry in the form of nanocellulose in nature. Such features make cellulose an ideal bio-template for directing the bio-inspired mineralization of inorganic components into hierarchical nanostructures that are promising in biomedical applications. In this review, we will summarize the chemistry and nanostructure characteristics of cellulose and discuss how these favorable characteristics regulate the bio-inspired mineralization process for manufacturing the desired nanostructured bio-composites. We will focus on uncovering the design and manipulation principles of local chemical compositions/constituents and structural arrangement, distribution, dimensions, nanoconfinement and alignment of bio-inspired mineralization over multiple length-scales. In the end, we will underline how these cellulose biomineralized composites benefit biomedical applications. It is expected that this deep understanding of design and fabrication principles will enable construction of outstanding structural and functional cellulose/inorganic composites for more challenging biomedical applications. [ABSTRACT FROM AUTHOR]

Nanolimes have been commercially available for over a decade as a remineralization agent for natural stone to combat deterioration. While they have been applied successfully and studied extensively, their penetration abilities in different materials have not yet been readily quantifiable in situ and in real time. Using two transparent pore-imitating test systems (acrylic glass (PMMA) and polydimethylsiloxane (PDMS)) and light microscopy, the penetration coefficients (PCs) of two nanolimes (CaLoSiL (CLS) and Nanorestore Plus (NRP)), as well as their solvents, were determined experimentally in square channels of about 100 µm diameter. Their PCs and those for a previously published glass–resin-based test system were also predicted based on measurable material parameters or literature values using the Lucas–Washburn equation. Additionally, a liquid mineral precursor (LMP) of calcium carbonate based on complex coacervation (CC) was investigated as an alternative to the solid particle dispersions of nanolime. In general, the dispersions behaved like their pure solvents. Overall, trends could be reasonably well predicted with both literature and experimentally determined properties using the Lucas–Washburn equation. In absolute terms, the prediction of observed infiltration behavior was satisfactory for alcohols and nanolimes but deviated substantially for water and the aqueous LMP. The commercially available PMMA chips and newly designed PDMS devices were mostly superior to the previously published glass–resin-based test system, except for the long-term monitoring of material deposition. Lastly, the transfer of results from these investigated systems to a different, nontransparent mineral, calcite, yielded similar PC values independently of the original data when used as the basis for the conversion (all PC types and all material/liquid combinations except aqueous solutions in PDMS devices). This knowledge can be used to improve the targeted design of tailor-made remineralization treatments for different application cases by guiding solvent choice, and to reduce destructive sampling by providing a micromodel for pretesting, if transferability to real stone samples proves demonstrable in the future. [ABSTRACT FROM AUTHOR]

Layered double hydroxides (LDHs), whose formation is strongly related to OH− concentration, have attracted significant interest in various fields. However, the effect of the real‐time change of OH− concentration on LDHs' formation has not been fully explored due to the unsuitability of the existing synthesis methods for in situ characterization. Here, the deliberately designed combination of NH3 gas diffusion and in situ pH measurement provides a solution to the above problem. The obtained results revealed the formation mechanism and also guided us to synthesize a library of LDHs with the desired attributes in water at room temperature without using any additives. After evaluating their oxygen evolution reaction performance, we found that FeNi‐LDH with a Fe/Ni ratio of 25/75 exhibits one of the best performances so far reported. [ABSTRACT FROM AUTHOR]

Copyright of Angewandte Chemie is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Organic–inorganic composite materials with tailored properties can be designed in the lab through bio-inspired approaches. In this context, we exploited the particle-based crystallisation process of calcium sulfate, a technologically important mineral, to hybridise inorganic and organic matter. We identified and synthesised an organic polymer showing strong affinity to bind to the surfaces of mineral precursors as well as intrinsic tendency to self-organise. Subsequently, polymer-coated building units were allowed to self-assemble via oriented attachment, aggregation and phase transformation, which produced ordered superstructures where the organic polymer is intercalated between the subunits and surrounds the hybrid core as a shell. This specific architecture across multiple length scales leads to unique mechanical properties, comparable to those of natural biominerals. Thus, our results devise a straightforward pathway to prepare organic–inorganic hybrid structures via bottom-up self-assembly processes innate to the crystallisation of the inorganic phase. This approach can likely be transferred to other inorganic minerals, affording next-generation materials for applications in the construction sector, biomedicine and beyond. [ABSTRACT FROM AUTHOR]

