Mesoporous Hydrophobic Silica Nanoparticles as Flow-Enhancing Additives for Fire and Explosion Suppression Formulations

Saenko, E. V.; Yan, Huijie; Shamsutdinov, Artem Sh.; Кондрашова, Н. Б.; Вальцифер, И. В.; Вальцифер, В. А.

doi:10.1021/acsanm.9b02309

Cited by 18 publications

(7 citation statements)

References 42 publications

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“…However, the issue of using hydrophobic materials in extinguishing processes is a current scienti c topic, e.g. hydrophobic coatings in dry water methods 49 , extinguishing gel 50 , hydrophobic silica nanoparticles as additives to improve extinguishing agents 51 . Methods of controlled afterburning of ignitable material are justi ed and, as Kerber and Walton in 2005 point out, PPV can contribute to an increase in the rate of combustion 52 .…”

Section: Resultsmentioning

confidence: 99%

Problems of operation of positive pressure ventilators on the basis of surveys of Polish officers of the State Fire Service

Kaczmarzyk,

Warguła,

Janik

et al. 2024

Preprint

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Positive pressure ventilators used by 97.7% of officers of the National Fire Service in Poland, are characterized by work that is not in line with the expectations of the firefighters. In order to improve the technical and operational features of these devices, a survey was conducted among 25,000 eligible firefighters, identifying the application of these devices, problems in use and expected development directions. A total of 682 officers voluntarily completed the survey. Based on their findings, it was determined that ventilators are most often used to smoke out buildings after or during a fire. Mentioned problems when using these devices were mainly noise (78.2%), exhaust emissions (68.5%), and impediments to mobility through the device’s relatively heavy weight (40.2%). Other inconveniences were mentioned by less than 20% of firefighters. Polish firefighters expect the development of these devices mainly in terms of the above-mentioned features (noise reduction (81.7%) and reduction of the weight and size of the ventilators (about 50%)). Other expectations relate to the improvement of smoke removal in buildings: increasing the efficiency of smoke removal (46.4%) and efficiency regarding the rate of smoke removal in a building by increasing the size of the incoming airflow from the building’s surroundings (33.2%). About 15% of firefighters expect changes in the operation of the ventilator itself, that is, an increase in the effective operating time (electric ventilators) and an increase in the device’s uptime. The article also presents suggestions for device development based on the available state of the art.

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Section: Resultsmentioning

confidence: 99%

Problems of operation of positive pressure ventilators on the basis of surveys of Polish officers of the State Fire Service

Kaczmarzyk,

Warguła,

Janik

et al. 2024

Preprint

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“…Our work clearly demonstrates for the first time that water vapor adsorption experiments and a novel water intrusion technique coupled with NMR relaxometry can be used as complementary techniques to quantitatively analyze the wettability behavior and surface chemistry of nanoporous materials. This novel toolset will allow for better understanding of the nanoscale wettability of nanoporous materials applied in chromatographic separations. − In addition, information about the wettability is also crucial for other applications such as catalysis and membrane separations − as well as tailored material synthesis.…”

Section: Introductionmentioning

confidence: 99%

Characterization of Functionalized Chromatographic Nanoporous Silica Materials by Coupling Water Adsorption and Intrusion with Nuclear Magnetic Resonance Relaxometry

Schlumberger,

Collados,

Söllner

et al. 2024

ACS Appl. Nano Mater.

