Desorption of Emulsifiers from Polystyrene Latexes Studied by Various Surface Techniques:  A Comparison between XPS, ISS, and Static SIMS

Abstract

The results obtained with three surface spectroscopic methods (XPS, ISS, and static SIMS with quadrupole or time-of-flight analyzers) available for the characterization of the particle surface of polystyrene latexes have been compared. The main point was to quantify the desorption of the surfactants used in the emulsion polymerization (Aerosol MA and sodium dodecylbenzenesulfonate) by the study of both unpurified and purified latexes. A comparison was made between these results and those obtained on a latex prepared by emulsion polymerization without any tensioactive stabilizer, therefore bearing only sulfate groups issued from the initiator. Sodium dodecyl sulfate was used as a reference for the presence of sulfate groups. The pure emulsifiers were also investigated separately. The various samples were analyzed as either powders or films, and the results obtained on films are discussed in terms of the migration of the surfactant toward the interface during the preparation of the films. On the other hand, our results showed clearly that static SIMS with a time-of-flight analyzer is the most suitable technique to study the desorption of emulsifier from latex particles. These results demonstrate that, after extensive purification by mixed-bed ion exchange resins, the strong acid emulsifier (Aerosol MA) can be completely desorbed.

Facile one-pot preparation of goethite/parabutlerite nanocomposites and their removal properties and mechanism toward As(V) ions

“…The S 2p 3/2 binding energy of the goethite/parabutlerite nanocomposites is 168.5 eV. This value was agree well with the ones of sulfate (SO 4 2− ) or more exactly (O SO 3 − ) [23].…”

“…Fig. 3b shows the S 2p spectrum, which can be perfectly fitted with the S 2p doublet (S2p 3/2 and S2p 1/2 ) by imposing the surface area ratio S2p 3/2 /S 2p 1/2 = 2 [22,23]. The S 2p 3/2 binding energy of the goethite/parabutlerite nanocomposites is 168.5 eV.…”

Controlled Sulfonation of Poly(N-vinylcarbazole)

“…This suggests that sulfur in the sulfonated PVKs exits in a form similar to sulfonate (SO 3 ). However, as this binding energy is also close to that of sulfate groups in polymers (∼189 eV), it is difficult from the XPS data alone to conclude whether sulfur exists in sulfonate or sulfate form and determine whether sulfur is attached to carbazole units or the backbone of the PVK polymer.

2 XPS S 2p spectrum of sulfonated PVK (PVK-60).

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Adsorption and Desorption of Triton X-100 in Polystyrene Particles with Different Functionality

“…This fact facilitates total desorption by the use of adsorbent with a high affinity for surfactant, i.e., ion exchange resins. In this way, a recent work (6) showed that after extensive purification by mixed-bed ion exchange resins, the strong acid emulsifier (Aerosol MA) can be completely desorbed. However, the main objective of this paper goes in another direction.…”