Title: Synthesis of Core-Shell CS/APCS Particle via Electrostatic Self-Assembly
Author(s): Dongmin Wang and Chunlong Huang
Publication: Symposium Paper
Appears on pages(s): 389-402
Keywords: colloidal nanosilica; amphoteric polycarboxylate superplasticizer; core-shell structure; electrostatic self- assembly; microwave irradiation
The durability and mechanical properties of cement-based materials reinforced by nano-SiO2 particles strongly depend on the dispersion characteristics of the nano-SiO2 particles in the cement pore solution. This study presents a simple, inexpensive and environmentally friendly method to improve the distribution of colloidal nano-SiO2 particles. Amphoteric polycarboxylate superplasticizer containing a cationic moiety in its backbone, was synthetized under microwave irradiation and introduced onto the surface of colloidal nano-SiO2 particles being negatively charged using electrostatic self-assembly technique. The above method guarantees the formation of a core-shell structure nano-SiO2 particle, wherein the amphoteric polycarboxylate superplasticizer shell exhibits enhanced steric hindrance repulsion and electrostatic repulsion. Moreover, the proposed method application guarantees a higher dispersion stability of colloidal nano-SiO2 in the saturated calcium hydroxide solution, which makes it favorable for the production of cement-based materials.