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This article reports on a novel category of hybrid nanoparticles (NPs) consisting of a unique organic core (composed of optically active helical polyacetylene) and an inorganic shell (composed of silica). The NPs were synthesized by combining in one system the aqueous catalytic microemulsion polymerization of substituted acetylene monomer to form the core and the sol−gel approach of TEOS to form the shell. The substituted polyacetylene forming the core adopted helical conformations of predominant one handedness while the silica shell provided desirable protection for the core. The obtained emulsions exhibited high stability. The NPs possessed large optical activities, arising from the helical polymer chains constituting the core. The investigations are important in chemistry since two diverse research fields (organic helical polymers and inorganic materials) were combined for the first time in a specific system. The obtained hybrid core/shell NPs induced enantioselective crystallization of alanine enantiomers, attesting to the potential applications of the novel core/shell NPs.

General polymeric microspheres are not satisfactorily thermostable. This article reports on an unprecedented type of poly(N-phenylmaleimide-co-α-methyl styrene) [denoted as poly(N-PMI-co-AMS)] microspheres showing remarkable thermal stability. The microspheres were prepared by free-radical precipitation polymerization in a solvent mixture consisting of methyl ethyl ketone (favorable solvent) and heptane (unfavorable solvent). Microspheres of good morphology and narrow size distribution were obtained in high yield (>85%) under appropriate conditions. Growth of poly(N-PMI-co-AMS) microspheres was characterized by scanning electron microscopy. The microspheres, although without cross-linking, exhibited excellent thermal stability, and their decomposition temperature was up to about 370 °C. This feature cannot be achieved in typical polymeric microspheres. Also, notably, this is the first precipitation polymerization of maleimide and AMS and their derivatives for preparing microspheres. The present novel microspheres are expected to find practical applications as novel heat-resistant additives, solid carriers for catalysts, and so on.

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Polymerization of M1, a chiral N-propargylamide monomer, was carried out with (nbd)Rh + B À (C 6 H 5 ) 4 as the catalyst in five solvents to explore the effect of solvents on polymerization. All the polymerizations occurred smoothly and provided polymers in high yield, however the number-average molecular weights of the polymers differ largely, which is attributed to the different solubility of the polymers in solvents. The helical structure and the optical activity of the polymer prepared in THF was examined by CD and UV-Vis spectroscopy measurements in the five solvents and in solvent mixtures consisting of CH 2 Cl 2 (a relatively good solvent) and THF (a relatively not-so-good solvent) in varied ratios. The polymer could adopt helical conformations in all the solvents, but different CD intensities and UV-Vis absorptions were observed. In CH 2 Cl 2 , the polymer exhibited lower intensity in both CD effect and UV-Vis absorption, while they were higher when the polymer was examined in THF, demonstrating that solvophobic effects made large contribution for the polymer chains to adopt helical conformations.Scheme 1 The structure of the monomer (M1) and the polymer.