Publications by authors named "Ayman Ben Mabrouk"

Stable biobased waterborne Pickering dispersions of acrylated epoxidized soybean oil (AESO) were developed using chitin nanocrystals (ChNCs) as sole emulsifier without any additives. Thin AESO-ChNC nanocomposite films were produced by UV-curing thin-coated layers of the AESO emulsion after water evaporation. The kinetics of photopolymerization were assessed by monitoring the consumption of the AESO acrylate groups by infrared spectroscopy (Fourier transform infrared (FTIR)).

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Chitin nanocrystals (ChNCs) produced by hydrochloric acid hydrolysis of chitin were used as stabilizing agent for oil-in-water (O/W) emulsification of soybean oil (SO), acrylated soybean oil (ASO), and epoxidized soybean oil (ESO). The emulsion stability, droplet size, and rheology of the emulsion were found to be significantly affected by the oil chemical structure. Strong interaction between ChNCs and the oil droplets enhanced the stabilizing efficiency of ChNCs through a Pickering effect, resulting in emulsions with low droplet size and long-term stability.

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Soap-free emulsion polymerization of vinyl acetate (AVM) in the presence of cellulose nanocrystals (CNCs) was performed using persulfate/metabisulfite as initiator. The effect of the addition of MPEG comonomer on the locus of CNCs with respect to polymer particles was investigated. It was shown that the presence of MPEG strongly favors the accumulation of CNCs on the polymer particle thus contributing to a stabilization of polymer particle through Pickering effect.

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Aldehyde-functionalized cellulose nanocrystals (CN) with two aldehyde contents were produced by periodate oxidation and gentle sonication. The aldehyde-functionalized CNCs were shown to be an effective stabilizer in the Pickering emulsion polymerization of acrylate monomers using potassium persulfate (KPS)/metabisulfite redox initiation system at 50 °C without any added surfactant. The effect of CNC content on the particle size, zeta-potential, colloidal stability and film properties were discussed.

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Cellulose nanofibrils (CNFs) from oxidized never dried Eucalyptus pulps have been produced by using twin screw extrusion (TSE) and high pressure homogenizer (HPH), and their properties were compared. CNFs from TSE are produced at 10% solid content and then diluted to 1% for purpose of comparison against HPH. The nanosized fraction (NF) was around 90% for CNFs from HPH compared to 70% when TSE was used.

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Stable film-forming nanocomposite particles with diameters ranging from 120 to 300 nm, based on polybutylmethacrylate (PBMA) and cellulose whiskers in water dispersions, were successfully synthesized in one step through mini-emulsion polymerization. The nanocomposite dispersion with a solid content of 25 wt.% and up to 5 wt.

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