Articoli di riviste: "Natural nacre"

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Yin, Z., F. Hannard e F. Barthelat. "Impact-resistant nacre-like transparent materials". Science 364, n. 6447 (27 giugno 2019): 1260–63. http://dx.doi.org/10.1126/science.aaw8988.

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Glass has outstanding optical properties, hardness, and durability, but its applications are limited by its inherent brittleness and poor impact resistance. Lamination and tempering can improve impact response but do not suppress brittleness. We propose a bioinspired laminated glass that duplicates the three-dimensional “brick-and-mortar” arrangement of nacre from mollusk shells, with periodic three-dimensional architectures and interlayers made of a transparent thermoplastic elastomer. This material reproduces the “tablet sliding mechanism,” which is key to the toughness of natural nacre but has been largely absent in synthetic nacres. Tablet sliding generates nonlinear deformations over large volumes and significantly improves toughness. This nacre-like glass is also two to three times more impact resistant than laminated glass and tempered glass while maintaining high strength and stiffness.

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Vasiliu, Ana. "Natural Pearls". Key Engineering Materials 672 (gennaio 2016): 80–102. http://dx.doi.org/10.4028/www.scientific.net/kem.672.80.

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A literature less traveled – peaking between 1900-1920 – draws on pre-classical concepts of crystal growth and a trove of field biology, to understand ectopic shell production, the natural source of pearls. By 1907, grafts from the calcifying mantle epithelium on gonads induced nacre mineralization consistently in Pinctada margaritifera, suggesting that anomalously displaced, readily specialized cells are at least a sufficient cause of natural pearl formation. Otherwise, the epithelial sacks wrapping natural nacreous pearls must specialize for nacre production independently from the shell producing mantle – an idea supported by experiments with shell regeneration, but not amenable to a method of inducing pearl formation. At the time, chasing epithelial cell migration was technically unfeasible, signalling was news, stemness was fiction. Boldly, Jameson & Rubbel [1902-1912] marshalled natural pearl nuclei and shell repairs as mineral records of cells specializing de novo into the shell’s secretory regimes. Much of this paper reenacts the historic debate on the origin of pearls: thence bold ideas connect smoothly with new work both on bone or shell. I replicate Jameson’s choice of samples and revisit his proposal to search for an “agency [other than the] shell-secreting mechanism“ acting on ”replacement cells” as the origin of pearls. Much has changed: specialized epithelial cells reportedly migrate; non-differentiated cells remain available throughout and near the calcifying mantle epithelium – both, open possibilities for natural pearl nucleation. Interest in understanding the latter now connects with results sketching the signalling cascade in cell specialization toward bone morphogenesis. Replicating Jameson’s choice of samples, I describe the more spectacular structural changes in the mineralization of pearls associated with two instances of cell specialization: toward producing one shell material – in the event of natural pearl nucleation, or switching between two in later pearl growth. Clusters of cells producing distinctly novel mineralization – nacre over fibrous-prismatic aragonite – could be singled out next to natural pearls by Jameson. The possibility has not been probed in roughly a hundred years. Natural pearl nucleation as a cellular event has never been explored.

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Rousseau, Marthe, Xavier Bourrat, Philippe Stempflé, Marcel Brendlé e Evelyne Lopez. "Multi-Scale Structure of the Pinctada Mother of Pearl: Demonstration of a Continuous and Oriented Organic Framework in a Natural Ceramic". Key Engineering Materials 284-286 (aprile 2005): 705–8. http://dx.doi.org/10.4028/www.scientific.net/kem.284-286.705.

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Sheet nacre is a promising natural bioceramic, which consists on the internal lustrous “mother of pearl” layer of many molluscan shells, e.g. Pinctada, our model. The aim of this work is to study the structure of the flat polygonal tablets of nacre, in order to understand the multi-scale organization of this composite material and the role of the organic template during the growth of the biocrystal. We studied the organic matrix, in situ with techniques such as darkfield transmission electronic microscopy (TEM) on small cross-sections of nacre of Pinctada maxima, or intermittent-contact atomic force microscopy coupled with phase imaging on samples of nacre of Pinctada margaritifera polished parallel to the surface of the tablets. In this study, we demonstrate the continuity of the organic framework and the crystallographic orientation in the biocrystal at 2 relevant levels : nano- and micro-scale.

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Wang, Jiaen, Tianliang Song, Huaxiang Chen, Wei Ming, Zhiming Cheng, Jingwen Liu, Benliang Liang, Yuting Wang e Guangsheng Wang. "Bioinspired High-Strength Montmorillonite-Alginate Hybrid Film: The Effect of Different Divalent Metal Cation Crosslinking". Polymers 14, n. 12 (16 giugno 2022): 2433. http://dx.doi.org/10.3390/polym14122433.

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The natural nacre has a regular ordered layered structure of calcium carbonate tablets and ion crosslinking proteins stacked alternately, showing outstanding mechanical properties. Inspired by nacre, we fabricated different divalent metal cation-crosslinked montmorillonite-alginate hybrid films (MMT-ALG-X2+; X2+ = Cu2+, Cd2+, Ba2+, Ca2+, Ni2+, Co2+ or Mn2+). The effect of ionic crosslinking strength and hydrogen bond interaction on the mechanical properties of the nacre-mimetics was studied. With the cations affinities with ALG being increased (Mn2+ < Co2+ = Ni2+ < Ca2+ < Ba2+ < Cd2+ < Cu2+), the tensile strength of nacre-mimetics showed two opposite influence trends: Weak ionic crosslinking (Mn2+, Co2+, Ni2+ and Ca2+) can synergize with hydrogen bonds to greatly increase the tensile properties of the sample; Strong ionic crosslinking (Ba2+, Cd2+, Cu2+) and hydrogen bonding form a competitive relationship, resulting in a rapid decrease in mechanical properties. Mn2+ crosslinking generates optimal strength of 288.0 ± 15.2 MPa with an ultimate strain of 5.35 ± 0.6%, obviously superior to natural nacre (135 MPa and 2%). These excellent mechanical properties arise from the optimum synergy of ion crosslinking and interfacial hydrogen bonds between crosslinked ALG and MMT nanosheets. In addition, these metal ion-crosslinked composite films show different colors, high visible transparency, and excellent UV shielding properties.

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Xu, X., H. Guo, M. Li e H. Fu. "Improving microbially induced calcium carbonate precipitation effects by nacre extractions". Géotechnique Letters 12, n. 1 (marzo 2022): 20–26. http://dx.doi.org/10.1680/jgele.21.00068.

