Experimental study on the effect of release pressure on the extinguishing efficiency of dry water

Wang, Yang; Zhu, Guoqing; Chai, Guoqiang; Zhou, Ying; Chen, Chunna; Zhang, Wanying

doi:10.1016/j.csite.2021.101177

Cited by 16 publications

(1 citation statement)

References 18 publications

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“…Second, as a soft powder, the connection between stabilizing nano particles and water droplets will be easily broken under pressure, which then releases the encapsulated water. 39 Therefore, as the mechanical mixing progresses, the nanosilica gradually unzips to release the water droplets within dry water under the squeezing between solid particles of the precursor and also the mechanical pressure from the mixer blade. These water droplets now become a supplement to the existing filtered water in the mixture.…”

Section: Rheology Finalmentioning

confidence: 99%

Preparation of Geopolymers with Nanosilica and Water-in-Air Pickering Emulsion: Mechanisms Underlying Its Rheology, Polymerization, and Strength

Yi,

Boluk,

Bindiganavile

2024

Langmuir

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Geopolymers are alkaline-activated aluminosilicate binders recognized as a promising alternative to traditional Portland cement due to their significantly lower greenhouse emissions, energy consumption, and carbon footprint. However, the challenge is meeting or exceeding the strength of Portland cement concrete while being prepared within a desired setting time and possessing workable rheology. A "water-in-air" Pickering emulsion, also called dry water, was prepared by stabilizing water droplets with hydrophobic nano silica and using them to control the geopolymer's strength, setting time, and workability. The mechanisms that underlie the effects of dry water on the rheology, setting, and strength were studied in detail through a combination of rheological, thermal, morphological, chemical, and microstructural assessments. A reduction in the viscosity and yield shear stress manifests in a higher flow diameter, principally due to the particle size coarsening in the precursor and the flowability of hydrophobic nano silica. There was a rapid rise in temperature during the setting process as the dry water temporarily increased the local alkalinity in the mixture, which boosted the dissolution of the precursor and, hence, the reaction. Outcomes from X-ray diffraction, thermogravimetric analysis, and Fourier-transform infrared confirm the highest degree of polycondensation for the principal N-A-S-H framework in mixtures containing dry water. These eventually correspond to a denser microstructure under scanning electron microscopy and, in turn, a superior mechanical strength. Depending on the unique combination of characteristics, including size coarsening, temporary water encapsulation, microfilling effect, and supplementary silica source, dry water resolves the "trade-off" between geopolymer's fresh and hardened properties when introducing nanoparticles.

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Section: Rheology Finalmentioning

confidence: 99%