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Nanoporous silica is widely used as a support material for chemically bound stationary phases in chromatographic separations as well as for catalytic applications. Tuning of textural properties and surface chemistry of stationary phase materials (SPMs) is crucial to enhance their selectivity to certain compounds and the resulting process efficiency. Nanoporous silica supports are beneficial, as surface modifications are possible with a large variety of hydrophilic and hydrophobic functional groups, but their influence on the surface properties has not been evaluated in detail. In this sense, the contact angle is a key parameter for the assessment of surface chemistry, but its quantification in pores is challenging and requires a combination of various experimental techniques. This work demonstrates that combining water adsorption and intrusion measurements allows for the determination of the effective contact angle of adsorbed water on the pore walls for wetting, partial wetting, and nonwetting situations using functionalized hydrophilic and hydrophobic silica SPMs as model materials. Furthermore, NMR relaxometry experiments reveal that the ratio of the spin−lattice (T 1 ) to spin−spin (T 2 ) relaxation time of the adsorbed water film (T 1,ads.film /T 2,ads.film ratio) can be correlated with the effective adsorption strength of water on the surface. Indeed, a linear correlation between the negative inverse relaxation time ratio (−T 2,ads.film /T 1,ads.film ) and the contact angle is observed. Our work demonstrates that water vapor adsorption and water intrusion experiments coupled with NMR relaxometry can be used as complementary tools to quantify the wettability and surface chemistry of nanoporous materials. This approach allows for addressing important aspects of nanoscale wettability in the context of material synthesis as well as for their application in chromatographic separation processes and catalysis.

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“…The study [ 12 ] describes a method for the preparation of superhydrophobic mesoporous structures with an application of trifunctional alkoxysilane precursors (methyltrimethoxysilane and methyltriethoxysilane) containing a hydrophobic methyl group. Currently, a large number of works are dedicated to the utilization of modified silica materials as functional additives for powder compositions to improve the flowability of cohesive powders and impart hydrophobic properties to them [ 13 , 14 , 15 , 16 ].…”

Section: Introductionmentioning

confidence: 99%

“…On the one hand, a coating of nanosized silicon dioxide particles increases the distance and diminishes the contact area between the particles of powder composition, reducing the surface energy and electrostatic charge [ 13 ]. On the other hand, the coating particles are able to absorb water vapor and prevent the formation of capillary bridges between the components [ 14 ]. Thus, it is possible to achieve a free-flowing state of powder composition.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of Hydrophobic Nanosized Silicon Dioxide with a Spherical Particle Shape and Its Application in Fire-Extinguishing Powder Compositions Based on Struvite

et al. 2023

Self Cite

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Textural and morphological features of hydrophobic silicon dioxide, obtained by the hydrolysis of tetraethoxysilane in an ammonia medium followed by modification of a spherical SiO2 particles surface with a hydrophobic polymethylhydrosiloxane, were studied in this work. The size of silicon dioxide particles was controlled during preparation based on the Stöber process by variation of the amount of water (mol) in relation to other components. The ratio of components, synthesis time and amount of the hydrophobizing agent were determined to obtain superhydrophobic monodisperse silicon dioxide with a spherical particle size of 50–400 nm and a contact angle of more than 150°. In the case of the struvite example, it was demonstrated that the application of spherical- shaped hydrophobic silicon dioxide particles in powder compounds significantly improves the flowability of crystalline hydrates. The functional additive based on the developed silicon dioxide particles makes it possible to implement the use of crystalline hydrates in fire-extinguishing powders, preventing agglomeration and caking processes. The high fire-extinguishing efficiency of the powder composition based on struvite and the developed functional additive has been proven by using thermal analysis methods (TGA/DSC).

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Mesoporous Hydrophobic Silica Nanoparticles as Flow-Enhancing Additives for Fire and Explosion Suppression Formulations

Cited by 18 publications

References 42 publications

Problems of operation of positive pressure ventilators on the basis of surveys of Polish officers of the State Fire Service

Problems of operation of positive pressure ventilators on the basis of surveys of Polish officers of the State Fire Service

Characterization of Functionalized Chromatographic Nanoporous Silica Materials by Coupling Water Adsorption and Intrusion with Nuclear Magnetic Resonance Relaxometry

Synthesis of Hydrophobic Nanosized Silicon Dioxide with a Spherical Particle Shape and Its Application in Fire-Extinguishing Powder Compositions Based on Struvite

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