RESUMO
Here, we synthesized and characterized a novel two-dimensional (2D) conjugated electron donor-acceptor (D-A) copolymer (PBDB-T-Ge), wherein the substituent of triethyl germanium was added to the electron donor unit of the polymer. The Turbo-Grignard reaction was used to implement the group IV element into the polymer, resulting in a yield of 86%. This corresponding polymer, PBDB-T-Ge, exhibited a down-shift in the highest occupied molecular orbital (HOMO) level to -5.45 eV while the lowest unoccupied molecular orbital (LUMO) level was -3.64 eV. The peaks in UV-Vis absorption and the PL emission of PBDB-T-Ge were observed at 484 nm and 615 nm, respectively.
RESUMO
This study aimed to compare and assess phthalate contamination in various indoor environments. In this study, 44 floor dust samples from different indoor environments in Delaware, USA were collected and analyzed for 14 phthalates using gas chromatography-mass spectrometry. Phthalates were detected in all dust samples with the total concentration ranging from 84 to 7117 mg kg(-1). DEHP (di-2-ethylhexyl phthalate), BzBP (benzylbutyl phthalate), DBP (dibutyl phthalate), and DiBP (di-isobutyl phthalate) were both the most frequently and abundantly detected phthalates. The average concentration of total phthalates in dust from offices, student dorms, gyms, stores, and daycare centers was found to be significantly or insignificantly (P = 0.05) higher than that in dust from houses and apartments. Plastic flooring materials and the application of floor care chemical products were positively associated with total phthalate concentration in floor dust. Toxicological risk assessment indicated that an investigated daycare center in this study was the only indoor environment that may cause the intake amount of DEHP of infants, toddlers, and children via dust ingestion to exceed the reference dose established by the U.S. Environmental Protection Agency (USEPA). Regular monitoring on phthalate contamination in sensitive indoor environments is recommended.
