Electrophoresis hematite

Akhtar and Lai128) infer the adsorption mechanism of a collector on a mineral surface from the mutual position of IPpH and PZC which they determine by electrophoresis. Their deduction is based on experiments performed with hematite in solutions of Na oleate (NaOl) and dodecylamine hydrochloride (DDA-HC1). The surface of hematite is assumed to consist of MeOHj, MeOH and MeO-. Chemisorption of the collector is discussed according to Table 3 which is based on Eq. 72 for charge density at the inner Helmholtz plane ... 

An introduction to electrokinetic phenomena can be found in [240] and in handbooks of colloid chemistry. The choice of method and instrument suitable for the character of a sample is key to successful electrokinetic measurements. In principle, all techniques and all instruments should produce the same potential and the same IEP in a system of interest. A few multi-instrument studies have been published. For example, [241] reports lEPs obtained by streaming potential and by electrophoresis (using a commercial apparatus). A multi-instrument electrokinetic study of alumina in O.OIM NitNO, is reported in [242]. The IEP was also relatively consistent with different solid-to-liquid ratios. Glass capillaries with inner sides coated with spherical nanosize hematite particles showed an IEP at pH = 5, while the IEP of the original hematite obtained by electrophoresis was at pH 9.3 [243]. 

The IEP of rutile in the presence of three alkali chlorides is reported in [327], and [328] reports a similar study of hematite (three sodium salts). Reference [329] reports potentials obtained at two ionic strengths in five electrolytes, and [330] reports potentials in the presence of two salts, each at two ionic strengths. Reference [331] reports potentials obtained by means of electrophoresis with two instruments, at five and two ionic strengths, respectively. 

A shift in the lEPs of the following metal oxides to high pH was induced by concentrated solutions of Li and Na salts alumina [492] (electroacoustic method and electrophoresis), [494,1018] (only Li induced a shift in the IEP Na did not), ceria [1224], hematite [430], India and niobia [1674], rutile [430], anatase [495] (multi-instrument, multilaboratory study), [1985], [1986] (the shift in the IEP was accompanied by a shift in the maximum of viscosity), [1987,1988], and zirconia... 

A Mark II particle micro-electrophoresis apparatus (Rank Brothers, London) was used to measure hematite electrophoretic mobility. These studies were performed at 25 C in a KCl solution. In each measurement at least 20 particles were timed in each direction of movement (16). 

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