Fusion of Seashell Nacre and Marine Bioadhesive Analogs: High‐Strength Nanocomposite by Layer‐by‐Layer Assembly of Clay and L‐3,4‐Dihydroxyphenylalanine Polymer

Abstract

Nature has evolved materials that possess mechanical properties surpassing many man-made composites. Bones, teeth, spider silk, or nacre, are just a few well-known examples of biomaterials that exhibit exceptionally high tensile strengths, hardness, or toughness. [1][2][3][4][5][6] These remarkable properties have driven scientists to study and model their architectures and compositions, from micro-to nanoscales, in the hope of developing analogous synthetic materials. Of these, probably the most studied is nacre. [4,[7][8][9][10][11][12][13][14][15] It is composed of 95 % brittle CaCO 3 plates with just a few percent of organic "glue", yet it is twice as hard and more than ca. 1000 times as tough as its constituent phases. [16] These exceptional mechanical properties together with the macroscopic beauty and elegance of its nanoscale hierarchy serve as a model for design of high-performance materials. Preparation of artificial analogs of nacre has been approached by using several different methods and the resulting materials capture some of the characteristics of the natural composite. [17][18][19][20][21][22][23] In our own work, we have used a layerby-layer (LBL) assembly technique to prepare a nanostructured analogue of nacre from inorganic nanometer-sized sheets of Na + -Montmorillonite clay (C) and a polyelectrolyte, poly(diallyldimethylammonium chloride) (PDDA).[24] The structure, deformation mechanism, and mechanical properties of this material were found to be comparable with those of natural nacre and lamellar bones (tensile strength, r = (100 ± 10) MPa, and Young's modulus, Y = (11 ± 2) GPa). Contrary to other preparation techniques the LBL method is relatively simple and highly versatile in merging different functionalities into a single composite. [25][26][27] At the same time, a vast array of available assembly components allows us to generate alternative designs as a means of understanding the different interactions necessary for preparation of nacrelike composites with application-tailored mechanical responses. LBL technique has proven to be an ideal method for preparation of multifunctional, nanostructured materials. Since its inception in 1990s, [28] there has been a virtual explosion in the amount of scientific literature in this subject. Similarly, LBL assembly of clays was also pioneered and further studied in the 1990s by Ferguson's group. [29,30] Since then, the LBL technique has been found to be applicable for the preparation of superhydrophobic surfaces, [31] sensors and semipermeable membranes, [32][33][34][35] drug and biomolecules delivery, [36,37] optically active and responsive films, [38][39][40] fuel cells and photovoltaic materials, [41,42] biomimetic and bioresponsive coatings, [43] semiconductors, [44,45] catalysts, [46] and magnetic devices, [26,47] to name a few. All of the potential applications mentioned above also require both control and improvement of mechanical properties. Using the mix-and-match approach to LBL films, that is, stratified multilayers, [25,26,44] the mecha...

Fusion of nacre, mussel, and lotus leaf: bio-inspired graphene composite paper with multifunctional integration

“…Optimized biological solutions provide a source of inspiration for scientists to design rationally and to construct reproducibly multiscale structures for multifunctional integration. [4][5][6][7][8] In nature, nacre, glass sponges, teeth, bones, and other biomaterials have evolved different solutions to overcome the brittleness of their building materials. [9][10][11] Among the variety of biological materials, nacre is one of most promising owing to its superior mechanical strength and toughness (Fig.…”

Composites, Multifunctional

“…Using layer by layer assembly technique, Podsiadlo et al [84] have been able to prepare a nanostruc tured analogue of nacre from nanometer sized sheets of montmorillonite clay and a polyelectrolyte. Artificial nacre has also been synthesized [103].…”

Nacre‐Inspired Structural Composites: Performance‐Enhancement Strategy and Perspective

“…Since then, more clay-based nacre-like films have been synthesized through the LBL method, and the mechanical properties are promoted by modifying the MTM [14] or crosslinking the polymer. [15] However, the thickness of the nacre-inspired films synthesized by the LBL method is limited to sub-10 µm as LBL is extremely time-consuming. [4] To increase the thickness of nacre-like films, efficient methods such as vacuum-assisted filtration, [16,17] electrophoretic-assisted deposition, [18] evaporation, [19,20] and dip-coating [21] have been developed in the following years.…”