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In microbially induced calcium carbonate precipitation (MICP) process, it is the precipitated calcium carbonate that cements loose sand particles together to improve their mechanical properties. Seashell nacre composed of calcium carbonate is a natural product, which is worth researching for its remarkable hardness, strength and toughness. However, there has been no study that bridges this natural nacre mineralisation with MICP. Therefore, a precedent herein is established to modify the MICP process by way of the water-soluble matrix (WSM) extracted from nacre, where WSM contributes to the great mechanical properties of nacre. This study examines the effects of WSM with different concentrations on urease activity of bacteria and strength as well as the microstructure of bio-cemented sand samples. The results show that a small number of WSM (50 mg/l) can improve the average strength of bio-cemented sand samples by 1·5 times. This is because 50 mg/l WSM can significantly improve the urease activity. Thus, more calcium carbonate crystals are precipitated, and the higher unconfined compressive strength of bio-cemented sand samples is achieved. The microstructures are investigated by x-ray diffraction and scanning electron microscopy. Overall, this study is an unprecedented exploration imitating nacre that hopefully paves way for future studies.

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Li, Xuan Qi, e Hua Chun Zeng. "Calcium Carbonate Nanotablets: Bridging Artificial to Natural Nacre". Advanced Materials 24, n. 47 (14 settembre 2012): 6277–82. http://dx.doi.org/10.1002/adma.201202733.

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Gong, Shanshan, Qi Zhang, Ruliang Wang, Lei Jiang e Qunfeng Cheng. "Synergistically toughening nacre-like graphene nanocomposites via gel-film transformation". Journal of Materials Chemistry A 5, n. 31 (2017): 16386–92. http://dx.doi.org/10.1039/c7ta03535g.

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Luz, Gisela M., e João F. Mano. "Biomimetic design of materials and biomaterials inspired by the structure of nacre". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 367, n. 1893 (28 aprile 2009): 1587–605. http://dx.doi.org/10.1098/rsta.2009.0007.

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The micro-architecture of nacre (mother of pearl) has been classically illustrated as a ‘brick-and-mortar’ arrangement. It is clear now that hierarchical organization and other structural features play an important role in the amazing mechanical properties of this natural nanocomposite. The more important structural characteristics and mechanical properties of nacre are exposed as a base that has inspired scientists and engineers to develop biomimetic strategies that could be useful in areas such as materials science, biomaterials development and nanotechnology. A strong emphasis is given on the latest advances on the synthetic design and production of nacre-inspired materials and coatings, in particular to be used in biomedical applications.

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Sumitomo, Taro, Hideki Kakisawa, Yusuke Owaki e Yutaka Kagawa. "Structure of Natural Nano-Laminar Composites: TEM Observation of Nacre". Materials Science Forum 561-565 (ottobre 2007): 713–16. http://dx.doi.org/10.4028/www.scientific.net/msf.561-565.713.

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Nacre is a natural composite material making up the inner structure of mollusk shells. It has been of great interest in materials research due to its mechanical properties far exceeding that of its individual components: well ordered plates of aragonite (a CaCO3 polymorph) within an organic polymer matrix. Generally the aragonite plates had been treated as single crystals and mechanical behavior explained as the result of micro-scale mechanisms between plates and matrix. However, recent work has shown that the plates themselves are made up of smaller nano-scale structures, which are also thought to contribute to the bulk properties. In this work, transmission electron microscopy (TEM) was used to observe the nano-scale structure of nacre from abalone. “Nanograins” of aragonite surrounded by organic material was observed, showing composite structure within aragonite plates.

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Shao, Yue, Hong-Ping Zhao e Xi-Qiao Feng. "On flaw tolerance of nacre: a theoretical study". Journal of The Royal Society Interface 11, n. 92 (6 marzo 2014): 20131016. http://dx.doi.org/10.1098/rsif.2013.1016.

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As a natural composite, nacre has an elegant staggered ‘brick-and-mortar’ microstructure consisting of mineral platelets glued by organic macromolecules, which endows the material with superior mechanical properties to achieve its biological functions. In this paper, a microstructure-based crack-bridging model is employed to investigate how the strength of nacre is affected by pre-existing structural defects. Our analysis demonstrates that owing to its special microstructure and the toughening effect of platelets, nacre has a superior flaw-tolerance feature. The maximal crack size that does not evidently reduce the tensile strength of nacre is up to tens of micrometres, about three orders higher than that of pure aragonite. Through dimensional analysis, a non-dimensional parameter is proposed to quantify the flaw-tolerance ability of nacreous materials in a wide range of structural parameters. This study provides us some inspirations for optimal design of advanced biomimetic composites.

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Khayrani, Apriliana Cahya, Nonni Soraya Sambudi, Hans Wijaya, Yose Fachmi Buys, Fitri Ayu Radini, Norwahyu Jusoh, Norashikin Ahmad Kamal e Hazwani Suhaimi. "Review of Artificial Nacre for Oil–Water Separation". Separations 10, n. 3 (15 marzo 2023): 205. http://dx.doi.org/10.3390/separations10030205.

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Due to their extraordinary prospective uses, particularly in the areas of oil–water separation, underwater superoleophobic materials have gained increasing attention. Thus, artificial nacre has become an attractive candidate for oil–water separation due to its superhydrophilicity and underwater superoleophobicity properties. Synthesized artificial nacre has successfully achieved a high mechanical strength that is close to or even surpasses the mechanical strength of natural nacre. This can be attributed to suitable synthesis methods, the selection of inorganic fillers and polymer matrices, and the enhancement of the mechanical properties through cross-linking, covalent group modification, or mineralization. The utilization of nacre-inspired composite membranes for emerging applications, i.e., is oily wastewater treatment, is highlighted in this review. The membranes show that full separation of oil and water can be achieved, which enables their applications in seawater environments. The self-cleaning mechanism’s basic functioning and antifouling tips are also concluded in this review.

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Rademaker, Hanna, e Malte Launspach. "Detection of interaction between biomineralising proteins and calcium carbonate microcrystals". Beilstein Journal of Nanotechnology 2 (27 aprile 2011): 222–27. http://dx.doi.org/10.3762/bjnano.2.26.

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The natural composite nacre is characterised by astonishing mechanical properties, although the main constituent is a brittle mineral shaped as tablets interdispersed by organic layers. To mimic the natural formation process which takes place at ambient conditions an understanding of the mechanism responsible for a defined microstructure of nacre is necessary. Since proteins are assumed to be involved in this mechanism, it is advantageous to identify distinct proteins interacting with minerals from the totality of proteins contained in nacre. Here, we adopted and modified a recently published approach given by Suzuki et al. Suzuki, M.; Saruwatari, K.; Kogure, T.; Yamamoto, Y.; Nishimura, T.; Kato, T.; Nagasawa, H. Science 2009, 325, 1388–1390. doi:10.1126/science.1173793 that gives a hint of specific protein–mineral interactions. Synthesised aragonite or calcite microcrystals were incubated with a protein mixture extracted from nacre of Haliotis laevigata. After incubation the mineral phase was dissolved and investigated for attached proteins. The results give a hint of one protein that seems to bind specifically to aragonite and not to calcite. The presented protocol seems to be suitable to detect mineral binding proteins quickly and therefore can point to proteins whose mineral binding capabilities should be investigated further.

