Fullerene-based Biocomponents : New Concepts For Functionalising Membranes

Lipophilic hexakisadducts of fullerene C60 form unprecedented rod-like nanoaggregates in phospholipid-membrane bilayers, resulting in modification of the micromechanic properties and stabilisation of the membrane. Lipofullerenes with amphiphilic side chains enable additionally derivatisation and molecular recognition at the membrane surface. The amphiphilic spacer acts as a transmembrane anchor and provides the terminal functionality outside of the membrane. New systems derived from parent compound 3 carry two functional groups each and can be easily modified due to the modular synthesis. Terminal functionalities to be investigated include D(+)-biotin and IDA (iminodiacetic acid) ligands, as used in nickel-histidine tags. Modification of the lipophilic region, for instance with unsaturated addends is also possible. These addends should allow polymerisation inside the membrane and potentially lead to a tremendous increase of the membrane rigidity. Furthermore, mono- and bilayer-forming fullerene derivatives without the membrane-forming support of lecithins are investigated and exhibit interesting features

Effect of ball-milling time on mechanical and magnetic properties of carbon nanotube reinforced FeCo alloy composites

Carbon nanotubes (CNTs) reinforced FeCo alloys were produced by high energy ball-milling and spark plasma sintering (SPS). CNTs distribution in the FeCo alloy was gradually improved as ball-milling time increased, with a uniform dispersion achieved after 6 h ball-milling. Tensile tests demonstrated that, as the ball-milling time increased, the yield strength increased in the composites; a maximum 50% relative increase in tensile strength due to the addition of CNTs was achieved after 1 h ball-milling, which then decreased with further ball-milling. The elongation to fracture was significantly increased after 1 h ball-milling and then decreased with further ball-milling. SEM results show a patch of dimples in the fracture surface of the composite, indicating improved ductility due to CNTs. The coercivity was increased with increased ball-milling time, while the saturation induction showed a peak value after 1 h of ball-milling and then decreased with further ball-milling. Raman spectra of the composite indicated that no serious damage had been imparted to the CNTs during ball-milling