The use of a new class of graft polymer surfactants, based on inulin, in emulsion polymerization of poly(methyl methacrylate) (PMMA) and polystyrene (PS) particles is described. PS and PMMA were synthesized by emulsion polymerization, and stable particles with a high monomer content (50 wt %) were obtained with a very small amount of polymeric surfactant ([surfactant]/[monomer] = 0.0033). The latex dispersions were characterized by dynamic light scattering and by transmission electron microscopy to obtain the average particle size and the polydispersity index, and the stability was determined by turbidimetry measurements and expressed in terms of critical coagulation concentration. The last section gives a comparison of PMMA particles prepared by emulsion polymerization using classical surfactants from different types as emulsifiers with that obtained using the copolymer surfactant. It shows the superiority of INUTEC SP1 as it is the only one that allows stable particles at 20 wt % monomer content, with a smaller ratio [surfactant]/[monomer] = 0.002.

The adsorption isotherm of a hydrophobically modified inulin (INUTEC SP1) on Polystyrene (PS) and Poly(methyl methacrylate) (PMMA) particles was determined. The results show a high affinity isotherm for both particles as expected for a polymeric surfactant adsorption. The interactions forces between two layers of the hydrophobically modified inulin surfactant adsorbed onto a glass sphere and plate was determined using a modified atomic force microscope (AFM) apparatus. In the absence of any polymer, the interaction was attractive although the energy of interaction was lower than predicted by the van der Waals forces. The results between two layers of the adsorbed polymer confirms the adsorption isotherms results and provides an explanation to the high stability of the particles covered by INUTEC SP1 at high electrolyte concentration. Stability of dispersions against strong flocculation could be attributed to the conformation of the polymeric surfactant at the solid/liquid interface (multipoint attachment with several loops) which remains efficient at Na 2 SO 4 concentration reaching 1.5 mol.dm -3 . The thickness of the adsorbed polymer layer in water determined both by AFM and rheology measurements, was found to be about 9 nm.3

A new simple one-step method has been developed to obtain SiO(2) monolithic materials with a bimodal meso- and macroporous pore-size distribution. Sol-gel reactions were carried out in the continuous phase of highly concentrated emulsions with a cubic liquid crystal in this external phase, using a polyoxyethylene alkyl ether surfactant and containing a novel glycol-modified silane, tetra(2-hydroxyethyl) orthosilicate (abbreviated as THEOS). The hydrolysis and condensation reactions of this precursor have been carried out in basic pH, between pH 8.8 and 11.4. Interestingly, the ethylene glycol released during condensation reactions does not affect significantly the structure of the cubic liquid crystalline phase, which was stable during the sol-gel reactions. As a result, the cubic phase based emulsions could template the formation of meso/macroporous dual materials, which possess interconnected polydisperse macropores, between 1 and 5 μm, and cubic-ordered mesopores, with a narrow pore size distribution around 4 nm. Monoliths with a specific surface area higher than 550 m(2) g(-1) and bulk density of 0.16 g cm(-3) have been obtained.

A novel and simple single-step method for the preparation of meso/macroporous silica materials is described, which consists in templating in highly concentrated emulsions with a cubic liquid crystal in the continuous phase. Tetraethyl orthosilicate (TEOS) was solubilized in the aqueous continuous phase of highly concentrated emulsions stabilized by C(12)(EO)(8) and a PEO-PPO-PEO block copolymer nonionic surfactant, with a cubic liquid crystalline phase of the Fd3m type. The resulting silica materials were characterized by small-angle X-ray scattering, nitrogen sorption and transmission electron microscopy. The results showed that a dual pore size distribution was obtained, consisting of mesopores in the nanometer range and macropores between 1 and 5 μm. These dual meso/macroporous silicas with bimodal pore size distribution can possess specific surface areas higher than 400 m(2)/g.