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Yang, Yang, Xiangjia Li, Ming Chu, Haofan Sun, Jie Jin, Kunhao Yu, Qiming Wang, Qifa Zhou e Yong Chen. "Electrically assisted 3D printing of nacre-inspired structures with self-sensing capability". Science Advances 5, n. 4 (aprile 2019): eaau9490. http://dx.doi.org/10.1126/sciadv.aau9490.

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Lightweight and strong structural materials attract much attention due to their strategic applications in sports, transportation, aerospace, and biomedical industries. Nacre exhibits high strength and toughness from the brick-and-mortar–like structure. Here, we present a route to build nacre-inspired hierarchical structures with complex three-dimensional (3D) shapes by electrically assisted 3D printing. Graphene nanoplatelets (GNs) are aligned by the electric field (433 V/cm) during 3D printing and act as bricks with the polymer matrix in between as mortar. The 3D-printed nacre with aligned GNs (2 weight %) shows lightweight property (1.06 g/cm3) while exhibiting comparable specific toughness and strength to the natural nacre. In addition, the 3D-printed lightweight smart armor with aligned GNs can sense its damage with a hesitated resistance change. This study highlights interesting possibilities for bioinspired structures, with integrated mechanical reinforcement and electrical self-sensing capabilities for biomedical applications, aerospace engineering, as well as military and sports armors.

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Gao, Kefeng, Guoqi Tan, Yanyan Liu, Qiang Wang, Qian Tang, Xuegang Wang, Qiqiang Duan, Zengqian Liu, Zhe Yi e Zhefeng Zhang. "Compression fatigue properties of bioinspired nacre-like composites compared with natural nacre: Effects of architectures and orientations". International Journal of Fatigue 179 (febbraio 2024): 108062. http://dx.doi.org/10.1016/j.ijfatigue.2023.108062.

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Suwannasing, Chanyatip, Ausanai Prapan, Piyaporn Surinlert, Chanyarak Sombutkayasith e Wattana Weerachatyanukul. "The Osteoinductive Effect of Water-Soluble Matrix from Nano-Nacre Particles of Haliotis diversicolor (H. diversicolor) Abalone on MC3T3-E1 Osteoblasts". Applied Sciences 15, n. 6 (7 marzo 2025): 2907. https://doi.org/10.3390/app15062907.

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Osteoporosis is characterized by an imbalance between osteoblastic bone formation and osteoclastic bone resorption, leading to an increased risk of fractures. The water-soluble matrix (WSM) of nacre exhibits osteoinductive properties in osteoblastic cells, both in vitro and in vivo. However, its release from natural nacre remains challenging due to its solid and compact surface. This study aimed to prepare nano-nacre particles with smaller diameters than intact aragonite crystals to enhance WSM release and to investigate its effects on osteoblast differentiation. Size analysis and SEM imaging showed that the nano-nacre particles had an average size of about 600 nm. Furthermore, their effects on osteoblast differentiation and mineralization were evaluated through qPCR and ARS assay. The results showed that WSM significantly upregulated key osteogenic genes, including RUNX2, ALP, and OCN, in a dose- and time-dependent manner over 14 days, with fold-changes ranging from 1.6 to 3.6. Additionally, the mineralization effects showed calcium deposition levels comparable to those of the positive group. These findings suggest that WSM may be a promising soluble factor for osteoblast differentiation and mineralization. Therefore, understanding the effects of the WSM from H. diversicolor nano-nacre particles on osteoblasts in vitro may provide evidence suggesting that it could be a promising anti-osteoporosis agent.

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Murphy, Jennifer N., Céline M. Schneider, Lilo K. Mailänder, Quentin Lepillet, Kelly Hawboldt e Francesca M. Kerton. "Wealth from waste: blue mussels (Mylitus edulis) offer up a sustainable source of natural and synthetic nacre". Green Chemistry 21, n. 14 (2019): 3920–29. http://dx.doi.org/10.1039/c9gc01244c.

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Reddy, Vantari Swathi, Jayaprada Reddy Surakanti e Deepak Kumar Sharma. "A comparative evaluation of human enamel remineralization ability of biomimetic nacre against casein phosphopeptide-amorphous calcium phosphate: An in vitro study". Journal of Conservative Dentistry and Endodontics 27, n. 9 (settembre 2024): 954–61. http://dx.doi.org/10.4103/jcde.jcde_460_24.

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Introduction: This study aimed to assess and compare the efficacy of Nacre and casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on the remineralization of enamel using surface microhardness analysis, scanning electron microscopy (SEM), and energy dispersive X-ray (EDX) spectroscopy. Materials and Methods: Twenty human maxillary premolars extracted for orthodontic reasons were collected. Under cool water spray, the crowns were sectioned mesiodistally into buccal and palatal halves using a diamond disc. The samples were subsequently mounted in self-cure acrylic resin. The samples were then subjected to Vickers hardness testing and SEM-EDX for baseline. To simulate carious lesions, all of the samples were acid-etched with 37% phosphoric acid for 30 s in a specific area on the enamel samples and subjected to surface microhardness testing and SEM-EDX. The enamel samples were randomly assigned to Group 1: Nacre water-soluble matrix (WSM), Group 2: Nacre varnish, and Group 3: CPP-ACP for remineralization. After 21 days, remineralization assessment of the test samples was done using SMH analysis and SEM-EDX analysis. Data obtained were statistically analyzed using the one-way analysis of variance to reveal the significant differences between the groups. Tukey’s test was used for post hoc comparisons. Results: All three groups showed a significant increase in surface microhardness. All three groups showed a significant calcium and phosphorous ratio increase after remineralization. Among the three groups, the highest Ca:P ratio was seen in the Nacre WSM group (0.58) followed by the Nacre Varnish (0.57) and CPP-ACP group (0.57). SEM images of the Nacre surface revealed the presence of extensive interlocking. A layer of packed hydroxyapatite particles was formed on the surface of the nacre through surface reactions. Conclusion: All the groups in the present study showed some extent of remineralizing ability irrespective of the different materials and mechanisms of action. Nacre WSM showed a remarkable hardness spike close to natural enamel after demineralization.

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Yang, Xingzi, Md Jalal Uddin Rumi e Xiaowei Zeng. "Computational Investigation of the Mechanical Response of a Bioinspired Nacre-like Nanocomposite under Three-Point Bending". Journal of Composites Science 8, n. 5 (7 maggio 2024): 173. http://dx.doi.org/10.3390/jcs8050173.

