LAUSR

Cement and concretes are important construction materials throughout human history. There is an urgent need to explore novel and untraditional cementitious materials to enhance of durability of building material and structures in response to increased infrastructure demand worldwide. We report an exploratory study on a bio- composite cement based on large-scale computational study using density functional theory. An explicitly solvated mixture of a mineral calcium silicate hydrate (C-S-H) crystal suolunite (Ca2Si2O5(OH)2.H2O) and a silicon binding peptide with amino acid sequence PRO-PRO-PRO-TRP-LEU-PRO-TYR-MET-PRO-PRO-TRP-SER is constructed using ab initio molecular dynamics (AIMD). Detailed analysis on the interface structure, interatomic bonding, mechanical properties and solvent effect of this model reveal a complex interplay of different types of covalent and ionic bonding, including ubiquitous hydrogen bonding which play a crucial role in their properties. The use of the total bond order density (TBOD), a single quantum mechanical metric, for assessing the interfacial cohesion for this composite bio-cement is proposed. We find that the solvated model has a slightly larger TBOD than the dried one. These results could lead to a systematic search and rational design for different types of bio-inspired and hybrid functional materials with other inorganic minerals and organic peptides.