Amorphous calcium carbonate plays a key role as transient precursor in the early stages of biogenic calcium carbonate formation in nature. However, due to its instability in aqueous solution, there is still rare success to utilize amorphous calcium carbonate in biomedicine. Here, we report the mutual effect between paramagnetic gadolinium ions and amorphous calcium carbonate, resulting in ultrafine paramagnetic amorphous carbonate nanoclusters in the presence of both gadolinium occluded highly hydrated carbonate-like environment and poly(acrylic acid). Gadolinium is confirmed to enhance the water content in amorphous calcium carbonate, and the high water content of amorphous carbonate nanoclusters contributes to the much enhanced magnetic resonance imaging contrast efficiency compared with commercially available gadolinium-based contrast agents. Furthermore, the enhanced T1 weighted magnetic resonance imaging performance and biocompatibility of amorphous carbonate nanoclusters are further evaluated in various animals including rat, rabbit and beagle dog, in combination with promising safety in vivo. Overall, exceptionally facile mass-productive amorphous carbonate nanoclusters exhibit superb imaging performance and impressive stability, which provides a promising strategy to design magnetic resonance contrast agent. Sensitive, biocompatible and stable contrast agents for MRI are in demand. Here, the authors combine gadolinium ions with amorphous calcium carbonate to make stable paramagnetic amorphous carbonate nanoclusters with high MRI contrast and significantly improved biocompatibility over commercial gadolinium-based agents. [ABSTRACT FROM AUTHOR]

Colloidal crystals are arguably one of the most promising candidates when it comes to the fabrication of nanostructured metamaterials. Especially mesocrystals show exciting new properties that emerge from their inherent directional oriented assembly. With this work, the electrical conductivity of well‐defined micrometer‐sized platinum nanocube‐based mesocrystals is demonstrated and tuned through the variation of different capping agents. Herein, a method is presented to reproducibly quantify the intrinsic resistance of individual mesocrystals through electrical nanoprobing and focused ion beam deposition contacting. A thermally activated tunneling mechanism is identified as the main effect for electron propagation. In addition, the mesocrystals are altered through organically linking and mineral bridging the individual nanoparticles. This results in an increase in mesocrystal rigidity and, more importantly, conductivity by seven orders of magnitude while retaining shape, structure, and composition. In addition, these observations are transferred onto multicomponent superstructures in the form of binary mesocrystals. There, it is demonstrated that the electrical properties could be tuned through the ratio of nanoparticles incorporated into a mesocrystalline host system while simultaneously maintaining potential catalytic or superparamagnetic features of the guest particles. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) layered double hydroxides (LDH) are classic materials in fundamental research and practical application. 2D LDH have unique structural features, such as high aspect ratio, high specific surface area, quantum confinement in one direction, layered structure, tunable intercalated anions/ interlayer spacing/metal-cation compositions,, which endow 2D LDH with excellent chemical and physical properties. Since rational production is the first and crucial step towards their utilization, numerous efforts have been devoted to explore innovative and effective methods for their preparation. This review is a comprehensive overview of synthesis methods and aimed to capture the features of different synthesis methods to enable the selection of a suitable method to achieve the desired LDH characteristics. Therefore, we systematically summarized various preparation methods of 2D LDH, including a top-down approach, bottom-up approach, and decomposition-regrowth strategy. Besides, we listed and compared the important parameters relating to both the synthesis process and the obtained products of various synthesis methods, such as the synthesis temperature/pressure, the used device, the utilized reactants, the presence or absence of pre/post-treatment, the yield, the crystallinity and the lateral size and thickness. Finally, some current challenges and further tasks regarding the synthesis of LDH are presented. [ABSTRACT FROM AUTHOR]

Biomaterials such as seashells are intriguing due to their remarkable properties, including their hierarchical structure from the nanometer to the micro- or even macroscopic scale. Transferring this nanostructure to generate nanostructured polymers can improve their electrical conductivity. Here, we present the synthesis of polypyrrole using waste seashell powder as a template to prepare a polypyrrole/CaCO3 composite material. Various synthesis parameters were optimized to produce a composite material with an electrical conductivity of 2.1 × 10−4 ± 3.2 × 10−5 S/cm. This work presents the transformation of waste seashells into sustainable, electronically conductive materials and their application as an antistatic agent in polymers. The requirements of an antistatic material were met for a safety shoe sole. [ABSTRACT FROM AUTHOR]

The growth of crystalline nanoparticles (NPs) generally involves three processes: nucleation, growth, and shape evolution. Among them, the shape evolution is less understood, despite the importance of morphology for NP properties. Here, we propose a symmetry‐based kinematic theory (SBKT) based on classical growth theories to illustrate the process. Based on the crystal lattice, nucleus (or seed) symmetry, and the preferential growth directions under the experimental conditions, the SBKT can illustrate the growth trajectories. The theory accommodates the conventional criteria of the major existing theories for crystal growth and provides tools to better understand the symmetry‐breaking process during the growth of anisotropic structures. Furthermore, complex dendritic growth is theoretically and experimentally demonstrated. Thus, it provides a framework to explain the shape evolution, and extends the morphogenesis prediction to cases, which cannot be treated by other theories. [ABSTRACT FROM AUTHOR]

