Surface activated zinc-glutarate for the copolymerization of CO2 and epoxides.

Zinc-glutarate (ZnGA) is a promising catalyst that can form polymers from CO2 and epoxides, thereby contributing to the development of CO2 utilization technologies and future sustainability. One of the obstacles to commercializing ZnGA in polymer industries is its low catalytic activity. In this study, we introduced activated two-dimensional (2D) ZnGA to improve its catalytic activity in polymerization. The morphology-controlled 2D ZnGA was treated with H3Co(CN)6, and a porous granular-type Co-modified ZnGA (Co-ZnGA) was prepared. The morphology of 2D ZnGA is a prerequisite for the activation by H3Co(CN)6. The catalytic properties of Co-ZnGA were evaluated by copolymerization of various epoxides and CO2, and exhibited catalytic activity of 855, 1540, 1190, and 148 g g-cat-1 with propylene oxide, 1,2-epoxyhexane, 1,2-epoxybutane, and styrene oxide, respectively. This study provided a new strategy using 2D ZnGA instead of conventional ZnGA for increasing the catalytic activity in CO2 polymerization.

Core-Shell ZnO@Microporous Organic Polymer Nanospheres as Enhanced Piezo-Triboelectric Energy Harvesting Materials.

Core-shell nanospheres were prepared by the homogeneous coating of piezoelectric ZnO nanorod aggregates with triboelectric microporous organic polymer (MOP). The small energy harvesting performance of ZnO@MOP was significantly enhanced, compared with those of ZnO and MOP, due to the piezoelectrification-induced polarization of inner ZnO and the enhanced generation of tribopositive charges of MOP. Piezo-triboelectric nanogenerators (PTENGs) fabricated with ZnO@MOP showed peak-to-peak voltages of up to 534 V and a maximum power density of 1.19 mW cm-2 . In addition, the PTENGs showed excellent durability for 30 000 cycles, demonstrating as efficient power sources for charging electrolytic capacitors and for operating 200 green light emitting diode bulbs.

Hydroboration of Hollow Microporous Organic Polymers: A Promising Postsynthetic Modification Method for Functional Materials.

This work shows that hydroboration can be efficiently applied to the postsynthetic modification (PSM) of the Sonogashira-Hagihara coupling-based microporous organic polymers (MOPs). Hollow MOPs (H-MOPs) were prepared by template synthesis through the Sonogashira-Hagihara coupling of tetra(4-ethynylphenyl)methane with 1,4-diiodobenzene. The H-MOPs were used as platforms in the PSM-based functionalization. The heat-treatment of H-MOPs in the presence of a neat pinacolborane reagent resulted in the successful addition of pinacolborane groups to the internal alkynes of H-MOPs, generating H-MOPs with pinacolboranes (H-MOP-BPs). The pinacolborane moieties in the H-MOP-BP were further converted to boronic acid groups. The resultant H-MOP-BAs were used as heterogeneous organocatalysts in the CO2 fixation with epoxides to cyclic carbonates at ambient temperature (50 °C). Moreover, H-MOP-BAs could be recycled with retention of the catalytic performance in five successive reactions.

Bone regeneration by bioactive hybrid membrane containing FGF2 within rat calvarium.

This study examined the bone regeneration potential of a novel hybrid membrane consisting of collagen and nano-bioactive glass (nBG) incorporating basic fibroblast growth factor (FGF2) for use in guided bone regeneration. nBG was added to a reconstitution of collagen at a concentration of 30%, and the hybrid was formulated into a thin membrane. FGF2 (50 microg/ml) was adsorbed to the hybrid membrane. This level of FGF2 was found to be the optimal concentration to stimulate osteoblastic differentiation in vitro. Three membrane groups, including pure collagen, collagen-nBG hybrid and its combination with FGF2 were implanted within a rat calvarium defect (phi = 5 mm) for a period of 3 weeks. Histomorphometric analysis was carried out to evaluate the bone regeneration within the defect. The results showed that the defect in the collagen-nBG-FGF2 membrane was recovered almost completely, while partial recovery was observed in the other membrane groups (collagen and collagen-BG). However, there was little defect recovery in the blank control. The new bone formation was as high as approximately 60, approximately 45, and approximately 30% of the defect treated with the collagen-nBG-FGF2, collagen-BG, and collagen, respectively, whilst only 4% of new bone was observed in the blank control. Overall, the nBG was shown to stimulate bone formation of the collagen membrane, and FGF2 synergistically accelerated the bone regeneration within a rat calvarium defect.