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Title: Magnetically induced phase condensation with asymptotic critical temperature in an aqueous magnetic colloid
Published In: Magnetohydrodynamics Vol. 47, No. 2, pp. 201-206
Description: We investigated the phenomenon of magnetically induced phase condensation in a water-based magnetic nanocolloid with magnetite nanoparticles of 5 nm in diameter, sterically stabilized by a double surfactant layer of myristic acid (MA) and dodecyl-benzenesulphonic acid (DBS). It is found that the sample presents an asymptotic critical temperature T(infinity) approximate to 40 degrees C, above which no condensation occurs, no matter how intense the external magnetic field is. Below the asymptotic critical temperature there is a temperature dependent critical field H(c)(T), below which no condensation occurs and above which the amount and the size (in the micron range) of the condensed phase drops increase with the field intensity. The critical field exponentially increases as the temperature approaches T(infinity). From DLS investigations it was found that the magnetic nanoparticles spontaneously agglomerated, most likely due to van der Waals and/or hydrophobic interactions, into clusters whose population diminished with the increasing temperature.
ISSN:ISSN: 0024-998X
Publication year: 2011
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Authors: SOCOLIUC Vlad , BICA Doina , VEKAS Ladislau ,
Type: International Journal Article
Laboratory: Magnetometry Laboratory
Institution: ARFT