Copyright of Angewandte Chemie is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, we analysed for the first time heterogeneous nucleation with anisotropic nanoparticles as a model system for non-spherical building units on the nanoscale. Gold nanorods were synthesised and assembled to investigate the phenomenon of heterogeneous nucleation. To determine the influence of the particle shape on heterogeneous nucleation, we utilised gold nanorods with varying aspect ratios, ranging from 3.00 and 2.25 to 1.75, while keeping the surface chemistry constant. First, the nucleation of the gold nanorod assemblies in solution and the process kinetics were analyzed with UV-vis-NIR spectroscopy followed by a microscopic examination of the gold nanorod-based superstructures formed heterogeneously on substrates. Here, positively charged cetyltrimethylammonium bromide (CTAB)-functionalized gold nanorods and negatively charged polystyrene sulfonate (PSS) functionalized substrates ensured the directed heterogeneous nucleation on the substrates. A combination of light microscopy with simultaneous UV-vis-NIR spectroscopy allowed us to observe the gold nanorod-based superstructure formation on the substrates in situ and to determine the nucleation rates of the process. We analysed the resulting data with the classical nucleation theory, which revealed a dominating kinetic term and a negligible thermodynamic term in contrast to ionic systems like calcium carbonate. Our studies consistently exhibit an influence of the aspect ratio on the nucleation behaviour resulting in faster nucleation of superstructures as the aspect ratio decreases. Hence our studies show unprecedented insight into the influence of particle anisotropy on the nucleation and growth of nanorod-based superstructures and reveal significant differences in the nucleation of nanoparticle building units compared to the nucleation of atoms or molecules as building units. [ABSTRACT FROM AUTHOR]

Binary mesocrystals offer the combination of nanocrystal properties in an ordered superstructure. Here, we demonstrate the simultaneous self‐assembly of platinum and iron oxide nanocubes into micrometer‐sized 3D mesocrystals using the gas‐phase diffusion technique. By the addition of minor amounts of a secondary particle type tailored to nearly identical size, shape and surface chemistry, we were able to promote a random incorporation of foreign particles into a self‐assembling host lattice. The random distribution of the binary particle types on the surface and within its bulk has been visualized using advanced transmission and scanning electron microscopy techniques. The 20–40 μm sized binary mesocrystals have been further characterized through wide and small angle scattering techniques to reveal a long‐range ordering on the atomic scale throughout the crystal while showing clear evidence that the material consists of individual building blocks. Through careful adjustments of the crystallization parameters, we could further obtain a reverse superstructure, where incorporated particles and host lattice switch roles. [ABSTRACT FROM AUTHOR]

Copyright of Angewandte Chemie is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In core–shell nanoparticle analysis, the determination of size distributions of the different particle parts is often complicated, especially in liquid media. Density matching is introduced as a method for analyzing core–shell nanoparticles using Analytical Ultracentrifugation (AUC), making it possible to obtain the core size distribution in liquid dispersions. For this approach, the density of the dispersion is adjusted to the density of the shell. Oil filled nanocapsules are utilized with component densities of around 1 g mL−1 to demonstrate this technique. The shell size distribution is calculated supposing the particle size distribution as a convolution of the shell‐ and core size distributions. Finally, the distributions of core size, shell thickness, particle size, and particle density and thus particle composition are obtained. To clarify the effect of swelling, AUC measurements are combined with further size characterization methods like Particle Tracking Microscopy and Dynamic Light Scattering. [ABSTRACT FROM AUTHOR]

Photochemical activation is proposed as a general method for controlling the crystallization of sparingly soluble carbonates in space and time. The photogeneration of carbonate in an alkaline environment is achieved upon photo‐decarboxylation of an organic precursor by using a conventional 365 nm UV LED. Local irradiation was conducted focusing the LED light on a 300 μm radius spot on a closed glass crystallization cell. The precursor solution was optimized to avoid the precipitation of the photoreaction organic byproducts and prevent photo‐induced pH changes to achieve the formation of calcium carbonate only in the corresponding irradiated area. The crystallization was monitored in real‐time by time‐lapse imaging. The method is also shown to work in gels. Similarly, it was also shown to photo‐activate locally the formation of barium carbonate biomorphs. In the last case, the morphology of these biomimetic structures was tuned by changing the irradiation intensity. [ABSTRACT FROM AUTHOR]

