Université de Fribourg

Liquid crystalline period variations in self-assembled block copolypeptides-surfactant ionic complexes

Li, Chaoxu ; Li, Jingguo ; Zhang, Xiuqiang ; Zhang, Afang ; Mezzenga, Raffaele

In: Macromolecular Rapid Communications, 2010, vol. 31, no. 3, p. 265-269

We investigate the complexation of ampholytic poly(N-isopropylacylamide)-block-poly- (L-glutamic acid)-block-poly(L-lysine) (PNiPAM-b-PLG-b-PLLys) triblock copolymers and PNiPAM-block-(PLG-co-PLLys) diblock copolymers with counter charged anionic and cationic surfactants. Both triblock and diblock copolymers are able to selectively form complexes...

Université de Fribourg

Quantitative self-sensitized photooxidation of 1,2-diarylcyclobutene derivatives by singlet oxygen

Kühni, Joël ; Debieux, Jean-Luc ; Belser, Peter

In: Synthesis, 2007, p. 1421-1425

Ligands 1 and 2 underwent quantitative photooxidation when they were reacted with singlet oxygen sensitized by methylene blue. However, the quantitative reaction became self-sensitized for the compound Ru(1) wherein the ruthenium complex acted as a sensitizer.

Université de Fribourg

Hydrogen density in nanostructured carbon, metals and complex materials

Züttel, Andreas ; Wenger, Pascal ; Sudan, Patrick ; Mauron, Philippe ; Orimo, Shin-ichi

In: Materials Science and Engineering B, 2004, vol. 108, p. 9-18

The challenge in the research on hydrogen storage materials is to pack hydrogen atoms or molecules as close as possible. Hydrogen absorbed in metals can reach a density of more than 150 kg m⁻³ (e.g. Mg₂FeH₆ or Al(BH₄)₃) at atmospheric pressure. For metallic hydrides, however, due to the large atomic mass of the transition metals the gravimetric hydrogen density is limited to less than...