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Natural biological nanocomposites, like nacre, demonstrate extraordinary fracture toughness, surpassing their base materials, attributed to their intricate staggered hierarchical architectures integrating hard and soft phases. The enhancement of toughness in these composites is often linked to the crack-deflection mechanism. Leveraging the core design principles that enhance durability, resilience, and robustness in organic materials, this paper describes the use of computational modeling and simulation to perform a three-point bending test on a 3D staggered nanocomposite intentionally crafted to mimic the detailed microstructure of nacre. We adopted a previously proposed interfacial zone model that conceptualizes the “relatively soft” layer as an interface between the “hard” mineral tablets and the microstructure’s interlayer spaces to examine how the microstructure and interface characteristics affect the mechanical responses and failure mechanisms. By comparing the model’s predictions with experimental data on natural nacre, the simulations unveil the mechanisms of tablet separation through adjacent layer sliding and crack deflection across interfacial zones. This study offers a robust numerical method for investigating the fracture toughening mechanisms and damage evolution and contributes to a deeper understanding of the complex interplays within biomimetic materials.

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Gunnison, Katie E., Mehmet Sarikaya e Ilhan A. Aksay. "Toughening mechanisms in abalone shell". Proceedings, annual meeting, Electron Microscopy Society of America 48, n. 4 (agosto 1990): 196–97. http://dx.doi.org/10.1017/s0424820100174114.

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Abalone shell (Haliotis Rufescens) is a naturally ocurring ceramic/polymer composite material. The system displays a unique laminated structure of calcium carbonate (aragonite) crystals in a matrix of biological macromolecules. The CaCO3 crystals and the organic matrix are arranged in a miniature “brick and mortar” structure referred to as nacre. Figure 1 is a TEM bright field micrograph illustrating the high degree of order observed in this microstructure.Although the nacre region of the shell is more than 95% CaCO3 by volume, the natural matrix material and the arrangement of the microstructure lead to a substantial increase in the observed mechanical properties. Mechanical tests performed on the nacre region show a fifty-fold increase over that of pure bulk CaCO3 (Fig. 2), which also compares with other ceramic and cermet systems.Vickers microhardness testing was performed on samples polished for optical microscopy. Crack propagation features were observed by standard SEM techniques and analyzed in an attempt to identify the possible toughening mechanisms that are operating in the nacre structure. The cracks generally travel by a tortuous path, often displaying microcracks and crack branching. However, these mechanisms alone are not sufficient to account for the observed mechanical properties.

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Zhang, Gangsheng, e Xiaodong Li. "Uncovering Aragonite Nanoparticle Self-assembly in Nacre—A Natural Armor". Crystal Growth & Design 12, n. 9 (13 agosto 2012): 4306–10. http://dx.doi.org/10.1021/cg3010344.

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Chan-Colli, Danny G., Eliana M. Agaliotis, David Frias-Bastar, Luming Shen, Jose G. Carrillo, Pedro J. Herrera-Franco e Emmanuel A. Flores-Johnson. "Ballistic Behavior of Bioinspired Nacre-like Composites". Biomimetics 8, n. 4 (1 agosto 2023): 341. http://dx.doi.org/10.3390/biomimetics8040341.

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In this paper, the ballistic performance of a multilayered composite inspired by the structural characteristics of nacre is numerically investigated using finite element (FE) simulations. Nacre is a natural composite material found in the shells of some marine mollusks, which has remarkable toughness due to its hierarchical layered structure. The bioinspired nacre-like composites investigated here were made of five wavy aluminum alloy 7075-T651 (AA7075) layers composed of ~1.1-mm thick square tablets bonded together with toughened epoxy resin. Two composite configurations with continuous layers (either wavy or flat) were also studied. The ballistic performance of the composite plates was compared to that of a bulk monolithic AA7075 plate. The ballistic impact was simulated in the 300–600 m/s range using two types of spherical projectiles, i.e., rigid and elastoplastic. The results showed that the nacre plate exhibited improved ballistic performance compared to the bulk plate and the plates with continuous layers. The structural design of the nacre plate improved the ballistic performance by producing a more ductile failure and enabling localized energy absorption via the plastic deformation of the tablets and the globalized energy dissipation due to interface debonding and friction. All the plate configurations exhibited a better ballistic performance when impacted by an elastoplastic projectile compared to a rigid one, which is explained by the projectile plastic deformation absorbing some of the impact energy and the enlarged contact area between the projectile and the plates producing more energy absorption by the plates.

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Wang, Xiao Xiang, Lei Xie, Cheng Luo e Ri Zhi Wang. "Natural Nacre Coatings on Titanium Implant Grown by Fresh Water Bivalve Shell". Key Engineering Materials 309-311 (maggio 2006): 743–46. http://dx.doi.org/10.4028/www.scientific.net/kem.309-311.743.

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Titanium dental implant screws were implanted into the pearl sacs of a fresh water bivalve (hyriopsis cumingii Lea) by replacing the pearls. After 45 days of cultivation, the implant surfaces were deposited with a nacre coating with iridescent luster. The coating was about 200-600 µm in thickness and composed of a laminated nacreous layer and a transitional non-laminated layer that consisted mainly of vaterite and calcite polymorphs of calcium carbonate. The transitional layer was around 2-10 µm thick in the convex and flat region of the implant surface and could form close contact with titanium surface; while the transitional layer was much thicker in the steep concave regions and could not form close contact with the titanium surface. The improvement to the design of the dental implant with respect to this coating method was suggested in the paper. The results suggest that it is possible to fabricate a biologically active and degradable, and mechanically tough and strong nacre coating on titanium dental implant by this novel coating technology.

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Meng, Yufeng, Bo Yang, Libo Mao e Shuhong Yu. "Multifunctional artificial nacre via biomimetic matrix-directed mineralization". JUSTC 52 (2022): 1. http://dx.doi.org/10.52396/justc-2022-0022.

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Natural nacre, one of the most studied biological structural materials with delicate hierarchical structures and extraordinary performance, has inspired the design and fabrication of artificial structural ceramics with high fracture toughness. However, to meet the diverse requirements of different applications, future structural materials must be multifunctional with superior mechanical properties, such as strength, hardness, and toughness. Herein, based on the matrix-directed mineralization method for producing biomimetic structural materials, we introduce nanoparticles with different inherent functions into the platelets of artificial nacre via the co-mineralization of aragonite and the nanoparticles. Besides their enhanced mechanical properties, the obtained artificial nacre materials also exhibit different functions depending on the type of the nanoparticles. To extend the versatility of this strategy, the effects of nanoparticles of different sizes and zeta potentials on mineralization are also analyzed. This universal strategy can be applied to the fabrication of other types of functionalized biomimetic structural ceramics that have potential applications in various fields, such as biomedical science.

