Investigation of composite silane emulsion modified by in-situ functionalized graphene oxide for cement-based materials

Investigation of Composite Protective Coatings Coregulated by Core–Shell Structures and Graphene Oxide Interfaces

“…An increase in the core–shell ratio leads to an increasing MWD value due to the greater randomness of the multichain polymerization of siloxane molecules. The MWD value of Pickering-A emulsions decreases with increasing GO content, which is attributed to the spatial modulation of the chain growth reaction of polysiloxane molecules by the GO interface . However, the molecular weight variation of Pickering-B emulsions is essentially independent of the GO content, and its MWD value is always above 1.7.…”

“…The internal surface of the blank specimen has a large number of granular hydration products. The cement specimen treated with silane emulsion is internally covered with flocculated layers, which are calcium silicate minerals formed by the reaction of siloxane molecules with cement hydrates including Ca­(OH) 2 and C–S–H gels . Cement specimens coated with CSP emulsions show a high number of interconnected clustered structures inside.…”

“…Cement specimens coated with CSP emulsions show a high number of interconnected clustered structures inside. The floccule within the cement substrate is continuously deposited and developed with the decreased core–shell ratios due to the rapid penetration and directional adsorption of polysiloxane molecules along the capillary channels . There are more numerous and evenly scattered flocculent structures inside the cement samples that corresponded to Pickering-A emulsions; some of the flocs intersect and develop into columnar structures.…”

“…A superficial shielding layer and an internal hydrophobic layer are formed after film formation, resulting in an advantageous adhesion and cooperativity between the polymer component and the cement hydrates. Besides, the core–shell structure facilitates the secondary hydration reaction between polysiloxane chains and cement hydration products, thus inhibiting the transport of H 2 O in the capillary and gel pores . Simultaneously, the paraffin molecules in CSP emulsions weaken the disorderly entanglement and excessive cross-linking between long-chain polymer molecules, significantly improving the dispersibility and permeability of the composite emulsion.…”

Understanding the wetting discrepancy in calcium alumino silicate hydrate induced by Al/Si ratio

“…In macro experiments, the wettability of water droplets at the interface of concrete or modified concrete has been studied and significant achievements have been made. 3–8 Li et al 6 investigated the contact angle (CA) of concrete at different cure times and found that the CA value of a water droplet on concrete in 3 d is 34.34° and in 28 d is 24.5°, suggesting that the interfacial wettability of concrete is positively correlated with the amount of cement hydration products. Flores-Vivian et al 8 measured the interface CA of concrete before and after superhydrophobic modification with a self-assembled material and observed that the CA value improved from approximately 33° to 156°.…”