Multi-walled carbon nanotubes (MWNTs) have been solubilized in water and in various organic solvents by noncovalent side-wall functionalization by pyrene containing polymers.

The ring-opening polymerization of ε-caprolactone (CL) initiated by dibutyltin dimethoxide was studied in supercritical carbon dioxide at 40 °C, under a pressure of 210−215 bar. The polymerization is controlled as assessed by the linear dependence of M n,SEC on conversion and of ln([CL]0/[CL]) on time. Moreover, there is a good agreement between M n,SEC and M n,calc, at least until 20 000 g/mol. The apparent rate constants of polymerization in different media increase as follows: sc CO2, CFC-113, toluene, bulk. The kinetic order in initiator for the polymerization in solution and in sc CO2 was extracted from the slope of ln k app vs ln [Sn]0. It appears to depend on the initiator concentration in solution, which is not the case in sc CO2.

Large-grained CuInSe 2 absorber layers are synthesized using a non-vacuum process based on nanoparticle ink precursors and selenization by rapid thermal processing (RTP). The use of hydroxide-based particles in organic solvents allows for the conversion with elemental selenium without the need to employ explosive and/or toxic H 2 or H 2 Se gasses. Lateral grain sizes up to 4 μm are obtained through a novel RTP route, overcoming the inherently high layer porosity for previous nanoparticle processes. Morphological and elemental characterization at interrupted selenization steps suggests that liquid selenium can play a beneficial role in promoting layer densification and grain growth. Long carrier collection lengths in CuInSe 2 enable notable conversion efficiencies, despite the low minority carrier lifetimes of below 1 ns. Record efficiencies up to 8.73% highlight the potential of low-cost, non-vacuum deposition of chalcopyrite absorber layers with safe and simple precursors and processing routes.

Ring-opening polymerization (ROP) of (L,L)-lactide (LA) has been initiated by dibutyltin dimethoxide in supercritical carbon dioxide (sc CO 2 ). Polymerization is controlled and proceeds at quasi the same rate as in toluene, which indicates that the reactivity of the propagating species is not impaired by parasitic carbonation reaction. Random copolymerization of LA with e-caprolactone (CL) has also been studied in sc CO 2 , and the reactivity ratios have been determined as 5.8 6 0.5 for LA and 0.7 6 0.25 for CL. These values have to be compared to 0.7 6 0.25 for LA and 0.15 6 0.05 for CL in toluene. Good control on ROP of CL and LA in sc CO 2 has been confirmed by the successful synthesis of diblock copolymers by sequential polymerization of CL and LA.

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