KINETIC-STUDIES OF MAGNETIC LATEX-PARTICLES SELF-ASSEMBLY UNDER APPLIED MAGNETIC-FIELD

The applied field and concentration dependence of growth of the magnet ic latex particles was traced by microscopy and small angle light scat tering methods. Magnetic latex particles, diameter 0.8 mu m and ion ox ide contents 68%, have been studied at the solution concentration 0.05 -0.2 wt% and magnetic field strength 3-24 gauss. When the magnetic fie ld was applied, the particles make the linear alignments and growth-re lease occurs through reversible processes. The cluster formation is ex perimentally investigated under the low magnetic field strength where the aggregation is not disrupted by the side-by-side interaction betwe en the linear clusters. The cluster size growth mechanism and the rate of cluster formation was compared by two different techniques, micros cope and small angle light scattering (SALS). Good agreement was obtai ned between the two methods, and (s(t)) = s(0)[1 + (t/tau)(1.0)] was o bserved during the initial stage of growth, where (s(t)) is a cluster size distribution function, s(0) is the initial size of the particle, t is time, and tau is the characteristic time. Then the clusters are s aturated and time dependent increment of the clusters slows down.