Cyclization in glycerol dibiphytanyl glycerol tetraethers (GDGTs) results in internal cyclopentane moieties which are believed to confer thermal stability to crenarchaeal membranes. While the average number of rings per GDGT lipid (ring index) is positively correlated with temperature in many temperate environments, poor correlations are often observed in geothermal environments, suggesting that additional parameters may influence GDGT core lipid composition in these systems. However, the physical and chemical parameters likely to influence GDGT cyclization which are often difficult to decouple in geothermal systems, making it challenging to assess their influence on lipid composition. In the present study, the influence of temperature (range 65-81°C), pH (range 3.0-5.0), and ionic strength (range 10.1-55.7 mM) on GDGT core lipid composition was examined in the hyperthermoacidophile Acidilobus sulfurireducens, a crenarchaeon originally isolated from a geothermal spring in Yellowstone National Park, Wyoming. When cultivated under defined laboratory conditions, the composition of individual and total GDGTs varied significantly with temperature and to a lesser extent with the pH of the growth medium. Ionic strength over the range of values tested did not influence GDGT composition. The GDGT core lipid ring index was positively correlated with temperature and negatively correlated with pH, suggesting that A. sulfurireducens responds to increasing temperature and acidity by increasing the number of cyclopentyl rings in GDGT core membrane lipids.

The conformation of silk fibroin in silk fibroin/chitosan (SF/CS) blend membrane was analyzed by infrared spectrum, X‐ray diffractometry, and Raman spectrum. The results demonstrated that the SF could show β‐sheet conformation when the SF content in blend membranes was 10% (w/w) and 60–80% (w/w), while the pure SF membrane showed random coil conformation. A mechanism of the conformation transition was suggested in that the SF chain could use the rigid CS chain as a mold plate to stretch itself to form a β‐sheet structure according to the strong hydrogen bond between CS and SF. Therefore, a new concept, named “Polymer‐Induced Conformation Transition,” was proposed. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35: 2293–2296, 1997

When the spent lithium ion battery is processed pyrometallurgically, lithium is generally fixed as slag with a high melting/boiling point which is difficult to be treated further. In this research, an innovative method to recycle lithium from pyro-slag by evaporation during chlorination roasting was proposed. Different chlorine donors, namely NaCl, AlCl3, and CaCl2 were evaluated by HSC software and experiments, among which CaCl2 possessed a stronger ability of chlorine donation in the chlorination roasting process. Experiments proved that 97.45% lithium was evaporated with the Cl/Li molar ratio of 1.8:1 when the mixture of a simulated slag and CaCl2 was roasted at 1000 °C for 90 min. XRD results demonstrated that the majority of LiAl­(SiO3)2 in the slag was transformed into LiCl. All results implied that chlorination roasting should be a promising strategy for lithium recovery from the pyrometallurgical slag after pyro-treatment of the spent lithium ion battery.

A novel natural polymer blend, namely, a semi-interpenetrating polymer network (semi-IPN) composed of crosslinked chitosan with glutaraldehyde and silk fibroin was prepared. The FTIR spectra of the semi-IPN manifested that the chitosan and silk fibroin had a strong hydrogen-bond interaction and formed an interpolymer complex. The semi-IPN showed good pH sensitivity and ion sensitivity. According to the different swelling ratios of the semi-IPN in the buffer solution with different pH values or the AlCl 3 aqueous solution with different concentrations, the semi-IPN could swell and shrink while being put alternately into different pH buffer solutions or AlCl 3 aqueous with different concentrations. The semi-IPN could also act as an ''artificial muscle'' because its swelling-shrinking behavior exhibited a fine reversibility.

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A novel natural polymer blend membrane, namely chitosan/silk fibroin blend membrane, was prepared. The selective solubility and the pervaporation properties of alcohol-water mixture were studied. The results showed that the membrane was water selective and the separation factor of ethanol-water mixture could be improved compared to pure chitosan membrane, when silk fibroin content in blend membrane was no more than 40 wt %. The blend membrane exhibited a best performance, (i.e., the water in permeate was large than 99 wt % when silk content was 20 wt % and the crosslinking agent-glutaraldehyde content was 0.5 mol %). The mechanism of improvement on pervaporation properties was explained by reducing the free volume and freeing hydrophilic groups of chitosan because of the strong intermolecular hydrogen bond forming between chitosan and silk fibroin in blend membrane. In addition, the influence of operation temperature and feed concentration as well as the pervaporation properties of isopropanol-water mixture were also studied.

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