Transparent and tough bulk composites inspired by nacre

Abstract

Materials combining optical transparency and mechanical strength are highly demanded for electronic displays, structural windows and in the arts, but the oxide-based glasses currently used in most of these applications suffer from brittle fracture and low crack tolerance. We report a simple approach to fabricate bulk transparent materials with a nacre-like architecture that can effectively arrest the propagation of cracks during fracture. Mechanical characterization shows that our glass-based composites exceed up to a factor of 3 the fracture toughness of common glasses, while keeping flexural strengths comparable to transparent polymers, silica- and soda-lime glasses. Due to the presence of stiff reinforcing platelets, the hardness of the obtained composites is an order of magnitude higher than that of transparent polymers. By implementing biological design principles into glass-based materials at the microscale, our approach opens a promising new avenue for the manufacturing of structural materials combining antagonistic functional properties.

Strong and tough nacre-like aluminas: Process–structure–performance relationships and position within the nacre-inspired composite landscape

“…Ice templating [29,30], laser engraving [31,32], heatassisted slip casting [33], spray forming [34], coextrusion [35], sedimentation [36], or lamination [37] has been used to produce brick and mortar structures at the hundreds to tens of micron scale with alumina [30], silicon carbides [38], or hydroxyapatite [39], whereas another branch focused on using 2D materials and paper-making process [40,41,42,43,44]. Because of Griffith scaling law, smaller reinforcement sizes usually mean stronger composites, so the next development was to use micron-sized bricks, with alumina platelets [45,46,47], glass flakes [33,48], or brushite platelets [49]. Several secondary phases have been used in these composites, from polymers [47,50,51] to metal [52,53,54,55,56] and even graphene [57] or metallic glasses [58].…”

Amorphous Alumina Nanosheets/Polylactic Acid Artificial Nacre

“…[29][30][31] The almost transparent nanocomposite film (e.g., the transmittance is 92.1% for AAN with 0.75 wt % AAs) is obtained by assembling the hybrid solution, and the refractive index (n = 1.19) is between the values of glass and air: n glass z 1.52 and n air z 1.00 ( Figures 1G, 1H, S5A, and S5B). 12 However, its transmittance gradually decreases with increase of the AA content. The total transmittance probably indicates the uniform orientation of AAs in the polymer matrix.…”

“…For example, the toughness of nacre is three orders of magnitude higher than that of pure aragonite, providing important implications on engineering material design. [10][11][12] Therefore, the delicate reinforcement structures in the biomineralization process have been widely recognized as inspiration for preparing further high-performance structural materials. [1][2][3][4]13,14 However, the diversity of reinforcement structures in natural materials has not been fully copied by existing biomimetic efforts.…”

“…[1][2][3][4]13,14 However, the diversity of reinforcement structures in natural materials has not been fully copied by existing biomimetic efforts. 7,12,15 Reinforcement architectures in artificial composites are currently limited, partially by the inability to fully control or adjust the local hybrid interfacial interactions between stiff fillers and the soft matrix that comprise the basic reinforcement architecture.…”

Water-mediated crystallohydrate–polymer composite as a phase-change electrolyte

“…O rganic-inorganic composite materials have been widely used in many applications, including biomaterials [1][2][3][4] , catalysts [5][6][7] , automotive materials 8,9 , electronic device [10][11][12][13][14] , and building materials 15,16 . The major challenge for composite material properties is their interfacial compatibility between organic and inorganic components 17 .…”