Three types of micro-photoreactor setups were investigated using DMBP-sensitized additions of isopropanol to furanones as model reactions. The results were compared to experiments using a conventional batch reactor. Based on conversion rates, reactor geometries and energy efficiency calculations the microsystems showed superior performances over the batch process. Of the three micro setups examined, the LED-driven microchip gave the best overall results.
The DMBP-sensitized addition of isopropanol to furanones was studied in a novel LED-driven microchip reactor. Complete conversions were achieved after just 2.5 to 5 min of irradiation with 6 × 365 nm high-power LEDs. The results were compared to analogous experiments using a conventional batch reactor.
Furfural obtained from pentose containing biomass such as hemicelluloses is subjected to photooxygenation. The resulting hydroxyfuranone obtained in high yields undergoes acetalization with fatty alcohols. Using NaHSO 3 , surfactants are obtained by addition of a sulfonate group to α,β-unsaturated carboxyl or carbonyl compounds. Addition occurred either at the CvC double bond (6) or at the aldehyde function (7). Compared to conventional surfactants of this type, the resulting compounds possess similar good detergent properties. In the case of compound family 6 and when compared to the corresponding alkylsulfate and alkylsulfonate surfactants, even lower critical micelle concentrations (CMC) are observed. Biodegradation of the new surfactants was determined according to the OECD Test guideline 301 F. Compounds of family 6 are biodegradable. Biodegradation of compounds of family 7 stopped after 10 days.
The synthesis of new meridianin derivatives substituted at the C-5′ position of the 2-aminopyrimidine ring by various aryl groups and substituted or not by a methyl group on the indole nitrogen is described. The 2-aminopyrimidine ring was obtained via a Bredereck synthesis. Aryl groups were introduced by Suzuki cross-coupling after bromination of the 2-aminopyrimidine ring at the C-5′ positio
Potassium hydroxide-activated carbons (CK21, CK11, and CK12) were prepared from pistachio nutshells. Physicochemical properties of activated carbons were characterized by TGA, pH pzc , Fourier transform infrared spectroscopy, scanning electron microscopy, and N 2 -adsorption at -196°C. The examinations showed that activated carbons have high surface area ranging between 695-1218 m 2 /g, total pore volume ranging between 0.527-0.772 mL/g, and a pore radius around 1.4 nm. The presence of acidic and basic surface C-O groups was confirmed. Batch adsorption experiments were carried out to study the effects of adsorbent dosage, temperature, initial concentration of adsorbate, and contact time on deltamethrin adsorption by activated carbons. The kinetic studies showed that the adsorption data followed a pseudo-second order kinetic model. The Langmuir model showed a maximum adsorption capacity of 162.6 mg/g at 35°C on CK12. Thermodynamic studies indicated that adsorption was spontaneous and increased with temperature, suggesting an endothermic process.
The surface properties of two perfluoroalkylethyl acrylic copolymers-aqueous, Zonyl V R 329 and solvent-based, Zonyl V R 225-were studied. Zonyl V R 329 is a water-based dispersion and Zonyl V R 225 a solvent-based copolymer solution; both polymers have the same perfluoroalkyethyl side chains [F(CF 2 ) n CH 2 CH 2 A] but have different comonomer compositions. Thin films, prepared by dip coating onto mica and quartz, with and without annealing, were characterized by contact angle and by X-ray photoelectron spectroscopy (XPS). The contact angle measurements showed little variation with polymer and with substrate, consistent with the supposition that the perfluoroalkylethyl chains aggregate on the surface and thus dominate surface properties, irrespective of the composition of the rest of the polymer. XPS revealed only small variations in surface chemistry for studied films. Annealed films showed improved segregation for solvent-based Zonyl V R 225, which has both hydrocarbon alkyl and perfluoroalkylethyl side chains; the presence of hydrocarbon alkyl chains enables the perfluoroalkylethyl chains to reorganize after annealing. Depending on the external conditions, this thermal treatment can enable more perfluoroalkylethyl chains to reach the film surface (solid/air interface), leading to a reduction in the dispersive-dominant surface and enhancement in perfluoroalkylethyl segregation. This suggested that perfluoroalkylethyl side chains dominate the surface properties, which are thus not dependent on substrate, backbone composition, or formulation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.