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Xu, Junhua, Liang Liu, Juan Yu, Yujun Zou, Wenhui Pei, Lili Zhang, Wenbo Ye et al. "Simple synthesis of self-assembled nacre-like materials with 3D periodic layers from nanochitin via hydrogelation and mineralization". Green Chemistry 24, n. 3 (2022): 1308–17. http://dx.doi.org/10.1039/d1gc03988a.

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A one-step ion diffusion process was used to synthesize hydrogel composites with designable, regularly interspaced organic/inorganic strata. “Brick-and-mortar” structures with a strength similar to that of natural nacre were formed after hot pressing.

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Xu, P., T. Erdem e E. Eiser. "A simple approach to prepare self-assembled, nacre-inspired clay/polymer nanocomposites". Soft Matter 16, n. 23 (2020): 5497–505. http://dx.doi.org/10.1039/c9sm01585j.

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Inspired by the relationship between the ordered architecture of aragonite crystals and biopolymers found in natural nacre, we present a facile strategy to construct organic/inorganic nanocomposites with hierarchical structure via a water-evaporation driven self-assembly process.

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Daud, Norlinda, e Robert A. Shanks. "Highly-filled hybrid composites prepared using centrifugal deposition". Journal of Polymer Engineering 34, n. 9 (1 dicembre 2014): 875–81. http://dx.doi.org/10.1515/polyeng-2013-0160.

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Abstract Natural composites of high filler content, such as nacre, a composite comprised of 95–99% w/w aragonite layers, have been of interest due to their hardness, strength and toughness. High filler content composites have been prepared synthetically, although due to viscosity and processing requirements, the filler content was limited compared with natural systems. In this paper we describe hybrid high filler content composites prepared to be biomimetic of nacre. Development of processing conditions increased the filler content from 50% w/w using a laboratory stirrer to obtain hybrid composites with 77–86% w/w filler content, prepared by centrifugal deposition and hot compression molding techniques. Both methods were very different from natural formation from layer-by-layer (LBL) construction, however, the composites formed were of high filler content approaching the level in nature. The composites exhibited high modulus and strength, although deformation at break was low, consistent with highly filled materials. Glass transition of the resin phase was increased slightly, while damping was decreased by filler content. Surface morphology of the fractured composite showed a layered structure of well dispersed fillers with minute voids scattered evenly, indicating that the composite was effectively compacted.

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Tabrizian, Parinaz, Huijun Sun, Urangua Jargalsaikhan, Tan Sui, Sean Davis e Bo Su. "Biomimetic Nacre-Like Hydroxyapatite/Polymer Composites for Bone Implants". Journal of Functional Biomaterials 14, n. 8 (25 luglio 2023): 393. http://dx.doi.org/10.3390/jfb14080393.

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One of the most ambitious goals for bone implants is to improve bioactivity, incapability, and mechanical properties; to reduce the need for further surgery; and increase efficiency. Hydroxyapatite (HA), the main inorganic component of bones and teeth, has high biocompatibility but is weak and brittle material. Cortical bone is composed of 70% calcium phosphate (CaP) and 30% collagen and forms a complex hierarchical structure with anisotropic and lamellar microstructure (osteons) which makes bone a light, strong, tough, and durable material that can support large loads. However, imitation of concentric lamellar structure of osteons is difficult to achieve in fabrication. Nacre from mollusk shells with layered structures has now become the archetype of the natural “model” for bio-inspired materials. Incorporating a nacre-like layered structure into bone implants can enhance their mechanical strength, toughness, and durability, reducing the risk of implant catastrophic failure or fracture. The layered structure of nacre-like HA/polymer composites possess high strength, toughness, and tunable stiffness which matches that of bone. The nacre-like HA/polymer composites should also possess excellent biocompatibility and bioactivity which facilitate the bonding of the implant with the surrounding bone, leading to improved implant stability and long-term success. To achieve this, a bi-directional freeze-casting technique was used to produce elongated lamellar HA were further densified and infiltrated with polymer to produce nacre-like HA/polymer composites with high strength and fracture toughness. Mechanical characterization shows that increasing the ceramic fractions in the composite increases the density of the mineral bridges, resulting in higher flexural and compressive strength. The nacre-like HA/(methyl methacrylate (MMA) + 5 wt.% acrylic acid (AA)) composites with a ceramic fraction of 80 vol.% showed a flexural strength of 158 ± 7.02 MPa and a Young’s modulus of 24 ± 4.34 GPa, compared with 130 ± 5.82 MPa and 19.75 ± 2.38 GPa, in the composite of HA/PMMA, due to the higher strength of the polymer and the interface of the composite. The fracture toughness in the composition of 5 wt.% PAA to PMMA improves from 3.023 ± 0.98 MPa·m1/2 to 5.27 ± 1.033 MPa·m1/2 by increasing the ceramic fraction from 70 vol.% to 80 vol.%, respectively.

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Pan, Guiran, Yimin Yao, Xiaoliang Zeng, Jiajia Sun, Jiantao Hu, Rong Sun, Jian-Bin Xu e Ching-Ping Wong. "Learning from Natural Nacre: Constructing Layered Polymer Composites with High Thermal Conductivity". ACS Applied Materials & Interfaces 9, n. 38 (13 settembre 2017): 33001–10. http://dx.doi.org/10.1021/acsami.7b10115.

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Barthelat, Francois, e Deju Zhu. "A novel biomimetic material duplicating the structure and mechanics of natural nacre". Journal of Materials Research 26, n. 10 (19 maggio 2011): 1203–15. http://dx.doi.org/10.1557/jmr.2011.65.

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Zhang, Ganggang, Alice Brion, Anne-Sophie Willemin, Marie-Hélène Piet, Vanessa Moby, Arnaud Bianchi, Didier Mainard, Laurent Galois, Pierre Gillet e Marthe Rousseau. "Nacre, a natural, multi-use, and timely biomaterial for bone graft substitution". Journal of Biomedical Materials Research Part A 105, n. 2 (7 novembre 2016): 662–71. http://dx.doi.org/10.1002/jbm.a.35939.

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Naveen, Jesuarockiam, Mohammad Jawaid, Kheng Lim Goh, Degalhal Mallikarjuna Reddy, Chandrasekar Muthukumar, Tamil Moli Loganathan e Koduri Naga Ganapathy Lakshmi Reshwanth. "Advancement in Graphene-Based Materials and Their Nacre Inspired Composites for Armour Applications—A Review". Nanomaterials 11, n. 5 (8 maggio 2021): 1239. http://dx.doi.org/10.3390/nano11051239.