For bone implants, osseointegration resulting in a good and fast bone–implant contact is of primary importance to secure a proper implant function and to avoid implant loosening or inflammation resulting in necessary revision surgeries causing pain to the patients and immense costs. In particular, polyetheretherketone (PEEK) is a promising implant material due to the close mechanical properties to bone, but it is entirely bio‐inert, hindering osseointegration and making surface functionalization necessary. Many different surface functionalization technologies have been reported of both physical and chemical nature. The same is true for the other prominent implant materials titanium and ceramics. Although they already have inherently better osseointegration than PEEK, they are much harder and stiffer than bone and brittle in the case of ceramics. Surface functionalization, which can be subdivided into surface coating and material modification, needs to be judged from a quality and safety viewpoint. However, a literature research resulted in the realization that no quality standard yet exists for implant surface functionalizations. This makes it difficult to near impossible to compare the safety and performance of different surface‐functionalized bone implants, clearly showing the need to establish a transparent quality evaluation system for bone implants. This perspective article gives the state of the art and then develops a quality evaluation system based on six main categories as important benchmarks for the quality of surface‐functionalized bone implant materials. A simple catalog of questions can be answered, and from the resulting scores the Safety and Performance Evidence Level (SPEL) representing the safety and quality of a given implant can be calculated as a percentage. This simple SPEL system allows an easy and transparent judgment and comparison of bone implants, ensuring the easy identification of safe and well‐performing high‐quality bone implants in the future. © 2020 The Authors. Polymer International published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The rational preparation of ultrathin two-dimensional metal oxide and hydroxide nanosheets is the first and crucial step towards their utilization in both fundamental research and practical applications. From the perspective of the production cost, the further development of such materials remains a challenging task. Therefore, it is highly desirable to synthesize these materials via a simple and general strategy at room temperature. Besides, less attention has been paid to investigate their growth process, leading to ambiguous formation mechanisms and the lack of guiding principles for designing the targeted ultrathin 2D metal oxides and hydroxides. Here, 6 different ultrathin (<5 nm) 2D metal oxides and hydroxides have been successfully synthesized via a simple precipitation route in formamide aqueous solution at room temperature. Detailed investigations demonstrate that the formation of the ultrathin morphology relies on the inhibition of the z-direction growth by the –NH2 groups of the formamide molecules. These findings broaden the fundamental understanding of 2D material formation mechanisms and inspire interest in extending this strategy to further systems. Our study opens a new avenue for an easy, general and room temperature synthesis of ultrathin 2D metal oxides and hydroxides. [ABSTRACT FROM AUTHOR]

Post‐polymerization modification provides an elegant way to introduce chemical functionalities onto macromolecules to produce tailor‐made materials with superior properties. This concept was adapted to well‐defined block copolymers of the poly(2‐oxazoline) family and demonstrated the large potential of these macromolecules as universal toolkit for numerous applications. Triblock copolymers with separated water‐soluble, alkyne‐ and alkene‐containing segments were synthesized and orthogonally modified with various low‐molecular weight functional molecules by copper(I)‐catalyzed azide‐alkyne cycloaddition (CuAAC) and thiol‐ene (TE) click reactions, respectively. Representative toolkit polymers were used for the synthesis of gold, iron oxide and silica nanoparticles. [ABSTRACT FROM AUTHOR]

We use the model system ethanol–dodecane to demonstrate that giant critical fluctuations induced by easily accessible weak centrifugal fields as low as 2000g can be observed above the miscibility gap of a binary liquid mixture. Moreover, several degrees above the phase transition, i.e. in the one-phase region, strong gradients of ethanol concentration occur upon centrifugation. In this case, the standard interpretation of sedimentation equilibrium in the analytical ultracentrifuge (AUC) yields an apparent molar mass of ethanol three orders of magnitude higher than the real value. Notably, these composition gradients have no influence on the distribution gradient of solutes such as dyes like Nile red. The thick opaque interphase formed upon centrifugation does not appear as the commonly observed sharp meniscus, but as a turbidity zone, similar to critical opalescence. This layer is a few millimeters thick and separates two fluids with low compositional gradients. All these effects can be qualitatively understood and explained using the Flory–Huggins solution model coupled to classical density functional theory (DFT). In this domain hetero-phase fluctuations can be triggered by gravity even far from the critical point. Taking into account Jean Perrin's approach to external fields in colloids, a self-consistent definition of the Flory effective volume and an explicit calculation of the total free energy per unit volume is possible. [ABSTRACT FROM AUTHOR]

Using X‐ray scattering, we measured detailed maps of the diffuse scattering intensity distribution and a number of phonon dispersion branches for a single crystal of inorganically formed natural calcite and for high‐quality mesocrystals of biogenic calcite from a Mediterranean sea urchin spine. A comparison shows that the known differences in the mechanical properties between the 'strong' biogenic and 'brittle' abiotic material should be attributed to the mesoscopic architecture of the crystal rather than to a modification of the calcite crystal structure. The data are rationalized by comparing them to the results of ab initio model calculations of lattice dynamics. For the mesocrystal, they are augmented by the evaluation of the faceting of the constituent nanocrystals. [ABSTRACT FROM AUTHOR]