Surfactant stabilized emulsions of dicyclopentadiene and 50%, 60%, 70% or 80% of water were cured using ring opening metathesis polymerisation. All formulations gave open porous architectures featuring excellent mechanical properties which change upon oxidation.
COBISS.SI-ID: 15575062
By polymerisation of high internal phase emulsions (HIPEs), containing styrene (STY), divinylbenzene (DVB) and methacrylic acid (MAA) in the continuous phase, highly porous polymers including carboxylic functional groups were prepared. The ratio of methacrylic acid to divinylbenzene was varied in order to obtain polyHIPEs with a different degree of crosslinking which influenced a surface area of the polymers, being substantially higher (185 m2/g) with a higher degree of crosslinking (51% DVB) than with a lower degree of crosslinking (24% DVB, 46 m2/g). Up to 90% porous samples were prepared and the optimum hidrophilicity-lipophilicity balance (HLB) of the surfactant was found to be around 4.8-4.9. Both thermal and photo initiation were used to induce polymerisation. The resulting polymers had an open cellular morphology with cavity diameters between 21.8 lm and 44.2 lm and with interconnecting pores between 2.2 lm and 5.0 lm. Monolithic supports were used for further functionalisation with thionyl chloride and multifunctional amines, namely 1,4-diaminobutane and 1,12-diaminododecane. The functionalisation degree with thionyl chloride was 76%.
COBISS.SI-ID: 15805462
Emulsion templating of high internal phase emulsions (HIPEs) was used to synthesise microcellular poly(styrene-co-divinylbenzene) magnetic nanoparticle composites with open, interconnected, porous structures. The emulsions were stabilised by a combination of a surfactant and maghemite/magnetite(uncoated or coated with oleic acid) nanoparticles and then cured thermally. Up to 23 wt% (with regards to complete composite mass) of magnetic nanoparticles were incorporated into the polymer matrix. Composite polymers exhibited magnetic properties with a saturation magnetisation of 13 emu/g and a substantial heating effect at the AC magnetic field of 3.8 kA/m and a frequency of 104 kHz.
COBISS.SI-ID: 15984406
The inhibition behaviour of the TRITON-X-405 mixed with KBr or C4H12NI in 2.0 M H2SO4 on the ferritic SS was studied using potentiodynamic and EIS measurements. The electrochemical data showed that mixtures used in this study adsorbed on the SS’s surface, in agreement with the Flory–Huggins adsorption isotherm. Polarization and EIS measurements indicated that KBr or C4H12NI had a significant synergistic effect with TRITON-X-405 in 2.0 M H2SO4. This effect was more pronounced when adding C4H12NI, and at concentrations above the CMC of the used mixtures, which had been determined via corrosion-kinetic parameters. The inhibitive mechanism is proposed.
COBISS.SI-ID: 15809558
The inhibiting action of a nonionic surfactant of the TRITON-X series (TRITON-X-405) on stainless steel type X4Cr13 in 1.0 M H2SO4 solution within the temperature range of 25–45 °C was studied using the gravimetric and potentiodynamic technique. The inhibition efficiency was found to increase with the inhibitor concentration and decrease with temperature. The satisfactory inhibition efficiency of TRITON-X-405 on SS type X4Cr13 in 1.0 M H2SO4 was limited to temperatures below 35 °C or at the surfactant concentration higher than c = 10–5 M. The adsorption of TRITON-X-405 on stainless steel type X4Cr13 in one molar of sulphuric acid within the chosen temperature range follows the Flory–Huggins adsorption model with very high negative values of the free energy of adsorption ΔGads. The thermodynamic parameters, such as the heat of adsorption and adsorption entropy, were calculated by employing thermodynamic equations. Activation parameters such as apparent activation energy, activation enthalpy, and activation entropy were evaluated from the effect of temperature on corrosion and inhibition processes. Those entire apparent activation parameters show an increase–decrease characteristic (a nonmonotonic function). They increased at concentrations lower than the cmc of added surfactant and decreased when the concentration of TRITON-X-405 was higher than c = 10–5 M.
COBISS.SI-ID: 15674134