We identify Stoner ferromagnetism in fcc C60H(n) (n=odd) by using a local density approximation in the framework of the density functional theory. Hydrogen chemisorption on fullerenes creates quasilocalized π electrons on the fullerene surface, overlapping of their wave functions giving rise to a narrow half filled impurity band in the fcc C60H(n). The Stoner-type ferromagnetic exchange between the itinerant electrons leads to spin-split impurity bands. The magnetic moment per C60H(n) molecule is 1  μ(B) (for n=odd) or 0 (for n=even, including zero), only one of the hydrogens contributing to the spin-split states. Direct overlapping of the quasilocalized π-electron orbitals is essential for the ferromagnetism.

This study aims to develop a simple, low-cost method for synthesis of highly branched polycaprolactone (hbPCL) for use as effective “green” plasticizers for poly­(vinyl chloride) (PVC). We demonstrate the facile synthesis of hbPCL with tunable molecular architecture using glycidol as a branching monomer. A series of hbPCLs is prepared via one-pot, solvent-free copolymerization of ε-caprolactone and glycidol, wherein the molecular architecture is readily controlled by varying the molar ratio of glycidol to ε-caprolactone. Further, studying the kinetics of copolymerization reveals the preferential reaction of glycidol over ε-caprolactone, resulting in a multiarm star-like copolymer after the ring-opening of the two monomers. The crystallization ability of hbPCL is found to gradually weaken with the introduction of the branching structure, and its molecular mobility is improved substantially by esterification with butyric anhydride, following which a maximum mobility is realized at an intermediate level of branching. The butyl-esterified hbPCL (hbPCL-C4) is miscible with PVC, and their mixtures have excellent flexibility comparable to that of PVC/bis­(2-ethylhexyl) phthalate (DEHP). In particular, the stretchability of PVC/hbPCL-C4 is superior to that of PVC/DEHP, owing to its better structural homogeneity. Furthermore, PVC/hbPCL-C4 shows outstanding migration stability with the weight loss after extraction being >85% lower than that of PVC/DEHP.

We developed a plasticizer composed of alkyl terminal hyperbranched polyglycerol (alkyl-HPG) for the production of non-toxic, phthalate-free flexible poly(vinyl chloride) (PVC).

Hydrogen shallow donors in undoped and doped ZnO systems have been studied by means of the electron paramagnetic resonance and nuclear magnetic resonance measurements. Experimental evidence is given in this work for coupling of hydrogen shallow donors and Mn ions in Mn-doped ZnO mediating short-range ferromagnetic spin-spin interaction.