Addition Of Polycyclic Aromatic Hydrocarbons Research Articles

Facile Synthesis and Photoluminescent Properties of Asymmetric Perylene Diimides Capable of Tuning Emission Colors in Polymeric Matrices.

We report the facile synthesis of asymmetric perylene diimides (asym-PDIs) using readily available reagents, demonstrating their distinct photoluminescent properties. In CHCl3, asym-PDIs exhibit higher solubility compared to traditional perylene dyes, of which solubilities can be varied by substituent selections. Among them, UV-vis absorption spectra of CPE in CHCl3 solution displayed no aggregate peaks in the ground state, maintaining high photoluminescent quantum yields. Also, CPE can be readily dispersed into poly(methyl methacrylate) PMMA (CPE-PMMA), forming thin films without aggregate formation. Importantly, the emission color of CPE-PMMA thin films significantly changes with the addition of polycyclic aromatic hydrocarbons (PAHs). These color changes should be strongly correlated with the HOMO level of the added PAHs.

Effects of combined remediation of pre-ozonation and bioaugmentation on degradation of benzo[a]pyrene and microbial community structure in soils.

The combination technique of pre-ozonation and bioaugmentation is promising for remediating benzo[a]pyrene (BaP)-contaminated soil. However, little is known about the effect of coupling remediation on the soil biotoxicity, soil respiration, enzyme activity, microbial community structure, and microbial in the process of remediation. This study developed two coupling remediation strategies (pre-ozonation coupled with bioaugmentation by addition of polycyclic aromatic hydrocarbons (PAHs) specific degrading bacteria or activated sludge), compared with sole ozonation and sole bioaugmentation, to improve degradation of BaP and recovery of soil microbial activity and community structure. Results showed that the higher removal efficiency of BaP (92.69-93.19%) was found in coupling remediation, compared with sole bioaugmentation (17.71-23.28%). Meanwhile, coupling remediation significantly reduced the soil biological toxicity, promoted the rebound of microbial counts and activity, and recovered the species numbers and microbial community diversity, compared with sole ozonation and sole bioaugmentation. Besides, it was feasible to replace microbial screening with activated sludge, and coupling remediation by addition of activated sludge was more conducive to the recovery of soil microbial communities and diversity. This work provides a strategy of pre-ozonation coupled with bioaugmentation to further degrade BaP in soil by promoting the rebound of microbial counts and activity, as well as the recovery of species numbers and microbial community diversity.

Influence of Benz[a]anthracene on Bone Metabolism and on Liver Metabolism in Nibbler Fish, Girella punctata.

It has been reported that spinal deformity was induced in developing fish by the addition of polycyclic aromatic hydrocarbons (PAHs). To examine the mechanism of the disruption of fish bone metabolism, the effect of benz[a]anthracene (BaA), a kind of PAH, on plasma calcium, inorganic phosphorus, osteoblasts, and osteoclasts was investigated in this study. We also measured several plasma components to analyze the toxicity of BaA on other metabolisms. BaA (1 or 10 ng/g body weight) was intraperitoneally injected (four times) into nibbler fish during breeding, for 10 days, and it was indicated, for the first time, that injecting high doses of BaA to nibbler fish induced both hypocalcemia and hypophosphatemia. Furthermore, in the scales of nibbler fish treated with high doses of BaA, both osteoclastic and osteoblastic marker messengerRNA (mRNA) expressions decreased. These results are a cause of disruption of bone metabolism and, perhaps, the induction of spinal deformities. In addition, we found that total protein, metabolic enzymes in the liver, total cholesterol, free cholesterol, and high-density lipoprotein cholesterol levels significantly decreased in BaA-injected fish. These results indicate that BaA may affect liver diseases and emphasize the importance of prevention of aquatic PAH pollution.

Characterization of large carbonaceous molecules in cosmic dust analogues and meteorites.

We present a new experimental setup called AROMA (The Aromatic Research of Organics with Molecular Analyzer) based on the use of laser mass spectrometry techniques. We demonstrate the potential of AROMA for the analysis of meteoritic samples and cosmic dust analogues. Tens of peaks are identified in the mass spectra with notable discrepancies across the different samples. These discrepancies provide clues on the chemical history of each sample and are not a bias of our analysis. A double bound-equivalent (DBE) method is applied to sort the detected carbonaceous molecules into families of compounds. It reveals in addition of polycyclic aromatic hydrocarbons, the presence of other populations such as mixed aromatic-aliphatic species and carbon clusters.

Simultaneous Particle and Molecule Modeling (SPAMM): An Approach for Combining Sectional Aerosol Equations and Elementary Gas-Phase Reactions

ABSTRACT A method for writing the sectional aerosol equations in a form suitable for combination with a detailed kinetic model for gas-phase reactions has been developed. The sectional equations are given for arbitrary values of d, the ratio of molecular weights of adjacent bin boundaries, and are solved for d ≥ 2 for three different cases of the intra-bin distribution: (1) constant mass density w.r.t. ln(v), where v = molecular weight; (2) constant number density w.r.t. ln(v), or alternately, constant mass density w.r.t. v; (3) constant number density w.r.t. v. All the solutions given conserve mass; the extent of deviation from conservation of particle number is evaluated. An example of the approach is given for soot formation in combustion. The aerosol sections describe mass above 400 amu, with d = 2. Aerosol reactions are: bin-bin coagulation; addition of C2H2; addition of polycyclic aromatic hydrocarbons (PAH) with 2 to 10 benzenoid rings; oxidation via OH attack. The set of aerosol reactions is appended to a detailed elementary-step kinetic mechanism describing the gas-phase chemistry, including growth of PAH up to C32H14 (398 amu). The method also directly calculates the effect of the soot aerosol upon concentrations of gas-phase species such as PAH—a new capability for soot formation models. Predictions for a given set of conditions for the three cases of the intrabin distribution show striking changes not only in the particle size distribution but also in predictions of total aerosol mass and number concentrations. The extent of deviation from conservation of particle number for the three cases is shown to have a direct effect upon the predicted aerosol dynamics.