Silicas properties

Hench, L.L. (1998) Sol-Gel Silica. Properties, Processing and Technology Transfer, Noyes Publications, Westwood, New Jersey, USA. 

Ca-O-Sil. Untreated Fumed Silica Properties and Functions. CGEN-8A. Cabot, Tuscola, 1993. 

Ludox CL from Dupont (Commercial Alumina-Coated Silica) Properties Alumina silica mass ratio 4 26 [1799]. The potential (0.001 M KCl, 20°C, Malvem Zetasizer II c) was positive at pH 3-8 and negative outside that range. [1799]. 

In summary, the processing parameters that have the greatest impact on precipitated silica properties, and consequently on suitability for various end uses, are the following ... 

DuPont. Ludox Colloidal Silica Properties, Uses, Storage, and Handling. E.I. DuPont de Nemours and Co., Industrial Chemicals Dept. Product Information Bulletin H-47771-2, Wilmington, DE. 

Over the years there have been many anecdotes and much controversy over the wide variations in silica properties reported in the literature and the mechanisms of the processes by which silica and silicate species exert their influence. Much of the discussion results from the fact that both the exact nature of the speciation of silica in diluted solution and at the interface between sdicas and silicates and water and how this speciation changes in mixtures with other substances is unclear (25,26). Also, from a very practical standpoint sdica in some form is already present in many natural systems and in vitro experiments must seek to replicate the speciation to have any chance of learning from them. Complicating the situation, the extensive literature contains many observations drawn from experiments carried out under conditions where soluble silica might have been present in an uncontrolled manner and at concentrations sufficient to exert significant effects or conclusions drawn from insufficient mathematical models. The high potential for artifacts, which can influence the behavior of silica, even in the simplest systems, was well characterized by Hazel (my first college chemistry professor) [27], Debye [28] and Her [29] who made it clear that one had to be aware of the purity and/or preparation history of the silica. 

TABLE 9.19 Effect or Surface Hydration on Silica Properties... 

Features High brightness improved sheet formation, drainage, resin distrib., and heat dissipation < 0.1% respirable cryst. silica Properties SI. off-wh. fine powd. odorless 10 median particle size < 7% -r325 mesh sol. in HF negligible sol. in water sp.gr. 2.2 water absorp. 150% brightness 82 pH 8... 

M., From a Hyperhranched Polyethoxysiloxane Toward Molecular Forms of Silica A Polymer-Based Approach to the Monitoring of Silica Properties. In Silicones and Silicone-Modified Materials, Clarson, S. J. Fitzgerald, J. J. Owen, M. J. Smith, S. D., Eds. American Chemical Society Washington, DC, 2000 Vol. 729, pp 503-515. 

The positive effect of replacement of some carbon black by precipitated silica was further evaluated in a compound for wire adhesion that also contained an organocobalt adhesion promoter. Up to 20 phr of different types of silicas with widely varying surface areas was added. It was found that the energy of adhesion, which increased linearly with the phr of silica, did not correlate with any of the silica properties. Thus, the observed improvement of wire adhesion was not a physical effect due to increased compound tear strength, but was again related to changes in the interfacial layer formed on the wire [40]. 

Tisse VF, Prades F, Briquel R, Mckenna TFL (2010) Role of silica properties in the polymerisation of ethylene using suppmted metallocene catalysts. Macromol Chem Phys 211(1) 91-102... 

From a Hyperbranched Polyethoxysiloxane Toward Molecular Forms of Silica A Polymer-Based Approach to the Monitoring of Silica Properties... 

Some Properties. See Sec. 6.2.9, High-Silica Glasses, for a further discussion of silica properties. 

Uses Defoamer for mastics and ambient cure coalings recoalable fumed silicas Properties Liq. 

Uses Brownstock defoamer effective on hardwood and softwood defoamer on systems with oxygen delignification Features Low wax and silica Properties 100% act. 

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