Changes in Composition of Birch Outer Bark Extractives After Recrystallization with C2-C5 Alkanols

The effects on birch outer bark (BOB) ethanolic extractives’ chemical composition after recrystallization with C2–C5 alkanols were studied in this paper. Ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, and 1-pentanol were used as solvents. The solubility of BOB extractives at the solvents boiling point was determined empirically. It was found that, with an increase of the boiling point of the solvents, the solubility of the extractives increased, reaching up to 486 g/L in 1pentanol at 142.2 °C. Recrystallization yields reached up to 67 wt% using 2-butanol and the purity of betulin up to 96 wt% using 2‐propanol as a solvent. Considering the yield of recrystallization, betulin content, boiling point of the solvent, solvent loss, toxicity and eco-friendliness of the solvent, ethanol was chosen to be the most suitable solvent for industrial scale purification of betulin in the BOB extractives. Using only one recrystallization step the content of betulin was increased by 20% — from 75 to 95 wt% and the yield of recrystallization was 32.1 g per liter of solvent.

A Non-Linear Dynamic Model of Ionic Polymer-Metal Composite (IPMC) Cantilever Actuator

This work presents development of an effective non-linear mathematical model for dynamic analysis of Ionic polymer-metal composites (IPMCs) cantilever actuators undergoing large bending deformations under AC excitation voltages. As the IPMC actuator experiences dehydration (solvent loss) in open environment, a model has been proposed to calculate the solvent loss due to applied electric potential following Cobb-Douglas production method. D’Alembert’s principle has been used for the derivation of the governing equation of motion of the system. Generalized Galerkin’s method has been followed to reduce the governing equation to the second-order temporal differential equation of motion. Method of multiple scales has been used to solve the non-linear equation of motion of the system and dehydration effect on the vibration response has been demonstrated numerically.

Solvent Effects on the Spin Crossover Properties of Iron(II) Imidazolylimine Complexes

A series of Fe(II) complexes, fac-[Fe(4-ima-Bp)3](Y)2⋅sol (Y = ClO4; sol = 3EtOH 1, 3MeOH 2; Y= BF4; sol = EtOH⋅4H2O 3, 4H2O 4 and 3.5MeCN 5) have been prepared and structurally and magnetically characterized. The low temperature structures of 1, 2 and 5 have been determined by X-ray crystallography with LS Fe(II) centres found in all cases. Extensive C–H···π interactions between the cations form 2D layers, which are linked to one another through N-H···O and O-H···O hydrogen bonds, resulting in high cooperativity. Despite 5 containing MeCN, N-H···O/F hydrogen bonds, and C–H···π and π-π interactions combine to give similar 2D layers. Magnetic measurements reveal moderately abrupt spin crossover for 1-4; becoming more gradual and only 50% complete in 1 due to solvent loss. The MeCN solvate shows more gradual SCO and reinforces how subtle changes in packing can significantly influence SCO behaviour.

Rapid desorption of CO2 from deep eutectic solvents based on polyamines at lower temperatures: an alternative technology with industrial potential

Environment friendly and thermally stable deep eutectic solvents (DESs) based on polyamines with low price, low solvent loss and oxidatively non-degradable characteristic for reversible CO2 capture.

Open and closed forms of the interpenetrated [Cu2(Tae)(Bpa)2](NO3)2·nH2O: magnetic properties and high pressure CO2/CH4 gas sorption

Cationic [Cu2(Tae)(Bpa)2]2+[NO3]22−·nH2O interpenetrated networks show a solvent loss triggering dynamic aperture of the porous structure from a closed to an open form with a difference of 29% of the volume cell.

Heteroleptic iron(iii) Schiff base spin crossover complexes: halogen substitution, solvent loss and crystallite size effects

New heteroleptic iron(iii) spin crossover complexes, [Fe(qsal-X)(thsa)]·nMeCN, have been investigated. Halogen substitution, solvent and crystallite size effects are discussed.

Effective fractionation of lignocellulose in herbaceous biomass and hardwood using a mild acetone organosolv process

Key features of this process are the high yield of cellulose, monomeric hemicellulose sugars and lignin combined with limited solvent loss due to acetone self-condensation.