Lightweight Calcium-Silicate-Hydrate Nacre with High Strength and High Toughness

TY - JOUR

T1 - Lightweight Calcium-Silicate-Hydrate Nacre with High Strength and High Toughness

AU - Wang, Yuhuan

AU - Bao, Yi

AU - Meng, Weina

N1 - Publisher Copyright: © 2024 American Chemical Society.

PY - 2024/8/27

Y1 - 2024/8/27

N2 - Low flexural strength and toughness have posed enduring challenges to cementitious materials. As the main hydration product of cement, calcium silicate hydrate (C-S-H) plays important roles in the mechanical performance of cementitious materials while exhibiting random microstructures with pores and defects, which hinder mechanical enhancement. Inspired by the “brick-and-mortar” microstructure of natural nacre, this paper presents a method combining freeze casting, freeze-drying, in situ polymerization, and hot pressing to fabricate C-S-H nacre with high flexural strength, high toughness, and lightweight. Poly(acrylamide-co-acrylic acid) was used to disperse C-S-H and toughen C-S-H building blocks, which function as “bricks”, while poly(methyl methacrylate) was impregnated as “mortar”. The flexural strength, toughness, and density of C-S-H nacre reached 124 MPa, 5173 kJ/m3, and 0.98 g/cm3, respectively. The flexural strength and toughness of the C-S-H nacre are 18 and 1230 times higher than those of cement paste, respectively, with a 60% reduction in density, outperforming existing cementitious materials and natural nacre. This research establishes the relationship between material composition, fabrication process, microstructure, and mechanical performance, facilitating the design of high-performance C-S-H-based and cement-based composites for scalable engineering applications.

AB - Low flexural strength and toughness have posed enduring challenges to cementitious materials. As the main hydration product of cement, calcium silicate hydrate (C-S-H) plays important roles in the mechanical performance of cementitious materials while exhibiting random microstructures with pores and defects, which hinder mechanical enhancement. Inspired by the “brick-and-mortar” microstructure of natural nacre, this paper presents a method combining freeze casting, freeze-drying, in situ polymerization, and hot pressing to fabricate C-S-H nacre with high flexural strength, high toughness, and lightweight. Poly(acrylamide-co-acrylic acid) was used to disperse C-S-H and toughen C-S-H building blocks, which function as “bricks”, while poly(methyl methacrylate) was impregnated as “mortar”. The flexural strength, toughness, and density of C-S-H nacre reached 124 MPa, 5173 kJ/m3, and 0.98 g/cm3, respectively. The flexural strength and toughness of the C-S-H nacre are 18 and 1230 times higher than those of cement paste, respectively, with a 60% reduction in density, outperforming existing cementitious materials and natural nacre. This research establishes the relationship between material composition, fabrication process, microstructure, and mechanical performance, facilitating the design of high-performance C-S-H-based and cement-based composites for scalable engineering applications.

KW - C−S−H nacre

KW - C−S−H/polymer composite

KW - calcium silicate hydrate (C−S−H)

KW - flexural performance

KW - lightweight

KW - “brick-and-mortar” hierarchical microstructure

UR - https://www.scopus.com/pages/publications/85201428582

UR - https://www.scopus.com/pages/publications/85201428582#tab=citedBy

U2 - 10.1021/acsnano.4c08200

DO - 10.1021/acsnano.4c08200

M3 - Article

C2 - 39141799

SN - 1936-0851

VL - 18

SP - 23655

EP - 23671

JO - ACS Nano

JF - ACS Nano

IS - 34

ER -