Silica control

In addition to these products, many other specialist chemical formulations are available. For example, products may incorporate a proprietary polymer for very high silica control or blend in a carboxylate/... 

Problem-specific polymers include terpolymers, used for iron dispersion, iron transport, and silica control. 

Silica control requirements are the same as for phosphate-cycle programs. 

PMA is useful as a calcium sulfate inhibitor and more recently has been promoted as an antiscalent for control of high-silica waters, countering newer silica control terpolymers (such as Acumer 5000). 

Amjad, Zahid Zibrida, John F. Zuhl, Robert W. Silica Control Technology for Reverse Osmosis Systems. Ultrapure Water, Tall Oaks Publishing, Inc., USA, February 1999. 

These same factors probably also determine the quite different kinetic profile of Cr/silica, whose sites are slower to form and slower to die. The reduction assumes more importance on silica, controlling the development of activity. Alkylmetals accelerate the reduction but do not create a vast new population of sites. 

Most chemical treatment programs have not in the past specifically focused on controlling silica levels in cooling water, and as a consequence almost all analyses of scales and deposits taken from the waterside of cooling systems, especially from heat exchangers, have shown the presence of small percentages of silica. Research over the last five years or so has led to the introduction of silica-specific deposit control polymers and has also led, with some success, to the reevaluation and promotion of some established calcium carbonate polymer products for effective silica control. 

The 1990s has seen the entry of terpolymers with basic calcium carbonate control, but with designer functional groups to provide various additional properties such as excellent high-stress dispersion, iron control, phosphate control, zinc stabilization, and silica control, all on the same polymeric molecule ... 

Merckogel Si Porous silica, controlled porosity, gel permeation... 

Treguer, P., and Pondaven, P. (2000). Silica control of carbon dioxide. Nature 406, 358—359. 

The considerable increase of elastic modulus with low amoimt of ultrafine amorphous silica Si02 (< 0.1 pm) shows the nanoparticles to be well dispersed. It cannot be explained by classical models (Kemer, Nielsen) we have to take into account that a part of the polymer matrix is occluded in the aggregates. It can also be explained by adsorption of the polymer on the surface of the silica. Silica-PP adhesion is high, and so the molecular mobility is reduced this effect is all the more important as the surface area is high (> 150 m /g). This effect has been observed on elastomeric materials, where polymer adsorption on silica control the modulus [23]. 

Adsorption of Argon and Xenon in Silica Controlled Porous Glass A Grand Canonical Monte-Carlo Study... 

The so-called medium performance AC supports can withstand higher pressures, and have particle sizes of 40 pm. Examples include hydrophylic polyacrylamides (pH 1-14, 100 psi), as well as the bonded-phase silica/controlled-pore glass supports (pH 2-8, >1000 psi). 

Size-exclusion Molecular size Sulfonated divinyl benzene Divinylbenzene Silica gel Porous gel Aqueous gel Organic gel Controlled pore silica Controlled pore glass... 

D. W. Ashman, O. J. Delong and W. A. Jankola, "Silica Control During Zinc Calcine Leaching at Cominco s Trail Operations", World Zinc 93. I. G. Matthew, Ed., The Australasian Institute of Mining and Metallurgy, Victoria, Australia, 1993,217-226. 

Garcia JJ, Gresh RE, Gareis MB, Haney RA. Effectiveness of cabs for dust and silica control on mobile mining equipment. In Proceedings of the 8th US Mine Ventilation Symposium. University of Missouri at Rolla June 1999. 

Another type of inorganic matrix that is similar to controlled-pore glass but considerably less expensive can be prepared by fusing inorganic compounds such as finely pulverized silica and zirconium oxide to form a porous body. Although the pore distribution is less imiform, the surface composition is almost imiform in the case of silica, the surface is nearly 100% silica. Controlled-pore... 

Tang Q, Chen Y, Chen J, Li J, Xu Y, Wu D, SunY (2010) Drug delivery from hydrophobic-modified mesoporous silicas control via modification level and site-selective modification. J Solid State Chem 183 76-83... 

Gunter Biichel, Michael Griin, and Klaus K. Unger Tailored syntheses of nanostructured silicas Control of particle morphology, particle size and pore size, Supramol. Sd., 5 (1998) 2530-2539... 

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