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Abstract (sommario):

The development of armour systems with higher ballistic resistance and light weight has gained considerable attention as an increasing number of countries are recognising the need to build up advanced self-defence system to deter potential military conflicts and threats. Graphene is a two dimensional one-atom thick nanomaterial which possesses excellent tensile strength (130 GPa) and specific penetration energy (10 times higher than steel). It is also lightweight, tough and stiff and is expected to replace the current aramid fibre-based polymer composites. Currently, insights derived from the study of the nacre (natural armour system) are finding applications on the development of artificial nacre structures using graphene-based materials that can achieve high toughness and energy dissipation. The aim of this review is to discuss the potential of graphene-based nanomaterials with regard to the penetration energy, toughness and ballistic limit for personal body armour applications. This review addresses the cutting-edge research in the ballistic performance of graphene-based materials through theoretical, experimentation as well as simulations. The influence of fabrication techniques and interfacial interactions of graphene-based bioinspired polymer composites for ballistic application are also discussed. This review also covers the artificial nacre which is shown to exhibit superior mechanical and toughness behaviours.

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Yao, Nan, Alexander K. Epstein, Wendy W. Liu, Franz Sauer e Ning Yang. "Organic–inorganic interfaces and spiral growth in nacre". Journal of The Royal Society Interface 6, n. 33 (26 agosto 2008): 367–76. http://dx.doi.org/10.1098/rsif.2008.0316.

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Abstract (sommario):

Nacre, the crown jewel of natural materials, has been extensively studied owing to its remarkable physical properties for over 160 years. Yet, the precise structural features governing its extraordinary strength and its growth mechanism remain elusive. In this paper, we present a series of observations pertaining to the red abalone ( Haliotis rufescens ) shell's organic–inorganic interface, organic interlayer morphology and properties, large-area crystal domain orientations and nacre growth. In particular, we describe unique lateral nano-growths and paired screw dislocations in the aragonite layers, and demonstrate that the organic material sandwiched between aragonite platelets consists of multiple organic layers of varying nano-mechanical resilience. Based on these novel observations and analysis, we propose a spiral growth model that accounts for both [001] vertical propagation via helices that surround numerous screw dislocation cores and simultaneous 〈010〉 lateral growth of aragonite sheet structure. These new findings may aid in creating novel organic–inorganic micro/nano composites through synthetic or biomineralization pathways.

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Melaibari, Ammar, e Pal Molian. "Picosecond Laser Micromachining of Ultra-Hard AlMgB₁₄ Thin Films". Advanced Materials Research 804 (settembre 2013): 17–22. http://dx.doi.org/10.4028/www.scientific.net/amr.804.17.

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Ultra-hard AlMgB14 (30-50 GPa) thin films were deposited on silicon substrate for a nominal thickness of 100 nm using a pulsed excimer laser and then subjected to direct micromachining using a 532 nm, 30 picosecond pulsed Nd:YAG laser. The application is targeted towards synthesizing an artificial nacre material composed of hexagonal bricks and particle bridges of superhard AlMgB14 thin film and mortars of Ti thin film that biomimic the hierarchical architecture of natural nacre. The effects of pulse energy (0.1 to 1 μJ) and laser scanning speed (0.5 to 1.5 m/sec) on ablation depth and quality of scribed channels were evaluated. The morphology of the channels was characterized using confocal microscope and optical profilometer. Results indicated a clean material removal process characterized by absence of heat affected zone, high-speed scribing and small feature size. The energy fluence for the removal of 100 nm thin film without affecting the silicon substrate was 0.3 J/cm2. An interesting observation is that particulate matter present in the thin film was not ablated suggesting a size effect. Analysis of thermal transport reveals that the material removal has occurred via spallation and phase explosion mechanisms. The picosecond laser thus offers a high-speed energy source for precisely ablating ultra-hard thin films that in turn will allow the potential for fabrication of novel artificial nacre with exceptional strength and toughness.

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Valashani, Seyed Mohammad Mirkhalaf, e Francois Barthelat. "A laser-engraved glass duplicating the structure, mechanics and performance of natural nacre". Bioinspiration & Biomimetics 10, n. 2 (30 marzo 2015): 026005. http://dx.doi.org/10.1088/1748-3190/10/2/026005.

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Khayer Dastjerdi, Ahmad, Reza Rabiei e Francois Barthelat. "The weak interfaces within tough natural composites: Experiments on three types of nacre". Journal of the Mechanical Behavior of Biomedical Materials 19 (marzo 2013): 50–60. http://dx.doi.org/10.1016/j.jmbbm.2012.09.004.

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Pattiasina, B. J., R. H. Miru, J. W. Loupatty, A. Y. Pattinasarany, B. M. Laimeheriwa, V. D. Loupatty e P. A. Wenno. "Red Seaweed Porphyra spp. (Bangiales) from Urimessing Waters of Ambon Island - Maluku". IOP Conference Series: Earth and Environmental Science 1207, n. 1 (1 luglio 2023): 012005. http://dx.doi.org/10.1088/1755-1315/1207/1/012005.

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Abstract (sommario):

Abstract A study on the cultivation of Porphyra spp. has been carried out in the waters of Ambon Island. This plant is in great favor with local communities but has not been able to meet broader demands. The purpose of this research was to look into the future of mass culture. In the splashing zone, which is about 10 m above sea level, samples of gametophyte foliose or thalli were taken. The thallus was brought to the laboratory and maintained in a 100-liter container. During the rearing period, the thallus released spermatia and fertilized carpogonia. Carpogonia develop into carposporangia and release zygotospores outside the thallus. A small zygotospore develops into a large carpospore. Carpospores are the forerunners of new sporophytes if they find the correct substrate. In the laboratory, the nacre layer of pearl oyster shells was used to replace the natural substrates. Carpospores attached to the nacre layer germinated and grew into conchocelis. The conchocelis then develops the conchosporangia outward, followed by the release of the conchospores. Conchospores are a source of new thalli grown on polyethylene nylon nets. Conchospores that grew into new thalli on nylon nets were then moved to their natural environments so they could keep growing.

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Li, Xuan Qi, e Hua Chun Zeng. "Self-Assembly: Calcium Carbonate Nanotablets: Bridging Artificial to Natural Nacre (Adv. Mater. 47/2012)". Advanced Materials 24, n. 47 (6 dicembre 2012): 6252. http://dx.doi.org/10.1002/adma.201290301.

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Liu, Tao, Zheng Liu, Zhezhe Zhou, Sheldon Q. Shi, Yi Tan, Hui Chen, Xinyan Sun, Hong Ni, Shanshan Gong e Jianzhang Li. "A high-performance, sustainable nacre-mimetic film with montmorillonite nanosheets crosslinked natural wood powders". Industrial Crops and Products 193 (marzo 2023): 116202. http://dx.doi.org/10.1016/j.indcrop.2022.116202.

