Oleanolic acid (OA) and ursolic acid (UA) were extracted from Hedyotis diffusa using a hyphenated procedure of ultrasound-assisted and supercritical carbon dioxide (HSC-CO2) extraction at different temperatures, pressures, cosolvent percentages, and SC-CO2 flow rates. The results indicated that these parameters significantly affected the extraction yield. The maximal yields of OA (0.917 mg/g of...

We report a new nonaqueous polymerization-induced self-assembly (PISA) formulation based on the reversible addition-fragmentation chain transfer (RAFT) dispersion alternating copolymerization of styrene with N-phenylmaleimide using a nonionic poly(N,N-dimethylacrylamide) stabilizer in a 50/50 w/w ethanol/methyl ethyl ketone (MEK) mixture. The MEK cosolvent is significantly less toxic than the 1...

Pulsed field gradient (PFG) NMR has been used to probe self-diffusion of molecular and ionic species in aqueous mixtures of choline chloride (ChCl) based deep eutectic solvents (DESs), in order to elucidate the effect of water on motion and inter-molecular interactions between the different species in the mixtures, namely the Ch(+) cation and hydrogen bond donor (HBD). The results reveal an int...

Silver and gold nanoparticles (of average size ∼20-27 nm) were incorporated in PU (Polyurethane), PCLm (Polycaprolactam), PC (polycarbonate) and PMMA (Polymethylmethaacrylate) by swelling and casting methods under ambient conditions. In the latter method the nanoparticle would be present not only on the surface, but also inside the polymer. These nanoparticles were prepared initially by using a...

We have computed the Soret coefficient in aqueous mixtures using a boundary driven nonequilibrium molecular dynamics algorithm and standard molecular force fields. The choice of this specific approach is justified by the nature of the mixtures studied here. Four aqueous solutions, including methanol, ethanol, acetone, and dimethyl-sulfoxide (DMSO) have been studied at ambient conditions for dif...

The densities of water-methanol and water-ethanol mixtures were measured with the laser-doppler type vibrating tube densimeter at 673.15 K in the pressure range of 25–40 MPa. The excess molar volumes Vm E for all mixtures studied were evaluated from the experimental values, and the dependences of alcohol composition for Vm E were fitted with Redlich-Kister equation. For all mixtures studied, Vm...

using the evaporating method, the solubility of potassium nitrate was determined in various mixtures containing water and ethanol at 25°c. the results show that the solubility of kno3 decreases with increasing the mass percent of ethanol in the mixtures. this trend is along with decreasing the dielectric constant of water+ethanol mixtures. moreover, it can be concluded that the totqal solubilit...

Urethan, a potent teratogenic and carcinogenic agent in experimental animals, has been used in Japan for the past 25 years as a cosolvent of water-insoluble analgesic and sedative drugs. Urethan is used also as a solubilizer and cosolvent for pesticides, fumigants, and cosmetics, because it is a good solvent for various organic materials (6). In the past, urethan was used clinically as an antin...

We found that addition of N,N-dimethylformamide (DMF) induces phase separation of 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP)-water mixtures. The phase diagram of a DMF-HFIP-water ternary system at 298 K showed that phase separation occurs in a closed-loop area in the water-rich mole fraction range of x(H(2)O) > ∼0.4. To clarify the mechanism of DMF-induced phase separation of DMF-HFIP-water mixtu...

The isomerization of 1,3-dihydroxyactone and d-glucose over Sn-Beta zeolite was investigated by in situ 13 C NMR spectroscopy. The conversion rate at room temperature is higher when the zeolite is dehydrated before exposure to the aqueous sugar solution. Mass transfer limitations in the zeolite micropores were excluded by comparing Sn-Beta samples with different crystal sizes. Periodic density ...