Sensing of volatile organic compounds (VOCs) is a growing research topic because of the concern about their hazard for the environment and health. Furan is a VOC produced during food processing, and it has been classified as a risk molecule for human health and a possible biomarker of prostate cancer. The use of carbon nanotubes for VOCs sensing systems design could be a good alternative. In this work, a theoretical evaluation of the interactions between furan and zigzag single-wall carbon nanotubes takes into account different positions and orientations of the furan molecule, within a density-functional theory first-principles approach. The van der Waals interactions are considered using different exchange-correlation functionals (BH,C09, DRSLL and KBM). The results indicate that vdW-functionals do not significantly affect geometry; however, the binding energy and the distance between furan and nanotube are strongly dependent on the selected exchange-correlation functional. On the other hand, the effects of single and double vacancies on carbon nanotube are considered. It was found that the redistribution of charge around the single-vacancy affects the bandgap, magnetic moment, and binding energy of the complex, while furan interaction with a double-vacancy does not considerably change the electronic structure of the system. Our results suggest that to induce changes in the electronic properties of carbon nanotubes by furan, it is necessary to change the nanotube surface, for example, by means of structural defects.
As a specialty oil, furan fatty acids have gained special attentions since they are known to play important roles in biological systems including human. Although several studies reported chemical synthesis of furan fatty acids, their synthesis consisted of complicated chemical multistep with chemical catalysts. Recently, a simple one-step heat treatment method was developed to produce a novel furan fatty acid, 7,10-epoxy-octadeca-7,9-dienoic acid (7,10-EODA) from a dihydroxyl fatty acid 7,10-dihydroxy-8(E)-octadecenoic acid (DOD). In this report we studied about optimization of environmental conditions for the maximum production of 7,10-EODA from DOD by heat treatment. Production of 7,10-EODA was maximized at over 85℃ for at least over 48 hour in hexane. Solvent volume for maximum production should be over 300 mL per 10 mg DOD.
Concentrations of dioxins, furans and dioxin-like polychlorinated biphenyls (DL-PCBs) were determined in crucian carp collected from eight locations mainly along the Nakdong River during 2004. Total dioxin concentrations which include concentrations of dioxins, furans and DL-PCBs ranged from 0.053 to 0.614 pg WHO-TEQ g-1 wet wt. with a mean of 0.342±0.213 pg WHO-TEQ g-1 wet wt. The proportions of dioxins, furans and DL-PCBs to total dioxin TEQ were 4%, 12% and 84%, respectively. The results suggest that concentrations of dioxin-like polychlorinated biphenyls should be determined when total dioxin TEQ accumulated in freshwater fish is investigated.
The thiophene or furan-containing hexadentate ligands 1,12-bis (2-theophene)-2,5,8,11-tetraazadodecane(Thiotrien ․4HCl) and 1,12-bis (2-furan)-2,5,8,11-tetraazadodecane(Furatrien․4HCl) were synthesized as their tetrahydrochloride salt and characterized by EA, IR, NMR, and Mass spectrum. Their protonation constants (logKnH) and stability constants (logKML) for Cd2+, Pb2+, Zn2+ and Cu2+ ions were determined in aqueous solution by potentiometry and compared with 1,12-bis(2-pyridyl)-2,5,8,11-tetra-azadodecane(Pytrien) of pyridyl-containing ligand. The effect stability constants of ligands and metal ion for removal of heavy metals in aqueous solution were described.