Carlos Montes

Bio: Carlos Montes is an academic researcher from Louisiana Tech University. The author has contributed to research in topics: Geopolymer & Fly ash. The author has an hindex of 7, co-authored 18 publications receiving 219 citations.

Geopolymer mortar and method

Abstract: A geopolymer mortar formed by mixing about 35% to about 45% by weight pozzolanic material, about 35% to about 45% by weight silicon oxide source, about 15% to about 20% by weight alkaline activator solution, and about 0.3% to about 2.5% by weight copper ion source. The pozzolanic material may be fly ash and the silicon oxide source may be sand. The alkaline activator solution may be a sodium hydroxide solution containing sodium silicate. The geopolymer mortar may have a viscosity in the range of about 25,000 to about 50,000 centipoise. The geopolymer mortar may be formed by further mixing one or more additives, such as surfactants, thermal spheres, anti-sagging agents, adhesion primers, or fibers. The geopolymer mortar may be applied as a protective coating on a surface of a structure.

Rheological behavior of fly ash-based geopolymers with the addition of superplasticizers

Abstract: Geopolymers are novel cementitious binders that are finding new industrial applications every day. One of the most important aspects for the commercialization of these products is their behavior in plastic state. The workability of fresh geopolymer paste can be measured with several common tests used for Portland cement concrete, like flow and slump; however, a more in-depth characterization of their rheology is essential to understand its basic setting mechanisms. In this article, the rheological behavior of geopolymer paste prepared under different mix design formulations is studied. Special consideration is given to the rheological behavior of geopolymer paste under the action of a superplasticizer. The effect of the superplasticizers on the viscosity of fresh geopolymers was evaluated and recommendations about the use of these additives are provided.

Halloysite Clay Nanotubes for Loading and Sustained Release of Functional Compounds.

Abstract: Halloysite is an alumosilicate tubular clay with a diameter of 50 nm, an inner lumen of 15 nm and a length of 600-900 nm. It is a natural biocompatible nanomaterial available in thousands of tons at low price, which makes it a good candidate for nanoarchitectural composites. The inner lumen of halloysite may be adjusted by etching to 20-30% of the tube volume and loading with functional agents (antioxidants, anticorrosion agents, flame-retardant agents, drugs, or proteins) allowing for formulations with sustained release tuned by the tube end-stoppers for hours and days. Clogging the tube ends in polymeric composites allows further extension of the release time. Thus, antioxidant-loaded halloysite doped into rubber enhances anti-aging properties for at least 12 months. The addition of 3-5 wt% of halloysite increases the strength of polymeric materials, and the possibility of the tube's orientation promises a gradient of properties. Halloysite nanotubes are a promising mesoporous media for catalytic nanoparticles that may be seeded on the tube surface or synthesized exclusively in the lumens, providing enhanced catalytic properties, especially at high temperatures. In vitro and in vivo studies on biological cells and worms indicate the safety of halloysite, and tests for efficient adsorption of mycotoxins in animals' stomachs are also carried out.