Silica Fume
Silica Fume - Related Videos
05:48
Fume Hoods and Laminar Flow Cabinets
0 Views •
2023
Robert M. Rioux & William A. Elliott, Pennsylvania State University, University Park, PA Fume hoods and laminar flow cabinets are engineering controls that operate under similar principles. Both use a constant flow of air to prevent contamination of the laboratory environment and its inhabitants. Fume hoods prevent hazardous substances from exiting the hood workspace, whereas laminar flow cabinets prevent contaminants from entering the cabinet workspace. Fume hoods are ventilation systems...
06:54
Preparing Silica Aerogel Monoliths via a Rapid Supercritical Extraction Method
0 Views •
Cited by 26 •
2014
This article describes a rapid supercritical extraction method for fabricating silica aerogels. By utilizing a confined mold and hydraulic hot press, monolithic aerogels can be made in eight hours or less.
09:11
Porosimetry of a Silica Alumina Powder
0 Views •
2023
Source: Kerry M. Dooley and Michael G. Benton, Department of Chemical Engineering, Louisiana State University, Baton Rouge, LA Surface area and pore size distribution are attributes used by adsorbent and catalyst manufacturers and users to ensure quality control and to determine when products are at the end of their useful lives. The surface area of a porous solid is directly related to its adsorption capacity or catalytic activity. The pore size distribution of an adsorbent or catalyst is...
07:51
Fabrication of Silica Ultra High Quality Factor Microresonators
0 Views •
Cited by 22 •
2012
We describe the use of a carbon dioxide laser reflow technique to fabricate silica resonant cavities, including free-standing microspheres and on-chip microtoroids. The reflow method removes surface imperfections, allowing long photon lifetimes within both devices. The resulting devices have ultra high quality factors, enabling applications ranging from telecommunications to biodetection.
09:35
Attaching Biological Probes to Silica Optical Biosensors Using Silane Coupling Agents
0 Views •
Cited by 13 •
2012
Biosensors interface with complex, biological environments and perform targeted detection by combining highly sensitive sensors with highly specific probes attached to the sensor via surface modification. Here, we demonstrate the surface functionalization of silica optical sensors with biotin using silane coupling agents to bridge the sensor and the biological environment.
FAQs
The particle-filling effect improves packing within cement-based mixtures. Because silica fume particles are extremely small, they occupy gaps that remain between larger cement grains, leaving fewer connected pathways through the hardened material. This denser arrangement helps refine the pore structure, which is important when engineers need concrete with lower permeability and stronger resistance to environmental ingress.
Chemical reactivity provides a second mechanism beyond physical filling. During the pozzolanic reaction, reactive silica consumes calcium hydroxide and produces additional calcium silicate hydrate, the cementing phase associated with improved concrete performance. This reaction further refines the pore network, helping explain why silica fume can contribute to strength and protection from aggressive chemical exposure.
Its benefits depend on a properly designed mixture rather than on addition alone. When proportioning is appropriate, the combined effects of particle packing and pozzolanic reaction can increase compressive strength, abrasion resistance, and resistance to aggressive chemical exposure. Poorly designed mixtures may not realize these reported advantages, so engineering performance must be considered together with proportioning.
The physical and chemical effects address different features of the material. Fine particles improve packing by filling spaces among cement grains, while the pozzolanic reaction creates additional calcium silicate hydrate and refines pores chemically. Together, these mechanisms produce a denser cement-based structure, linking silica fume use to both lower permeability and improved mechanical performance.
Silica fume is suited to high-performance concrete where multiple durability and strength demands occur at once. The overview identifies bridges, marine structures, industrial floors, and other demanding applications. Its value in these settings comes from the combined potential for higher compressive strength, improved abrasion resistance, reduced permeability, and better protection against aggressive chemical exposure when the mixture is properly designed.
Project selection should connect the required performance with the exposure and service conditions described in the overview. Engineers can consider whether the concrete needs higher compressive strength, abrasion resistance, lower permeability, or protection against aggressive chemicals. This approach helps identify demanding applications in which a properly designed silica fume mixture can provide relevant benefits.