Latex gradient centrifugation

The upper part of Figure 4 shows the results of the rapid density gradient centrifugation of a latex mixture of poly(styrene) and two chemically uniform co-... 

In Figure 5 the results obtained by rapid density gradient centrifugation of a polymer latex of unknown composition are shown. The gradient system consists of pure H2O and D2O. The density distribution of the particles has two broad peaks at the density values... 

In Figure 6 the result of a rapid density gradient centrifugation is shown using this system. It deals with a graft copolymer latex of butadiene and styrene acrylonitrile. The gradient media are different mixtures of 3-butene-2-ol and ethylene glycol. 

Figure 6. Density and extinction profile in rapid density gradient centrifugation of a graft copolymer latex of butadiene and styrene acrylonitrile (c 5 mg L 1, N — 40.000 min1, t 10 = 60 min, v = 546 nm)...

Thus the density and the density distribution and consequently the chemical composition and heterogeneity and also the cross-linking of polymer latex particles can be determined in a few minutes by rapid density gradient centrifugation. 

Figure 2. Sedimentation curves of polystyrene latexes with nominal diameters of 0.45 and 0.765 urn disk centrifuged at 4000 rpm in 20 mL of spin fluid with gradients of (a) 0/4%, (b) 0/3%, (c) 0/2% sucrose. Reproduced with permission from Ref. 3. Copyright 1985, Academic Press.

Figure 5. Particle size distribution of a mixture of polystyrene latexes with nominal diameters of 0.804 and 1.09 pm obtained by disk centrifugation at 4000 rpm in a 1/4% sucrose gradient.

The localization of enzymes and alkaloidal metabolites in Papaver som-niferum was studied by Roberts et al. by using latex from capsules and stems (13). The expelled latex from the cut end of the capsule or stem was centrifuged at 1000 g for 30 min. The pellet was then layered onto a continuous sucrose gradient. Two fractions sedimenting at 30 and 55-60% sucrose contained a... 

---