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N., Kurganov, Havrin S., Grigor'yeva I., Chugunova K., Povolotskaya A., Pan'kin D. e Kurochkin A. "Interdisciplinary investigation of jet buckles of the Xiongnu epoch with inlay". Archaeological news 30 (2020): 254–62. http://dx.doi.org/10.31600/1817-6976-2020-30-254-262.

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Abstract (sommario):

The paper presents the results of natural science studies of the base and colour inlay of four buckles of the Xiongnu period: three from the burial ground of Ala-Tey 1 (Tuva) and one from the cemetery of Kamenka V (Khakassia). Buckles with many-coloured incrustation and the best preserved inserts were selected for examination. The base of the buckles was made from fossilized coal, probably of the boghead type. Among the inlay materials of the buckles, cornelian, moganite, turquoise, fuchsite and nacre were identified.

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Deville, Sylvain, Eduardo Saiz, Ravi K. Nalla e Antoni P. Tomsia. "Strong Biomimetic Hydroxyapatite Scaffolds". Advances in Science and Technology 49 (ottobre 2006): 148–52. http://dx.doi.org/10.4028/www.scientific.net/ast.49.148.

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Despite extensive efforts in the development of fabrication methods to prepare porous ceramic scaffolds for osseous tissue regeneration, all porous materials have a fundamental limitation- the inherent lack of strength associated with porosity. Shells (nacre), tooth and bone are frequently used as examples for how nature achieves strong and tough materials made out of weak components. So, the unresolved engineering dilemma is how to create a scaffold that is both porous and strong. The objective of this study was to mimic the architecture of natural materials in order to create a new generation of strong hydroxyapatite-based porous scaffolds. The porous inorganic scaffolds were fabricated by the controlled freezing of water-based hydroxyapatite (HA) slurries. The scaffolds obtained by this process have a lamellar architecture that exhibits similarities with the meso- and micro- structure of the inorganic component of nacre. Compressive strengths of 20 MPa were measured for lamellar scaffolds with densities of 32%, significantly better than for the HA with random porosity. In addition, the lamellar materials exhibit gradual fracture unlike conventional porous HA scaffolds. These biomimetic scaffolds could be the basis for a new generation of porous and composite biomaterials.

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Denkena, Berend, Jens Koehler e Analía Moral. "Ductile and brittle material removal mechanisms in natural nacre—A model for novel implant materials". Journal of Materials Processing Technology 210, n. 14 (novembre 2010): 1827–37. http://dx.doi.org/10.1016/j.jmatprotec.2010.06.014.

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42

Singh, Param Punj, e Raghavan Ranganathan. "Tensile and Viscoelastic Behavior in Nacre-Inspired Nanocomposites: A Coarse-Grained Molecular Dynamics Study". Nanomaterials 12, n. 19 (24 settembre 2022): 3333. http://dx.doi.org/10.3390/nano12193333.

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Abstract (sommario):

Organisms hold an extraordinarily evolutionary advantage in forming complex, hierarchical structures across different length scales that exhibit superior mechanical properties. Mimicking these structures for synthesizing high-performance materials has long held a fascination and has seen rapid growth in the recent past thanks to high-resolution microscopy, design, synthesis, and testing methodologies. Among the class of natural materials, nacre, found in mollusk shells, exhibits remarkably high mechanical strength and toughness. The highly organized “brick and mortar” structure at different length scales is a basis for excellent mechanical properties and the capability to dissipate energy and propagation in nacre. Here, we employ large-scale atomistic coarse-grained molecular dynamics simulations to study the mechanical and viscoelastic behavior of nacre-like microstructures. Uniaxial tension and oscillatory shear simulations were performed to gain insight into the role of complex structure-property relationships. Specifically, the role played by the effect of microstructure (arrangement of the crystalline domain) and polymer-crystal interactions on the mechanical and viscoelastic behavior is elucidated. The tensile property of the nanocomposite was seen to be sensitive to the microstructure, with a staggered arrangement of the crystalline tablets giving rise to a 20–30% higher modulus and lower tensile strength compared to a columnar arrangement. Importantly, the staggered microstructure is shown to have a highly tunable mechanical behavior with respect to the polymer-crystal interactions. The underlying reasons for the mechanical behavior are explained by showing the effect of polymer chain mobility and orientation and the load-carrying capacity for the constituents. Viscoelastic responses in terms of the storage and loss moduli and loss tangent are studied over three decades in frequency and again highlight the differences brought about by the microstructure. We show that our coarse-grained models offer promising insights into the design of novel biomimetic structures for structural applications.

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Chen, Si-Ming, Huai-Ling Gao, Yin-Bo Zhu, Hong-Bin Yao, Li-Bo Mao, Qi-Yun Song, Jun Xia et al. "Biomimetic twisted plywood structural materials". National Science Review 5, n. 5 (30 luglio 2018): 703–14. http://dx.doi.org/10.1093/nsr/nwy080.

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Abstract Biomimetic designs based on micro/nanoscale manipulation and scalable fabrication are expected to develop new-style strong, tough structural materials. Although the mimicking of nacre-like ‘brick-and-mortar’ structure is well studied, many highly ordered natural architectures comprising 1D micro/nanoscale building blocks still elude imitation owing to the scarcity of efficient manipulation techniques for micro/nanostructural control in practical bulk counterparts. Herein, inspired by natural twisted plywood structures with fascinating damage tolerance, biomimetic bulk materials that closely resemble natural hierarchical structures and toughening mechanisms are successfully fabricated through a programmed and scalable bottom-up assembly strategy. By accurately engineering the arrangement of 1D mineral micro/nanofibers in biopolymer matrix on the multiscale, the resultant composites display optimal mechanical performance, superior to many natural, biomimetic and engineering materials. The design strategy allows for precise micro/nanostructural control at the macroscopic 3D level and can be easily extended to other materials systems, opening up an avenue for many more micro/nanofiber-based biomimetic designs.

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Yang, Yang, Ziyu Wang, Qingqing He, Xiangjia Li, Gengxi Lu, Laiming Jiang, Yushun Zeng et al. "3D Printing of Nacre-Inspired Structures with Exceptional Mechanical and Flame-Retardant Properties". Research 2022 (27 gennaio 2022): 1–12. http://dx.doi.org/10.34133/2022/9840574.

