Biomimetic layer-by-layer assembly of artificial nacre

Abstract

nacre is a technologically remarkable organic-inorganic composite biomaterial. It consists of an ordered multilayer structure of crystalline calcium carbonate platelets separated by porous organic layers. This microstructure exhibits both optical iridescence and mechanical toughness, which transcend those of its constituent components. Replication of nacre is essential for understanding this complex biomineral, and paves the way for tough coatings fabricated from cheap abundant materials. Fabricating a calcitic nacre imitation with biologically similar optical and mechanical properties will likely require following all steps taken in biogenic nacre synthesis. Here we present a route to artificial nacre that mimics the natural layer-bylayer approach to fabricate a hierarchical crystalline multilayer material. Its structure-function relationship was confirmed by nacre-like mechanical properties and striking optical iridescence. our biomimetic route uses the interplay of polymer-mediated mineral growth, combined with layer-by-layer deposition of porous organic films. This is the first successful attempt to replicate nacre, using CaCo 3 .

Nacre-mimetics with synthetic nanoclays up to ultrahigh aspect ratios

“…However, this is a major scientific and technological challenge as precise nanostructuration at such biomimetic compositions with high fractions of reinforcements is hard to combine with large-scale processing methods. Various efforts have been undertaken to mimic the layered hard/soft composite structure of nacre 9 via for example, several sequential approaches, such as LbL [10][11][12][13][14][15][16][17][18] and other multilayer deposition strategies 19,20 , ice-templating and sintering of ceramics [21][22][23] , spray coating 24,25 , glow discharge plasma deposition 26 , uncontrolled co-casting of polymer/clay mixtures 27,28 , or processes at interfaces 29,30 . Unfortunately, many of these approaches are limited to a very small scale, and remain technologically infeasible owing to energy-intensive and laborious multistep procedures.…”

Preventing structural aging with synthetic tooth enamel

“…The production of nacre-like artificial material with exceptional combination of properties is now utterly scalable as exemplified by Mao et al [6], utilizing a chitosan matrix for matrix-directed mineralization of CaCO3 aragonite microcrystals to mimic well-ordered laminated structures of nacre. Also other synthetic approaches have been developed to realize such planar structural motif in artificial nanocomposites [7,8,9]. However, studies on the artificial nanocomposites with columnar structures have been barely performed so far, although we can find such motif in a wide range of biomaterials.…”

Scalable Production of Nanostructured Particles using Atomic Layer Deposition

“…Nevertheless, ALD is an inherently rational technique relying on a layer-by-layer (or cluster-by-cluster) assembly of the deposited materials. Similar to the production of layered composite natural or biomimetic materials such as nacre (Finnemore et al, 2012), ALD can be considered as a bio-inspired approach for the fabrication of tailored nanomaterials. ALD proceeds through a sequence of self-terminated gas-solid reactions (R 1 and R 2 ) that can be expressed as (King et al, 2007):…”