New Imidazole Compounds Derived from Pyrrolidonic and Piperidonic Acids as NON-Steroidic Aromatase Inhibitors

International audienc

Low temperature ionic liquid pretreatment of lignocellulosic biomass to enhance bioethanol yield

International audienceAmong pretreatments existing to overcome the recalcitrance of the lignocellulosic biomass, imidazolium-based ionic liquids (ILs) are gaining interest to make cellulose more accessible to hydrolytic enzymes and generate fermentable sugars that are finally converted into ethanol by microbial fermentation. However, these pretreatments are usually implemented at a temperature between 80 C and 160 C raising realistically an energy demand problem. Here, we present an eco-friendly pretreatment strategy using the 1-ethyl-3-methylimidazolium acetate [Emim][OAc] IL at 45 C. This energy efficient method was studied on three substrates: a model cellulose and two industrial forest residues, spruce and oak sawdusts. The viscosity of the three samples in [Emim][OAc] were followed depending on the temperature. The structures of the pretreated substrates were analyzed by scanning electron microscopy and by Fourier transform infrared spectra. Then the pretreated samples were submitted to enzymatic hydrolysis catalyzed by cellulases from Trichoderma reesei and to ethanolic fermentation by the yeast Saccharomyces cerevisiae. The ethanolic yields obtained from (ligno)cellulosic substrates were 2.6e3.9 times higher after the soft pretreatment with [Emim][OAc]. Thus, [Emim][OAc]-pretreatment at low temperature is a promising gentle method for LCB valorization into biofuels

Impact of the aqueous pyrrolidinium hydrogen sulfate electrolyte formulation on transport properties and electrochemical performances for polyaniline-based supercapacitor

International audienceDuring this work, the protic ionic liquid (PIL) pyrrolidinium hydrogen sulfate, [Pyrr][HSO4], is synthesized and its mixture with water is then characterized prior to be used as a potential electrolyte for polyaniline (Pani) based supercapacitors. The transport properties of the [Pyrr][HSO4] – water binary mixture is determined at three different PIL/water weight ratios (i.e. 14/86, 41/59 and 70/30) as a function of the temperature from 5 to 70 °C. In the light of such an analysis, the optimum value of the ionic conductivity, reaching 178 mS/cm at 25 °C, is obtained for the [Pyrr][HSO4]/water weight ratio close to 41/59. The electrochemical behavior of Pani is then investigated in these electrolytes to further examine the impact of their formulation on supercapacitor performances. Based on this work, the Pani electrode shows the best electrochemical performances using the electrolyte 41/59 [Pyrr][HSO4]/water weight ratio leading to a specific capacitance of 380 F/g at 10 mV/s, a low relaxation time constant τ0 close to 5 s and a gravimetric capacitance retention of 68% after 1000 cycles at 2 A/g