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Flame-retardant and thermal management structures have attracted great attention due to the requirement of high-temperature exposure in industrial, aerospace, and thermal power fields, but the development of protective fire-retardant structures with complex shapes to fit arbitrary surfaces is still challenging. Herein, we reported a rotation-blade casting-assisted 3D printing process to fabricate nacre-inspired structures with exceptional mechanical and flame-retardant properties, and the related fundamental mechanisms are studied. 3-(Trimethoxysilyl)propyl methacrylate (TMSPMA) modified boron nitride nanoplatelets (BNs) were aligned by rotation-blade casting during the 3D printing process to build the “brick and mortar” architecture. The 3D printed structures are more lightweight, while having higher fracture toughness than the natural nacre, which is attributed to the crack deflection, aligned BN (a-BNs) bridging, and pull-outs reinforced structures by the covalent bonding between TMSPMA grafted a-BNs and polymer matrix. Thermal conductivity is enhanced by 25.5 times compared with pure polymer and 5.8 times of anisotropy due to the interconnection of a-BNs. 3D printed heat-exchange structures with vertically aligned BNs in complex shapes were demonstrated for efficient thermal control of high-power light-emitting diodes. 3D printed helmet and armor with a-BNs show exceptional mechanical and fire-retardant properties, demonstrating integrated mechanical and thermal protection.

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Rocha, Katari P., Santiago Botasini e Eduardo Méndez. "Physicochemical characterization of biogenic calcium carbonate". MRS Advances 3, n. 61 (2018): 3569–74. http://dx.doi.org/10.1557/adv.2018.528.

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ABSTRACTBiogenic minerals are widely studied materials for their particular properties derived from their hierarchical structure, using building blocks with sizes spanning several orders of magnitude. These special features can be assessed with different analytical tools, and it is important to know their capabilities and limitations. In order to determine the hierarchical structure of the shells, the nacre and prismatic layers of two marine animals were characterized by infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. Based on these assessments, we found that the combination of these three techniques is useful to describe each structure level, and to explain some of the unique properties observed in these natural materials.

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Agathopoulos, Simeon, L. S. Ozyegin, Z. Ahmad, O. Gunduz, E. S. Kayali, Onur Meydanoglu e F. N. Oktar. "Nano-Bioceramics Production from Razor Shell". Key Engineering Materials 493-494 (ottobre 2011): 775–80. http://dx.doi.org/10.4028/www.scientific.net/kem.493-494.775.

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The regeneration potential of human bone is limited in the cases of repairing large bone defects, such as those associated with comminuted fractures or bone tumor resection. In most cases, autogenous and allogenic bones are used as bone grafts. However, the amount of both of them is severely limited. Nowadays, natural biomaterials are in question, like corals, cuttlefish, and various nacre species, or hydroxyapatite (HA) made from egg shells. The present work aims at preparing inexpensive nano-sized HA and whitlockite particles from various raw materials of natural-biological origin. Razor shells (ensis ensis) were collected from beaches of Thessaloniki in Greece. Each sample was reduced to particle size <100 µm and DTA/TG was employed to determine their exact CaCO3content. The suspended raw powders were put on a hotplate. The temperature was set to 80°C for 15 min. Then, equivalent amount of H3PO4was added, drop by drop, into the solution. Different Ca/P ratios were tried. The reaction was ultrasonically assisted and continued for 8h. Then, to evaporate the liquid part, the mixture was put into an incubator at 100°C for 24 h and the resulting dried sediment was collected. The morphology of the produced powders was examined by SEM and revealed nano-sized particles. X-ray diffraction analysis indicated various Ca-phosphate phases, i.e. monetite and calcium phosphate hydrate. Thus, razor shells could be an alternative source for calcium phosphate ceramics production. In this study, long nacre shells were converted to various bioceramic structures with simple ultrasonic method without using hydrothermal method, which is carried out in a close vessel heated in a furnace and could cause accident if the vessel is worn. Chemical ultrasonic method is very safe and reliable method for bioceramic production from aragonite structures.

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Ferrand, Hortense Le. "Could Bio-Inspired Nacre-Like Ceramics be Suitable to Fabricate Musical Instruments?" Music & Science 5 (gennaio 2022): 205920432211461. http://dx.doi.org/10.1177/20592043221146184.

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In the past, natural ceramic biomaterials like bones and seashells were used to make music. Today, ceramics are largely absent from the musical scene. Yet, recent development of bio-inspired ceramics could be used to create musical instruments that emulate sound from ancient times, that do not make use of endangered animal species or that enable exploration of new types of music. In this paper, the question of whether bio-inspired ceramics would be suitable for usage in musical instrument is posed. The study focusses on nacre-like alumina ceramics of various compositions and their suitability to be used, fabricated, and to produce sound are discussed based on materials’ properties. It is found that flat pieces could be produced with high throughput for making idiophones or parts of musical instruments to increase the sound radiance, for example, and that complex shapes could be produced by a craftsperson to reproduce other musical instruments’ designs or create new ones using 3D printing technologies. The potential application of such ceramics for music could also open ideas in architecture where tiles are used, for example. Future work to enable these applications should be on more thorough characterisation of dynamic properties according to standards, scaled-up and reliable fabrication processes, and evaluation of the sound produced.

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Nikitina, Natalia, e Natalia Tuliakova. "Translation of Anatole France’s L’Étui de nacre in Russia: Reception and Perception". Interlitteraria 21, n. 1 (4 luglio 2016): 79. http://dx.doi.org/10.12697/il.2016.21.1.7.

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The paper analyzes and compares the numerous translations of L’Étui de nacre by Anatole France into Russian. The undertaken research aims at establishing the tendencies in the long series of translations, taking into account the possible reasons for the translators’ long-lasting interest in the text.We first analyze the translational theories of the time and highlight their evolution during the first half of the 20th century. Then, we suggest an analysis of France’s cycle, and consider the motives behind its appeal to the translators. Finally, we compare the strategies chosen by the translators and the way they may affect the perception of the text. We argue that the flow of translations may be explained by the complexity of France’s text, which has resulted in a constant search for a perfect translation. The complexity comprised both linguistic difficulties, such as France’s balance of natural speech and elevated objects of description, and extralinguistic hurdles, for instance, the abundance of realias belonging to different epochs and countries. It is obvious that translations done in different years from 1890 to 1959 reflect the development of translation theory and also the political and social changes which Russia underwent during this period. Another conclusion that we are coming to is that the existing translations tend to demonstrate a significant decrease in ambiguity, inherent in France’s cycle.

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Wan, Yizao, Xiangbo Zhu, Zhihuan Huang, Mengxia Peng e Honglin Luo. "Incorporation of dual nanoplatelets to a natural polymer for foldable, robust, bioactive, and biocompatible nacre-like nanocomposites". Composites Part B: Engineering 214 (giugno 2021): 108747. http://dx.doi.org/10.1016/j.compositesb.2021.108747.

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Willemin, Anne‐Sophie, Ganggang Zhang, Emilie Velot, Arnaud Bianchi, Veronique Decot, Marthe Rousseau, Pierre Gillet e Vanessa Moby. "The effect of nacre extract on cord blood‐derived endothelial progenitor cells: A natural stimulus to promote angiogenesis?" Journal of Biomedical Materials Research Part A 107, n. 7 (25 febbraio 2019): 1406–13. http://dx.doi.org/10.1002/jbm.a.36655.

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